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Sample records for confers enhanced tolerance

  1. GmCLC1 Confers Enhanced Salt Tolerance through Regulating Chloride Accumulation in Soybean

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    Peipei Wei

    2016-07-01

    Full Text Available The family of chloride channel proteins that mediate Cl- transportation play vital roles in plant nutrient supply, cellular action potential and turgor pressure adjustment, stomatal movement, hormone signal recognition and transduction, Cl- homeostasis, and abiotic and biotic stress tolerance. The anionic toxicity, mainly caused by chloride ions (Cl-, on plants under salt stress remains poorly understood. In this work, we investigated the function of soybean Cl-/H+ antiporter GmCLC1 under salt stress in transgenic Arabidopsis thaliana, soybean, and yeast. We found that GmCLC1 enhanced salt tolerance in transgenic A. thaliana by reducing the Cl- accumulation in shoots and hence released the negative impact of salt stress on plant growth. Overexpression of GmCLC1 in the hairy roots of soybean sequestered more Cl- in their roots and transferred less Cl- to their shoots, leading to lower relative electrolyte leakage values in the roots and leaves. When either the soybean GmCLC1 or the yeast chloride transporter gene, GEF1, was transformed into the yeast gef1 mutant, and then treated with different chloride salts (MnCl2, KCl, NaCl, enhanced survival rate was observed. The result indicates that GmCLC1 and GEF1 exerted similar effects on alleviating the stress of diverse chloride salts on the yeast gef1 mutant. Together, this work suggests a protective function of GmCLC1 under Cl- stress.

  2. Insertion of transposon in the vicinity of SSK2 confers enhanced tolerance to furfural in Saccharomyces cerevisiae

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    Kim, Hyun-Soo [Ewha Womans Univ., Seoul (Korea, Republic of). Dept. of Life Science; Kim, Na-Rae [Ewha Womans Univ., Seoul (Korea, Republic of). Div. of Life and Pharmaceutical Sciences; Kim, Wankee [Ewha Womans Univ., Seoul (Korea, Republic of). Dept. of Life Science; Ajou Univ., Suwon (Korea, Republic of). Inst. for Medical Sciences; Choi, Wonja [Ewha Womans Univ., Seoul (Korea, Republic of). Dept. of Life Science; Ewha Womans Univ., Seoul (Korea, Republic of). Microbial Resources Research Center

    2012-07-15

    Furfural is one of the major inhibitors generated during sugar production from cellulosic materials and, as an aldehyde, inhibits various cellular activities of microorganisms used, leading to prolonged lag time during ethanologenic fermentation. Since Saccharomyces cerevisiae strains tolerant to furfural are of great economic benefit in producing bioethanol, much effort to obtain more efficient strains continues to be made. In this study, we examined the furfural tolerance of transposon mutant strains (Tn 1-5) with enhanced ethanol tolerance and found that one of them (Tn 2), in which SSK2 is downregulated at the transcriptional level, displayed improved furfural tolerance. Such phenotype was abolished by complementation of the entire open reading frame of SSK2, which encodes a mitogen-activated protein (MAP) kinase kinase kinase of the high osmolarity glycerol (HOG) signaling pathway, suggesting an inhibitory effect of SSK2 in coping with furfural stress. Tn 2 showed a significant decrease in the intracellular level of reactive oxygen species (ROS) and early and high activation of Hog1p, a MAP kinase integral to the HOG pathway in response to furfural. The transcriptional levels of CTT1 and GLR1, two of known Hog1p downstream target genes whose protein products are involved in reducing ROS, were increased by 43 % and 56 % respectively compared with a control strain, probably resulting in the ROS decrease. Tn 2 also showed a shortened lag time during fermentation in the presence of furfural, resulting from efficient conversion of furfural to non-toxic (or less toxic) furfuryl alcohol. Taken together, the enhanced furfural tolerance of Tn 2 is suggested to be conferred by the combined effect of an early event of less ROS accumulation and a late event of efficient detoxification of furfural. (orig.)

  3. Insertion of transposon in the vicinity of SSK2 confers enhanced tolerance to furfural in Saccharomyces cerevisiae.

    Science.gov (United States)

    Kim, Hyun-Soo; Kim, Na-Rae; Kim, Wankee; Choi, Wonja

    2012-07-01

    Furfural is one of the major inhibitors generated during sugar production from cellulosic materials and, as an aldehyde, inhibits various cellular activities of microorganisms used, leading to prolonged lag time during ethanologenic fermentation. Since Saccharomyces cerevisiae strains tolerant to furfural are of great economic benefit in producing bioethanol, much effort to obtain more efficient strains continues to be made. In this study, we examined the furfural tolerance of transposon mutant strains (Tn 1-5) with enhanced ethanol tolerance and found that one of them (Tn 2), in which SSK2 is downregulated at the transcriptional level, displayed improved furfural tolerance. Such phenotype was abolished by complementation of the entire open reading frame of SSK2, which encodes a mitogen-activated protein (MAP) kinase kinase kinase of the high osmolarity glycerol (HOG) signaling pathway, suggesting an inhibitory effect of SSK2 in coping with furfural stress. Tn 2 showed a significant decrease in the intracellular level of reactive oxygen species (ROS) and early and high activation of Hog1p, a MAP kinase integral to the HOG pathway in response to furfural. The transcriptional levels of CTT1 and GLR1, two of known Hog1p downstream target genes whose protein products are involved in reducing ROS, were increased by 43 % and 56 % respectively compared with a control strain, probably resulting in the ROS decrease. Tn 2 also showed a shortened lag time during fermentation in the presence of furfural, resulting from efficient conversion of furfural to non-toxic (or less toxic) furfuryl alcohol. Taken together, the enhanced furfural tolerance of Tn 2 is suggested to be conferred by the combined effect of an early event of less ROS accumulation and a late event of efficient detoxification of furfural.

  4. Expression of miRNAs confers enhanced tolerance to drought and salt stress in Finger millet (Eleusine coracona

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    Nageshbabu R.

    2013-08-01

    Full Text Available Plants respond to the environmental cues in various ways, recent knowledge of RNA interference in conferring stress tolerance had become a new hope of developing tolerant varieties. Here we attempt to unfold the molecular mechanism of stress tolerance through miRNA profiling and expression analysis in Finger millet (Eleusine coracona under salt and drought stress conditions. The expression analysis of 12 stress specific conserved miRNAs was studied using semi-quantitative real time PCR and Northern blot assay. Our studies revealed that, although most of the miRNAs responded to the stresses, the expression of particular miRNA differed with the nature of stress and the tissue. The expression analysis was correlated with the existing data of their target genes. Abiotic stress up-regulated miRNAs are expected to target negative regulators of stress responses or positive regulators of processes that are inhibited by stresses. On the other hand, stress down-regulated miRNAs may repress the expression of positive regulators and/or stress up-regulated genes. Thus the current study of miRNAs and their targets under abiotic stress conditions displays miRNAs may be good candidates to attribute the stress tolerance in plants by transgenic technology.

  5. Novel NAC transcription factor TaNAC67 confers enhanced multi-abiotic stress tolerances in Arabidopsis.

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    Xinguo Mao

    Full Text Available Abiotic stresses are major environmental factors that affect agricultural productivity worldwide. NAC transcription factors play pivotal roles in abiotic stress signaling in plants. As a staple crop, wheat production is severely constrained by abiotic stresses whereas only a few NAC transcription factors have been characterized functionally. To promote the application of NAC genes in wheat improvement by biotechnology, a novel NAC gene designated TaNAC67 was characterized in common wheat. To determine its role, transgenic Arabidopsis overexpressing TaNAC67-GFP controlled by the CaMV-35S promoter was generated and subjected to various abiotic stresses for morphological and physiological assays. Gene expression showed that TaNAC67 was involved in response to drought, salt, cold and ABA treatments. Localization assays revealed that TaNAC67 localized in the nucleus. Morphological analysis indicated the transgenics had enhanced tolerances to drought, salt and freezing stresses, simultaneously supported by enhanced expression of multiple abiotic stress responsive genes and improved physiological traits, including strengthened cell membrane stability, retention of higher chlorophyll contents and Na(+ efflux rates, improved photosynthetic potential, and enhanced water retention capability. Overexpression of TaNAC67 resulted in pronounced enhanced tolerances to drought, salt and freezing stresses, therefore it has potential for utilization in transgenic breeding to improve abiotic stress tolerance in crops.

  6. Overexpression of LOV KELCH protein 2 confers dehydration tolerance and is associated with enhanced expression of dehydration-inducible genes in Arabidopsis thaliana.

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    Miyazaki, Yuji; Abe, Hiroshi; Takase, Tomoyuki; Kobayashi, Masatomo; Kiyosue, Tomohiro

    2015-05-01

    The overexpression of LKP2 confers dehydration tolerance in Arabidopsis thaliana ; this is likely due to enhanced expression of dehydration-inducible genes and reduced stomatal opening. LOV KELCH protein 2 (LKP2) modulates the circadian rhythm and flowering time in plants. In this study, we observed that LKP2 overexpression enhanced dehydration tolerance in Arabidopsis. Microarray analysis demonstrated that expression of water deprivation-responsive genes was higher in the absence of dehydration stress in transgenic Arabidopsis plants expressing green fluorescent protein-tagged LKP2 (GFP-LKP2) than in control transgenic plants expressing GFP. After dehydration followed by rehydration, GFP-LKP2 plants developed more leaves and roots and exhibited higher survival rates than control plants. In the absence of dehydration stress, four dehydration-inducible genes, namely DREB1A, DREB1B, DREB1C, and RD29A, were expressed in GFP-LKP2 plants, whereas they were not expressed or were expressed at low levels in control plants. Under dehydration stress, the expression of DREB2B and RD29A peaked faster in the GFP-LKP2 plants than in control plants. The stomatal aperture of GFP-LKP2 plants was smaller than that of control plants. These results suggest that the dehydration tolerance of GFP-LKP2 plants is caused by upregulation of DREB1A-C/CBF1-3 and their downstream targets; restricted stomatal opening in the absence of dehydration stress also appears to contribute to the phenotype. The rapid and high expression of DREB2B and its downstream target genes also likely accounts for some features of the GFP-LKP2 phenotype. Our results suggest that LKP2 can be used for biotechnological applications not only to adjust the flowering time control but also to enhance dehydration tolerance.

  7. Plastid-expressed betaine aldehyde dehydrogenase gene in carrot cultured cells, roots, and leaves confers enhanced salt tolerance.

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    Kumar, Shashi; Dhingra, Amit; Daniell, Henry

    2004-09-01

    Salinity is one of the major factors that limits geographical distribution of plants and adversely affects crop productivity and quality. We report here high-level expression of betaine aldehyde dehydrogenase (BADH) in cultured cells, roots, and leaves of carrot (Daucus carota) via plastid genetic engineering. Homoplasmic transgenic plants exhibiting high levels of salt tolerance were regenerated from bombarded cell cultures via somatic embryogenesis. Transformation efficiency of carrot somatic embryos was very high, with one transgenic event per approximately seven bombarded plates under optimal conditions. In vitro transgenic carrot cells transformed with the badh transgene were visually green in color when compared to untransformed carrot cells, and this offered a visual selection for transgenic lines. BADH enzyme activity was enhanced 8-fold in transgenic carrot cell cultures, grew 7-fold more, and accumulated 50- to 54-fold more betaine (93-101 micromol g(-1) dry weight of beta-Ala betaine and Gly betaine) than untransformed cells grown in liquid medium containing 100 mm NaCl. Transgenic carrot plants expressing BADH grew in the presence of high concentrations of NaCl (up to 400 mm), the highest level of salt tolerance reported so far among genetically modified crop plants. BADH expression was 74.8% in non-green edible parts (carrots) containing chromoplasts, and 53% in proplastids of cultured cells when compared to chloroplasts (100%) in leaves. Demonstration of plastid transformation via somatic embryogenesis utilizing non-green tissues as recipients of foreign DNA for the first time overcomes two of the major obstacles in extending this technology to important crop plants.

  8. The SbSOS1 gene from the extreme halophyte Salicornia brachiata enhances Na+ loading in xylem and confers salt tolerance in transgenic tobacco

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    Yadav Narendra

    2012-10-01

    Full Text Available Abstract Background Soil salinity adversely affects plant growth and development and disturbs intracellular ion homeostasis resulting cellular toxicity. The Salt Overly Sensitive 1 (SOS1 gene encodes a plasma membrane Na+/H+ antiporter that plays an important role in imparting salt stress tolerance to plants. Here, we report the cloning and characterisation of the SbSOS1 gene from Salicornia brachiata, an extreme halophyte. Results The SbSOS1 gene is 3774 bp long and encodes a protein of 1159 amino acids. SbSOS1 exhibited a greater level of constitutive expression in roots than in shoots and was further increased by salt stress. Overexpressing the S. brachiata SbSOS1 gene in tobacco conferred high salt tolerance, promoted seed germination and increased root length, shoot length, leaf area, fresh weight, dry weight, relative water content (RWC, chlorophyll, K+/Na+ ratio, membrane stability index, soluble sugar, proline and amino acid content relative to wild type (WT plants. Transgenic plants exhibited reductions in electrolyte leakage, reactive oxygen species (ROS and MDA content in response to salt stress, which probably occurred because of reduced cytosolic Na+ content and oxidative damage. At higher salt stress, transgenic tobacco plants exhibited reduced Na+ content in root and leaf and higher concentrations in stem and xylem sap relative to WT, which suggests a role of SbSOS1 in Na+ loading to xylem from root and leaf tissues. Transgenic lines also showed increased K+ and Ca2+ content in root tissue compared to WT, which reflect that SbSOS1 indirectly affects the other transporters activity. Conclusions Overexpression of SbSOS1 in tobacco conferred a high degree of salt tolerance, enhanced plant growth and altered physiological and biochemical parameters in response to salt stress. In addition to Na+ efflux outside the plasma membrane, SbSOS1 also helps to maintain variable Na+ content in different organs and also affect the other

  9. The SbSOS1 gene from the extreme halophyte Salicornia brachiata enhances Na(+) loading in xylem and confers salt tolerance in transgenic tobacco.

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    Yadav, Narendra Singh; Shukla, Pushp Sheel; Jha, Anupama; Agarwal, Pradeep K; Jha, Bhavanath

    2012-10-11

    Soil salinity adversely affects plant growth and development and disturbs intracellular ion homeostasis resulting cellular toxicity. The Salt Overly Sensitive 1 (SOS1) gene encodes a plasma membrane Na(+)/H(+) antiporter that plays an important role in imparting salt stress tolerance to plants. Here, we report the cloning and characterisation of the SbSOS1 gene from Salicornia brachiata, an extreme halophyte. The SbSOS1 gene is 3774 bp long and encodes a protein of 1159 amino acids. SbSOS1 exhibited a greater level of constitutive expression in roots than in shoots and was further increased by salt stress. Overexpressing the S. brachiata SbSOS1 gene in tobacco conferred high salt tolerance, promoted seed germination and increased root length, shoot length, leaf area, fresh weight, dry weight, relative water content (RWC), chlorophyll, K(+)/Na(+) ratio, membrane stability index, soluble sugar, proline and amino acid content relative to wild type (WT) plants. Transgenic plants exhibited reductions in electrolyte leakage, reactive oxygen species (ROS) and MDA content in response to salt stress, which probably occurred because of reduced cytosolic Na(+) content and oxidative damage. At higher salt stress, transgenic tobacco plants exhibited reduced Na(+) content in root and leaf and higher concentrations in stem and xylem sap relative to WT, which suggests a role of SbSOS1 in Na(+) loading to xylem from root and leaf tissues. Transgenic lines also showed increased K(+) and Ca(2+) content in root tissue compared to WT, which reflect that SbSOS1 indirectly affects the other transporters activity. Overexpression of SbSOS1 in tobacco conferred a high degree of salt tolerance, enhanced plant growth and altered physiological and biochemical parameters in response to salt stress. In addition to Na(+) efflux outside the plasma membrane, SbSOS1 also helps to maintain variable Na(+) content in different organs and also affect the other transporters activity indirectly. These

  10. The SbSOS1 gene from the extreme halophyte Salicornia brachiata enhances Na+ loading in xylem and confers salt tolerance in transgenic tobacco

    Science.gov (United States)

    2012-01-01

    Background Soil salinity adversely affects plant growth and development and disturbs intracellular ion homeostasis resulting cellular toxicity. The Salt Overly Sensitive 1 (SOS1) gene encodes a plasma membrane Na+/H+ antiporter that plays an important role in imparting salt stress tolerance to plants. Here, we report the cloning and characterisation of the SbSOS1 gene from Salicornia brachiata, an extreme halophyte. Results The SbSOS1 gene is 3774 bp long and encodes a protein of 1159 amino acids. SbSOS1 exhibited a greater level of constitutive expression in roots than in shoots and was further increased by salt stress. Overexpressing the S. brachiata SbSOS1 gene in tobacco conferred high salt tolerance, promoted seed germination and increased root length, shoot length, leaf area, fresh weight, dry weight, relative water content (RWC), chlorophyll, K+/Na+ ratio, membrane stability index, soluble sugar, proline and amino acid content relative to wild type (WT) plants. Transgenic plants exhibited reductions in electrolyte leakage, reactive oxygen species (ROS) and MDA content in response to salt stress, which probably occurred because of reduced cytosolic Na+ content and oxidative damage. At higher salt stress, transgenic tobacco plants exhibited reduced Na+ content in root and leaf and higher concentrations in stem and xylem sap relative to WT, which suggests a role of SbSOS1 in Na+ loading to xylem from root and leaf tissues. Transgenic lines also showed increased K+ and Ca2+ content in root tissue compared to WT, which reflect that SbSOS1 indirectly affects the other transporters activity. Conclusions Overexpression of SbSOS1 in tobacco conferred a high degree of salt tolerance, enhanced plant growth and altered physiological and biochemical parameters in response to salt stress. In addition to Na+ efflux outside the plasma membrane, SbSOS1 also helps to maintain variable Na+ content in different organs and also affect the other transporters activity indirectly

  11. Isolation of cowpea genes conferring drought tolerance ...

    African Journals Online (AJOL)

    The main objective of this study was to identify and isolate the genes conferring drought tolerance in cowpea. A cDNA library enriched for cowpea genes expressed specifically during responses to drought was constructed. A procedure called suppression subtractive hybridisation (SSH) was successfully employed to obtain ...

  12. Overexpression of an Arabidopsis cysteine-rich receptor-like protein kinase, CRK5, enhances abscisic acid sensitivity and confers drought tolerance

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    Lu, Kai; Liang, Shan; Wu, Zhen; Bi, Chao; Yu, Yong-Tao; Wang, Xiao-Fang; Zhang, Da-Peng

    2016-01-01

    Receptor-like kinases (RLKs) have been reported to regulate many developmental and defense process, but only a few members have been functionally characterized. In the present study, our observations suggest that one of the RLKs, a membrane-localized cysteine-rich receptor-like protein kinase, CRK5, is involved in abscisic acid (ABA) signaling in Arabidopsis thaliana. Overexpression of CRK5 increases ABA sensitivity in ABA-induced early seedling growth arrest and promotion of stomatal closure and inhibition of stomatal opening. Interestingly, and importantly, overexpression of CRK5 enhances plant drought tolerance without affecting plant growth at the mature stages and plant productivity. Transgenic lines overexpressing a mutated form of CRK5, CRK5 K372E with the change of the 372nd conserved amino acid residue from lysine to glutamic acid in its kinase domain, result in wild-type ABA and drought responses, supporting the role of CRK5 in ABA signaling. The loss-of-function mutation of the CRK5 gene does not affect the ABA response, while overexpression of two homologs of CRK5, CRK4 and CRK19, confers ABA responses, suggesting that these CRK members function redundantly. We further showed that WRKY18, WRKY40 and WRKY60 transcription factors repress the expression of CRK5, and that CRK5 likely functions upstream of ABI2 in ABA signaling. These findings help in understanding the complex ABA signaling network. PMID:27406784

  13. Overexpression of an Arabidopsis cysteine-rich receptor-like protein kinase, CRK5, enhances abscisic acid sensitivity and confers drought tolerance.

    Science.gov (United States)

    Lu, Kai; Liang, Shan; Wu, Zhen; Bi, Chao; Yu, Yong-Tao; Wang, Xiao-Fang; Zhang, Da-Peng

    2016-09-01

    Receptor-like kinases (RLKs) have been reported to regulate many developmental and defense process, but only a few members have been functionally characterized. In the present study, our observations suggest that one of the RLKs, a membrane-localized cysteine-rich receptor-like protein kinase, CRK5, is involved in abscisic acid (ABA) signaling in Arabidopsis thaliana Overexpression of CRK5 increases ABA sensitivity in ABA-induced early seedling growth arrest and promotion of stomatal closure and inhibition of stomatal opening. Interestingly, and importantly, overexpression of CRK5 enhances plant drought tolerance without affecting plant growth at the mature stages and plant productivity. Transgenic lines overexpressing a mutated form of CRK5, CRK5 (K372E) with the change of the 372nd conserved amino acid residue from lysine to glutamic acid in its kinase domain, result in wild-type ABA and drought responses, supporting the role of CRK5 in ABA signaling. The loss-of-function mutation of the CRK5 gene does not affect the ABA response, while overexpression of two homologs of CRK5, CRK4 and CRK19, confers ABA responses, suggesting that these CRK members function redundantly. We further showed that WRKY18, WRKY40 and WRKY60 transcription factors repress the expression of CRK5, and that CRK5 likely functions upstream of ABI2 in ABA signaling. These findings help in understanding the complex ABA signaling network. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  14. Heterologous Expression of Panax ginseng PgTIP1 Confers Enhanced Salt Tolerance of Soybean Cotyledon Hairy Roots, Composite, and Whole Plants

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    Jing An

    2017-07-01

    Full Text Available The Panax ginseng TIP gene PgTIP1 was previously demonstrated to have high water channel activity by its heterologous expression in Xenopus laevis oocytes and in yeast; it also plays a significant role in growth of PgTIP1-transgenic Arabidopsis plants under favorable conditions and has enhanced tolerance toward salt and drought treatment. In this work, we first investigated the physiological effects of heterologous PgTIP1 expression in soybean cotyledon hairy roots or composite plants mediated by Agrobacterium rhizogenes toward enhanced salt tolerance. The PgTIP1-transgenic soybean plants mediated by the pollen tube pathway, represented by the lines N and J11, were analyzed at the physiological and molecular levels for enhanced salt tolerance. The results showed that in terms of root-specific heterologous expression, the PgTIP1-transformed soybean cotyledon hairy roots or composite plants displayed superior salt tolerance compared to the empty vector-transformed ones according to the mitigatory effects of hairy root growth reduction, drop in leaf RWC, and rise in REL under salt stress. Additionally, declines in K+ content, increases in Na+ content and Na+/K+ ratios in the hairy roots, stems, or leaves were effectively alleviated by PgTIP1-transformation, particularly the stems and leaves of composite soybean plants. At the whole plant level, PgTIP1-trasgenic soybean lines were found to possess stronger root vigor, reduced root and leaf cell membrane damage, increased SOD, POD, CAT, and APX activities, steadily increased leaf Tr, RWC, and Pn values, and smaller declines in chlorophyll and carotenoid content when exposed to salt stress compared to wild type. Moreover, the distribution patterns of Na+, K+, and Cl- in the roots, stems, and leaves of salt-stressed transgenic plants were readjusted, in that the absorbed Na+ and Cl- were mainly restricted to the roots to reduce their transport to the shoots, and the transport of root-absorbed K+ to the

  15. Metabolic engineering of the chloroplast genome reveals that the yeast ArDH gene confers enhanced tolerance to salinity and drought in plants

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    Muhammad Sarwar Khan

    2015-09-01

    Full Text Available Osmoprotectants stabilize proteins and membranes against the denaturing effect of high concentrations of salts and other harmful solutes. In yeast, arabitol dehydrogenase (ArDH reduces D-ribulose to D-arabitol where D-ribulose is derived by dephosphorylating D-ribulose-5-PO4 in the oxidized pentose pathway. Osmotolerance in plants could be developed through metabolic engineering of chloroplast genome by introducing genes encoding polyols. Here, we report that ArDH expression in chloroplasts confers tolerance to NaCl (up to 400 mM. Transgenic plants compared to wild type survived for four to five weeks on 400 mM NaCl. Nevertheless, plants remained green and grew normal on concentrations up to 350 mM NaCl. Further, a-week-old seedlings were also challenged with poly ethylene glycol (PEG, up to 6% in the liquid medium, considering that membranes and proteins are protected under stress conditions due to accumulation of arabitol in chloroplasts. Seedlings were tolerant to 6% PEG, suggesting that ARDH enzyme maintains integrity of membranes in chloroplasts under drought conditions via metabolic engineering. Hence, the gene could be expressed in agronomic plants to withstand abiotic stresses.

  16. Activated Expression of WRKY57 Confers Drought Tolerance in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Yanjuan Jiang; Gang Liang; Diqiu Yu

    2012-01-01

    Drought is one of the most serious environmental factors that limit the productivity of agricultural crops worldwide.However,the mechanism underlying drought tolerance in plants is unclear.WRKY transcription factors are known to function in adaptation to abiotic stresses.By screening a pool of WRKY-associated T-DNA insertion mutants,we isolated a gain-of-function mutant,acquired drought tolerance (adt),showing improved drought tolerance.Under drought stress conditions,adt accumulated higher levels of ABA than wild-type plants.Stomatal aperture analysis indicated that adt was more sensitive to ABA than wild-type plants.Molecular genetic analysis revealed that a T-DNA insertion in adt led to activated expression of a WRKY gene that encodes the WRKR57 protein.Constitutive expression of WRKY57 also conferred similar drought tolerance.Consistently with the high ABA content and enhanced drought tolerance,three stress-responsive genes (RD29A,NCED3,and ABA3) were up-regulated in adt.ChIP assays demonstrated that WRKY57 can directly bind the W-box of RD29A and NCED3 promoter sequences.In addition,during ABA treatment,seed germination and early seedling growth of adt were inhibited,whereas,under high osmotic conditions,adt showed a higher seed germination frequency.In summary,our results suggested that the activated expression of WRKY57 improved drought tolerance of Arabidopsis by elevation of ABA levels.Establishment of the functions of WRKY57 will enable improvement of plant drought tolerance through gene manipulation approaches.

  17. A proteomics approach to study the molecular basis of enhanced salt tolerance in barley (Hordeum vulgare L.) conferred by the root mutualistic fungus Piriformospora indica.

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    Alikhani, Mehdi; Khatabi, Behnam; Sepehri, Mozhgan; Nekouei, Mojtaba Khayam; Mardi, Mohsen; Salekdeh, Ghasem Hosseini

    2013-06-01

    Piriformospora indica is a root-interacting mutualistic fungus capable of enhancing plant growth, increasing plant resistance to a wide variety of pathogens, and improving plant stress tolerance under extreme environmental conditions. Understanding the molecular mechanisms by which P. indica can improve plant tolerance to stresses will pave the way to identifying the major mechanisms underlying plant adaptability to environmental stresses. We conducted greenhouse experiments at three different salt levels (0, 100 and 300 mM NaCl) on barley (Hordeum vulgare L.) cultivar "Pallas" inoculated with P. indica. Based on the analysis of variance, P. indica had a significant impact on the barley growth and shoot biomass under normal and salt stress conditions. P. indica modulated ion accumulation in colonized plants by increasing the foliar potassium (K(+))/sodium (Na(+)) ratio, as it is considered a reliable indicator of salt stress tolerance. P. indica induced calcium (Ca(2+)) accumulation and likely influenced the stress signal transduction. Subsequently, proteomic analysis of the barley leaf sheath using two-dimensional electrophoresis resulted in detection of 968 protein spots. Of these detected spots, the abundance of 72 protein spots changed significantly in response to salt treatment and P. indica-root colonization. Mass spectrometry analysis of responsive proteins led to the identification of 51 proteins. These proteins belonged to different functional categories including photosynthesis, cell antioxidant defense, protein translation and degradation, energy production, signal transduction and cell wall arrangement. Our results showed that P. indica induced a systemic response to salt stress by altering the physiological and proteome responses of the plant host.

  18. Drastic anthocyanin increase in response to PAP1 overexpression in fls1 knockout mutant confers enhanced osmotic stress tolerance in Arabidopsis thaliana.

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    Lee, Won Je; Jeong, Chan Young; Kwon, Jaeyoung; Van Kien, Vu; Lee, Dongho; Hong, Suk-Whan; Lee, Hojoung

    2016-11-01

    KEY MESSAGE : pap1 - D/fls1ko double mutant plants that produce substantial amounts of anthocyanin show tolerance to abiotic stress. Anthocyanins are flavonoids that are abundant in various plants and have beneficial effects on both plants and humans. Many genes in flavonoid biosynthetic pathways have been identified, including those in the MYB-bHLH-WD40 (MBW) complex. The MYB gene Production of Anthocyanin Pigment 1 (PAP1) plays a particularly important role in anthocyanin accumulation. PAP1 expression in many plant systems strongly increases anthocyanin levels, resulting in a dark purple color in many plant organs. In this study, we generated double mutant plants that harbor fls1ko in the pap1-D background (i.e., pap1-D/fls1ko plants), to examine whether anthocyanins can be further enhanced by blocking flavonol biosynthesis under PAP1 overexpression. We also wanted to examine whether the increased anthocyanin levels contribute to defense against osmotic stresses. The pap1-D/fls1ko mutants accumulated higher anthocyanin levels than pap1-D plants in both control and sucrose-treated conditions. However, flavonoid biosynthesis genes were slightly down-regulated in the pap1-D/fls1ko seedlings as compared to their expression in pap1-D seedlings. We also report the performance of pap1-D/fls1ko seedlings in response to plant osmotic stresses.

  19. Co-silencing of tomato S-adenosylhomocysteine hydrolase genes confers increased immunity against Pseudomonas syringae pv. tomato DC3000 and enhanced tolerance to drought stress

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    Li Xiao Hui

    2015-09-01

    Full Text Available S-adenosylhomocysteine hydrolase (SAHH, catalyzing the reversible hydrolysis of S-adenosylhomocysteine to adenosine and homocysteine, is a key enzyme that maintain the cellular methylation potential in all organisms. We report here the biological functions of tomato SlSAHHs in stress response. The tomato genome contains three SlSAHH genes that encode SlSAHH proteins with high level of sequence identity. qRT-PCR analysis revealed that SlSAHHs responded with distinct expression induction patterns to Pseudomonas syringae pv. tomato (Pst DC3000 and Botrytis cinerea as well as to defense signaling hormones such as salicylic acid, jasmonic acid and a precursor of ethylene. Virus-induced gene silencing-based knockdown of individual SlSAHH gene did not affect the growth performance and the response to Pst DC3000. However, co-silencing of three SlSAHH genes using a conserved sequence led to significant inhibition of vegetable growth. The SlSAHH-co-silenced plants displayed increased resistance to Pst DC3000 but did not alter the resistance to B. cinerea. Co-silencing of SlSAHHs resulted in constitutively activated defense responses including elevated SA level, upregulated expression of defense-related and PAMP-triggered immunity marker genes and increased callose deposition and H2O2 accumulation. Furthermore, the SlSAHH-co-silenced plants also exhibited enhanced drought stress tolerance although they had relatively small roots. These data demonstrate that, in addition to the functions in growth and development, SAHHs also play important roles in regulating biotic and abiotic stress responses in plants.

  20. Overexpression of the OsIMP Gene Increases the Accumulation of Inositol and Confers Enhanced Cold Tolerance in Tobacco through Modulation of the Antioxidant Enzymes’ Activities

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    Rong-Xiang Zhang

    2017-07-01

    Full Text Available Inositol is a cyclic polyol that is involved in various physiological processes, including signal transduction and stress adaptation in plants. l-myo-inositol monophosphatase (IMPase is one of the metal-dependent phosphatase family members and catalyzes the last reaction step of biosynthesis of inositol. Although increased IMPase activity induced by abiotic stress has been reported in chickpea plants, the role and regulation of the IMP gene in rice (Oryza sativa L. remains poorly understood. In the present work, we obtained a full-length cDNA sequence coding IMPase in the cold tolerant rice landraces in Gaogonggui, which is named as OsIMP. Multiple alignment results have displayed that this sequence has characteristic signature motifs and conserved enzyme active sites of the phosphatase super family. Phylogenetic analysis showed that IMPase is most closely related to that of the wild rice Oryza brachyantha, while transcript analysis revealed that the expression of the OsIMP is significantly induced by cold stress and exogenous abscisic acid (ABA treatment. Meanwhile, we cloned the 5’ flanking promoter sequence of the OsIMP gene and identified several important cis-acting elements, such as LTR (low-temperature responsiveness, TCA-element (salicylic acid responsiveness, ABRE-element (abscisic acid responsiveness, GARE-motif (gibberellin responsive, MBS (MYB Binding Site and other cis-acting elements related to defense and stress responsiveness. To further investigate the potential function of the OsIMP gene, we generated transgenic tobacco plants overexpressing the OsIMP gene and the cold tolerance test indicated that these transgenic tobacco plants exhibit improved cold tolerance. Furthermore, transgenic tobacco plants have a lower level of hydrogen peroxide (H2O2 and malondialdehyde (MDA, and a higher content of total chlorophyll as well as increased antioxidant enzyme activities of superoxide dismutase (SOD, catalase (CAT and peroxidase (POD

  1. Overexpression of the OsIMP Gene Increases the Accumulation of Inositol and Confers Enhanced Cold Tolerance in Tobacco through Modulation of the Antioxidant Enzymes' Activities.

    Science.gov (United States)

    Zhang, Rong-Xiang; Qin, Li-Jun; Zhao, De-Gang

    2017-07-20

    Inositol is a cyclic polyol that is involved in various physiological processes, including signal transduction and stress adaptation in plants. l- myo -inositol monophosphatase (IMPase) is one of the metal-dependent phosphatase family members and catalyzes the last reaction step of biosynthesis of inositol. Although increased IMPase activity induced by abiotic stress has been reported in chickpea plants, the role and regulation of the IMP gene in rice ( Oryza sativa L.) remains poorly understood. In the present work, we obtained a full-length cDNA sequence coding IMPase in the cold tolerant rice landraces in Gaogonggui, which is named as OsIMP . Multiple alignment results have displayed that this sequence has characteristic signature motifs and conserved enzyme active sites of the phosphatase super family. Phylogenetic analysis showed that IMPase is most closely related to that of the wild rice Oryza brachyantha , while transcript analysis revealed that the expression of the OsIMP is significantly induced by cold stress and exogenous abscisic acid (ABA) treatment. Meanwhile, we cloned the 5' flanking promoter sequence of the OsIMP gene and identified several important cis -acting elements, such as LTR (low-temperature responsiveness), TCA-element (salicylic acid responsiveness), ABRE-element (abscisic acid responsiveness), GARE-motif (gibberellin responsive), MBS (MYB Binding Site) and other cis -acting elements related to defense and stress responsiveness. To further investigate the potential function of the OsIMP gene, we generated transgenic tobacco plants overexpressing the OsIMP gene and the cold tolerance test indicated that these transgenic tobacco plants exhibit improved cold tolerance. Furthermore, transgenic tobacco plants have a lower level of hydrogen peroxide (H₂O₂) and malondialdehyde (MDA), and a higher content of total chlorophyll as well as increased antioxidant enzyme activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD

  2. Enhancing drought tolerance in C(4) crops.

    Science.gov (United States)

    Lopes, Marta S; Araus, Jose Luis; van Heerden, Philippus D R; Foyer, Christine H

    2011-05-01

    Adaptation to abiotic stresses is a quantitative trait controlled by many different genes. Enhancing the tolerance of crop plants to abiotic stresses such as drought has therefore proved to be somewhat elusive in terms of plant breeding. While many C(4) species have significant agronomic importance, most of the research effort on improving drought tolerance has focused on maize. Ideally, drought tolerance has to be achieved without penalties in yield potential. Possibilities for success in this regard are highlighted by studies on maize hybrids performed over the last 70 years that have demonstrated that yield potential and enhanced stress tolerance are associated traits. However, while our understanding of the molecular mechanisms that enable plants to tolerate drought has increased considerably in recent years, there have been relatively few applications of DNA marker technologies in practical C(4) breeding programmes for improved stress tolerance. Moreover, until recently, targeted approaches to drought tolerance have concentrated largely on shoot parameters, particularly those associated with photosynthesis and stay green phenotypes, rather than on root traits such as soil moisture capture for transpiration, root architecture, and improvement of effective use of water. These root traits are now increasingly considered as important targets for yield improvement in C(4) plants under drought stress. Similarly, the molecular mechanisms underpinning heterosis have considerable potential for exploitation in enhancing drought stress tolerance. While current evidence points to the crucial importance of root traits in drought tolerance in C(4) plants, shoot traits may also be important in maintaining high yields during drought.

  3. Enhanced Salt Tolerance Conferred by the Complete 2.3 kb cDNA of the Rice Vacuolar Na(+)/H(+) Antiporter Gene Compared to 1.9 kb Coding Region with 5' UTR in Transgenic Lines of Rice.

    Science.gov (United States)

    Amin, U S M; Biswas, Sudip; Elias, Sabrina M; Razzaque, Samsad; Haque, Taslima; Malo, Richard; Seraj, Zeba I

    2016-01-01

    Soil salinity is one of the most challenging problems that restricts the normal growth and production of rice worldwide. It has therefore become very important to produce more saline tolerant rice varieties. This study shows constitutive over-expression of the vacuolar Na(+)/H(+) antiporter gene (OsNHX1) from the rice landrace (Pokkali) and attainment of enhanced level of salinity tolerance in transgenic rice plants. It also shows that inclusion of the complete un-translated regions (UTRs) of the alternatively spliced OsNHX1 gene provides a higher level of tolerance to the transgenic rice. Two separate transformation events of the OsNHX1 gene, one with 1.9 kb region containing the 5' UTR with CDS and the other of 2.3 kb, including 5' UTR, CDS, and the 3' UTR regions were performed. The transgenic plants with these two different constructs were advanced to the T3 generation and physiological and molecular screening of homozygous plants was conducted at seedling and reproductive stages under salinity (NaCl) stress. Both transgenic lines were observed to be tolerant compared to WT plants at both physiological stages. However, the transgenic lines containing the CDS with both the 5' and 3' UTR were significantly more tolerant compared to the transgenic lines containing OsNHX1 gene without the 3' UTR. At the seedling stage at 12 dS/m stress, the chlorophyll content was significantly higher (P kb > 1.9 kb > and WT lines. Yield in g/plant in the best line from the 2.3 kb plants was significantly more (P kb line and WT plants at stress of 6 dS/m. Transformation with the complete transcripts rather than the CDS may therefore provide more durable level of tolerance.

  4. Enhanced Accident Tolerant LWR Fuels National Metrics Workshop Report

    Energy Technology Data Exchange (ETDEWEB)

    Lori Braase

    2013-01-01

    The U.S. Department of Energy Office of Nuclear Energy (DOE-NE), in collaboration with the nuclear industry, has been conducting research and development (R&D) activities on advanced Light Water Reactor (LWR) fuels for the last few years. The emphasis for these activities was on improving the fuel performance in terms of increased burnup for waste minimization and increased power density for power upgrades, as well as collaborating with industry on fuel reliability. After the events at the Fukushima Nuclear Power Plant in Japan in March 2011, enhancing the accident tolerance of LWRs became a topic of serious discussion. In the Consolidated Appropriations Act, 2012, Conference Report 112-75, the U.S. Congress directed DOE-NE to: • Give “priority to developing enhanced fuels and cladding for light water reactors to improve safety in the event of accidents in the reactor or spent fuel pools.” • Give “special technical emphasis and funding priority…to activities aimed at the development and near-term qualification of meltdown-resistant, accident-tolerant nuclear fuels that would enhance the safety of present and future generations of light water reactors.” • Report “to the Committee, within 90 days of enactment of this act, on its plan for development of meltdown-resistant fuels leading to reactor testing and utilization by 2020.” Fuels with enhanced accident tolerance are those that, in comparison with the standard UO2-zirconium alloy system currently used by the nuclear industry, can tolerate loss of active cooling in the reactor core for a considerably longer time period (depending on the LWR system and accident scenario) while maintaining or improving the fuel performance during normal operations, and operational transients, as well as design-basis and beyond design-basis events. The overall draft strategy for development and demonstration is comprised of three phases: Feasibility Assessment and Down-selection; Development and Qualification; and

  5. Selective chemical binding enhances cesium tolerance in plants through inhibition of cesium uptake.

    Science.gov (United States)

    Adams, Eri; Chaban, Vitaly; Khandelia, Himanshu; Shin, Ryoung

    2015-03-05

    High concentrations of cesium (Cs(+)) inhibit plant growth but the detailed mechanisms of Cs(+) uptake, transport and response in plants are not well known. In order to identify small molecules with a capacity to enhance plant tolerance to Cs(+), chemical library screening was performed using Arabidopsis. Of 10,000 chemicals tested, five compounds were confirmed as Cs(+) tolerance enhancers. Further investigation and quantum mechanical modelling revealed that one of these compounds reduced Cs(+) concentrations in plants and that the imidazole moiety of this compound bound specifically to Cs(+). Analysis of the analogous compounds indicated that the structure of the identified compound is important for the effect to be conferred. Taken together, Cs(+) tolerance enhancer isolated here renders plants tolerant to Cs(+) by inhibiting Cs(+) entry into roots via specific binding to the ion thus, for instance, providing a basis for phytostabilisation of radiocesium-contaminated farmland.

  6. Coordinated Actions of Glyoxalase and Antioxidant Defense Systems in Conferring Abiotic Stress Tolerance in Plants

    Directory of Open Access Journals (Sweden)

    Mirza Hasanuzzaman

    2017-01-01

    Full Text Available Being sessile organisms, plants are frequently exposed to various environmental stresses that cause several physiological disorders and even death. Oxidative stress is one of the common consequences of abiotic stress in plants, which is caused by excess generation of reactive oxygen species (ROS. Sometimes ROS production exceeds the capacity of antioxidant defense systems, which leads to oxidative stress. In line with ROS, plants also produce a high amount of methylglyoxal (MG, which is an α-oxoaldehyde compound, highly reactive, cytotoxic, and produced via different enzymatic and non-enzymatic reactions. This MG can impair cells or cell components and can even destroy DNA or cause mutation. Under stress conditions, MG concentration in plants can be increased 2- to 6-fold compared with normal conditions depending on the plant species. However, plants have a system developed to detoxify this MG consisting of two major enzymes: glyoxalase I (Gly I and glyoxalase II (Gly II, and hence known as the glyoxalase system. Recently, a novel glyoxalase enzyme, named glyoxalase III (Gly III, has been detected in plants, providing a shorter pathway for MG detoxification, which is also a signpost in the research of abiotic stress tolerance. Glutathione (GSH acts as a co-factor for this system. Therefore, this system not only detoxifies MG but also plays a role in maintaining GSH homeostasis and subsequent ROS detoxification. Upregulation of both Gly I and Gly II as well as their overexpression in plant species showed enhanced tolerance to various abiotic stresses including salinity, drought, metal toxicity, and extreme temperature. In the past few decades, a considerable amount of reports have indicated that both antioxidant defense and glyoxalase systems have strong interactions in conferring abiotic stress tolerance in plants through the detoxification of ROS and MG. In this review, we will focus on the mechanisms of these interactions and the coordinated

  7. Coordinated Actions of Glyoxalase and Antioxidant Defense Systems in Conferring Abiotic Stress Tolerance in Plants

    Science.gov (United States)

    Hasanuzzaman, Mirza; Nahar, Kamrun; Hossain, Md. Shahadat; Mahmud, Jubayer Al; Rahman, Anisur; Inafuku, Masashi; Oku, Hirosuke; Fujita, Masayuki

    2017-01-01

    Being sessile organisms, plants are frequently exposed to various environmental stresses that cause several physiological disorders and even death. Oxidative stress is one of the common consequences of abiotic stress in plants, which is caused by excess generation of reactive oxygen species (ROS). Sometimes ROS production exceeds the capacity of antioxidant defense systems, which leads to oxidative stress. In line with ROS, plants also produce a high amount of methylglyoxal (MG), which is an α-oxoaldehyde compound, highly reactive, cytotoxic, and produced via different enzymatic and non-enzymatic reactions. This MG can impair cells or cell components and can even destroy DNA or cause mutation. Under stress conditions, MG concentration in plants can be increased 2- to 6-fold compared with normal conditions depending on the plant species. However, plants have a system developed to detoxify this MG consisting of two major enzymes: glyoxalase I (Gly I) and glyoxalase II (Gly II), and hence known as the glyoxalase system. Recently, a novel glyoxalase enzyme, named glyoxalase III (Gly III), has been detected in plants, providing a shorter pathway for MG detoxification, which is also a signpost in the research of abiotic stress tolerance. Glutathione (GSH) acts as a co-factor for this system. Therefore, this system not only detoxifies MG but also plays a role in maintaining GSH homeostasis and subsequent ROS detoxification. Upregulation of both Gly I and Gly II as well as their overexpression in plant species showed enhanced tolerance to various abiotic stresses including salinity, drought, metal toxicity, and extreme temperature. In the past few decades, a considerable amount of reports have indicated that both antioxidant defense and glyoxalase systems have strong interactions in conferring abiotic stress tolerance in plants through the detoxification of ROS and MG. In this review, we will focus on the mechanisms of these interactions and the coordinated action of

  8. Newly Identified Wild Rice Accessions Conferring High Salt Tolerance Might Use a Tissue Tolerance Mechanism in Leaf

    Science.gov (United States)

    Prusty, Manas R.; Kim, Sung-Ryul; Vinarao, Ricky; Entila, Frederickson; Egdane, James; Diaz, Maria G. Q.; Jena, Kshirod K.

    2018-01-01

    Cultivated rice (Oryza sativa L.) is very sensitive to salt stress. So far a few rice landraces have been identified as a source of salt tolerance and utilized in rice improvement. These tolerant lines primarily use Na+ exclusion mechanism in root which removes Na+ from the xylem stream by membrane Na+ and K+ transporters, and resulted in low Na+ accumulation in shoot. Identification of a new donor source conferring high salt tolerance is imperative. Wild relatives of rice having wide genetic diversity are regarded as a potential source for crop improvement. However, they have been less exploited against salt stress. Here, we simultaneously evaluated all 22 wild Oryza species along with the cultivated tolerant lines including Pokkali, Nona Bokra, and FL478, and sensitive check varieties under high salinity (240 mM NaCl). Based on the visual salt injury score, three species (O. alta, O. latifolia, and O. coarctata) and four species (O. rhizomatis, O. eichingeri, O. minuta, and O. grandiglumis) showed higher and similar level of tolerance compared to the tolerant checks, respectively. All three CCDD genome species exhibited salt tolerance, suggesting that the CCDD genome might possess the common genetic factors for salt tolerance. Physiological and biochemical experiments were conducted using the newly isolated tolerant species together with checks under 180 mM NaCl. Interestingly, all wild species showed high Na+ concentration in shoot and low concentration in root unlike the tolerant checks. In addition, the wild-tolerant accessions showed a tendency of a high tissue tolerance in leaf, low malondialdehyde level in shoot, and high retention of chlorophyll in the young leaves. These results suggest that the wild species employ tissue tolerance mechanism to manage salt stress. Gene expression analyses of the key salt tolerance-related genes suggested that high Na+ in leaf of wild species might be affected by OsHKT1;4-mediated Na+ exclusion in leaf and the following Na

  9. The Technology Enhanced Conference - A Board Game!

    DEFF Research Database (Denmark)

    Pedersen, Annette

    ITMEDIA at the University of Copenhagen have been working with taking the academic conference online for years. Streaming events, using backchannel chat systems and Twitter, producing introductory pre-event videos, setting up audio debates with keynotes to enrich and prolong the conference...... aid: turning it into a board game simply called The Conference Game. By making a children's board game, we let organizers play around with the options, get an overview – and the game element makes it just a little bit less dangerous, and more fun to play around with new technologies. Reception has...

  10. An Acetyltransferase Conferring Tolerance to Toxic Aromatic Amine Chemicals

    Science.gov (United States)

    Martins, Marta; Rodrigues-Lima, Fernando; Dairou, Julien; Lamouri, Aazdine; Malagnac, Fabienne; Silar, Philippe; Dupret, Jean-Marie

    2009-01-01

    Aromatic amines (AA) are a major class of environmental pollutants that have been shown to have genotoxic and cytotoxic potentials toward most living organisms. Fungi are able to tolerate a diverse range of chemical compounds including certain AA and have long been used as models to understand general biological processes. Deciphering the mechanisms underlying this tolerance may improve our understanding of the adaptation of organisms to stressful environments and pave the way for novel pharmaceutical and/or biotechnological applications. We have identified and characterized two arylamine N-acetyltransferase (NAT) enzymes (PaNAT1 and PaNAT2) from the model fungus Podospora anserina that acetylate a wide range of AA. Targeted gene disruption experiments revealed that PaNAT2 was required for the growth and survival of the fungus in the presence of toxic AA. Functional studies using the knock-out strains and chemically acetylated AA indicated that tolerance of P. anserina to toxic AA was due to the N-acetylation of these chemicals by PaNAT2. Moreover, we provide proof-of-concept remediation experiments where P. anserina, through its PaNAT2 enzyme, is able to detoxify the highly toxic pesticide residue 3,4-dichloroaniline in experimentally contaminated soil samples. Overall, our data show that a single xenobiotic-metabolizing enzyme can mediate tolerance to a major class of pollutants in a eukaryotic species. These findings expand the understanding of the role of xenobiotic-metabolizing enzyme and in particular of NATs in the adaptation of organisms to their chemical environment and provide a basis for new systems for the bioremediation of contaminated soils. PMID:19416981

  11. The arbuscular mycorrhizal fungus Glomus mosseae can enhance arsenic tolerance in Medicago truncatula by increasing plant phosphorus status and restricting arsenate uptake

    International Nuclear Information System (INIS)

    Xu Pengliang; Christie, Peter; Liu Yu; Zhang Junling; Li Xiaolin

    2008-01-01

    A pot experiment examined the biomass and As uptake of Medicago truncatula colonized by the arbuscular mycorrhizal (AM) fungus Glomus mosseae in low-P soil experimentally contaminated with different levels of arsenate. The biomass of G. mosseae external mycelium was unaffected by the highest addition level of As studied (200 mg kg -1 ) but shoot and root biomass declined in both mycorrhizal and non-mycorrhizal plants, indicating that the AM fungus was more tolerant than M. truncatula to arsenate. Mycorrhizal inoculation increased shoot and root dry weights by enhancing host plant P nutrition and lowering shoot and root As concentrations compared with uninoculated plants. The AM fungus may have been highly tolerant to As and conferred enhanced tolerance to arsenate on the host plant by enhancing P nutrition and restricting root As uptake. - G. mosseae was more tolerant than M. truncatula to As and may have conferred enhanced host tolerance by restricting root As uptake and enhancing P nutrition

  12. The arbuscular mycorrhizal fungus Glomus mosseae can enhance arsenic tolerance in Medicago truncatula by increasing plant phosphorus status and restricting arsenate uptake

    Energy Technology Data Exchange (ETDEWEB)

    Xu Pengliang [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China); Christie, Peter [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China); Agricultural and Environmental Science Department, Queen' s University Belfast, Belfast BT9 5PX (United Kingdom); Liu Yu [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China); Zhang Junling [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China)], E-mail: junlingz@cau.edu.cn; Li Xiaolin [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China)

    2008-11-15

    A pot experiment examined the biomass and As uptake of Medicago truncatula colonized by the arbuscular mycorrhizal (AM) fungus Glomus mosseae in low-P soil experimentally contaminated with different levels of arsenate. The biomass of G. mosseae external mycelium was unaffected by the highest addition level of As studied (200 mg kg{sup -1}) but shoot and root biomass declined in both mycorrhizal and non-mycorrhizal plants, indicating that the AM fungus was more tolerant than M. truncatula to arsenate. Mycorrhizal inoculation increased shoot and root dry weights by enhancing host plant P nutrition and lowering shoot and root As concentrations compared with uninoculated plants. The AM fungus may have been highly tolerant to As and conferred enhanced tolerance to arsenate on the host plant by enhancing P nutrition and restricting root As uptake. - G. mosseae was more tolerant than M. truncatula to As and may have conferred enhanced host tolerance by restricting root As uptake and enhancing P nutrition.

  13. Microorganisms having enhanced tolerance to inhibitors and stress

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Steven D.; Yang, Shihui

    2014-07-29

    The present invention provides genetically modified strains of microorganisms that display enhanced tolerance to stress and/or inhibitors such as sodium acetate and vanillin. The enhanced tolerance can be achieved by increasing the expression of a protein of the Sm-like superfamily such as a bacterial Hfq protein and a fungal Sm or Lsm protein. Further, the present invention provides methods of producing alcohol from biomass materials by using the genetically modified microorganisms of the present invention.

  14. Expression of a finger millet transcription factor, EcNAC1, in tobacco confers abiotic stress-tolerance.

    Directory of Open Access Journals (Sweden)

    Venkategowda Ramegowda

    Full Text Available NAC (NAM, ATAF1-2, and CUC2 proteins constitute one of the largest families of plant-specific transcription factors and have been shown to be involved in diverse plant processes including plant growth, development, and stress-tolerance. In this study, a stress-responsive NAC gene, EcNAC1, was isolated from the subtracted stress cDNA library generated from a drought adapted crop, finger millet, and characterized for its role in stress-tolerance. The expression analysis showed that EcNAC1 was highly induced during water-deficit and salt stress. EcNAC1 shares high amino acid similarity with rice genes that have been phylogenetically classified into stress-related NAC genes. Our results demonstrated that tobacco transgenic plants expressing EcNAC1 exhibit tolerance to various abiotic stresses like simulated osmotic stress, by polyethylene glycol (PEG and mannitol, and salinity stress. The transgenic plants also showed enhanced tolerance to methyl-viologen (MV induced oxidative stress. Reduced levels of reactive oxygen species (ROS and ROS-induced damage were noticed in pot grown transgenic lines under water-deficit and natural high light conditions. Root growth under stress and recovery growth after stress alleviation was more in transgenic plants. Many stress-responsive genes were found to be up-regulated in transgenic lines expressing EcNAC1. Our results suggest that EcNAC1 overexpression confers tolerance against abiotic stress in susceptible species, tobacco.

  15. Drought Tolerance Conferred to Sugarcane by Association with Gluconacetobacter diazotrophicus: A Transcriptomic View of Hormone Pathways

    Science.gov (United States)

    Vargas, Lívia; Santa Brígida, Ailton B.; Mota Filho, José P.; de Carvalho, Thais G.; Rojas, Cristian A.; Vaneechoutte, Dries; Van Bel, Michiel; Farrinelli, Laurent; Ferreira, Paulo C. G.; Vandepoele, Klaas; Hemerly, Adriana S.

    2014-01-01

    Sugarcane interacts with particular types of beneficial nitrogen-fixing bacteria that provide fixed-nitrogen and plant growth hormones to host plants, promoting an increase in plant biomass. Other benefits, as enhanced tolerance to abiotic stresses have been reported to some diazotrophs. Here we aim to study the effects of the association between the diazotroph Gluconacetobacter diazotrophicus PAL5 and sugarcane cv. SP70-1143 during water depletion by characterizing differential transcriptome profiles of sugarcane. RNA-seq libraries were generated from roots and shoots of sugarcane plants free of endophytes that were inoculated with G. diazotrophicus and subjected to water depletion for 3 days. A sugarcane reference transcriptome was constructed and used for the identification of differentially expressed transcripts. The differential profile of non-inoculated SP70-1143 suggests that it responds to water deficit stress by the activation of drought-responsive markers and hormone pathways, as ABA and Ethylene. qRT-PCR revealed that root samples had higher levels of G. diazotrophicus 3 days after water deficit, compared to roots of inoculated plants watered normally. With prolonged drought only inoculated plants survived, indicating that SP70-1143 plants colonized with G. diazotrophicus become more tolerant to drought stress than non-inoculated plants. Strengthening this hypothesis, several gene expression responses to drought were inactivated or regulated in an opposite manner, especially in roots, when plants were colonized by the bacteria. The data suggests that colonized roots would not be suffering from stress in the same way as non-inoculated plants. On the other hand, shoots specifically activate ABA-dependent signaling genes, which could act as key elements in the drought resistance conferred by G. diazotrophicus to SP70-1143. This work reports for the first time the involvement of G. diazotrophicus in the promotion of drought-tolerance to sugarcane cv. SP70

  16. Drought tolerance conferred to sugarcane by association with Gluconacetobacter diazotrophicus: a transcriptomic view of hormone pathways.

    Directory of Open Access Journals (Sweden)

    Lívia Vargas

    Full Text Available Sugarcane interacts with particular types of beneficial nitrogen-fixing bacteria that provide fixed-nitrogen and plant growth hormones to host plants, promoting an increase in plant biomass. Other benefits, as enhanced tolerance to abiotic stresses have been reported to some diazotrophs. Here we aim to study the effects of the association between the diazotroph Gluconacetobacter diazotrophicus PAL5 and sugarcane cv. SP70-1143 during water depletion by characterizing differential transcriptome profiles of sugarcane. RNA-seq libraries were generated from roots and shoots of sugarcane plants free of endophytes that were inoculated with G. diazotrophicus and subjected to water depletion for 3 days. A sugarcane reference transcriptome was constructed and used for the identification of differentially expressed transcripts. The differential profile of non-inoculated SP70-1143 suggests that it responds to water deficit stress by the activation of drought-responsive markers and hormone pathways, as ABA and Ethylene. qRT-PCR revealed that root samples had higher levels of G. diazotrophicus 3 days after water deficit, compared to roots of inoculated plants watered normally. With prolonged drought only inoculated plants survived, indicating that SP70-1143 plants colonized with G. diazotrophicus become more tolerant to drought stress than non-inoculated plants. Strengthening this hypothesis, several gene expression responses to drought were inactivated or regulated in an opposite manner, especially in roots, when plants were colonized by the bacteria. The data suggests that colonized roots would not be suffering from stress in the same way as non-inoculated plants. On the other hand, shoots specifically activate ABA-dependent signaling genes, which could act as key elements in the drought resistance conferred by G. diazotrophicus to SP70-1143. This work reports for the first time the involvement of G. diazotrophicus in the promotion of drought-tolerance to

  17. Drought tolerance conferred to sugarcane by association with Gluconacetobacter diazotrophicus: a transcriptomic view of hormone pathways.

    Science.gov (United States)

    Vargas, Lívia; Santa Brígida, Ailton B; Mota Filho, José P; de Carvalho, Thais G; Rojas, Cristian A; Vaneechoutte, Dries; Van Bel, Michiel; Farrinelli, Laurent; Ferreira, Paulo C G; Vandepoele, Klaas; Hemerly, Adriana S

    2014-01-01

    Sugarcane interacts with particular types of beneficial nitrogen-fixing bacteria that provide fixed-nitrogen and plant growth hormones to host plants, promoting an increase in plant biomass. Other benefits, as enhanced tolerance to abiotic stresses have been reported to some diazotrophs. Here we aim to study the effects of the association between the diazotroph Gluconacetobacter diazotrophicus PAL5 and sugarcane cv. SP70-1143 during water depletion by characterizing differential transcriptome profiles of sugarcane. RNA-seq libraries were generated from roots and shoots of sugarcane plants free of endophytes that were inoculated with G. diazotrophicus and subjected to water depletion for 3 days. A sugarcane reference transcriptome was constructed and used for the identification of differentially expressed transcripts. The differential profile of non-inoculated SP70-1143 suggests that it responds to water deficit stress by the activation of drought-responsive markers and hormone pathways, as ABA and Ethylene. qRT-PCR revealed that root samples had higher levels of G. diazotrophicus 3 days after water deficit, compared to roots of inoculated plants watered normally. With prolonged drought only inoculated plants survived, indicating that SP70-1143 plants colonized with G. diazotrophicus become more tolerant to drought stress than non-inoculated plants. Strengthening this hypothesis, several gene expression responses to drought were inactivated or regulated in an opposite manner, especially in roots, when plants were colonized by the bacteria. The data suggests that colonized roots would not be suffering from stress in the same way as non-inoculated plants. On the other hand, shoots specifically activate ABA-dependent signaling genes, which could act as key elements in the drought resistance conferred by G. diazotrophicus to SP70-1143. This work reports for the first time the involvement of G. diazotrophicus in the promotion of drought-tolerance to sugarcane cv. SP70

  18. A glutathione s-transferase confers herbicide tolerance in rice

    Directory of Open Access Journals (Sweden)

    Tingzhang Hu

    2014-07-01

    Full Text Available Plant glutathione S-transferases (GSTs have been a focus of attention due to their role in herbicide detoxification. OsGSTL2 is a glutathione S-transferase, lambda class gene from rice (Oryza sativa L.. Transgenic rice plants over-expressing OsGSTL2 were generated from rice calli by the use of an Agrobacterium transformation system, and were screened by a combination of hygromycin resistance, PCR and Southern blot analysis. In the vegetative tissues of transgenic rice plants, the over-expression of OsGSTL2 not only increased levels of OsGSTL2 transcripts, but also GST and GPX expression, while reduced superoxide. Transgenic rice plants also showed higher tolerance to glyphosate and chlorsulfuron, which often contaminate agricultural fields. The findings demonstrate the detoxification role of OsGSTL2 in the growth and development of rice plants. It should be possible to apply the present results to crops for developing herbicide tolerance and for limiting herbicide contamination in the food chain.

  19. International Conference on Nuclear Security: Enhancing Global Efforts. Summary of an International Conference

    International Nuclear Information System (INIS)

    2014-01-01

    The International Conference on Nuclear Security: Enhancing Global Efforts was organized by the IAEA and held in Vienna on 1-5 July 2013. The conference was organized in cooperation with the following organizations and initiatives: the European Union; the Global Initiative to Combat Nuclear Terrorism (GICNT); the International Criminal Police Organization (INTERPOL); the Institute of Nuclear Materials Management (INMM); the Nuclear Threat Initiative (NTI); the Organization for Security and Co-operation in Europe (OSCE); the Partnership for Global Security; the Police Community of the Americas (AMERIPOL); the United Nations Interregional Crime and Justice Research Institute (UNICRI); the United Nations Office on Drugs and Crime (UNODC); the World Institute for Nuclear Security (WINS); the World Nuclear Association (WNA); and the World Nuclear Transport Institute (WNTI). A total of 34 ministers participated in the ministerial session of the conference. Altogether, the conference attracted more than 1300 registered participants from 125 IAEA Member States and 21 organizations. The aim of the conference was to review the international community's experience and achievements to date in strengthening nuclear security, to enhance the understanding of current approaches to nuclear security worldwide and identify trends, and to provide a global forum for ministers, policymakers and senior officials to formulate views on future directions and priorities for nuclear security. This book contains the President's Summary of the conference and a summary of the ministerial session, the full text of the ministerial declaration adopted by the conference and summaries of the main conference sessions. The attached CD-ROM contains the full conference programme, the list of conference participants, the national statements from the ministerial session and a selection of papers

  20. International Conference on Biotechnology for Salinity and Drought Tolerance in Plants

    International Nuclear Information System (INIS)

    Malik, K.A.; Mahmood, K.

    2005-01-01

    International Conference on Biotechnology for Salinity and Drought Tolerance in Plants was held from 28-29 March, 2005 at Islamabad, Pakistan. Abstracts of this conference have been presented in this proceeding. There were six technical sessions like 1) Stress Physiology/Ion Transport, 2) Stress Sensing and Signaling, 3) Genomis, Metabolomics and Proteomics, 4) Genetic Engineering, 5) Gene Expression, 6) Field Studies and Management. This seminar was quite useful specially drought resistance and salinity in the soil. Researches exchange their views in the seminar. (A.B.)

  1. Yeast functional screen to identify genes conferring salt stress tolerance in Salicornia europaea.

    Science.gov (United States)

    Nakahara, Yoshiki; Sawabe, Shogo; Kainuma, Kenta; Katsuhara, Maki; Shibasaka, Mineo; Suzuki, Masanori; Yamamoto, Kosuke; Oguri, Suguru; Sakamoto, Hikaru

    2015-01-01

    Salinity is a critical environmental factor that adversely affects crop productivity. Halophytes have evolved various mechanisms to adapt to saline environments. Salicornia europaea L. is one of the most salt-tolerant plant species. It does not have special salt-secreting structures like a salt gland or salt bladder, and is therefore a good model for studying the common mechanisms underlying plant salt tolerance. To identify candidate genes encoding key proteins in the mediation of salt tolerance in S. europaea, we performed a functional screen of a cDNA library in yeast. The library was screened for genes that allowed the yeast to grow in the presence of 1.3 M NaCl. We obtained three full-length S. europaea genes that confer salt tolerance. The genes are predicted to encode (1) a novel protein highly homologous to thaumatin-like proteins, (2) a novel coiled-coil protein of unknown function, and (3) a novel short peptide of 32 residues. Exogenous application of a synthetic peptide corresponding to the 32 residues improved salt tolerance of Arabidopsis. The approach described in this report provides a rapid assay system for large-scale screening of S. europaea genes involved in salt stress tolerance and supports the identification of genes responsible for such mechanisms. These genes may be useful candidates for improving crop salt tolerance by genetic transformation.

  2. Yeast functional screen to identify genes conferring salt stress tolerance in Salicornia europaea

    Directory of Open Access Journals (Sweden)

    Yoshiki eNakahara

    2015-10-01

    Full Text Available Salinity is a critical environmental factor that adversely affects crop productivity. Halophytes have evolved various mechanisms to adapt to saline environments. Salicornia europaea L. is one of the most salt-tolerant plant species. It does not have special salt-secreting structures like a salt gland or salt bladder, and is therefore a good model for studying the common mechanisms underlying plant salt tolerance. To identify candidate genes encoding key proteins in the mediation of salt tolerance in S. europaea, we performed a functional screen of a cDNA library in yeast. The library was screened for genes that allowed the yeast to grow in the presence of 1.3 M NaCl. We obtained three full-length S. europaea genes that confer salt tolerance. The genes are predicted to encode (1 a novel protein highly homologous to thaumatin-like proteins, (2 a novel coiled-coil protein of unknown function, and (3 a novel short peptide of 32 residues. Exogenous application of a synthetic peptide corresponding to the 32 residues improved salt tolerance of Arabidopsis. The approach described in this report provides a rapid assay system for large-scale screening of S. europaea genes involved in salt stress tolerance and supports the identification of genes responsible for such mechanisms. These genes may be useful candidates for improving crop salt tolerance by genetic transformation.

  3. Novel AroA from Pseudomonas putida Confers Tobacco Plant with High Tolerance to Glyphosate

    Science.gov (United States)

    Yan, Hai-Qin; Chang, Su-Hua; Tian, Zhe-Xian; Zhang, Le; Sun, Yi-Cheng; Li, Yan; Wang, Jing; Wang, Yi-Ping

    2011-01-01

    Glyphosate is a non-selective broad-spectrum herbicide that inhibits 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS, also designated as AroA), a key enzyme in the aromatic amino acid biosynthesis pathway in microorganisms and plants. Previously, we reported that a novel AroA (PpAroA1) from Pseudomonas putida had high tolerance to glyphosate, with little homology to class I or class II glyphosate-tolerant AroA. In this study, the coding sequence of PpAroA1 was optimized for tobacco. For maturation of the enzyme in chloroplast, a chloroplast transit peptide coding sequence was fused in frame with the optimized aroA gene (PparoA1optimized) at the 5′ end. The PparoA1optimized gene was introduced into the tobacco (Nicotiana tabacum L. cv. W38) genome via Agrobacterium-mediated transformation. The transformed explants were first screened in shoot induction medium containing kanamycin. Then glyphosate tolerance was assayed in putative transgenic plants and its T1 progeny. Our results show that the PpAroA1 from Pseudomonas putida can efficiently confer tobacco plants with high glyphosate tolerance. Transgenic tobacco overexpressing the PparoA1optimized gene exhibit high tolerance to glyphosate, which suggest that the novel PpAroA1 is a new and good candidate applied in transgenic crops with glyphosate tolerance in future. PMID:21611121

  4. In silico design and functional assessment of semisynthetic genes that confer tolerance to phosphinothricin

    Directory of Open Access Journals (Sweden)

    Jenny Paola Jiménez

    2016-07-01

    Full Text Available Herbicide tolerance is one of the features most used in GM crops, which has shown positive results for farmers and the environment. The starting point is the development of expression cassettes that express the characteristic of interest, they are initially constructed by standard molecular biology techniques. Currently, by bioinformatics and synthetic biology tools, it is possible to design and test the construct in silico, and then hire their synthesis. This approach allows optimizing expression by modifying the codon usage. In this work there were designed and evaluated semi-synthetic versions of genes in Nicotiana benthamiana, these genes confer tolerance to the herbicide phosphinothricin. It was made an analysis of freedom to operate in order to ensure that the designed constructs not violate intellectual property in Colombia. There were obtained two expression cassettes with freedom to operate, which express versions of the bar gene.

  5. The sunflower transcription factor HaHB11 confers tolerance to water deficit and salinity to transgenic Arabidopsis and alfalfa plants.

    Science.gov (United States)

    Cabello, Julieta V; Giacomelli, Jorge I; Gómez, María C; Chan, Raquel L

    2017-09-10

    Homeodomain-leucine zipper (HD-Zip) transcription factors are unique to the plant kingdom; members of subfamily I are known to be involved in abiotic stress responses. HaHB11 belongs to this subfamily and it was previously shown that it is able to confer improved yield and tolerance to flooding via a quiescent strategy. Here we show that HaHB11 expression is induced by ABA, NaCl and water deficit in sunflower seedlings and leaves. Arabidopsis transgenic plants expressing HaHB11, controlled either by its own promoter or by the constitutive 35S CaMV, presented rolled leaves and longer roots than WT when grown under standard conditions. In addition, these plants showed wider stems and more vascular bundles. To deal with drought, HaHB11 transgenic plants closed their stomata faster and lost less water than controls, triggering an enhanced tolerance to such stress condition and also to salinity stress. Concomitantly, ABA-synthesis and sensing related genes were differentially regulated in HaHB11 transgenic plants. Either under long-term salinity stress or mild drought stress, HaHB11 transgenic plants did not exhibit yield penalties. Moreover, alfalfa transgenic plants were generated which also showed enhanced drought tolerance. Altogether, the results indicated that HaHB11 was able to confer drought and salinity tolerance via a complex mechanism which involves morphological, physiological and molecular changes. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. The flavoprotein Tah18-dependent NO synthesis confers high-temperature stress tolerance on yeast cells

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Akira; Kawahara, Nobuhiro [Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192 (Japan); Takagi, Hiroshi, E-mail: hiro@bs.naist.jp [Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192 (Japan)

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer NO is produced from L-arginine in response to elevated temperature in yeast. Black-Right-Pointing-Pointer Tah18 was first identified as the yeast protein involved in NO synthesis. Black-Right-Pointing-Pointer Tah18-dependent NO synthesis confers tolerance to high-temperature on yeast cells. -- Abstract: Nitric oxide (NO) is a ubiquitous signaling molecule involved in the regulation of a large number of cellular functions. In the unicellular eukaryote yeast, NO may be involved in stress response pathways, but its role is poorly understood due to the lack of mammalian NO synthase (NOS) orthologues. Previously, we have proposed the oxidative stress-induced L-arginine synthesis and its physiological role under stress conditions in yeast Saccharomyces cerevisiae. Here, our experimental results indicated that increased conversion of L-proline into L-arginine led to NO production in response to elevated temperature. We also showed that the flavoprotein Tah18, which was previously reported to transfer electrons to the Fe-S cluster protein Dre2, was involved in NO synthesis in yeast. Gene knockdown analysis demonstrated that Tah18-dependent NO synthesis confers high-temperature stress tolerance on yeast cells. As it appears that such a unique cell protection mechanism is specific to yeasts and fungi, it represents a promising target for antifungal activity.

  7. The flavoprotein Tah18-dependent NO synthesis confers high-temperature stress tolerance on yeast cells

    International Nuclear Information System (INIS)

    Nishimura, Akira; Kawahara, Nobuhiro; Takagi, Hiroshi

    2013-01-01

    Highlights: ► NO is produced from L-arginine in response to elevated temperature in yeast. ► Tah18 was first identified as the yeast protein involved in NO synthesis. ► Tah18-dependent NO synthesis confers tolerance to high-temperature on yeast cells. -- Abstract: Nitric oxide (NO) is a ubiquitous signaling molecule involved in the regulation of a large number of cellular functions. In the unicellular eukaryote yeast, NO may be involved in stress response pathways, but its role is poorly understood due to the lack of mammalian NO synthase (NOS) orthologues. Previously, we have proposed the oxidative stress-induced L-arginine synthesis and its physiological role under stress conditions in yeast Saccharomyces cerevisiae. Here, our experimental results indicated that increased conversion of L-proline into L-arginine led to NO production in response to elevated temperature. We also showed that the flavoprotein Tah18, which was previously reported to transfer electrons to the Fe–S cluster protein Dre2, was involved in NO synthesis in yeast. Gene knockdown analysis demonstrated that Tah18-dependent NO synthesis confers high-temperature stress tolerance on yeast cells. As it appears that such a unique cell protection mechanism is specific to yeasts and fungi, it represents a promising target for antifungal activity.

  8. Over-Expression of Arabidopsis EDT1 Gene Confers Drought Tolerance in Alfalfa (Medicago sativa L.

    Directory of Open Access Journals (Sweden)

    Guangshun Zheng

    2017-12-01

    Full Text Available Alfalfa (Medicago sativa L. is an important legume forage crop with great economic value. However, as the growth of alfalfa is seriously affected by an inadequate supply of water, drought is probably the major abiotic environmental factor that most severely affects alfalfa production worldwide. In an effort to enhance alfalfa drought tolerance, we transformed the Arabidopsis Enhanced Drought Tolerance 1 (AtEDT1 gene into alfalfa via Agrobacterium-mediated transformation. Compared with wild type plants, drought stress treatment resulted in higher survival rates and biomass, but reduced water loss rates in the transgenic plants. Furthermore, transgenic alfalfa plants had increased stomatal size, but reduced stomatal density, and these stomatal changes contributed greatly to reduced water loss from leaves. Importantly, transgenic alfalfa plants exhibited larger root systems with larger root lengths, root weight, and root diameters than wild type plants. The transgenic alfalfa plants had reduced membrane permeability and malondialdehyde content, but higher soluble sugar and proline content, higher superoxide dismutase activity, higher chlorophyll content, enhanced expression of drought-responsive genes, as compared with wild type plants. Notably, transgenic alfalfa plants grew better in a 2-year field trial and showed enhanced growth performance with increased biomass yield. All of our morphological, physiological, and molecular analyses demonstrated that the ectopic expression of AtEDT1 improved growth and enhanced drought tolerance in alfalfa. Our study provides alfalfa germplasm for use in forage improvement programs, and may help to increase alfalfa production in arid lands.

  9. Short communication: Lactose enhances bile tolerance of yogurt culture bacteria.

    Science.gov (United States)

    Mena, Behannis; Aryana, Kayanush

    2018-03-01

    Lactose is an energy source for culture bacteria. Bile tolerance is an important probiotic property. Our aim was to elucidate the effect of lactose on bile tolerance of yogurt starter culture Lactobacillus bulgaricus LB-12 and Streptococcus thermophilus ST-M5. Bile tolerance of pure cultures was determined using 0.3% oxgall in MRS THIO broth (Difco, Becton Dickinson, Sparks, MD) for L. bulgaricus and 0.3% oxgall in M17 broth (Oxoid, Basingstoke, UK) for Strep. thermophilus. Lactose was added to both broths at 0 (control), 1, 3, and 5% (wt/vol) broth. Dilutions were plated hourly for 12 h. Experiments were replicated 3 times. At 2, 4, and 12 h of incubation, lactose incorporated at all amounts, 1, 3, and 5% (wt/vol), showed higher counts of Strep. thermophilus ST-M5 compared with the control. Lactose use at 5% (wt/vol) significantly enhanced bile tolerance of both L. bulgaricus and Strep. thermophilus compared with control. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  10. Cloning of the Lycopene β-cyclase Gene in Nicotiana tabacum and Its Overexpression Confers Salt and Drought Tolerance

    Directory of Open Access Journals (Sweden)

    Yanmei Shi

    2015-12-01

    Full Text Available Carotenoids are important pigments in plants that play crucial roles in plant growth and in plant responses to environmental stress. Lycopene β cyclase (β-LCY functions at the branch point of the carotenoid biosynthesis pathway, catalyzing the cyclization of lycopene. Here, a β-LCY gene from Nicotiana tabacum, designated as Ntβ-LCY1, was cloned and functionally characterized. Robust expression of Ntβ-LCY1 was found in leaves, and Ntβ-LCY1 expression was obviously induced by salt, drought, and exogenous abscisic acid treatments. Strong accumulation of carotenoids and expression of carotenoid biosynthesis genes resulted from Ntβ-LCY1 overexpression. Additionally, compared to wild-type plants, transgenic plants with overexpression showed enhanced tolerance to salt and drought stress with higher abscisic acid levels and lower levels of malondialdehyde and reactive oxygen species. Conversely, transgenic RNA interference plants had a clear albino phenotype in leaves, and some plants did not survive beyond the early developmental stages. The suppression of Ntβ-LCY1 expression led to lower expression levels of genes in the carotenoid biosynthesis pathway and to reduced accumulation of carotenoids, chlorophyll, and abscisic acid. These results indicate that Ntβ-LCY1 is not only a likely cyclization enzyme involved in carotenoid accumulation but also confers salt and drought stress tolerance in Nicotiana tabacum.

  11. An Alcohol Dehydrogenase Gene from Synechocystis sp. Confers Salt Tolerance in Transgenic Tobacco

    Directory of Open Access Journals (Sweden)

    So Young Yi

    2017-11-01

    Full Text Available Synechocystis salt-responsive gene 1 (sysr1 was engineered for expression in higher plants, and gene construction was stably incorporated into tobacco plants. We investigated the role of Sysr1 [a member of the alcohol dehydrogenase (ADH superfamily] by examining the salt tolerance of sysr1-overexpressing (sysr1-OX tobacco plants using quantitative real-time polymerase chain reactions, gas chromatography-mass spectrometry, and bioassays. The sysr1-OX plants exhibited considerably increased ADH activity and tolerance to salt stress conditions. Additionally, the expression levels of several stress-responsive genes were upregulated. Moreover, airborne signals from salt-stressed sysr1-OX plants triggered salinity tolerance in neighboring wild-type (WT plants. Therefore, Sysr1 enhanced the interconversion of aldehydes to alcohols, and this occurrence might affect the quality of green leaf volatiles (GLVs in sysr1-OX plants. Actually, the Z-3-hexenol level was approximately twofold higher in sysr1-OX plants than in WT plants within 1–2 h of wounding. Furthermore, analyses of WT plants treated with vaporized GLVs indicated that Z-3-hexenol was a stronger inducer of stress-related gene expression and salt tolerance than E-2-hexenal. The results of the study suggested that increased C6 alcohol (Z-3-hexenol induced the expression of resistance genes, thereby enhancing salt tolerance of transgenic plants. Our results revealed a role for ADH in salinity stress responses, and the results provided a genetic engineering strategy that could improve the salt tolerance of crops.

  12. Review of progress on enhanced accident tolerant fuel

    International Nuclear Information System (INIS)

    McCoy, K.; Dunn, B.; Kochendarfer, R.

    2015-01-01

    The accident at Fukushima has resulted in renewed interest in understanding the performance of nuclear power plants under accident conditions. Part of that interest is directed toward determining how to improve the performance of fuel during an accident that involves long exposures of the fuel to high temperatures. This paper describes the method being used by AREVA to select and evaluate approaches for improving the accident tolerance of nuclear fuel. The method involves starting with a large number of approaches that might enhance accident tolerance, and reviewing how well each approach satisfies a set of engineering requirements and goals. Among the approaches investigated we have the development of fuel pellets that contain a second phase to improve thermal conductivity, the use of molybdenum alloy tubing as fuel cladding, the use of oxidation-resistant coatings to zirconium cladding, and the use of nanoparticles in the coolant to improve heat transfer

  13. Gibberellin Deficiency Confers Both Lodging and Drought Tolerance in Small Cereals

    Directory of Open Access Journals (Sweden)

    Sonia ePlaza-Wüthrich

    2016-05-01

    Full Text Available Tef [Eragrostis tef (Zucc. Trotter] and finger millet [Eleusine coracana Gaertn] are staple cereal crops in Africa and Asia with several desirable agronomic and nutritional properties. Tef is becoming a life-style crop as it is gluten-free while finger millet has a low glycemic index which makes it an ideal food for diabetic patients. However, both tef and finger millet have extremely low grain yields mainly due to moisture scarcity and susceptibility of the plants to lodging. In this study, the effects of gibberellic acid (GA inhibitors particularly paclobutrazol (PBZ on diverse physiological and yield-related parameters were investigated and compared to GA mutants in rice (Oryza sativa L.. The application of PBZ to tef and finger millet significantly reduced the plant height and increased lodging tolerance. Remarkably, PBZ also enhanced the tolerance of both tef and finger millet to moisture deficit. Under moisture scarcity, tef plants treated with PBZ did not exhibit drought-related symptoms and their stomatal conductance was unaltered, leading to higher shoot biomass and grain yield. Semi-dwarf rice mutants altered in GA biosynthesis, were also shown to have improved tolerance to dehydration. The combination of traits (drought tolerance, lodging tolerance and increased yield that we found in plants with altered GA pathway is of importance to breeders who would otherwise rely on extensive crossing to introgress each trait individually. The key role played by PBZ in the tolerance to both lodging and drought calls for further studies using mutants in the GA biosynthesis pathway in order to obtain candidate lines which can be incorporated into crop-breeding programs to create lodging tolerant and climate-smart crops.

  14. Heterologous expression of three Camellia sinensis small heat shock protein genes confers temperature stress tolerance in yeast and Arabidopsis thaliana.

    Science.gov (United States)

    Wang, Mingle; Zou, Zhongwei; Li, Qinghui; Xin, Huahong; Zhu, Xujun; Chen, Xuan; Li, Xinghui

    2017-07-01

    CsHSP17.7, CsHSP18.1, and CsHSP21.8 expressions are induced by heat and cold stresses, and CsHSP overexpression confers tolerance to heat and cold stresses in transgenic Pichia pastoris and Arabidopsis thaliana. Small heat shock proteins (sHSPs) are crucial for protecting plants against biotic and abiotic stresses, especially heat stress. However, knowledge concerning the functions of Camellia sinensis sHSP in heat and cold stresses remains poorly understood. In this study, three C. sinensis sHSP genes (i.e., CsHSP17.7, CsHSP18.1, and CsHSP21.8) were isolated and characterized using suppression subtractive hybridization (SSH) technology. The CsHSPs expression levels in C. sinensis leaves were significantly up-regulated by heat and cold stresses. Phylogenetic analyses revealed that CsHSP17.7, CsHSP18.1, and CsHSP21.8 belong to sHSP Classes I, II, and IV, respectively. Heterologous expression of the three CsHSP genes in Pichia pastoris cells enhanced heat and cold stress tolerance. When exposed to heat and cold treatments, transgenic Arabidopsis thaliana plants overexpressing CsHSP17.7, CsHSP18.1, and CsHSP21.8 had lower malondialdehyde contents, ion leakage, higher proline contents, and transcript levels of stress-related genes (e.g., AtPOD, AtAPX1, AtP5CS2, and AtProT1) compared with the control line. In addition, improved seed germination vigor was also observed in the CsHSP-overexpressing seeds under heat stress. Taken together, our results suggest that the three identified CsHSP genes play key roles in heat and cold tolerance.

  15. MsZEP, a novel zeaxanthin epoxidase gene from alfalfa (Medicago sativa), confers drought and salt tolerance in transgenic tobacco.

    Science.gov (United States)

    Zhang, Zhiqiang; Wang, Yafang; Chang, Leqin; Zhang, Tong; An, Jie; Liu, Yushi; Cao, Yuman; Zhao, Xia; Sha, Xuyang; Hu, Tianming; Yang, Peizhi

    2016-02-01

    The zeaxanthin epoxidase gene ( MsZEP ) was cloned and characterized from alfalfa and validated for its function of tolerance toward drought and salt stresses by heterologous expression in Nicotiana tabacum. Zeaxanthin epoxidase (ZEP) plays important roles in plant response to various environment stresses due to its functions in ABA biosynthetic and the xanthophyll cycle. To understand the expression characteristics and the biological functions of ZEP in alfalfa (Medicago sativa), a novel gene, designated as MsZEP (KM044311), was cloned, characterized and overexpressed in Nicotiana tabacum. The open reading frame of MsZEP contains 1992 bp nucleotides and encodes a 663-amino acid polypeptide. Amino acid sequence alignment indicated that deduced MsZEP protein was highly homologous to other plant ZEP sequences. Phylogenetic analysis showed that MsZEP was grouped into a branch with other legume plants. Real-time quantitative PCR revealed that MsZEP gene expression was clearly tissue-specific, and the expression levels were higher in green tissues (leaves and stems) than in roots. MsZEP expression decreased in shoots under drought, cold, heat and ABA treatment, while the expression levels in roots showed different trends. Besides, the results showed that nodules could up-regulate the MsZEP expression under non-stressful conditions and in the earlier stage of different abiotic stress. Heterologous expression of the MsZEP gene in N. tabacum could confer tolerance to drought and salt stress by affecting various physiological pathways, ABA levels and stress-responsive genes expression. Taken together, these results suggested that the MsZEP gene may be involved in alfalfa responses to different abiotic stresses and nodules, and could enhance drought and salt tolerance of transgenic tobacco by heterologous expression.

  16. Root bacterial endophytes confer drought resistance and enhance expression and activity of a vacuolar H+ -pumping pyrophosphatase in pepper plants.

    Science.gov (United States)

    Vigani, Gianpiero; Rolli, Eleonora; Marasco, Ramona; Dell'Orto, Marta; Michoud, Grégoire; Soussi, Asma; Raddadi, Noura; Borin, Sara; Sorlini, Claudia; Zocchi, Graziano; Daffonchio, Daniele

    2018-05-22

    It has been previously shown that the transgenic overexpression of the plant root vacuolar proton pumps H + -ATPase (V-ATPase) and H + -PPase (V-PPase) confer tolerance to drought. Since plant-root endophytic bacteria can also promote drought tolerance, we hypothesize that such promotion can be associated to the enhancement of the host vacuolar proton pumps expression and activity. To test this hypothesis, we selected two endophytic bacteria endowed with an array of in vitro plant growth promoting traits. Their genome sequences confirmed the presence of traits previously shown to confer drought resistance to plants, such as the synthesis of nitric oxide and of organic volatile organic compounds. We used the two strains on pepper (Capsicuum annuum L.) because of its high sensitivity to drought. Under drought conditions, both strains stimulated a larger root system and enhanced the leaves' photosynthetic activity. By testing the expression and activity of the vacuolar proton pumps, H + -ATPase (V-ATPase) and H + -PPase (V-PPase), we found that bacterial colonization enhanced V-PPase only. We conclude that the enhanced expression and activity of V-PPase can be favoured by the colonization of drought-tolerance-inducing bacterial endophytes. This article is protected by copyright. All rights reserved. © 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.

  17. Halotolerant rhizobacteria promote growth and enhance salinity tolerance in peanut

    Directory of Open Access Journals (Sweden)

    Sandeep Sharma

    2016-10-01

    Full Text Available Use of Plant growth promoting rhizobacteria (PGPR is a promising strategy to improve the crop production under optimal or sub-optimal conditions. In the present study, five diazotrophic salt tolerant bacteria were isolated from the roots of a halophyte, Arthrocnemum indicum. The isolates were partially characterized in vitro for plant growth promoting traits and evaluated for their potential to promote growth and enhanced salt tolerance in peanut. The 16S rRNA gene sequence homology indicated that these bacterial isolates belong to the genera, Klebisiella, Pseudomonas, Agrobacterium and Ochrobactrum. All isolates were nifH positive and able to produce indole -3-acetic acid (ranging from 11.5 to 19.1 µg ml-1. The isolates showed phosphate solubilisation activity (ranging from 1.4 to 55.6 µg phosphate /mg dry weight, 1-aminocyclopropane-1-carboxylate deaminase activity (0.1 to 0.31 µmol α-kB/µg protein/h and were capable of reducing acetylene in acetylene reduction assay (ranging from 0.95 to 1.8 µmol C2H4 mg protein/h. These isolates successfully colonized the peanut roots and were capable of promoting the growth under non-stress condition. A significant increase in total nitrogen (N content (up to 76% was observed over the non-inoculated control. All isolates showed tolerance to NaCl ranging from 4-8% in nutrient broth medium. Under salt stress, inoculated peanut seedlings maintained ion homeostasis, accumulated less reactive oxygen species (ROS and showed enhanced growth compared to non-inoculated seedlings. Overall, the present study has characterized several potential bacterial strains that showed an enhanced growth promotion effect on peanut under control as well as saline conditions. The results show the possibility to reduce chemical fertilizer inputs and may promote the use of bio-inoculants.

  18. Metabolic Pathways Involved in Carbon Dioxide Enhanced Heat Tolerance in Bermudagrass

    Directory of Open Access Journals (Sweden)

    Jingjin Yu

    2017-09-01

    Full Text Available Global climate changes involve elevated temperature and CO2 concentration, imposing significant impact on plant growth of various plant species. Elevated temperature exacerbates heat damages, but elevated CO2 has positive effects on promoting plant growth and heat tolerance. The objective of this study was to identify metabolic pathways affected by elevated CO2 conferring the improvement of heat tolerance in a C4 perennial grass species, bermudagrass (Cynodon dactylon Pers.. Plants were planted under either ambient CO2 concentration (400 μmol⋅mol-1 or elevated CO2 concentration (800 μmol⋅mol-1 and subjected to ambient temperature (30/25°C, day/night or heat stress (45/40°C, day/night. Elevated CO2 concentration suppressed heat-induced damages and improved heat tolerance in bermudagrass. The enhanced heat tolerance under elevated CO2 was attributed to some important metabolic pathways during which proteins and metabolites were up-regulated, including light reaction (ATP synthase subunit and photosystem I reaction center subunit and carbon fixation [(glyceraldehyde-3-phosphate dehydrogenase, GAPDH, fructose-bisphosphate aldolase, phosphoglycerate kinase, sedoheptulose-1,7-bisphosphatase and sugars of photosynthesis, glycolysis (GAPDH, glucose, fructose, and galactose and TCA cycle (pyruvic acid, malic acid and malate dehydrogenase of respiration, amino acid metabolism (aspartic acid, methionine, threonine, isoleucine, lysine, valine, alanine, and isoleucine as well as the GABA shunt (GABA, glutamic acid, alanine, proline and 5-oxoproline. The up-regulation of those metabolic processes by elevated CO2 could at least partially contribute to the improvement of heat tolerance in perennial grass species.

  19. Enhancing uncertainty tolerance in the modelling creep of ligaments

    International Nuclear Information System (INIS)

    Taha, M M Reda; Lucero, J

    2006-01-01

    The difficulty in performing biomechanical tests and the scarcity of biomechanical experimental databases necessitate extending the current knowledge base to allow efficient modelling using limited data sets. This study suggests a framework to reduce uncertainties in biomechanical systems using limited data sets. The study also shows how sparse data and epistemic input can be exploited using fuzzy logic to represent biomechanical relations. An example application to model collagen fibre recruitment in the medial collateral ligaments during time-dependent deformation under cyclic loading (creep) is presented. The study suggests a quality metric that can be employed to observe and enhance uncertainty tolerance in the modelling process

  20. NAC transcription factor JUNGBRUNNEN1 enhances drought tolerance in tomato

    KAUST Repository

    Thirumalaikumar, Venkatesh P.

    2017-06-22

    Water deficit (drought stress) massively restricts plant growth and the yield of crops; reducing the deleterious effects of drought is therefore of high agricultural relevance. Drought triggers diverse cellular processes including the inhibition of photosynthesis, the accumulation of cell-damaging reactive oxygen species, and gene expression reprogramming, besides others. Transcription factors (TF) are central regulators of transcriptional reprogramming and expression of many TF genes is affected by drought, including members of the NAC family. Here, we identify the NAC factor JUNGBRUNNEN1 (JUB1) as a regulator of drought tolerance in tomato (Solanum lycopersicum). Expression of tomato JUB1 (SlJUB1) is enhanced by various abiotic stresses, including drought. Inhibiting SlJUB1 by virus-induced gene silencing drastically lowers drought tolerance concomitant with an increase in ion leakage, an elevation of hydrogen peroxide (H2 O2 ) levels, and a decrease of the expression of various drought-responsive genes. In contrast, overexpression of AtJUB1 from Arabidopsis thaliana increases drought tolerance in tomato, alongside with a higher relative leaf water content during drought and reduced H2 O2 levels. AtJUB1 was previously shown to stimulate expression of DREB2A, a TF involved in drought responses, and of the DELLA genes GAI and RGL1. We show here that SlJUB1 similarly controls the expression of the tomato orthologs SlDREB1, SlDREB2, and SlDELLA. Furthermore, AtJUB1 directly binds to the promoters of SlDREB1, SlDREB2 and SlDELLA in tomato. Our study highlights JUB1 as a transcriptional regulator of drought tolerance and suggests considerable conservation of the abiotic stress-related gene regulatory networks controlled by this NAC factor between Arabidopsis and tomato. This article is protected by copyright. All rights reserved.

  1. N-acetyltransferase Mpr1 confers ethanol tolerance on Saccharomyces cerevisiae by reducing reactive oxygen species

    Energy Technology Data Exchange (ETDEWEB)

    Du, Xiaoyi [Fukui Prefectural Univ., Fukui (Japan). Dept. of Bioscience; Takagi, Hiroshi [Nara Inst. of Science and Technology, Ikoma, Nara (Japan). Graduate School of Biological Sciences

    2007-07-15

    N-Acetyltransferase Mpr1 of Saccharomyces cerevisiae can reduce intracellular oxidation levels and protect yeast cells under oxidative stress, including H{sub 2}O{sub 2}, heat-shock, or freeze-thaw treatment. Unlike many antioxidant enzyme genes induced in response to oxidative stress, the MPR1 gene seems to be constitutively expressed in yeast cells. Based on a recent report that ethanol toxicity is correlated with the production of reactive oxygen species (ROS), we examined here the role of Mpr1 under ethanol stress conditions. The null mutant of the MPR1 and MPR2 genes showed hypersensitivity to ethanol stress, and the expression of the MPR1 gene conferred stress tolerance. We also found that yeast cells exhibited increased ROS levels during exposure to ethanol stress, and that Mpr1 protects yeast cells from ethanol stress by reducing intracellular ROS levels. When the MPR1 gene was overexpressed in antioxidant enzyme-deficient mutants, increased resistance to H{sub 2}O{sub 2} or heat shock was observed in cells lacking the CTA1, CTT1, or GPX1 gene encoding catalase A, catalase T, or glutathione peroxidase, respectively. These results suggest that Mpr1 might compensate the function of enzymes that detoxify H{sub 2}O{sub 2}. Hence, Mpr1 has promising potential for the breeding of novel ethanol-tolerant yeast strains. (orig.)

  2. Does plant-Microbe interaction confer stress tolerance in plants: A review?

    Science.gov (United States)

    Kumar, Akhilesh; Verma, Jay Prakash

    2018-03-01

    The biotic and abiotic stresses are major constraints for crop yield, food quality and global food security. A number of parameters such as physiological, biochemical, molecular of plants are affected under stress condition. Since the use of inorganic fertilizers and pesticides in agriculture practices cause degradation of soil fertility and environmental pollutions. Hence it is necessary to develop safer and sustainable means for agriculture production. The application of plant growth promoting microbes (PGPM) and mycorrhizal fungi enhance plant growth, under such conditions. It offers an economically fascinating and ecologically sound ways for protecting plants against stress condition. PGPM may promote plant growth by regulating plant hormones, improve nutrition acquisition, siderophore production and enhance the antioxidant system. While acquired systemic resistance (ASR) and induced systemic resistance (ISR) effectively deal with biotic stress. Arbuscular mycorrhiza (AM) enhance the supply of nutrients and water during stress condition and increase tolerance to stress. This plant-microbe interaction is vital for sustainable agriculture and industrial purpose, because it depends on biological processes and replaces conventional agriculture practices. Therefore, microbes may play a key role as an ecological engineer to solve environmental stress problems. So, it is a feasible and potential technology in future to feed global population at available resources with reduced impact on environmental quality. In this review, we have attempted to explore about abiotic and biotic stress tolerant beneficial microorganisms and their modes of action to enhance the sustainable agricultural production. Copyright © 2017 Elsevier GmbH. All rights reserved.

  3. Co-expression of G2-EPSPS and glyphosate acetyltransferase GAT genes conferring high tolerance to glyphosate in soybean

    Directory of Open Access Journals (Sweden)

    Bingfu eGuo

    2015-10-01

    Full Text Available Glyphosate is a widely used non-selective herbicide with broad spectrum of weed control around the world. At present, most of the commercial glyphosate tolerant soybeans utilize glyphosate tolerant gene CP4-EPSPS or glyphosate acetyltransferase gene GAT separately. In this study, both glyphosate tolerant gene G2-EPSPS and glyphosate degraded gene GAT were co-transferred into soybean and transgenic plants showed high tolerance to glyphosate. Molecular analysis including PCR, Sothern blot, qRT-PCR and Western blot revealed that target genes have been integrated into genome and expressed effectively at both mRNA and protein levels. Furthermore, the glyphosate tolerance analysis showed that no typical symptom was observed when compared with a glyphosate tolerant line HJ06-698 derived from GR1 transgenic soybean even at four-fold labeled rate of Roundup. Chlorophyll and shikimic acid content analysis of transgenic plant also revealed that these two indexes were not significantly altered after glyphosate application. These results indicated that co-expression of G2-EPSPS and GAT conferred high tolerance to the herbicide glyphosate in soybean. Therefore, combination of tolerant and degraded genes provides a new strategy for developing glyphosate tolerant transgenic crops.

  4. Overexpression of a tea flavanone 3-hydroxylase gene confers tolerance to salt stress and Alternaria solani in transgenic tobacco.

    Science.gov (United States)

    Mahajan, Monika; Yadav, Sudesh Kumar

    2014-08-01

    Flavan-3-ols are the major flavonoids present in tea (Camellia sinensis) leaves. These are known to have antioxidant and free radical scavenging properties in vitro. Flavanone 3-hydroxylase is considered to be an important enzyme of flavonoid pathway leading to accumulation of flavan-3-ols in tea. Expression analysis revealed the upregulation in transcript levels of C. sinensis flavanone 3-hydroxylase (CsF3H) encoding gene under salt stress. In this study, the biotechnological potential of CsF3H was evaluated by gene overexpression in tobacco (Nicotiana tabacum cv. Xanthi). Overexpression of CsF3H cDNA increased the content of flavan-3-ols in tobacco and conferred tolerance to salt stress and fungus Alternaria solani infection. Transgenic tobaccos were observed for increase in primary root length, number of lateral roots, chlorophyll content, antioxidant enzyme expression and their activities. Also, they showed lesser malondialdehyde content and electrolyte leakage compared to control tobacco plants. Further, transgenic plants produced higher degree of pectin methyl esterification via decreasing pectin methyl esterase (PME) activity in roots and leaves under unstressed and salt stressed conditions. The effect of flavan-3-ols on pectin methyl esterification under salt stressed conditions was further validated through in vitro experiments in which non-transgenic (wild) tobacco seedlings were exposed to salt stress in presence of flavan-3-ols, epicatechin and epigallocatechin. The in vitro exposed seedlings showed similar trend of increase in pectin methyl esterification through decreasing PME activity as observed in CsF3H transgenic lines. Taken together, overexpression of CsF3H provided tolerance to salt stress and fungus A. solani infection to transgenic tobacco through improved antioxidant system and enhanced pectin methyl esterification.

  5. Enhanced Accident Tolerant Fuels for LWRS - A Preliminary Systems Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Gilles Youinou; R. Sonat Sen

    2013-09-01

    The severe accident at Fukushima Daiichi nuclear plants illustrates the need for continuous improvements through developing and implementing technologies that contribute to safe, reliable and cost-effective operation of the nuclear fleet. Development of enhanced accident tolerant fuel contributes to this effort. These fuels, in comparison with the standard zircaloy – UO2 system currently used by the LWR industry, should be designed such that they tolerate loss of active cooling in the core for a longer time period (depending on the LWR system and accident scenario) while maintaining or improving the fuel performance during normal operations, operational transients, and design-basis events. This report presents a preliminary systems analysis related to most of these concepts. The potential impacts of these innovative LWR fuels on the front-end of the fuel cycle, on the reactor operation and on the back-end of the fuel cycle are succinctly described without having the pretension of being exhaustive. Since the design of these various concepts is still a work in progress, this analysis can only be preliminary and could be updated as the designs converge on their respective final version.

  6. The Reaumuria trigyna transcription factor RtWRKY1 confers tolerance to salt stress in transgenic Arabidopsis.

    Science.gov (United States)

    Du, Chao; Zhao, Pingping; Zhang, Huirong; Li, Ningning; Zheng, Linlin; Wang, Yingchun

    2017-08-01

    Reaumuria trigyna (R. trigyna) is an endangered small shrub endemic to the Eastern Alxa-Western Ordos area in Inner Mongolia, China. Based on R. trigyna transcriptome data, the Group I WRKY transcription factor gene RtWRKY1 was cloned from R. trigyna. The full-length RtWRKY1 gene was 2100bp, including a 1261-bp open reading frame (ORF) encoding 573 amino acids. RtWRKY1 was mainly expressed in the stem and was induced by salt, cold stress, and ABA treatment. Overexpression of RtWRKY1 in Arabidopsis significantly enhanced the chlorophyll content, root length, and fresh weight of the transgenic lines under salt stress. RtWRKY1 transgenic Arabidopsis exhibited higher proline content, GSH-PX, POD, SOD, and CAT activities, and lower MDA content, Na + content, and Na + /K + ratio than wild-type Arabidopsis under salt stress conditions. Salt stress affected the expression of ion transport, proline biosynthesis, and antioxidant related genes, including AtAPX1, AtCAT1, AtSOD1, AtP5CS1, AtP5CS2, AtPRODH1, AtPRODH2, and AtSOS1 in transgenic lines. RtWRKY1 confers tolerance to salt stress in transgenic Arabidopsis by regulating plant growth, osmotic balance, Na + /K + homeostasis, and the antioxidant system. Copyright © 2017 Elsevier GmbH. All rights reserved.

  7. An Alfin-like gene from Atriplex hortensis enhances salt and drought tolerance and abscisic acid response in transgenic Arabidopsis.

    Science.gov (United States)

    Tao, Jian-Jun; Wei, Wei; Pan, Wen-Jia; Lu, Long; Li, Qing-Tian; Ma, Jin-Biao; Zhang, Wan-Ke; Ma, Biao; Chen, Shou-Yi; Zhang, Jin-Song

    2018-02-09

    Alfin-like (AL) is a small plant-specific gene family with prominent roles in root growth and abiotic stress response. Here, we aimed to identify novel stress tolerance AL genes from the stress-tolerant species Atriplex hortensis. Totally, we isolated four AhAL genes, all encoding nuclear-localized proteins with cis-element-binding and transrepression activities. Constitutive expression of AhAL1 in Arabidopsis facilitated plants to survive under saline condition, while expressing anyone of the other three AhAL genes led to salt-hypersensitive response, indicating functional divergence of AhAL family. AhAL1 also conferred enhanced drought tolerance, as judged from enhanced survival, improved growth, decreased malonaldehyde (MDA) content and reduced water loss in AhAL1-expressing plants compared to WT. In addition, abscisic acid (ABA)-mediated stomatal closure and inhibition of seed germination and primary root elongation were enhanced in AhAL1-transgenic plants. Further analysis demonstrated that AhAL1 could bind to promoter regions of GRF7, DREB1C and several group-A PP2C genes and repress their expression. Correspondingly, the expression levels of positive stress regulator genes DREB1A, DREB2A and three ABFs were all increased in AhAL1-expressing plants. Based on these results, AhAL1 was identified as a novel candidate gene for improving abiotic stress tolerance of crop plants.

  8. Overexpression of the wheat aquaporin gene, TaAQP7, enhances drought tolerance in transgenic tobacco.

    Directory of Open Access Journals (Sweden)

    Shiyi Zhou

    Full Text Available Aquaporin (AQP proteins have been shown to transport water and other small molecules through biological membranes, which is crucial for plants to combat stress caused by drought. However, the precise role of AQPs in drought stress response is not completely understood in plants. In this study, a PIP2 subgroup gene AQP, designated as TaAQP7, was cloned and characterized from wheat. Expression of TaAQP7-GFP fusion protein revealed its localization in the plasma membrane. TaAQP7 exhibited high water channel activity in Xenopus laevis oocytes and TaAQP7 transcript was induced by dehydration, and treatments with polyethylene glycol (PEG, abscisic acid (ABA and H(2O(2. Further, TaAQP7 was upregulated after PEG treatment and was blocked by inhibitors of ABA biosynthesis, implying that ABA signaling was involved in the upregulation of TaAQP7 after PEG treatment. Overexpression of TaAQP7 increased drought tolerance in tobacco. The transgenic tobacco lines had lower levels of malondialdehyde (MDA and H(2O(2, and less ion leakage (IL, but higher relative water content (RWC and superoxide dismutase (SOD and catalase (CAT activities when compared with the wild type (WT under drought stress. Taken together, our results show that TaAQP7 confers drought stress tolerance in transgenic tobacco by increasing the ability to retain water, reduce ROS accumulation and membrane damage, and enhance the activities of antioxidants.

  9. Glutathione Transferase from Trichoderma virens Enhances Cadmium Tolerance without Enhancing Its Accumulation in Transgenic Nicotiana tabacum

    Science.gov (United States)

    Dixit, Prachy; Mukherjee, Prasun K.; Ramachandran, V.; Eapen, Susan

    2011-01-01

    Background Cadmium (Cd) is a major heavy metal pollutant which is highly toxic to plants and animals. Vast agricultural areas worldwide are contaminated with Cd. Plants take up Cd and through the food chain it reaches humans and causes toxicity. It is ideal to develop plants tolerant to Cd, without enhanced accumulation in the edible parts for human consumption. Glutathione transferases (GST) are a family of multifunctional enzymes known to have important roles in combating oxidative stresses induced by various heavy metals including Cd. Some GSTs are also known to function as glutathione peroxidases. Overexpression/heterologous expression of GSTs is expected to result in plants tolerant to heavy metals such as Cd. Results Here, we report cloning of a glutathione transferase gene from Trichoderma virens, a biocontrol fungus and introducing it into Nicotiana tabacum plants by Agrobacterium-mediated gene transfer. Transgenic nature of the plants was confirmed by Southern blot hybridization and expression by reverse transcription PCR. Transgene (TvGST) showed single gene Mendelian inheritance. When transgenic plants expressing TvGST gene were exposed to different concentrations of Cd, they were found to be more tolerant compared to wild type plants, with transgenic plants showing lower levels of lipid peroxidation. Levels of different antioxidant enzymes such as glutathione transferase, superoxide dismutase, ascorbate peroxidase, guiacol peroxidase and catalase showed enhanced levels in transgenic plants expressing TvGST compared to control plants, when exposed to Cd. Cadmium accumulation in the plant biomass in transgenic plants were similar or lower than wild-type plants. Conclusion The results of the present study suggest that transgenic tobacco plants expressing a Trichoderma virens GST are more tolerant to Cd, without enhancing its accumulation in the plant biomass. It should be possible to extend the present results to crop plants for developing Cd tolerance and

  10. Glutathione transferase from Trichoderma virens enhances cadmium tolerance without enhancing its accumulation in transgenic Nicotiana tabacum.

    Directory of Open Access Journals (Sweden)

    Prachy Dixit

    Full Text Available BACKGROUND: Cadmium (Cd is a major heavy metal pollutant which is highly toxic to plants and animals. Vast agricultural areas worldwide are contaminated with Cd. Plants take up Cd and through the food chain it reaches humans and causes toxicity. It is ideal to develop plants tolerant to Cd, without enhanced accumulation in the edible parts for human consumption. Glutathione transferases (GST are a family of multifunctional enzymes known to have important roles in combating oxidative stresses induced by various heavy metals including Cd. Some GSTs are also known to function as glutathione peroxidases. Overexpression/heterologous expression of GSTs is expected to result in plants tolerant to heavy metals such as Cd. RESULTS: Here, we report cloning of a glutathione transferase gene from Trichoderma virens, a biocontrol fungus and introducing it into Nicotiana tabacum plants by Agrobacterium-mediated gene transfer. Transgenic nature of the plants was confirmed by Southern blot hybridization and expression by reverse transcription PCR. Transgene (TvGST showed single gene Mendelian inheritance. When transgenic plants expressing TvGST gene were exposed to different concentrations of Cd, they were found to be more tolerant compared to wild type plants, with transgenic plants showing lower levels of lipid peroxidation. Levels of different antioxidant enzymes such as glutathione transferase, superoxide dismutase, ascorbate peroxidase, guiacol peroxidase and catalase showed enhanced levels in transgenic plants expressing TvGST compared to control plants, when exposed to Cd. Cadmium accumulation in the plant biomass in transgenic plants were similar or lower than wild-type plants. CONCLUSION: The results of the present study suggest that transgenic tobacco plants expressing a Trichoderma virens GST are more tolerant to Cd, without enhancing its accumulation in the plant biomass. It should be possible to extend the present results to crop plants for

  11. Thermochemical Wastewater Valorization via Enhanced Microbial Toxicity Tolerance

    Energy Technology Data Exchange (ETDEWEB)

    Beckham, Gregg T [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Thelhawadigedara, Lahiru Niroshan Jayakody [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Johnson, Christopher W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Pleitner, Brenna P [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cleveland, Nicholas S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Michener, William E [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Olstad-Thompson, Jessica L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Vardon, Derek R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Whitham, Jason M. [Oak Ridge National Laboratory; Giannone, Richard J. [Oak Ridge National Laboratory; Klingeman, Dawn M. [Oak Ridge National Laboratory; Brown, Robert C. [Iowa State University; Brown, Steven D. [Oak Ridge National Laboratory; LanzaTech, Inc.; Hettich, Robert L. [Oak Ridge National Laboratory; Guss, Adam M. [Oak Ridge National Laboratory

    2018-04-17

    Thermochemical (TC) biomass conversion processes such as pyrolysis and liquefaction generate considerable amounts of wastewater, which often contains highly toxic compounds that are incredibly challenging to convert via standard wastewater treatment approaches such as anaerobic digestion. These streams represent a cost for TC biorefineries, and a potential valorization opportunity, if effective conversion methods are developed. The primary challenge hindering microbial conversion of TC wastewater is toxicity. In this study, we employ a robust bacterium, Pseudomonas putida, with TC wastewater streams to demonstrate that aldehydes are the most inhibitory compounds in these streams. Proteomics, transcriptomics, and fluorescence-based immunoassays of P. putida grown in a representative wastewater stream indicate that stress results from protein damage, which we hypothesize is a primary toxicity mechanism. Constitutive overexpression of the chaperone genes, groEL, groES, and clpB, in a genome-reduced P. putida strain improves the tolerance towards multiple TC wastewater samples up to 200-fold. Moreover, the concentration ranges of TC wastewater are industrially relevant for further bioprocess development for all wastewater streams examined here, representing different TC process configurations. Furthermore, we demonstrate proof-of-concept polyhydroxyalkanoate production from the usable carbon in an exemplary TC wastewater stream. Overall, this study demonstrates that protein quality control machinery and repair mechanisms can enable substantial gains in microbial tolerance to highly toxic substrates, including heterogeneous waste streams. When coupled to other metabolic engineering advances such as expanded substrate utilization and enhanced product accumulation, this study generally enables new strategies for biological conversion of highly-toxic, organic-rich wastewater via engineered aerobic monocultures or designer consortia.

  12. Metabolic pathway engineering based on metabolomics confers acetic and formic acid tolerance to a recombinant xylose-fermenting strain of Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Ishii Jun

    2011-01-01

    Full Text Available Abstract Background The development of novel yeast strains with increased tolerance toward inhibitors in lignocellulosic hydrolysates is highly desirable for the production of bio-ethanol. Weak organic acids such as acetic and formic acids are necessarily released during the pretreatment (i.e. solubilization and hydrolysis of lignocelluloses, which negatively affect microbial growth and ethanol production. However, since the mode of toxicity is complicated, genetic engineering strategies addressing yeast tolerance to weak organic acids have been rare. Thus, enhanced basic research is expected to identify target genes for improved weak acid tolerance. Results In this study, the effect of acetic acid on xylose fermentation was analyzed by examining metabolite profiles in a recombinant xylose-fermenting strain of Saccharomyces cerevisiae. Metabolome analysis revealed that metabolites involved in the non-oxidative pentose phosphate pathway (PPP [e.g. sedoheptulose-7-phosphate, ribulose-5-phosphate, ribose-5-phosphate and erythrose-4-phosphate] were significantly accumulated by the addition of acetate, indicating the possibility that acetic acid slows down the flux of the pathway. Accordingly, a gene encoding a PPP-related enzyme, transaldolase or transketolase, was overexpressed in the xylose-fermenting yeast, which successfully conferred increased ethanol productivity in the presence of acetic and formic acid. Conclusions Our metabolomic approach revealed one of the molecular events underlying the response to acetic acid and focuses attention on the non-oxidative PPP as a target for metabolic engineering. An important challenge for metabolic engineering is identification of gene targets that have material importance. This study has demonstrated that metabolomics is a powerful tool to develop rational strategies to confer tolerance to stress through genetic engineering.

  13. Aluminum-Tolerant Pisolithus Ectomycorrhizas Confer Increased Growth, Mineral Nutrition, and Metal Tolerance to Eucalyptus in Acidic Mine Spoil

    Directory of Open Access Journals (Sweden)

    Louise Egerton-Warburton

    2015-01-01

    Full Text Available Ectomycorrhizal fungi (ECM may increase the tolerance of their host plants to Al toxicity by immobilizing Al in fungal tissues and/or improving plant mineral nutrition. Although these benefits have been demonstrated in in vitro (pure culture or short-term nutrient solution (hydroponic experiments, fewer studies have examined these benefits in the field. This study examined the growth, mineral nutrition, and Al levels in two Eucalyptus species inoculated with three Pisolithus ecotypes that varied in Al tolerance (in vitro and grown in mine spoil in the greenhouse and field. All three ecotypes of Pisolithus improved Eucalyptus growth and increased host plant tolerance to Al in comparison to noninoculated plants. However, large variations in plant growth and mineral nutrition were detected among the Pisolithus-inoculated plants; these differences were largely explained by the functional properties of the Pisolithus inoculum. Seedlings inoculated with the most Al-tolerant Pisolithus inoculum showed significantly higher levels of N, P, Ca, Mg, and K and lower levels of Al than seedlings inoculated with Al-sensitive ecotypes of Pisolithus. These findings indicate an agreement between the fungal tolerance to Al in vitro and performance in symbiosis, indicating that both ECM-mediated mineral nutrient acquisition and Al accumulation are important in increasing the host plant Al tolerance.

  14. Proteomic Analyses Reveal the Mechanism of Dunaliella salina Ds-26-16 Gene Enhancing Salt Tolerance in Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Yanlong Wang

    Full Text Available We previously screened the novel gene Ds-26-16 from a 4 M salt-stressed Dunaliella salina cDNA library and discovered that this gene conferred salt tolerance to broad-spectrum organisms, including E. coli (Escherichia coli, Haematococcus pluvialis and tobacco. To determine the mechanism of this gene conferring salt tolerance, we studied the proteome of E. coli overexpressing the full-length cDNA of Ds-26-16 using the iTRAQ (isobaric tags for relative and absolute quantification approach. A total of 1,610 proteins were identified, which comprised 39.4% of the whole proteome. Of the 559 differential proteins, 259 were up-regulated and 300 were down-regulated. GO (gene ontology and KEGG (Kyoto encyclopedia of genes and genomes enrichment analyses identified 202 major proteins, including those involved in amino acid and organic acid metabolism, energy metabolism, carbon metabolism, ROS (reactive oxygen species scavenging, membrane proteins and ABC (ATP binding cassette transporters, and peptidoglycan synthesis, as well as 5 up-regulated transcription factors. Our iTRAQ data suggest that Ds-26-16 up-regulates the transcription factors in E. coli to enhance salt resistance through osmotic balance, energy metabolism, and oxidative stress protection. Changes in the proteome were also observed in E. coli overexpressing the ORF (open reading frame of Ds-26-16. Furthermore, pH, nitric oxide and glycerol content analyses indicated that Ds-26-16 overexpression increases nitric oxide content but has no effect on glycerol content, thus confirming that enhanced nitric oxide synthesis via lower intercellular pH was one of the mechanisms by which Ds-26-16 confers salt tolerance to E. coli.

  15. Humic Acid Confers HIGH-AFFINITY K+ TRANSPORTER 1-Mediated Salinity Stress Tolerance in Arabidopsis.

    Science.gov (United States)

    Khaleda, Laila; Park, Hee Jin; Yun, Dae-Jin; Jeon, Jong-Rok; Kim, Min Gab; Cha, Joon-Yung; Kim, Woe-Yeon

    2017-12-31

    Excessive salt disrupts intracellular ion homeostasis and inhibits plant growth, which poses a serious threat to global food security. Plants have adapted various strategies to survive in unfavorable saline soil conditions. Here, we show that humic acid (HA) is a good soil amendment that can be used to help overcome salinity stress because it markedly reduces the adverse effects of salinity on Arabidopsis thaliana seedlings. To identify the molecular mechanisms of HA-induced salt stress tolerance in Arabidopsis, we examined possible roles of a sodium influx transporter HIGH-AFFINITY K+ TRANSPORTER 1 (HKT1). Salt-induced root growth inhibition in HKT1 overexpressor transgenic plants (HKT1-OX) was rescued by application of HA, but not in wild-type and other plants. Moreover, salt-induced degradation of HKT1 protein was blocked by HA treatment. In addition, the application of HA to HKT1-OX seedlings led to increased distribution of Na+ in roots up to the elongation zone and caused the reabsorption of Na+ by xylem and parenchyma cells. Both the influx of the secondary messenger calcium and its cytosolic release appear to function in the destabilization of HKT1 protein under salt stress. Taken together, these results suggest that HA could be applied to the field to enhance plant growth and salt stress tolerance via post-transcriptional control of the HKT1 transporter gene under saline conditions.

  16. Overexpression of the Maize Sulfite Oxidase Increases Sulfate and GSH Levels and Enhances Drought Tolerance in Transgenic Tobacco

    Directory of Open Access Journals (Sweden)

    Zongliang Xia

    2018-03-01

    Full Text Available Sulfite oxidase (SO plays a pivotal role in sulfite metabolism. In our previous study, sulfite-oxidizing function of the SO from Zea mays (ZmSO was characterized. To date, the knowledge of ZmSO’s involvement in abiotic stress response is scarce. In this study, we aimed to investigate the role of ZmSO in drought stress. The transcript levels of ZmSO were relatively high in leaves and immature embryos of maize plants, and were up-regulated markedly by PEG-induced water stress. Overexpression of ZmSO improved drought tolerance in tobacco. ZmSO-overexpressing transgenic plants showed higher sulfate and glutathione (GSH levels but lower hydrogen peroxide (H2O2 and malondialdehyde (MDA contents under drought stress, indicating that ZmSO confers drought tolerance by enhancing GSH-dependent antioxidant system that scavenged ROS and reduced membrane injury. In addition, the transgenic plants exhibited more increased stomatal response than the wild-type (WT to water deficit. Interestingly, application of exogenous GSH effectively alleviated growth inhibition in both WT and transgenic plants under drought conditions. qPCR analysis revealed that the expression of several sulfur metabolism-related genes was significantly elevated in the ZmSO-overexpressing lines. Taken together, these results imply that ZmSO confers enhanced drought tolerance in transgenic tobacco plants possibly through affecting stomatal regulation, GSH-dependent antioxidant system, and sulfur metabolism-related gene expression. ZmSO could be exploited for developing drought-tolerant maize varieties in molecular breeding.

  17. Ectopic expression of phloem motor protein pea forisome PsSEO-F1 enhances salinity stress tolerance in tobacco.

    Science.gov (United States)

    Srivastava, Vineet Kumar; Raikwar, Shailendra; Tuteja, Renu; Tuteja, Narendra

    2016-05-01

    PsSEOF-1 binds to calcium and its expression is upregulated by salinity treatment. PsSEOF - 1 -overexpressing transgenic tobacco showed enhanced salinity stress tolerance by maintaining cellular ion homeostasis and modulating ROS-scavenging pathway. Calcium (Ca(2+)) plays important role in growth, development and stress tolerance in plants. Cellular Ca(2+) homeostasis is achieved by the collective action of channels, pumps, antiporters and by Ca(2+) chelators present in the cell like calcium-binding proteins. Forisomes are ATP-independent mechanically active motor proteins known to function in wound sealing of injured sieve elements of phloem tissue. The Ca(2+)-binding activity of forisome and its role in abiotic stress signaling were largely unknown. Here we report the Ca(2+)-binding activity of pea forisome (PsSEO-F1) and its novel function in promoting salinity tolerance in transgenic tobacco. Native PsSEO-F1 promoter positively responded in salinity stress as confirmed using GUS reporter. Overexpression of PsSEO-F1 tobacco plants confers salinity tolerance by alleviating ionic toxicity and increased ROS scavenging activity which probably results in reduced membrane damage and improved yield under salinity stress. Evaluation of several physiological indices shows an increase in relative water content, electrolyte leakage, proline accumulation and chlorophyll content in transgenic lines as compared with null-segregant control. Expression of several genes involved in cellular homeostasis is perturbed by PsSEO-F1 overexpression. These findings suggest that PsSEO-F1 provides salinity tolerance through cellular Ca(2+) homeostasis which in turn modulates ROS machinery providing indirect link between Ca(2+) and ROS signaling under salinity-induced perturbation. PsSEO-F1 most likely functions in salinity stress tolerance by improving antioxidant machinery and mitigating ion toxicity in transgenic lines. This finding should make an important contribution in our better

  18. Bulk Nanostructured FCC Steels With Enhanced Radiation Tolerance

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xinghang; Hartwig, K. Ted; Allen, Todd; Yang, Yong

    2012-10-27

    The objective of this project is to increase radiation tolerance in austenitic steels through optimization of grain size and grain boundary (GB) characteristics. The focus will be on nanocrystalline austenitic Fe-Cr-Ni alloys with an fcc crystal structure. The long-term goal is to design and develop bulk nanostructured austenitic steels with enhanced void swelling resistance and substantial ductility, and to enhance their creep resistance at elevated temperatures via GB engineering. The combination of grain refinement and grain boundary engineering approaches allows us to tailor the material strength, ductility, and resistance to swelling by 1) changing the sink strength for point defects, 2) by increasing the nucleation barriers for bubble formation at GBs, and 3) by changing the precipitate distributions at boundaries. Compared to ferritic/martensitic steels, austenitic stainless steels (SS) possess good creep and fatigue resistance at elevated temperatures, and better toughness at low temperature. However, a major disadvantage of austenitic SS is that they are vulnerable to significant void swelling in nuclear reactors, especially at the temperatures and doses anticipated in the Advanced Burner Reactor. The lack of resistance to void swelling in austenitic alloys led to the switch to ferritic/martensitic steels as the preferred material for the fast reactor cladding application. Recently a type of austenitic stainless steel, HT-UPS, was developed at ORNL, and is expected to show enhanced void swelling resistance through the trapping of point defects at nanometersized carbides. Reducing the grain size and increasing the fraction of low energy grain boundaries should reduce the available radiation-produced point defects (due to the increased sink area of the grain boundaries), should make bubble nucleation at the boundaries less likely (by reducing the fraction of high-energy boundaries), and improve the strength and ductility under radiation by producing a higher

  19. Tolerance

    DEFF Research Database (Denmark)

    Tønder, Lars

    is linked to a different set of circumstances than the ones suggested by existing models in contemporary democratic theory. Reorienting the discussion of tolerance, the book raises the question of how to disclose new possibilities within our given context of affect and perception. Once we move away from......Tolerance: A Sensorial Orientation to Politics is an experiment in re-orientation. The book is based on the wager that tolerance exceeds the more prevalent images of self-restraint and repressive benevolence because neither precludes the possibility of a more “active tolerance” motivated...... by the desire to experiment and to become otherwise. The objective is to discuss what gets lost, conceptually as well as politically, when we neglect the subsistence of active tolerance within other practices of tolerance, and to develop a theory of active tolerance in which tolerance's mobilizing character...

  20. Overexpression of yeast ArDH gene in chloroplasts confers salinity tolerance in plants (abstract)

    International Nuclear Information System (INIS)

    Khan, M.S.; Kanwal, B.; Khalid, A.M.; Zafar, Y.; Malik, K.A.

    2005-01-01

    Water stress due to salinity and drought is the main limiting factor for plant growth, productivity and quality. A common response to water deficit is the accumulation of osmoprotectants such as sugars and amino acids. In yeast, arabitol dehydrogenase is found responsible for the production of arabitol from ribulose-5-phosphate. All plants synthesize ribulose-5-phosphate via pentose pathway in chloroplasts.. Therefore, osmotolerance of the plants could be enhanced through metabolic engineering of chloroplasts by introducing ArDH gene into the plastome, which is responsible for the conversion of ribulose-5- phosphate to arabitol. Here we report high-level expression of arabitol dehydrogenase (ArDH) in chloroplasts. Homoplasmic transgenic plants were recovered on spectinomycin-containing regeneration medium. Transformed tobacco plants survived whereas non-transformed were severely stressed or killed when two weeks old seedlings were exposed to NaCl (up to 400 mM), suggesting a role for arabitol in salt tolerance. Seedlings survived up to five weeks on medium containing high salt concentrations (350-400 mM). Nevertheless, seedlings remained green and grew normal on concentrations up to 350 mM NaCl for several weeks. Hypothesis that membranes are protected under stress conditions due to the arabitol accumulation in chloroplasts, seedlings were grown in liquid medium containing polyethylene glycol (PEG, up to 6%). Seedlings were tolerant to 6% PEG, suggesting that ArDH enzyme protects membranes integrity under stress. Therefore, it is concluded that ArDH gene could be expressed in crop plants to withstand abiotic stresses. (author)

  1. In Utero Exposure to Exosomal and B-Cell Alloantigens Lessens Alloreactivity of Recipients’ Lymphocytes Rather than Confers Allograft Tolerance

    Directory of Open Access Journals (Sweden)

    Jeng-Chang Chen

    2018-03-01

    Full Text Available According to actively acquired tolerance, antigen exposure before full immune development in fetal or early neonatal life will cause tolerance to this specific antigen. In this study, we aimed to examine whether allogeneic tolerance could be elicited by in utero exposure to surface MHC antigens of allogenic cells or soluble form of MHC exosomes. Gestational day 14 FVB/N fetuses were subjected to intraperitoneal injection of allogeneic major histocompatibility complex (MHC exosomes or highly enriched B-cells. Postnatally, the recipients were examined for the immune responses to donor alloantigens by lymphocyte proliferative reactions and skin transplantation. In utero exposure to allogeneic MHC exosomes abolished the alloreactivity of recipients’ lymphocytes to the alloantigens, but could not confer skin allograft tolerance. In utero transplantation of highly enriched allogeneic B-cells generated low-level B-cell chimerism in the recipients. However, it only extended the survivals of skin allograft by a few days despite the lack of donor-specific alloreactivity of recipients’ lymphocyte. Thus, an early in utero contact with exosomal or B-cell alloantigens did not lead to full skin tolerance but rather, at best, only to delayed skin rejection in the presence of microchimerism made by B-cell inocula. These results argued against the theory of actively acquired tolerance, and implicated that in utero exposure to marrow cells in previous studies was a unique model of allo-tolerance induction that involved the establishment of significant hematopoietic chimerism. Taken together with the discovery of in utero sensitization to ovalbumin in our previous studies, the immunological consequences of fetal exposure to foreign antigens might vary according to the type or nature of antigens introduced.

  2. In Utero Exposure to Exosomal and B-Cell Alloantigens Lessens Alloreactivity of Recipients' Lymphocytes Rather than Confers Allograft Tolerance.

    Science.gov (United States)

    Chen, Jeng-Chang; Ou, Liang-Shiou; Chan, Cheng-Chi; Kuo, Ming-Ling; Tseng, Li-Yun; Chang, Hsueh-Ling

    2018-01-01

    According to actively acquired tolerance, antigen exposure before full immune development in fetal or early neonatal life will cause tolerance to this specific antigen. In this study, we aimed to examine whether allogeneic tolerance could be elicited by in utero exposure to surface MHC antigens of allogenic cells or soluble form of MHC exosomes. Gestational day 14 FVB/N fetuses were subjected to intraperitoneal injection of allogeneic major histocompatibility complex (MHC) exosomes or highly enriched B-cells. Postnatally, the recipients were examined for the immune responses to donor alloantigens by lymphocyte proliferative reactions and skin transplantation. In utero exposure to allogeneic MHC exosomes abolished the alloreactivity of recipients' lymphocytes to the alloantigens, but could not confer skin allograft tolerance. In utero transplantation of highly enriched allogeneic B-cells generated low-level B-cell chimerism in the recipients. However, it only extended the survivals of skin allograft by a few days despite the lack of donor-specific alloreactivity of recipients' lymphocyte. Thus, an early in utero contact with exosomal or B-cell alloantigens did not lead to full skin tolerance but rather, at best, only to delayed skin rejection in the presence of microchimerism made by B-cell inocula. These results argued against the theory of actively acquired tolerance, and implicated that in utero exposure to marrow cells in previous studies was a unique model of allo-tolerance induction that involved the establishment of significant hematopoietic chimerism. Taken together with the discovery of in utero sensitization to ovalbumin in our previous studies, the immunological consequences of fetal exposure to foreign antigens might vary according to the type or nature of antigens introduced.

  3. Tolerance

    DEFF Research Database (Denmark)

    Tønder, Lars

    Tolerance: A Sensorial Orientation to Politics is an experiment in re-orientation. The book is based on the wager that tolerance exceeds the more prevalent images of self-restraint and repressive benevolence because neither precludes the possibility of a more “active tolerance” motivated by the d...... these alternatives by returning to the notion of tolerance as the endurance of pain, linking this notion to exemplars and theories relevant to the politics of multiculturalism, religious freedom, and free speech....

  4. Over-expression of a Rab family GTPase from phreatophyte Prosopis juliflora confers tolerance to salt stress on transgenic tobacco.

    Science.gov (United States)

    George, Suja; Parida, Ajay

    2011-03-01

    Plant growth and productivity are adversely affected by various abiotic and biotic stress factors. In our previous study, we used Prosopis juliflora, an abiotic stress tolerant tree species of Fabaceae, as a model plant system for isolating genes functioning in abiotic stress tolerance. Here we report the isolation and characterization of a Rab family GTPase from P. juliflora (Pj Rab7) and the ability of this gene to confer salt stress tolerance in transgenic tobacco. Northern analysis for Pj Rab7 in P. juliflora leaf tissue revealed up-regulation of this gene under salt stress under the concentrations and time points analyzed. Pj Rab7 transgenic tobacco lines survived better under conditions of 150 mM NaCl stress compared to control un-transformed plants. Pj Rab7 transgenic plants were found to accumulate more sodium than control plants during salt stress. The results of our studies could be used as a starting point for generation of crop plants tolerant to abiotic stress.

  5. Exploration of wild relatives of tomato for enhanced stress tolerance

    NARCIS (Netherlands)

    Junming Li,

    2010-01-01

    Among the different abiotic and biotic stresses, Botrytis cinerea, Phytophthora infestans and high salt concentrations are world-wide the most destructive. Several wild relatives of tomato were identified as source for tolerance to these stresses. Three introgression line (IL) populations derived

  6. Highlighting the mechanisms by which proline can confer tolerance to salt stress in cakile maritima

    International Nuclear Information System (INIS)

    Messedi, D.; Farhani, F.; Hamed, K.B.; Trabelsi, N.; Ksouri, R.; Chedly Abdelly, C.; Athar, H.U.R.

    2016-01-01

    Cakile maritima is an oleaginous halophyte growing in the sandy dunes along the Tunisian coast. In order to investigate the role of proline in inducing high salinity tolerance (200 and 400 mM NaCl) in this halophyte, we studied several aspects of the salt responses of C. maritma under exogenous proline supply (20 mM). Salinity levels above 100 mM, reduced growth, photosynthetic activity, and quantum yield of photosystem II (FPSII), while increasing the non photochemical quenching (NPQ). Significant inhibition of the linear electron transport rate (ETR) was also observed in plants grown at 400 mM NaCl. In addition, polyphenol content, total antioxidant and DPPH scavenging activities increased due to increasing salinity stress, and the concentration of malondialdehyde (MDA) also increased. The application of proline counteracted all these adverse effects of salt stress in plants grown at 200 mM NaCl, while it improved some of these physiological attributes at 400 mM NaCl. In addition, contribution of Na+ for the osmotic adjustment decreased in the leaves of salt treated plants supplied with proline exogenously. Exogenous application of proline induced the accumulation of potassium, proline and soluble carbohydrates in salt stressed plants, particularly at 400 mM. This explained the reason of growth enhancement induced by proline application. All together, our Results showed that the beneficial effect of exogenous proline on the response of C. maritima to salinity was due to its role in the protection of chloroplast structures, antioxidant defenses and osmotic adjustment. (author)

  7. Development of LWR Fuels with Enhanced Accident Tolerance

    International Nuclear Information System (INIS)

    Lahoda, Edward J.; Boylan, Frank A.

    2015-01-01

    Significant progress was made on the technical, licensing, and business aspects of the Westinghouse Electric Company's Enhanced Accident Tolerant Fuel (ATF) by the Westinghouse ATF team. The fuel pellet options included waterproofed U 15 N and U 3 Si 2 and the cladding options SiC composites and zirconium alloys with surface treatments. Technology was developed that resulted in U 3 Si 2 pellets with densities of >94% being achieved at the Idaho National Laboratory (INL). The use of U 3 Si 2 will represent a 15% increase in U235 loadings over those in UO fuel pellets. This technology was then applied to manufacture pellets for 6 test rodlets which were inserted in the Advanced Test Reactor (ATR) in early 2015 in zirconium alloy cladding. The first of these rodlets are expected to be removed in about 2017. Key characteristics to be determined include verification of the centerline temperature calculations, thermal conductivity, fission gas release, swelling and degree of amorphization. Waterproofed UN pellets have achieved >94% density for a 32% U 3 Si 2 /68% UN composite pellet at Texas A&M University. This represents a U235 increase of about 31% over current UO 2 pellets. Pellets and powders of UO 2 , UN, and U 3 Si 2 the were tested by Westinghouse and Los Alamos National Laboratory (LANL) using differential scanning calorimetry to determine what their steam and 20% oxygen corrosion temperatures were as compared to UO 2 . Cold spray application of either the amorphous steel or the Ti 2 AlC was successful in forming an adherent ~20 micron coating that remained after testing at 420°C in a steam autoclave. Tests at 1200°C in 100% steam on coatings for Zr alloy have not been successful, possibly due to the low density of the coatings which allowed steam transport to the base zirconium metal. Significant modeling and testing has been carried out for the SiC/SiC composite/SiC monolith structures. A structure with the monolith on the outside and composite on the

  8. Development of LWR Fuels with Enhanced Accident Tolerance

    Energy Technology Data Exchange (ETDEWEB)

    Lahoda, Edward J. [Westinghouse Electric Company, LLC, Cranberry Woods, PA (United States); Boylan, Frank A. [Westinghouse Electric Company, LLC, Cranberry Woods, PA (United States)

    2015-10-30

    Significant progress was made on the technical, licensing, and business aspects of the Westinghouse Electric Company’s Enhanced Accident Tolerant Fuel (ATF) by the Westinghouse ATF team. The fuel pellet options included waterproofed U15N and U3Si2 and the cladding options SiC composites and zirconium alloys with surface treatments. Technology was developed that resulted in U3Si2 pellets with densities of >94% being achieved at the Idaho National Laboratory (INL). The use of U3Si2 will represent a 15% increase in U235 loadings over those in UO₂ fuel pellets. This technology was then applied to manufacture pellets for 6 test rodlets which were inserted in the Advanced Test Reactor (ATR) in early 2015 in zirconium alloy cladding. The first of these rodlets are expected to be removed in about 2017. Key characteristics to be determined include verification of the centerline temperature calculations, thermal conductivity, fission gas release, swelling and degree of amorphization. Waterproofed UN pellets have achieved >94% density for a 32% U3Si2/68% UN composite pellet at Texas A&M University. This represents a U235 increase of about 31% over current UO2 pellets. Pellets and powders of UO2, UN, and U3Si2the were tested by Westinghouse and Los Alamos National Laboratory (LANL) using differential scanning calorimetry to determine what their steam and 20% oxygen corrosion temperatures were as compared to UO2. Cold spray application of either the amorphous steel or the Ti2AlC was successful in forming an adherent ~20 micron coating that remained after testing at 420°C in a steam autoclave. Tests at 1200°C in 100% steam on coatings for Zr alloy have not been successful, possibly due to the low density of the coatings which allowed steam transport to the base zirconium metal. Significant modeling and testing

  9. Aluminum-activated citrate and malate transporters from the MATE and ALMT families function independently to confer Arabidopsis aluminum tolerance.

    Science.gov (United States)

    Liu, Jiping; Magalhaes, Jurandir V; Shaff, Jon; Kochian, Leon V

    2009-02-01

    Aluminum-activated root malate and citrate exudation play an important role in plant Al tolerance. This paper characterizes AtMATE, a homolog of the recently discovered sorghum and barley Al-tolerance genes, shown here to encode an Al-activated citrate transporter in Arabidopsis. Together with the previously characterized Al-activated malate transporter, AtALMT1, this discovery allowed us to examine the relationship in the same species between members of the two gene families for which Al-tolerance genes have been identified. AtMATE is expressed primarily in roots and is induced by Al. An AtMATE T-DNA knockdown line exhibited very low AtMATE expression and Al-activated root citrate exudation was abolished. The AtALMT1 AtMATE double mutant lacked both Al-activated root malate and citrate exudation and showed greater Al sensitivity than the AtALMT1 mutant. Therefore, although AtALMT1 is a major contributor to Arabidopsis Al tolerance, AtMATE also makes a significant but smaller contribution. The expression patterns of AtALMT1 and AtMATE and the profiles of Al-activated root citrate and malate exudation are not affected by the presence or absence of the other gene. These results suggest that AtALMT1-mediated malate exudation and AtMATE-mediated citrate exudation evolved independently to confer Al tolerance in Arabidopsis. However, a link between regulation of expression of the two transporters in response to Al was identified through work on STOP1, a transcription factor that was previously shown to be necessary for AtALMT1 expression. Here we show that STOP1 is also required for AtMATE expression and Al-activated citrate exudation.

  10. Overexpression AtNHX1 confers salt-tolerance of transgenic tall ...

    African Journals Online (AJOL)

    Saline soil is a serious problem worldwide, and it is necessary to improve the salt tolerance of plants so as to avoid the progressive deterioration of saline soil. Here we report that over-expression of AtNHX1 improves salt tolerance in transgenic tall fescue. The AtNHX1 gene driven with CaMV35S promoter was constructed ...

  11. Suppression of External NADPH Dehydrogenase—NDB1 in Arabidopsis thaliana Confers Improved Tolerance to Ammonium Toxicity via Efficient Glutathione/Redox Metabolism

    Science.gov (United States)

    Podgórska, Anna; Borysiuk, Klaudia; Tarnowska, Agata; Jakubiak, Monika; Burian, Maria; Rasmusson, Allan G.

    2018-01-01

    Environmental stresses, including ammonium (NH4+) nourishment, can damage key mitochondrial components through the production of surplus reactive oxygen species (ROS) in the mitochondrial electron transport chain. However, alternative electron pathways are significant for efficient reductant dissipation in mitochondria during ammonium nutrition. The aim of this study was to define the role of external NADPH-dehydrogenase (NDB1) during oxidative metabolism of NH4+-fed plants. Most plant species grown with NH4+ as the sole nitrogen source experience a condition known as “ammonium toxicity syndrome”. Surprisingly, transgenic Arabidopsis thaliana plants suppressing NDB1 were more resistant to NH4+ treatment. The NDB1 knock-down line was characterized by milder oxidative stress symptoms in plant tissues when supplied with NH4+. Mitochondrial ROS accumulation, in particular, was attenuated in the NDB1 knock-down plants during NH4+ treatment. Enhanced antioxidant defense, primarily concerning the glutathione pool, may prevent ROS accumulation in NH4+-grown NDB1-suppressing plants. We found that induction of glutathione peroxidase-like enzymes and peroxiredoxins in the NDB1-surpressing line contributed to lower ammonium-toxicity stress. The major conclusion of this study was that NDB1 suppression in plants confers tolerance to changes in redox homeostasis that occur in response to prolonged ammonium nutrition, causing cross tolerance among plants. PMID:29747392

  12. Haemophilus parasuis CpxRA two-component system confers bacterial tolerance to environmental stresses and macrolide resistance.

    Science.gov (United States)

    Cao, Qi; Feng, Fenfen; Wang, Huan; Xu, Xiaojuan; Chen, Huanchun; Cai, Xuwang; Wang, Xiangru

    2018-01-01

    Haemophilus parasuis is an opportunistic pathogen localized in the upper respiratory tracts of pigs, its infection begins from bacterial survival under complex conditions, like hyperosmosis, oxidative stress, phagocytosis, and sometimes antibiotics as well. The two-component signal transduction (TCST) system serves as a common stimulus-response mechanism that allows microbes to sense and respond to diverse environmental conditions via a series of phosphorylation reactions. In this study, we investigated the role of TCST system CpxRA in H. parasuis in response to different environmental stimuli by constructing the ΔcpxA and ΔcpxR single deletion mutants as well as the ΔcpxRA double deletion mutant from H. parasuis serotype 4 isolate JS0135. We demonstrated that H. parasuis TCST system CpxRA confers bacterial tolerance to stresses and bactericidal antibiotics. The CpxR was found to play essential roles in mediating oxidative stress, osmotic stresses and alkaline pH stress tolerance, as well as macrolide resistance (i.e. erythromycin), but the CpxA deletion did not decrease bacterial resistance to abovementioned stresses. Moreover, we found via RT-qPCR approach that HAPS_RS00160 and HAPS_RS09425, both encoding multidrug efflux pumps, were significantly decreased in erythromycin challenged ΔcpxR and ΔcpxRA mutants compared with wild-type strain JS0135. These findings characterize the role of the TCST system CpxRA in H. parasuis conferring stress response tolerance and bactericidal resistance, which will deepen our understanding of the pathogenic mechanism in H. parasuis. Copyright © 2017 Elsevier GmbH. All rights reserved.

  13. EPRI-DOE Conference on Environmentally-Enhanced Hydropower Turbines: Technical Papers

    Energy Technology Data Exchange (ETDEWEB)

    Hogan, T. [Alden Research Laboratory, Inc., Holden, MA (United States)

    2011-12-01

    The EPRI-DOE Conference on Environmentally-Enhanced Hydropower Turbines was a component of a larger project. The goal of the overall project was to conduct the final developmental engineering required to advance the commercialization of the Alden turbine. As part of this effort, the conference provided a venue to disseminate information on the status of the Alden turbine technology as well as the status of other advanced turbines and research on environmentally-friendly hydropower turbines. The conference was also a product of a federal Memorandum of Understanding among DOE, USBR, and USACE to share technical information on hydropower. The conference was held in Washington, DC on May 19 and 20, 2011 and welcomed over 100 attendees. The Conference Organizing Committee included the federal agencies with a vested interest in hydropower in the U.S. The Committee collaboratively assembled this conference, including topics from each facet of the environmentally-friendly conventional hydropower research community. The conference was successful in illustrating the readiness of environmentally-enhanced hydropower technologies. Furthermore, the topics presented illustrated the need for additional deployment and field testing of these technologies in an effort to promote the growth of environmentally sustainable hydropower in the U.S. and around the world.

  14. Molecular programs induced by heat acclimation confer neuroprotection against TBI and hypoxic insults via cross-tolerance mechanisms

    Directory of Open Access Journals (Sweden)

    Michal eHorowitz

    2015-07-01

    Full Text Available Neuroprotection following prolonged exposure to high ambient temperatures (heat acclimation HA develops via altered molecular programs such as cross-tolerance (Heat Acclimation -Neuroprotection Cross-Tolerance -HANCT. The mechanisms underlying cross-tolerance depend on enhanced on-demand protective pathways evolving during acclimation. The protection achieved is long lasting and limits the need for de novo recruitment of cytoprotective pathways upon exposure to novel stressors. Using mouse and rat acclimated phenotypes, we will focus on the impact of heat acclimation on Angiotensin II-AT2 receptors in neurogenesis and on HIF-1 as key mediators in spontaneous recovery and HANCT after traumatic brain injury (TBI. The neuroprotective consequences of heat acclimation on NMDA and AMPA receptors will be discussed using the global hypoxia model. A behavioral-molecular link will be crystallized. The differences between HANCT and consensus preconditioning will be reviewed.

  15. Expression of an Arabidopsis Ca2+/H+ antiporter CAX1 variant in petunia enhances cadmium tolerance and accumulation.

    Science.gov (United States)

    Wu, Qingyu; Shigaki, Toshiro; Williams, Kimberly A; Han, Jeung-Sul; Kim, Chang Kil; Hirschi, Kendal D; Park, Sunghun

    2011-01-15

    Phytoremediation is a cost-effective and minimally invasive technology to cleanse soils contaminated with heavy metals. However, few plant species are suitable for phytoremediation of metals such as cadmium (Cd). Genetic engineering offers a powerful tool to generate plants that can hyperaccumulate Cd. An Arabidopsis CAX1 mutant (CAXcd), which confers enhanced Cd transport in yeast, was ectopically expressed in petunia to evaluate whether the CAXcd expression would enhance Cd tolerance and accumulation in planta. The CAXcd-expressing petunia plants showed significantly greater Cd tolerance and accumulation than the controls. After being treated with either 50 or 100μM CdCl(2) for 6 weeks, the CAXcd-expressing plants showed more vigorous growth compared with controls, and the transgenic plants accumulated significantly more Cd (up to 2.5-fold) than controls. Moreover, the accumulation of Cd did not affect the development and morphology of the CAXcd-expressing petunia plants until the flowering and ultimately the maturing of seeds. Therefore, petunia has the potential to serve as a model species for developing herbaceous, ornamental plants for phytoremediation. Copyright © 2010 Elsevier GmbH. All rights reserved.

  16. Isolation and characterization of Arabidopsis mutants with enhanced tolerance to oxidative stress

    NARCIS (Netherlands)

    Qureshi, Muhammad K.; Radeva, Vesela; Genkov, Todor; Minkov, Ivan; Hille, Jacques; Gechev, Tsanko S.; Liu, J.-H.

    We have previously reported a method for isolation of mutants with enhanced tolerance to the fungal AAL toxin and given a detailed characterization of atr1 (AAL toxin resistant, Gechev et al. in Biochem Biophys Res Commun 375:639-644, 2008). Herewith, we report eight more mutants with enhanced

  17. Exploring traditional aus-type rice for metabolites conferring drought tolerance.

    Science.gov (United States)

    Casartelli, Alberto; Riewe, David; Hubberten, Hans Michael; Altmann, Thomas; Hoefgen, Rainer; Heuer, Sigrid

    2018-01-25

    Traditional varieties and landraces belonging to the aus-type group of rice (Oryza sativa L.) are known to be highly tolerant to environmental stresses, such as drought and heat, and are therefore recognized as a valuable genetic resource for crop improvement. Using two aus-type (Dular, N22) and two drought intolerant irrigated varieties (IR64, IR74) an untargeted metabolomics analysis was conducted to identify drought-responsive metabolites associated with tolerance. The superior drought tolerance of Dular and N22 compared with the irrigated varieties was confirmed by phenotyping plants grown to maturity after imposing severe drought stress in a dry-down treatment. Dular and N22 did not show a significant reduction in grain yield compared to well-watered control plants, whereas the intolerant varieties showed a significant reduction in both, total spikelet number and grain yield. The metabolomics analysis was conducted with shoot and root samples of plants at the tillering stage at the end of the dry-down treatment. The data revealed an overall higher accumulation of N-rich metabolites (amino acids and nucleotide-related metabolites allantoin and uridine) in shoots of the tolerant varieties. In roots, the aus-type varieties were characterised by a higher reduction of metabolites representative of glycolysis and the TCA cycle, such as malate, glyceric acid and glyceric acid-3-phosphate. On the other hand, the oligosaccharide raffinose showed a higher fold increase in both, shoots and roots of the sensitive genotypes. The data further showed that, for certain drought-responsive metabolites, differences between the contrasting rice varieties were already evident under well-watered control conditions. The drought tolerance-related metabolites identified in the aus-type varieties provide a valuable set of protective compounds and an entry point for assessing genetic diversity in the underlying pathways for developing drought tolerant rice and other crops.

  18. Physiological integration enhanced the tolerance of Cynodon dactylon to flooding.

    Science.gov (United States)

    Li, Z J; Fan, D Y; Chen, F Q; Yuan, Q Y; Chow, W S; Xie, Z Q

    2015-03-01

    Many flooding-tolerant species are clonal plants; however, the effects of physiological integration on plant responses to flooding have received limited attention. We hypothesise that flooding can trigger changes in metabolism of carbohydrates and ROS (reactive oxygen species) in clonal plants, and that physiological integration can ameliorate the adverse effects of stress, subsequently restoring the growth of flooded ramets. In the present study, we conducted a factorial experiment combining flooding to apical ramets and stolon severing (preventing physiological integration) between apical and basal ramets of Cynodon dactylon, which is a stoloniferous perennial grass with considerable flooding tolerance. Flooding-induced responses including decreased root biomass, accumulation of soluble sugar and starch, as well as increased activity of superoxide dismutase (SOD) and ascorbate peroxidase (APX) in apical ramets. Physiological integration relieved growth inhibition, carbohydrate accumulation and induction of antioxidant enzyme activity in stressed ramets, as expected, without any observable cost in unstressed ramets. We speculate that relief of flooding stress in clonal plants may rely on oxidising power and electron acceptors transferred between ramets through physiological integration. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  19. Overexpression of an AP2/ERF Type Transcription Factor OsEREBP1 Confers Biotic and Abiotic Stress Tolerance in Rice.

    Directory of Open Access Journals (Sweden)

    V Jisha

    Full Text Available AP2/ERF-type transcription factors regulate important functions of plant growth and development as well as responses to environmental stimuli. A rice AP2/ERF transcription factor, OsEREBP1 is a downstream component of a signal transduction pathway in a specific interaction between rice (Oryza sativa and its bacterial pathogen, Xoo (Xanthomonas oryzae pv. oryzae. Constitutive expression of OsEREBP1 in rice driven by maize ubiquitin promoter did not affect normal plant growth. Microarray analysis revealed that over expression of OsEREBP1 caused increased expression of lipid metabolism related genes such as lipase and chloroplastic lipoxygenase as well as several genes related to jasmonate and abscisic acid biosynthesis. PR genes, transcription regulators and Aldhs (alcohol dehydrogenases implicated in abiotic stress and submergence tolerance were also upregulated in transgenic plants. Transgenic plants showed increase in endogenous levels of α-linolenate, several jasmonate derivatives and abscisic acid but not salicylic acid. Soluble modified GFP (SmGFP-tagged OsEREBP1 was localized to plastid nucleoids. Comparative analysis of non-transgenic and OsEREBP1 overexpressing genotypes revealed that OsEREBP1 attenuates disease caused by Xoo and confers drought and submergence tolerance in transgenic rice. Our results suggest that constitutive expression of OsEREBP1 activates the jasmonate and abscisic acid signalling pathways thereby priming the rice plants for enhanced survival under abiotic or biotic stress conditions. OsEREBP1 is thus, a good candidate gene for engineering plants for multiple stress tolerance.

  20. bHLH106 Integrates Functions of Multiple Genes through Their G-Box to Confer Salt Tolerance on Arabidopsis.

    Science.gov (United States)

    Ahmad, Aftab; Niwa, Yasuo; Goto, Shingo; Ogawa, Takeshi; Shimizu, Masanori; Suzuki, Akane; Kobayashi, Kyoko; Kobayashi, Hirokazu

    2015-01-01

    An activation-tagging methodology was applied to dedifferentiated calli of Arabidopsis to identify new genes involved in salt tolerance. This identified salt tolerant callus 8 (stc8) as a gene encoding the basic helix-loop-helix transcription factor bHLH106. bHLH106-knockout (KO) lines were more sensitive to NaCl, KCl, LiCl, ABA, and low temperatures than the wild-type. Back-transformation of the KO line rescued its phenotype, and over-expression (OX) of bHLH106 in differentiated plants exhibited tolerance to NaCl. Green fluorescent protein (GFP) fused with bHLH106 revealed that it was localized to the nucleus. Prepared bHLH106 protein was subjected to electrophoresis mobility shift assays against E-box sequences (5'-CANNTG-3'). The G-box sequence 5'-CACGTG-3' had the strongest interaction with bHLH106. bHLH106-OX lines were transcriptomically analyzed, and resultant up- and down-regulated genes selected on the criterion of presence of a G-box sequence. There were 198 genes positively regulated by bHLH106 and 36 genes negatively regulated; these genes possessed one or more G-box sequences in their promoter regions. Many of these genes are known to be involved in abiotic stress response. It is concluded that bHLH106 locates at a branching point in the abiotic stress response network by interacting directly to the G-box in genes conferring salt tolerance on plants.

  1. Overexpression of a heat shock protein (ThHSP18.3) from Tamarix hispida confers stress tolerance to yeast.

    Science.gov (United States)

    Gao, Caiqiu; Jiang, Bo; Wang, Yucheng; Liu, Guifeng; Yang, Chuanping

    2012-04-01

    It is well known that plant heat shock proteins (HSPs) play important roles both in response to adverse environmental conditions and in various developmental processes. However, among plant HSPs, the functions of tree plant HSPs are poorly characterized. To improve our understanding of tree HSPs, we cloned and characterized an HSP gene (ThHSP18.3) from Tamarix hispida. Sequence alignment reveals that ThHSP18.3 belongs to the class I small heat shock protein family. A transient expression assay showed that ThHSP18.3 protein was targeted to the cell nucleus. Treatment of Tamarix hispida with cold and heat shock highly induced ThHSP18.3 expression in all studied leaves, roots and stems, whereas, treatment of T. hispida with NaCl, NaHCO(3), and PEG induced ThHSP18.3 expression in leaves and decreased its expression in roots and stems. Further, to study the role of ThHSP18.3 in stress tolerance under different stress conditions, we cloned ThHSP18.3 into the pYES2 vector, transformed and expressed the vector in yeast Saccharomyces cerevisiae. Yeast cells transformed with an empty pYES2 vector were employed as a control. Compared to the control, yeast cells expressing ThHSP18.3 showed greater tolerance to salt, drought, heavy metals, and both low and high temperatures, indicating that ThHSP18.3 confers tolerance to these stress conditions. These results suggested that ThHSP18.3 is involved in tolerance to a variety of stress conditions in T. hispida.

  2. Expression of Finger Millet EcDehydrin7 in Transgenic Tobacco Confers Tolerance to Drought Stress.

    Science.gov (United States)

    Singh, Rajiv Kumar; Singh, Vivek Kumar; Raghavendrarao, Sanagala; Phanindra, Mullapudi Lakshmi Venkata; Venkat Raman, K; Solanke, Amolkumar U; Kumar, Polumetla Ananda; Sharma, Tilak Raj

    2015-09-01

    One of the critical alarming constraints for agriculture is water scarcity. In the current scenario, global warming due to climate change and unpredictable rainfall, drought is going to be a master player and possess a big threat to stagnating gene pool of staple food crops. So it is necessary to understand the mechanisms that enable the plants to cope with drought stress. In this study, effort was made to prospect the role of EcDehydrin7 protein from normalized cDNA library of drought tolerance finger millet in transgenic tobacco. Biochemical and molecular analyses of T0 transgenic plants were done for stress tolerance. Leaf disc assay, seed germination test, dehydration assay, and chlorophyll estimation showed EcDehydrin7 protein directly link to drought tolerance. Northern and qRT PCR analyses shows relatively high expression of EcDehydrin7 protein compare to wild type. T0 transgenic lines EcDehydrin7(11) and EcDehydrin7(15) shows superior expression among all lines under study. In summary, all results suggest that EcDehydrin7 protein has a remarkable role in drought tolerance and may be used for sustainable crop breeding program in other food crops.

  3. Silencing of copine genes confers common wheat enhanced resistance to powdery mildew.

    Science.gov (United States)

    Zou, Baohong; Ding, Yuan; Liu, He; Hua, Jian

    2018-06-01

    Powdery mildew, caused by the biotrophic fungal pathogen Blumeria graminis f. sp. tritici (Bgt), is a major threat to the production of wheat (Triticum aestivum). It is of great importance to identify new resistance genes for the generation of Bgt-resistant or Bgt-tolerant wheat varieties. Here, we show that the wheat copine genes TaBON1 and TaBON3 negatively regulate wheat disease resistance to Bgt. Two copies of TaBON1 and three copies of TaBON3, located on chromosomes 6AS, 6BL, 1AL, 1BL and 1DL, respectively, were identified from the current common wheat genome sequences. The expression of TaBON1 and TaBON3 is responsive to both pathogen infection and temperature changes. Knocking down of TaBON1 or TaBON3 by virus-induced gene silencing (VIGS) induces the up-regulation of defence responses in wheat. These TaBON1- or TaBON3-silenced plants exhibit enhanced wheat disease resistance to Bgt, accompanied by greater accumulation of hydrogen peroxide and heightened cell death. In addition, high temperature has little effect on the up-regulation of defence response genes conferred by the silencing of TaBON1 or TaBON3. Our study shows a conserved function of plant copine genes in plant immunity and provides new genetic resources for the improvement of resistance to powdery mildew in wheat. © 2017 BSPP AND JOHN WILEY & SONS LTD.

  4. Enhancing expression of SSU1 genes in Saccharomyces uvarum leads to an increase in sulfite tolerance and a transcriptome profile change.

    Science.gov (United States)

    Liu, X Z; Sang, M; Zhang, X A; Zhang, T K; Zhang, H Y; He, X; Li, S X; Sun, X D; Zhang, Z M

    2017-05-01

    Saccharomyces uvarum is a good wine yeast species that may have great potential for the future. However, sulfur tolerance of most S. uvarum strains is very poor. In addition there is still little information about the SSU1 gene of S. uvarum, which encodes a putative transporter conferring sulfite tolerance. In order to analyze the function of the SSU1 gene, two expression vectors that contained different SSU1 genes were constructed and transferred into a sulfite-tolerant S. uvarum strain, A9. Then sulfite tolerance, SO2 production, and PCR, sequencing, RT-qPCR and transcriptome analyses were used to access the function of the S. uvarum SSU1 gene. Our results illustrated that enhancing expression of the SSU1 gene can promote sulfite resistance in S. uvarum, and an insertion fragment ahead of the additional SSU1 gene, as seen in some alleles, could affect the expression of other genes and the sulfite tolerance level of S. uvarum. This is the first report on enhancing the expression of the SSU1 gene of S. uvarum. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Enhanced pathway efficiency of Saccharomyces cerevisiae by introducing thermo-tolerant devices.

    Science.gov (United States)

    Liu, Yueqin; Zhang, Genli; Sun, Huan; Sun, Xiangying; Jiang, Nisi; Rasool, Aamir; Lin, Zhanglin; Li, Chun

    2014-10-01

    In this study, thermo-tolerant devices consisting of heat shock genes from thermophiles were designed and introduced into Saccharomyces cerevisiae for improving its thermo-tolerance. Among ten engineered thermo-tolerant yeasts, T.te-TTE2469, T.te-GroS2 and T.te-IbpA displayed over 25% increased cell density and 1.5-4-fold cell viability compared with the control. Physiological characteristics of thermo-tolerant strains revealed that better cell wall integrity, higher trehalose content and enhanced metabolic energy were preserved by thermo-tolerant devices. Engineered thermo-tolerant strain was used to investigate the impact of thermo-tolerant device on pathway efficiency by introducing β-amyrin synthesis pathway, showed 28.1% increased β-amyrin titer, 28-35°C broadened growth temperature range and 72h shortened fermentation period. The results indicated that implanting heat shock proteins from thermophiles to S. cerevisiae would be an efficient approach to improve its thermo-tolerance. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Exogenous Glutathione Enhances Mercury Tolerance by Inhibiting Mercury Entry into Plant Cells

    Science.gov (United States)

    Kim, Yeon-Ok; Bae, Hyeun-Jong; Cho, Eunjin; Kang, Hunseung

    2017-01-01

    Despite the increasing understanding of the crucial roles of glutathione (GSH) in cellular defense against heavy metal stress as well as oxidative stress, little is known about the functional role of exogenous GSH in mercury (Hg) tolerance in plants. Here, we provide compelling evidence that GSH contributes to Hg tolerance in diverse plants. Exogenous GSH did not mitigate the toxicity of cadmium (Cd), copper (Cu), or zinc (Zn), whereas application of exogenous GSH significantly promoted Hg tolerance during seed germination and seedling growth of Arabidopsis thaliana, tobacco, and pepper. By contrast, addition of buthionine sulfoximine, an inhibitor of GSH biosynthesis, severely retarded seed germination and seedling growth of the plants in the presence of Hg. The effect of exogenous GSH on Hg specific tolerance was also evident in the presence of other heavy metals, such as Cd, Cu, and Zn, together with Hg. GSH treatment significantly decreased H2O2 and O2- levels and lipid peroxidation, but increased chlorophyll content in the presence of Hg. Importantly, GSH treatment resulted in significantly less accumulation of Hg in Arabidopsis plants, and thin layer chromatography and nuclear magnetic resonance analysis revealed that GSH had much stronger binding affinity to Hg than to Cd, Cu, or Zn, suggesting that tight binding of GSH to Hg impedes Hg uptake, leading to low Hg accumulation in plant cells. Collectively, the present findings reveal that GSH is a potent molecule capable of conferring Hg tolerance by inhibiting Hg accumulation in plants. PMID:28507557

  7. Exogenous Glutathione Enhances Mercury Tolerance by Inhibiting Mercury Entry into Plant Cells

    Directory of Open Access Journals (Sweden)

    Yeon-Ok Kim

    2017-05-01

    Full Text Available Despite the increasing understanding of the crucial roles of glutathione (GSH in cellular defense against heavy metal stress as well as oxidative stress, little is known about the functional role of exogenous GSH in mercury (Hg tolerance in plants. Here, we provide compelling evidence that GSH contributes to Hg tolerance in diverse plants. Exogenous GSH did not mitigate the toxicity of cadmium (Cd, copper (Cu, or zinc (Zn, whereas application of exogenous GSH significantly promoted Hg tolerance during seed germination and seedling growth of Arabidopsis thaliana, tobacco, and pepper. By contrast, addition of buthionine sulfoximine, an inhibitor of GSH biosynthesis, severely retarded seed germination and seedling growth of the plants in the presence of Hg. The effect of exogenous GSH on Hg specific tolerance was also evident in the presence of other heavy metals, such as Cd, Cu, and Zn, together with Hg. GSH treatment significantly decreased H2O2 and O2- levels and lipid peroxidation, but increased chlorophyll content in the presence of Hg. Importantly, GSH treatment resulted in significantly less accumulation of Hg in Arabidopsis plants, and thin layer chromatography and nuclear magnetic resonance analysis revealed that GSH had much stronger binding affinity to Hg than to Cd, Cu, or Zn, suggesting that tight binding of GSH to Hg impedes Hg uptake, leading to low Hg accumulation in plant cells. Collectively, the present findings reveal that GSH is a potent molecule capable of conferring Hg tolerance by inhibiting Hg accumulation in plants.

  8. Dielectric platforms for surface-enhanced spectroscopies (Conference Presentation)

    Science.gov (United States)

    Maier, Stefan A.

    2016-03-01

    Plasmonic nanostructures serve as the main backbone of surface enhanced sensing methodologies, yet the associated optical losses lead to localized heating as well as quenching of molecules, complicating their use for enhancement of fluorescent emission. Additionally, conventional plasmonic materials are limited to operation in the visible part of the spectrum. We will elucidate how nanostructures consisting of conventional and polar dielectrics can be employed as a highly promising alternative platform. Dielectric nanostructures can sustain scattering resonances due to both electric and magnetic Mie modes. We have recently predicted high enhanced local electromagnetic field hot spots in dielectric nanoantenna dimers, with the hallmark of spot sizes comparable to those achievable with plasmonic antennas, but with lower optical losses. Here, we will present first experimental evidence for both fluorescence and Raman enhancement in dielectric nanoantennas, including a direct determination of localized heating, and compare to conventional Au dimer antennas. The second part of the talk will focus on the mid-infrared regime of the electromagnetic spectrum, outlining possibilities for surface enhanced infrared absorption spectroscopy based on polar and hyperbolic dielectrics.

  9. Salt-induced stabilization of EIN3/EIL1 confers salinity tolerance by deterring ROS accumulation in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Jinying Peng

    2014-10-01

    Full Text Available Ethylene has been regarded as a stress hormone to regulate myriad stress responses. Salinity stress is one of the most serious abiotic stresses limiting plant growth and development. But how ethylene signaling is involved in plant response to salt stress is poorly understood. Here we showed that Arabidopsis plants pretreated with ethylene exhibited enhanced tolerance to salt stress. Gain- and loss-of-function studies demonstrated that EIN3 (ETHYLENE INSENSITIVE 3 and EIL1 (EIN3-LIKE 1, two ethylene-activated transcription factors, are necessary and sufficient for the enhanced salt tolerance. High salinity induced the accumulation of EIN3/EIL1 proteins by promoting the proteasomal degradation of two EIN3/EIL1-targeting F-box proteins, EBF1 and EBF2, in an EIN2-independent manner. Whole-genome transcriptome analysis identified a list of SIED (Salt-Induced and EIN3/EIL1-Dependent genes that participate in salt stress responses, including several genes encoding reactive oxygen species (ROS scavengers. We performed a genetic screen for ein3 eil1-like salt-hypersensitive mutants and identified 5 EIN3 direct target genes including a previously unknown gene, SIED1 (At5g22270, which encodes a 93-amino acid polypeptide involved in ROS dismissal. We also found that activation of EIN3 increased peroxidase (POD activity through the direct transcriptional regulation of PODs expression. Accordingly, ethylene pretreatment or EIN3 activation was able to preclude excess ROS accumulation and increased tolerance to salt stress. Taken together, our study provides new insights into the molecular action of ethylene signaling to enhance plant salt tolerance, and elucidates the transcriptional network of EIN3 in salt stress response.

  10. Rapid crown root development confers tolerance to zinc deficiency in rice

    Directory of Open Access Journals (Sweden)

    Amrit Kaur eNanda

    2016-03-01

    Full Text Available Zinc (Zn deficiency is one of the leading nutrient disorders in rice (Oryza sativa. Many studies have identified Zn efficient rice genotypes, but causal mechanisms for Zn deficiency tolerance remain poorly understood. Here we report a detailed study of the impact of Zn deficiency on crown root development of rice genotypes, differing in their tolerance to this stress. Zn deficiency delayed crown root development and plant biomass accumulation in both Zn efficient and inefficient genotypes, with the effects being much stronger in the latter. Zn efficient genotypes had developed new crown roots as early as three days after transplanting (DAT to a Zn deficient field and that was followed by a significant increase in total biomass by 7 DAT. Zn-inefficient genotypes developed few new crown roots and did not increase biomass during the first seven days following transplanting. This correlated with Zn efficient genotypes retranslocating a higher proportion of shoot Zn to their roots, compared to Zn inefficient genotypes. These latter genotypes were furthermore not efficient in utilizing the limited Zn for root development. Histological analyses indicated no anomalies in crown tissue of Zn-efficient or inefficient genotypes that would have suggested crown root emergence was impeded. We therefore conclude that the rate of crown root initiation was differentially affected by Zn deficiency between genotypes. Rapid crown root development, following transplanting, was identified as a main causative trait for tolerance to Zn deficiency and better Zn retranslocation from shoot to root was a key attribute of Zn-efficient genotypes.

  11. Abscisic acid enhances cold tolerance in honeybee larvae

    Science.gov (United States)

    Sturla, Laura; Guida, Lucrezia; Vigliarolo, Tiziana; Maggi, Matías; Eguaras, Martín; Zocchi, Elena; Lamattina, Lorenzo

    2017-01-01

    The natural composition of nutrients present in food is a key factor determining the immune function and stress responses in the honeybee (Apis mellifera). We previously demonstrated that a supplement of abscisic acid (ABA), a natural component of nectar, pollen, and honey, increases honeybee colony survival overwinter. Here we further explored the role of ABA in in vitro-reared larvae exposed to low temperatures. Four-day-old larvae (L4) exposed to 25°C for 3 days showed lower survival rates and delayed development compared to individuals growing at a standard temperature (34°C). Cold-stressed larvae maintained higher levels of ABA for longer than do larvae reared at 34°C, suggesting a biological significance for ABA. Larvae fed with an ABA-supplemented diet completely prevent the low survival rate due to cold stress and accelerate adult emergence. ABA modulates the expression of genes involved in metabolic adjustments and stress responses: Hexamerin 70b, Insulin Receptor Substrate, Vitellogenin, and Heat Shock Proteins 70. AmLANCL2, the honeybee ABA receptor, is also regulated by cold stress and ABA. These results support a role for ABA increasing the tolerance of honeybee larvae to low temperatures through priming effects. PMID:28381619

  12. Abscisic acid enhances cold tolerance in honeybee larvae.

    Science.gov (United States)

    Ramirez, Leonor; Negri, Pedro; Sturla, Laura; Guida, Lucrezia; Vigliarolo, Tiziana; Maggi, Matías; Eguaras, Martín; Zocchi, Elena; Lamattina, Lorenzo

    2017-04-12

    The natural composition of nutrients present in food is a key factor determining the immune function and stress responses in the honeybee ( Apis mellifera ). We previously demonstrated that a supplement of abscisic acid (ABA), a natural component of nectar, pollen, and honey, increases honeybee colony survival overwinter. Here we further explored the role of ABA in in vitro -reared larvae exposed to low temperatures. Four-day-old larvae (L4) exposed to 25°C for 3 days showed lower survival rates and delayed development compared to individuals growing at a standard temperature (34°C). Cold-stressed larvae maintained higher levels of ABA for longer than do larvae reared at 34°C, suggesting a biological significance for ABA. Larvae fed with an ABA-supplemented diet completely prevent the low survival rate due to cold stress and accelerate adult emergence. ABA modulates the expression of genes involved in metabolic adjustments and stress responses: Hexamerin 70b, Insulin Receptor Substrate, Vitellogenin , and Heat Shock Proteins 70. AmLANCL2, the honeybee ABA receptor, is also regulated by cold stress and ABA. These results support a role for ABA increasing the tolerance of honeybee larvae to low temperatures through priming effects. © 2017 The Author(s).

  13. JUNGBRUNNEN1 Confers Drought Tolerance Downstream of the HD-Zip I Transcription Factor AtHB13

    Directory of Open Access Journals (Sweden)

    Saghar Ebrahimian-Motlagh

    2017-12-01

    Full Text Available Low water availability is the major environmental factor limiting growth and productivity of plants and crops and is therefore considered of high importance for agriculture affected by climate change. Identifying regulatory components controlling the response and tolerance to drought stress is thus of major importance. The NAC transcription factor (TF JUNGBRUNNEN1 (JUB1 from Arabidopsis thaliana extends leaf longevity under non-stress growth conditions, lowers cellular hydrogen peroxide (H2O2 level, and enhances tolerance against heat stress and salinity. Here, we additionally find that JUB1 strongly increases tolerance to drought stress in Arabidopsis when expressed from both, a constitutive (CaMV 35S and an abiotic stress-induced (RD29A promoter. Employing a yeast one-hybrid screen we identified HD-Zip class I TF AtHB13 as an upstream regulator of JUB1. AtHB13 has previously been reported to act as a positive regulator of drought tolerance. AtHB13 and JUB1 thereby establish a joint drought stress control module.

  14. Heterologous expression of the yeast Tpo1p or Pdr5p membrane transporters in Arabidopsis confers plant xenobiotic tolerance.

    Science.gov (United States)

    Remy, Estelle; Niño-González, María; Godinho, Cláudia P; Cabrito, Tânia R; Teixeira, Miguel C; Sá-Correia, Isabel; Duque, Paula

    2017-07-03

    Soil contamination is a major hindrance for plant growth and development. The lack of effective strategies to remove chemicals released into the environment has raised the need to increase plant resilience to soil pollutants. Here, we investigated the ability of two Saccharomyces cerevisiae plasma-membrane transporters, the Major Facilitator Superfamily (MFS) member Tpo1p and the ATP-Binding Cassette (ABC) protein Pdr5p, to confer Multiple Drug Resistance (MDR) in Arabidopsis thaliana. Transgenic plants expressing either of the yeast transporters were undistinguishable from the wild type under control conditions, but displayed tolerance when challenged with the herbicides 2,4-D and barban. Plants expressing ScTPO1 were also more resistant to the herbicides alachlor and metolachlor as well as to the fungicide mancozeb and the Co 2+ , Cu 2+ , Ni 2+ , Al 3+ and Cd 2+ cations, while ScPDR5-expressing plants exhibited tolerance to cycloheximide. Yeast mutants lacking Tpo1p or Pdr5p showed increased sensitivity to most of the agents tested in plants. Our results demonstrate that the S. cerevisiae Tpo1p and Pdr5p transporters are able to mediate resistance to a broad range of compounds of agricultural interest in yeast as well as in Arabidopsis, underscoring their potential in future biotechnological applications.

  15. Enhanced Maritime Safety through Diagnosis and Fault Tolerant Control

    DEFF Research Database (Denmark)

    Blanke, Mogens

    2001-01-01

    Faults in steering, navigation instruments or propulsion machinery are serious on a marine vessel since the consequence could be loss of maneuvering ability, and imply risk of damage to vessel personnel or environment. Early diagnosis and accomodation of faults could enhance safety. Fault...... of properties of a falty system; means to determine remedial actions. The paper illustrates the techniques by two marine examples, sensor fusion for automatic steering and control of the main engine....

  16. TaCIPK29, a CBL-interacting protein kinase gene from wheat, confers salt stress tolerance in transgenic tobacco.

    Directory of Open Access Journals (Sweden)

    Xiaomin Deng

    Full Text Available Calcineurin B-like protein-interacting protein kinases (CIPKs have been found to be responsive to abiotic stress. However, their precise functions and the related molecular mechanisms in abiotic stress tolerance are not completely understood, especially in wheat. In the present study, TaCIPK29 was identified as a new member of CIPK gene family in wheat. TaCIPK29 transcript increased after NaCl, cold, methyl viologen (MV, abscisic acid (ABA and ethylene treatments. Over-expression of TaCIPK29 in tobacco resulted in increased salt tolerance, which was demonstrated by higher germination rates, longer root lengths and better growth status of transgenic tobacco plants compared to controls when both were treated with salt stress. Physiological measurements indicated that transgenic tobacco seedlings retained high K(+/Na(+ ratios and Ca(2+ content by up-regulating some transporter genes expression and also possessed lower H2O2 levels and reduced membrane injury by increasing the expression and activities of catalase (CAT and peroxidase (POD under salt stress. Moreover, transgenic lines conferred tolerance to oxidative stress by increasing the activity and expression of CAT. Finally, TaCIPK29 was located throughout cells and it preferentially interacted with TaCBL2, TaCBL3, NtCBL2, NtCBL3 and NtCAT1. Taken together, our results showed that TaCIPK29 functions as a positive factor under salt stress and is involved in regulating cations and reactive oxygen species (ROS homeostasis.

  17. Transcriptome alteration in a rice introgression line with enhanced alkali tolerance.

    Science.gov (United States)

    Zhang, Yunhong; Lin, Xiuyun; Ou, Xiufang; Hu, Lanjuan; Wang, Jinming; Yang, Chunwu; Wang, Shucai; Liu, Bao

    2013-07-01

    Alkali stress inhibits plant growth and development and thus limits crop productivity. To investigate the possible genetic basis of alkali tolerance in rice, we generated an introgressed rice line (K83) with significantly enhanced tolerance to alkali stress compared to its recipient parental cultivar (Jijing88). By using microarray analysis, we examined the global gene expression profiles of K83 and Jijing88, and found that more than 1200 genes were constitutively and differentially expressed in K83 in comparison to Jijing88 with 572 genes up- and 654 down-regulated. Upon alkali treatment, a total of 347 genes were found up- and 156 down-regulated in K83 compared to 591 and 187, respectively, in Jijing88. Among the up-regulated genes in both K83 and Jijing88, only 34 were constitutively up-regulated in K83, suggesting that both the constitutive differentially expressed genes in K83 and those induced by alkali treatment are most likely responsible for enhanced alkali tolerance. A gene ontology analysis based on all annotated, differentially expressed genes revealed that genes with expression alterations were enriched in pathways involved in metabolic processes, catalytic activity, and transport and transcription factor activities, suggesting that these pathways are associated with alkali stress tolerance in rice. Our results illuminated the novel genetic aspects of alkali tolerance in rice and established a repertory of potential target genes for biotechnological manipulations that can be used to generate alkali-tolerant rice cultivars. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  18. Error-prone PCR mutation of Ls-EPSPS gene from Liriope spicata conferring to its enhanced glyphosate-resistance.

    Science.gov (United States)

    Mao, Chanjuan; Xie, Hongjie; Chen, Shiguo; Valverde, Bernal E; Qiang, Sheng

    2017-09-01

    Liriope spicata (Thunb.) Lour has a unique LsEPSPS structure contributing to the highest-ever-recognized natural glyphosate tolerance. The transformed LsEPSPS confers increased glyphosate resistance to E. coli and A. thaliana. However, the increased glyphosate-resistance level is not high enough to be of commercial value. Therefore, LsEPSPS was subjected to error-prone PCR to screen mutant EPSPS genes capable of endowing higher resistance levels. A mutant designated as ELs-EPSPS having five mutated amino acids (37Val, 67Asn, 277Ser, 351Gly and 422Gly) was selected for its ability to confer improved resistance to glyphosate. Expression of ELs-EPSPS in recombinant E. coli BL21 (DE3) strains enhanced resistance to glyphosate in comparison to both the LsEPSPS-transformed and -untransformed controls. Furthermore, transgenic ELs-EPSPS A. thaliana was about 5.4 fold and 2-fold resistance to glyphosate compared with the wild-type and the Ls-EPSPS-transgenic plants, respectively. Therefore, the mutated ELs-EPSPS gene has potential value for has potential for the development of glyphosate-resistant crops. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. More than visual literacy: art and the enhancement of tolerance for ambiguity and empathy.

    Science.gov (United States)

    Bentwich, Miriam Ethel; Gilbey, Peter

    2017-11-10

    Comfort with ambiguity, mostly associated with the acceptance of multiple meanings, is a core characteristic of successful clinicians. Yet past studies indicate that medical students and junior physicians feel uncomfortable with ambiguity. Visual Thinking Strategies (VTS) is a pedagogic approach involving discussions of art works and deciphering the different possible meanings entailed in them. However, the contribution of art to the possible enhancement of the tolerance for ambiguity among medical students has not yet been adequately investigated. We aimed to offer a novel perspective on the effect of art, as it is experienced through VTS, on medical students' tolerance of ambiguity and its possible relation to empathy. Quantitative method utilizing a short survey administered after an interactive VTS session conducted within mandatory medical humanities course for first-year medical students. The intervention consisted of a 90-min session in the form of a combined lecture and interactive discussions about art images. The VTS session and survey were filled by 67 students in two consecutive rounds of first-year students. 67% of the respondents thought that the intervention contributed to their acceptance of multiple possible meanings, 52% thought their visual observation ability was enhanced and 34% thought that their ability to feel the sufferings of other was being enhanced. Statistically significant moderate-to-high correlations were found between the contribution to ambiguity tolerance and contribution to empathy (0.528-0.744; p ≤ 0.01). Art may contribute especially to the development of medical students' tolerance of ambiguity, also related to the enhancement of empathy. The potential contribution of visual art works used in VTS to the enhancement of tolerance for ambiguity and empathy is explained based on relevant literature regarding the embeddedness of ambiguity within art works, coupled with reference to John Dewey's theory of learning. Given the

  20. Overexpression of the DNA mismatch repair factor, PMS2, confers hypermutability and DNA damage tolerance.

    Science.gov (United States)

    Gibson, Shannon L; Narayanan, Latha; Hegan, Denise Campisi; Buermeyer, Andrew B; Liskay, R Michael; Glazer, Peter M

    2006-12-08

    Inherited defects in genes associated with DNA mismatch repair (MMR) have been linked to familial colorectal cancer. Cells deficient in MMR are genetically unstable and demonstrate a tolerance phenotype in response to certain classes of DNA damage. Some sporadic human cancers also show abnormalities in MMR gene function, typically due to diminished expression of one of the MutL homologs, MLH1. Here, we report that overexpression of the MutL homolog, human PMS2, can also cause a disruption of the MMR pathway in mammalian cells, resulting in hypermutability and DNA damage tolerance. A mouse fibroblast cell line carrying a recoverable lambda phage shuttle vector for mutation detection was transfected with either a vector designed to express hPMS2 or with an empty vector control. Cells overexpressing hPMS2 were found to have elevated spontaneous mutation frequencies at the cII reporter gene locus. They also showed an increase in the level of mutations induced by the alkylating agent, methynitrosourea (MNU). Clonogenic survival assays demonstrated increased survival of the PMS2-overexpressing cells following exposure to MNU, consistent with the induction of a damage tolerance phenotype. Similar results were seen in cells expressing a mutant PMS2 gene, containing a premature stop codon at position 134 and representing a variant found in an individual with familial colon cancer. These results show that dysregulation of PMS2 gene expression can disrupt MMR function in mammalian cells and establish an additional carcinogenic mechanism by which cells can develop genetic instability and acquire resistance to cytotoxic cancer therapies.

  1. Enhanced salt tolerance of alfalfa (Medicago sativa) by rstB gene transformation.

    Science.gov (United States)

    Zhang, Wan-Jun; Wang, Tao

    2015-05-01

    Generating salt tolerance forage plant is essential for use of the land affected by high salinity. A salt tolerance gene rstB was used as a selectable marker gene in Agrobacterium-mediated transformation of tobacco under a selective regime of 170mM NaCl. The transgenic plants showed clear improvement in salt tolerance. To improve salt tolerance of alfalfa (Medicago sativa L.), rstB gene was introduced into alfalfa genome by Agrobacterium-mediated transformation. No abnormal phenotype was observed among the transgenic plants when compared with wild type (wt) plants. Significant enhancement of resistance to salt-shock treatment was noted on the rstB transgenic (T0) plants. Transgenic second-generation (T1) seeds showed improved germination rate and seedling growth under salt-stress condition. Hindered Na(+) accumulation, but enhanced Ca(2+) accumulation was observed on the rstB T1 plants when subjected to salt-stresses. Enhanced calcium accumulation in transgenic plants was also verified by cytohistochemical localization of calcium. Under salt-stress of 50mM NaCl, about 15% of the transgenic plants finished their life-cycle but the wt plants had no flower formation. The results demonstrated that the expression of rstB gene improved salt tolerance in transgenic alfalfa. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  2. Enhancing data from commercial space flights (Conference Presentation)

    Science.gov (United States)

    Sherman, Ariel; Paolini, Aaron; Kozacik, Stephen; Kelmelis, Eric J.

    2017-05-01

    Video tracking of rocket launches inherently must be done from long range. Due to the high temperatures produced, cameras are often placed far from launch sites and their distance to the rocket increases as it is tracked through the flight. Consequently, the imagery collected is generally severely degraded by atmospheric turbulence. In this talk, we present our experience in enhancing commercial space flight videos. We will present the mission objectives, the unique challenges faced, and the solutions to overcome them.

  3. B lymphocytes confer immune tolerance via cell surface GARP-TGF-β complex.

    Science.gov (United States)

    Wallace, Caroline H; Wu, Bill X; Salem, Mohammad; Ansa-Addo, Ephraim A; Metelli, Alessandra; Sun, Shaoli; Gilkeson, Gary; Shlomchik, Mark J; Liu, Bei; Li, Zihai

    2018-04-05

    GARP, a cell surface docking receptor for binding and activating latent TGF-β, is highly expressed by platelets and activated Tregs. While GARP is implicated in immune invasion in cancer, the roles of the GARP-TGF-β axis in systemic autoimmune diseases are unknown. Although B cells do not express GARP at baseline, we found that the GARP-TGF-β complex is induced on activated human and mouse B cells by ligands for multiple TLRs, including TLR4, TLR7, and TLR9. GARP overexpression on B cells inhibited their proliferation, induced IgA class-switching, and dampened T cell-independent antibody production. In contrast, B cell-specific deletion of GARP-encoding gene Lrrc32 in mice led to development of systemic autoimmune diseases spontaneously as well as worsening of pristane-induced lupus-like disease. Canonical TGF-β signaling more readily upregulates GARP in Peyer patch B cells than in splenic B cells. Furthermore, we demonstrated that B cells are required for the induction of oral tolerance of T cell-dependent antigens via GARP. Our studies reveal for the first time to our knowledge that cell surface GARP-TGF-β is an important checkpoint for regulating B cell peripheral tolerance, highlighting a mechanism of autoimmune disease pathogenesis.

  4. Enhancing and accelarating flavour formation by salt-tolerant yeasts in Japanese soy-sauce processes

    NARCIS (Netherlands)

    Sluis, van der C.; Tramper, J.; Wijffels, R.H.

    2001-01-01

    In soy-sauce processes salt-tolerant yeasts are very important for the flavour formation. This flavour formation is, however, slow and poorly understood. In the last decades, a concerted research effort has increased the understanding and resulted in the derivation of mutants with an enhanced

  5. Hollow metal nanostructures for enhanced plasmonics (Conference Presentation)

    Science.gov (United States)

    Genç, Aziz; Patarroyo, Javier; Sancho-Parramon, Jordi; Duchamp, Martial; Gonzalez, Edgar; Bastus, Neus G.; Houben, Lothar; Dunin-Borkowski, Rafal; Puntes, Victor F.; Arbiol, Jordi

    2016-03-01

    Complex metal nanoparticles offer a great playground for plasmonic nanoengineering, where it is possible to cover plasmon resonances from ultraviolet to near infrared by modifying the morphologies from solid nanocubes to nanoframes, multiwalled hollow nanoboxes or even nanotubes with hybrid (alternating solid and hollow) structures. We experimentally show that structural modifications, i.e. void size and final morphology, are the dominant determinants for the final plasmonic properties, while compositional variations allow us to get a fine tuning. EELS mappings of localized surface plasmon resonances (LSPRs) reveal an enhanced plasmon field inside the voids of hollow AuAg nanostructures along with a more homogeneous distributions of the plasmon fields around the nanostructures. With the present methodology and the appropriate samples we are able to compare the effects of hybridization at the nanoscale in hollow nanostructures. Boundary element method (BEM) simulations also reveal the effects of structural nanoengineering on plasmonic properties of hollow metal nanostructures. Possibility of tuning the LSPR properties of hollow metal nanostructures in a wide range of energy by modifying the void size/shell thickness is shown by BEM simulations, which reveals that void size is the dominant factor for tuning the LSPRs. As a proof of concept for enhanced plasmonic properties, we show effective label free sensing of bovine serum albumin (BSA) with some of our hollow nanostructures. In addition, the different plasmonic modes observed have also been studied and mapped in 3D.

  6. Overexpression of AmRosea1 Gene Confers Drought and Salt Tolerance in Rice

    Directory of Open Access Journals (Sweden)

    Mingzhu Dou

    2016-12-01

    Full Text Available Ectopic expression of the MYB transcription factor of AmROSEA1 from Antirrhinum majus has been reported to change anthocyanin and other metabolites in several species. In this study, we found that overexpression of AmRosea1 significantly improved the tolerance of transgenic rice to drought and salinity stresses. Transcriptome analysis revealed that a considerable number of stress-related genes were affected by exogenous AmRosea1 during both drought and salinity stress treatments. These affected genes are involved in stress signal transduction, the hormone signal pathway, ion homeostasis and the enzymes that remove peroxides. This work suggests that the AmRosea1 gene is a potential candidate for genetic engineering of crops.

  7. Disruption of Circadian rhythms enhances radiation tolerance in mice

    International Nuclear Information System (INIS)

    Patil, Shrikant L.; Krishna, A.P.; Somashekarappa, H.M.; Patil, Rajashekar K.

    2014-01-01

    Whether an alteration in responses to the radiations depends on the phase of Circadian rhythm, this has been explored previously. The results however have been inconclusive and only survival rate of animals has been considered to represent the effect. Circadian phase has been shown to be critical in many therapeutic procedures. The present study was conducted on control group of mice (12L: 12D), extended day length and night length by imposing 24 hrs of light followed by 24 hrs of darkness, a third group received (8L: 8D) light: day cycles. These regimes were operational for seven days, at the end of seventh day mice from three different groups were exposed to 3 Gy of total body gamma radiation. Survival study, extent of lipid peroxidation and antioxidant status was estimated. Radioresistance was found to be enhanced in mice maintained at 8L: 8D cycle. There was no significant changes observed in mice of time shift group (24L: 24D). The corresponding shift in the acrophase of radioresistance following a sudden time shift supports the effect of disrupted circadian rhythms. (author)

  8. Adaptation and survival of plants in high stress habitats via fungal endophyte conferred stress tolerance

    Science.gov (United States)

    Rodriguez, Rusty J.; Woodward, Claire; Redman, Regina S.

    2010-01-01

    From the Arctic to the Antarctic, plants thrive in diverse habitats that impose different levels of adaptive pressures depending on the type and degree of biotic and abiotic stresses inherent to each habitat (Stevens, 1989). At any particular location, the abundance and distribution of individual plant species vary tremendously and is theorized to be based on the ability to tolerate a wide range of edaphic conditions and habitat-specific stresses (Pianka, 1966). The ability of individual plant species to thrive in diverse habitats is commonly referred to as phenotypic plasticity and is thought to involve adaptations based on changes in the plant genome (Givnish, 2002; Pan et al., 2006; Robe and Griffiths, 2000; Schurr et al., 2006). Habitats that impose high levels of abiotic stress are typically colonized with fewer plant species compared to habitats imposing low levels of stress. Moreover, high stress habitats have decreased levels of plant abundance compared to low stress habitats even though these habitats may occur in close proximity to one another (Perelman et al., 2007). This is particularly interesting because all plants are known to perceive, transmit signals, and respond to abiotic stresses such as drought, heat, and salinity (Bartels and Sunkar, 2005; Bohnert et al., 1995). Although there has been extensive research performed to determine the genetic, molecular, and physiological bases of how plants respond to and tolerate stress, the nature of plant adaptation to high stress habitats remains unresolved (Leone et al., 2003; Maggio et al., 2003; Tuberosa et al., 2003). However, recent evidence indicates that a ubiquitous aspect of plant biology (fungal symbiosis) is involved in the adaptation and survival of at least some plants in high stress habitats (Rodriguez et al., 2008).

  9. Hydrogen sulfide enhances nitric oxide-induced tolerance of hypoxia in maize (Zea mays L.).

    Science.gov (United States)

    Peng, Renyi; Bian, Zhiyuan; Zhou, Lina; Cheng, Wei; Hai, Na; Yang, Changquan; Yang, Tao; Wang, Xinyu; Wang, Chongying

    2016-11-01

    Our data present H 2 S in a new role, serving as a multi-faceted transducer to different response mechanisms during NO-induced acquisition of tolerance to flooding-induced hypoxia in maize seedling roots. Nitric oxide (NO), serving as a secondary messenger, modulates physiological processes in plants. Recently, hydrogen sulfide (H 2 S) has been demonstrated to have similar signaling functions. This study focused on the effects of treatment with H 2 S on NO-induced hypoxia tolerance in maize seedlings. The results showed that treatment with the NO donor sodium nitroprusside (SNP) enhanced survival rate of submerged maize roots through induced accumulation of endogenous H 2 S. The induced H 2 S then enhanced endogenous Ca 2+ levels as well as the Ca 2+ -dependent activity of alcohol dehydrogenase (ADH), improving the capacity for antioxidant defense and, ultimately, the hypoxia tolerance in maize seedlings. In addition, NO induced the activities of key enzymes in H 2 S biosynthesis, such as L-cysteine desulfhydrases (L-CDs), O-acetyl-L-serine (thiol)lyase (OAS-TL), and β-Cyanoalanine Synthase (CAS). SNP-induced hypoxia tolerance was enhanced by the application of NaHS, but was eliminated by the H 2 S-synthesis inhibitor hydroxylamine (HA) and the H 2 S-scavenger hypotaurine (HT). H 2 S concurrently enhanced the transcriptional levels of relative hypoxia-induced genes. Together, our findings indicated that H 2 S serves as a multi-faceted transducer that enhances the nitric oxide-induced hypoxia tolerance in maize (Zea mays L.).

  10. Cloning of genes and developing transgenic crops with enhanced tolerance to salinity and drought (abstract)

    International Nuclear Information System (INIS)

    Bansal, K.C.; Chinnusamy, V.; Tayal, D.; Das, A.; Goel, D.; Yadav, V.; Singh, A.K.; Lakhshmi, K.

    2005-01-01

    Abiotic stresses represent the most limiting factors affecting agricultural productivity. In India more than 60% of total cultivated land is still rainfed and crops experience frequent droughts. Thus, we need to develop transgenic crops tolerant to drought, and other related abiotic stress factors such as salinity, low and high temperature stresses. At the National Research Centre on Plant Biotechnology, Indian Agricultural Research Institute (ICAR), we have initiated a programme on developing transgenic crops tolerant to a range of abiotic stresses. The major emphasis is on developing transgenic potato, tomato, mustard, rice and wheat. While, transgenic plants of potato. tomato and mustard have already been generated with osmotin gene and are at different stages of testing, other key genes imparting tolerance to abiotic stresses are being isolated from different species for producing transgenic rice and wheat cultivars tolerant to multiple stresses. Genes that have been isolated in our laboratory include ascorbate peroxidase gene (TaApx) and genes encoding transcription factor, CBFs (TaCBF2 and TaCBP3) from a drought tolerant wheat cultivar (C306), Lea1 cDNA from Brassica species, codA from Arthrobacter globiformis, and otsBA operon from E. coli. Apart from these stress-related genes, we have isolated a few stress-inducible promoters for deploying them in gene stacking in developing transgenic crops with enhanced tolerance to multiple abiotic stresses. The results will be presented. (author)

  11. Transgenic Alfalfa Plants Expressing the Sweetpotato Orange Gene Exhibit Enhanced Abiotic Stress Tolerance

    Science.gov (United States)

    Wang, Zhi; Ke, Qingbo; Kim, Myoung Duck; Kim, Sun Ha; Ji, Chang Yoon; Jeong, Jae Cheol; Lee, Haeng-Soon; Park, Woo Sung; Ahn, Mi-Jeong; Li, Hongbing; Xu, Bingcheng; Deng, Xiping; Lee, Sang-Hoon; Lim, Yong Pyo; Kwak, Sang-Soo

    2015-01-01

    Alfalfa (Medicago sativa L.), a perennial forage crop with high nutritional content, is widely distributed in various environments worldwide. We recently demonstrated that the sweetpotato Orange gene (IbOr) is involved in increasing carotenoid accumulation and enhancing resistance to multiple abiotic stresses. In this study, in an effort to improve the nutritional quality and environmental stress tolerance of alfalfa, we transferred the IbOr gene into alfalfa (cv. Xinjiang Daye) under the control of an oxidative stress-inducible peroxidase (SWPA2) promoter through Agrobacterium tumefaciens-mediated transformation. Among the 11 transgenic alfalfa lines (referred to as SOR plants), three lines (SOR2, SOR3, and SOR8) selected based on their IbOr transcript levels were examined for their tolerance to methyl viologen (MV)-induced oxidative stress in a leaf disc assay. The SOR plants exhibited less damage in response to MV-mediated oxidative stress and salt stress than non-transgenic plants. The SOR plants also exhibited enhanced tolerance to drought stress, along with higher total carotenoid levels. The results suggest that SOR alfalfa plants would be useful as forage crops with improved nutritional value and increased tolerance to multiple abiotic stresses, which would enhance the development of sustainable agriculture on marginal lands. PMID:25946429

  12. Enhanced fault-tolerant quantum computing in d-level systems.

    Science.gov (United States)

    Campbell, Earl T

    2014-12-05

    Error-correcting codes protect quantum information and form the basis of fault-tolerant quantum computing. Leading proposals for fault-tolerant quantum computation require codes with an exceedingly rare property, a transversal non-Clifford gate. Codes with the desired property are presented for d-level qudit systems with prime d. The codes use n=d-1 qudits and can detect up to ∼d/3 errors. We quantify the performance of these codes for one approach to quantum computation known as magic-state distillation. Unlike prior work, we find performance is always enhanced by increasing d.

  13. Rice leaf hydrophobicity and gas films are conferred by a wax synthesis gene (LGF1) and contribute to flood tolerance

    DEFF Research Database (Denmark)

    Kurokawa, Yusuke; Nagai, Keisuke; Hung, Phung Danh

    2018-01-01

    Floods impede gas (O2and CO2) exchange between plants and the environment. A mechanism to enhance plant gas exchange under water comprises gas films on hydrophobic leaves, but the genetic regulation of this mechanism is unknown. We used a rice mutant (dripping wet leaf 7, drp7) which does...... not retain gas films on leaves, and its wild-type (Kinmaze), in gene discovery for this trait. Gene complementation was tested in transgenic lines. Functional properties of leaves as related to gas film retention and underwater photosynthesis were evaluated. Leaf Gas Film 1 (LGF1) was identified as the gene...... determining leaf gas films. LGF1 regulates C30 primary alcohol synthesis, which is necessary for abundant epicuticular wax platelets, leaf hydrophobicity and gas films on submerged leaves. This trait enhanced underwater photosynthesis 8.2-fold and contributes to submergence tolerance. Gene function...

  14. A moso bamboo WRKY gene PeWRKY83 confers salinity tolerance in transgenic Arabidopsis plants.

    Science.gov (United States)

    Wu, Min; Liu, Huanlong; Han, Guomin; Cai, Ronghao; Pan, Feng; Xiang, Yan

    2017-09-15

    The WRKY family are transcription factors, involved in plant development, and response to biotic and abiotic stresses. Moso bamboo is an important bamboo that has high ecological, economic and cultural value and is widely distributed in the south of China. In this study, we performed a genome-wide identification of WRKY members in moso bamboo and identified 89 members. By comparative analysis in six grass genomes, we found the WRKY gene family may have experienced or be experiencing purifying selection. Based on relative expression levels among WRKY IIc members under three abiotic stresses, PeWRKY83 functioned as a transcription factor and was selected for detailed analysis. The transgenic Arabidopsis of PeWRKY83 showed superior physiological properties compared with the WT under salt stress. Overexpression plants were less sensitive to ABA at both germination and postgermination stages and accumulated more endogenous ABA under salt stress conditions. Further studies demonstrated that overexpression of PeWRKY83 could regulate the expression of some ABA biosynthesis genes (AtAAO3, AtNCED2, AtNCED3), signaling genes (AtABI1, AtPP2CA) and responsive genes (AtRD29A, AtRD29B, AtABF1) under salt stress. Together, these results suggested that PeWRKY83 functions as a novel WRKY-related TF which plays a positive role in salt tolerance by regulating stress-induced ABA synthesis.

  15. The Metallothionein Gene, TaMT3, from Tamarix androssowii Confers Cd2+ Tolerance in Tobacco

    Directory of Open Access Journals (Sweden)

    Boru Zhou

    2014-06-01

    Full Text Available Cadmium (Cd is a nonessential microelement and low concentration Cd2+ has strong toxicity to plant growth. Plant metallothioneins, a class of low molecular, cystein(Cys-rich and heavy-metal binding proteins, play an important role in both metal chaperoning and scavenging of reactive oxygen species (ROS with their large number of cysteine residues and therefore, protect plants from oxidative damage. In this study, a metallothionein gene, TaMT3, isolated from Tamarix androssowii was transformed into tobacco (Nicotiana tobacum through Agrobacterium-mediated leaf disc method, and correctly expressed under the control of 35S promoter. Under Cd2+ stress, the transgenic tobacco showed significant increases of superoxide dismutase (SOD activity and chlorophyll concentration, but decreases of peroxidase (POD activity and malondialdehyde (MDA accumulation when compared to the non-transgenic tobacco. Vigorous growth of transgenic tobacco was observed at the early development stages, resulting in plant height and fresh weight were significantly larger than those of the non-transgenic tobacco under Cd2+ stress. These results demonstrated that the expression of the exogenous TaMT3 gene increased the ability of ROS cleaning-up, indicating a stronger tolerance to Cd2+ stress.

  16. The metallothionein gene, TaMT3, from Tamarix androssowii confers Cd2+ tolerance in tobacco.

    Science.gov (United States)

    Zhou, Boru; Yao, Wenjing; Wang, Shengji; Wang, Xinwang; Jiang, Tingbo

    2014-06-10

    Cadmium (Cd) is a nonessential microelement and low concentration Cd2+ has strong toxicity to plant growth. Plant metallothioneins, a class of low molecular, cystein(Cys)-rich and heavy-metal binding proteins, play an important role in both metal chaperoning and scavenging of reactive oxygen species (ROS) with their large number of cysteine residues and therefore, protect plants from oxidative damage. In this study, a metallothionein gene, TaMT3, isolated from Tamarix androssowii was transformed into tobacco (Nicotiana tobacum) through Agrobacterium-mediated leaf disc method, and correctly expressed under the control of 35S promoter. Under Cd2+ stress, the transgenic tobacco showed significant increases of superoxide dismutase (SOD) activity and chlorophyll concentration, but decreases of peroxidase (POD) activity and malondialdehyde (MDA) accumulation when compared to the non-transgenic tobacco. Vigorous growth of transgenic tobacco was observed at the early development stages, resulting in plant height and fresh weight were significantly larger than those of the non-transgenic tobacco under Cd2+ stress. These results demonstrated that the expression of the exogenous TaMT3 gene increased the ability of ROS cleaning-up, indicating a stronger tolerance to Cd2+ stress.

  17. ThPOD3, a truncated polypeptide from Tamarix hispida, conferred drought tolerance in Escherichia coli.

    Science.gov (United States)

    Guo, Xiao-Hong; Jiang, Jing; Wang, Bai-Chen; Li, Hui-Yu; Wang, Yu-Cheng; Yang, Chuan-Ping; Liu, Gui-Feng

    2010-03-01

    The ThPOD1 gene encodes a peroxidase and was isolated from a Tamarix hispida NaCl-stress root cDNA library. We found that ThPOD1 expression could be induced by abiotic stresses such as cold, salt, drought and exogenous abscisic acid. These findings suggested that ThPOD1 might be involved in the plant response to environmental stresses and ABA treatment. To elucidate the function of this gene, recombinant plasmids expressing full-length ThPOD1 as well as ThPOD2 (aa 41-337), and ThPOD3 (aa 73-337) truncated polypeptides were constructed. SDS-PAGE and Western blot analyses of the fusion proteins revealed that the molecular weights of ThPOD1, ThPOD2 and ThPOD3 were approximately 57, approximately 50 and approximately 47 kDa, respectively. Stress assays of E. coli treated with the recombinant plasmids indicated that ThPOD3 could improve resistance to drought stress. This finding could potentially be used to improve plant tolerance to drought stress via gene transfer.

  18. Identification of genomic regions conferring drought tolerance in bread wheat using ISSR markers

    International Nuclear Information System (INIS)

    Maqsood, R.; Khaliq, I.; Amjid, M.W.

    2017-01-01

    Drought stress is one of ever escalating and disastrous situation for plantadaptations under changing climate. Quantitative Trait Loci (QTL) analysis was done to identify chromosomal locations containing QTLs for photosynthetic rate, relative water content and cell membrane stability under drought stress conditions. An F2 population was developed from an intraspecific cross between a drought tolerant genotype (Chakawal-50) and a drought susceptible genotype (9436) of Triticum aestivum. A total of 30 ISSR markers were used to screen both parents. Only 4 ISSR markers were found polymorphic which were used to score 180 F2 plants. A total of 73 bands produced were found polymorphic from these 4 markers using capillary electrophoresis. One QTL was found linked to Photosynthetic rate on chromosome 3A, one to relative water contents on chromosome 4D and one to cell membrane thermo-stability on chromosome 2B, respectively. As these traits were also positively correlated with thousand grain weight, so indirectly these QTLs might improve plant yield under limited water conditions. Therefore, these QTLs may be used through marker assisted selection while breeding wheat under limited water conditions. (author)

  19. Production of transgenic banana plants conferring tolerance to salt stress (abstract)

    International Nuclear Information System (INIS)

    Ismail, I.A.; Salama, M.; Hamid, A.A.; Sadiq, A.S.

    2005-01-01

    Production of bananas is limited in areas that have soils with excess sodium. In this study, a transformation system in banana Grand Nain cultivar was established using the apical meristem explant and plasmid pAB6 containing the herbicide-resistant gene (bar) as a selectable marker and gus reporter gene. The micro projectile bombardment transformation system using 650 psi was successfully used for introducing the studied genes in banana explants. The expression of the introduced genes was detected using leaf painting and GUS histochemical tests, respectively. The present results showed that among the selection stage, 36.5% of the bombarded explants survived on the BI3 medium supplemented with 3 mg/L bialaphos, while, 26.6% of the tested explants showed a positive reaction in the GUS assay. To detect the presence of bar and gus genes the PCR was successfully used. These results encourage the idea of possibility of banana crop improvement using in vitro technique through micro projectile bombardment. Therefore, the plasmid pNM1 that carries the bar and P5CS (delta 1 l-pyrroline-5-carboxylate synthetase for proline accumulation) genes was introduced in banana Grand Nain cultivar to produce transgenic plants expressing the salt tolerance gene. Results showed that the majority of herbicide-resistant banana plaptlets were successfully acclimatized. In studying the effects of different salt concentrations on the produced transgenic banana plants, results showed lower decrease in the percentage of survived plants, pseudostem diameter and leaf area with an increase of salt concentrations in case of transgenic plants compared with the controls. (author)

  20. Adaptive and freeze-tolerant heteronetwork organohydrogels with enhanced mechanical stability over a wide temperature range

    Science.gov (United States)

    Gao, Hainan; Zhao, Ziguang; Cai, Yudong; Zhou, Jiajia; Hua, Wenda; Chen, Lie; Wang, Li; Zhang, Jianqi; Han, Dong; Liu, Mingjie; Jiang, Lei

    2017-06-01

    Many biological organisms with exceptional freezing tolerance can resist the damages to cells from extra-/intracellular ice crystals and thus maintain their mechanical stability at subzero temperatures. Inspired by the freezing tolerance mechanisms found in nature, here we report a strategy of combining hydrophilic/oleophilic heteronetworks to produce self-adaptive, freeze-tolerant and mechanically stable organohydrogels. The organohydrogels can simultaneously use water and oil as a dispersion medium, and quickly switch between hydrogel- and organogel-like behaviours in response to the nature of the surrounding phase. Accordingly, their surfaces display unusual adaptive dual superlyophobic in oil/water system (that is, they are superhydrophobic under oil and superoleophobic under water). Moreover, the organogel component can inhibit the ice crystallization of the hydrogel component, thus enhancing the mechanical stability of organohydrogel over a wide temperature range (-78 to 80 °C). The organohydrogels may have promising applications in complex and harsh environments.

  1. 7th International Conference in Methodologies and Intelligent Systems for Technology Enhanced Learning

    CERN Document Server

    Gennari, Rosella; Mascio, Tania; Rodríguez, Sara; Prieta, Fernando; Ramos, Carlos; Silveira, Ricardo

    2017-01-01

    This book presents the outcomes of the 7th International Conference in Methodologies and Intelligent Systems for Technology Enhanced Learning (MIS4TEL'17), hosted by the Polytechnic of Porto, Portugal from 21 to 23 June 2017. Expanding on the topics of the previous conferences, it provided an open forum for discussing intelligent systems for technology enhanced learning (TEL) and their roots in novel learning theories, empirical methodologies for their design or evaluation, stand-alone and web-based solutions, and makerspaces. It also fostered entrepreneurship and business startup ideas, bringing together researchers and developers from industry, education and the academic world to report on the latest scientific research, technical advances and methodologies.

  2. A realistic appraisal of methods to enhance desiccation tolerance of entomopathogenic nematodes.

    Science.gov (United States)

    Perry, Roland N; Ehlers, Ralf-Udo; Glazer, Itamar

    2012-06-01

    Understanding the desiccation survival attributes of infective juveniles of entomopathogenic nematodes (EPN) of the genera Steinernema and Heterorhabditis, is central to evaluating the reality of enhancing the shelf-life and field persistence of commercial formulations. Early work on the structural and physiological aspects of desiccation survival focused on the role of the molted cuticle in controlling the rate of water loss and the importance of energy reserves, particularly neutral lipids. The accumulation of trehalose was also found to enhance desiccation survival. Isolation of natural populations that can survive harsh environments, such as deserts, indicated that some populations have enhanced abilities to survive desiccation. However, survival abilities of EPN are limited compared with those of some species of plant-parasitic nematodes inhabiting aerial parts of plants. Research on EPN stress tolerance has expanded on two main lines: i) to select strains of species, currently in use commercially, which have increased tolerance to environmental extremes; and ii) to utilize molecular information, including expressed sequence tags and genome sequence data, to determine the underlying genetic factors that control longevity and stress tolerance of EPN. However, given the inherent limitations of EPN survival ability, it is likely that improved formulation will be the major factor to enhance EPN longevity and, perhaps, increase the range of applications.

  3. Dispersion tolerance enhancement using an improved offset-QAM OFDM scheme.

    Science.gov (United States)

    Zhao, Jian; Townsend, Paul D

    2015-06-29

    Discrete-Fourier transform (DFT) based offset quadrature amplitude modulation (offset-QAM) orthogonal frequency division multiplexing (OFDM) without cyclic prefix (CP) was shown to offer a dispersion tolerance the same as that of conventional OFDM with ~20% CP overhead. In this paper, we analytically study the fundamental mechanism limiting the dispersion tolerance of this conventional scheme. It is found that the signal and the crosstalk from adjacent subcarriers, which are orthogonal with π/2 phase difference at back to back, can be in-phase when the dispersion increases to a certain value. We propose a novel scheme to overcome this limitation and significantly improve the dispersion tolerance to that of one subcarrier. Simulations show that the proposed scheme can support a 224-Gb/s polarization-division-multiplexed offset-4QAM OFDM signal over 160,000 ps/nm without any CP under 128 subcarriers, and this tolerance scales with the square of the number of subcarriers. It is also shown that this scheme exhibits advantages of greatly enhanced spectral efficiency, larger dispersion tolerance, and/or reduced complexity compared to the conventional CP-OFDM and reduced-guard-interval OFDM using frequency domain equalization.

  4. Hydrolyzed caseinomacropeptide conjugated galactooligosaccharides support the growth and enhance the bile tolerance in Lactobacillus strains.

    Science.gov (United States)

    Muthaiyan, Arunachalam; Hernandez-Hernandez, Oswaldo; Moreno, F Javier; Sanz, Maria Luz; Ricke, Steven C

    2012-07-11

    In this study bioactive caseinomacropeptide was conjugated with prebiotic galactooligosaccharides (hCMP:GOS) by Maillard reaction to synthesize value added prebiotic compounds to Lactobacillus strains. Growth study showed the ability of hCMP:GOS to serve as a sole carbon source for Lactobacillus strains. A significant amount of acetate and lactate was detected in cell free culture supernatant by HPLC. It demonstrated the ability of Lactobacillus strains to ferment the hCMP:GOS as a carbon source. In addition, hCMP:GOS grown Lactobacillus cells exhibited enhanced bile tolerance and retained 90% viability. Overall results of this study indicate that the hCMP conjugated GOS can be potential multipurpose prebiotic substrates to enhance the growth and bile tolerance in Lactobacillus strains and serve as a fermentable substrate to produce beneficial metabolites in the host.

  5. Heterologous expression of a rice metallothionein isoform (OsMTI-1b in Saccharomyces cerevisiae enhances cadmium, hydrogen peroxide and ethanol tolerance

    Directory of Open Access Journals (Sweden)

    Zahra Ansarypour

    Full Text Available Abstract Metallothioneins are a superfamily of low-molecular-weight, cysteine (Cys-rich proteins that are believed to play important roles in protection against metal toxicity and oxidative stress. The main purpose of this study was to investigate the effect of heterologous expression of a rice metallothionein isoform (OsMTI-1b on the tolerance of Saccharomyces cerevisiae to Cd2+, H2O2 and ethanol stress. The gene encoding OsMTI-1b was cloned into p426GPD as a yeast expression vector. The new construct was transformed to competent cells of S. cerevisiae. After verification of heterologous expression of OsMTI-1b, the new strain and control were grown under stress conditions. In comparison to control strain, the transformed S. cerevisiae cells expressing OsMTI-1b showed more tolerance to Cd2+ and accumulated more Cd2+ ions when they were grown in the medium containing CdCl2. In addition, the heterologous expression of GST-OsMTI-1b conferred H2O2 and ethanol tolerance to S. cerevisiae cells. The results indicate that heterologous expression of plant MT isoforms can enhance the tolerance of S. cerevisiae to multiple stresses.

  6. Salicylic acid confers salt tolerance in potato plants by improving water relations, gaseous exchange, antioxidant activities and osmoregulation.

    Science.gov (United States)

    Faried, Hafiz Nazar; Ayyub, Chaudhary Muhammad; Amjad, Muhammad; Ahmed, Rashid; Wattoo, Fahad Masoud; Butt, Madiha; Bashir, Mohsin; Shaheen, Muhammad Rashid; Waqas, Muhammad Ahmed

    2017-04-01

    Potato is an important vegetable; however, salt stress drastically affects its growth and yield. A pot experiment was therefore conducted to assess salicylic acid efficacy in improving performance of potato cultivars, grown under salt stress (50 mmol L -1 ). Salicylic acid at 0.5 mmol L -1 was sprayed on to potato plants after 1 week of salinity application. Salt stress effects were ameliorated by salicylic acid effectively in both the studied cultivars. N-Y LARA proved more responsive to salicylic acid application than 720-110 NARC, which confirmed genetic variation between cultivars. Salicylic acid scavenged reactive oxygen species by improving antioxidant enzyme activities (superoxide dismutase, catalase, peroxidases) and regulating osmotic adjustment (proline, phenolic contents), which led to enhanced water relation and gaseous exchange attributes, and thereby increased potassium availability and reduced sodium content in potato leaves. Moreover, potato tuber yield showed a positive correlation with potassium content, photosynthesis and antioxidant enzyme activities. Salt tolerance efficacy of salicylic acid is authenticated in improving potato crop performance under salt stress. Salicylic acid effect was more pronounced in N-Y LARA, reflecting greater tolerance than 720-110 NARC, which was confirmed as a susceptible cultivar. Hence salicylic acid at 0.5 mmol L -1 and cultivation of N-Y LARA may be recommended in saline soil. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  7. A wheat WRKY transcription factor TaWRKY10 confers tolerance to multiple abiotic stresses in transgenic tobacco.

    Directory of Open Access Journals (Sweden)

    Chen Wang

    Full Text Available WRKY transcription factors are reported to be involved in defense regulation, stress response and plant growth and development. However, the precise role of WRKY transcription factors in abiotic stress tolerance is not completely understood, especially in crops. In this study, we identified and cloned 10 WRKY genes from genome of wheat (Triticum aestivum L.. TaWRKY10, a gene induced by multiple stresses, was selected for further investigation. TaWRKY10 was upregulated by treatment with polyethylene glycol, NaCl, cold and H2O2. Result of Southern blot indicates that the wheat genome contains three copies of TaWRKY10. The TaWRKY10 protein is localized in the nucleus and functions as a transcriptional activator. Overexpression of TaWRKY10 in tobacco (Nicotiana tabacum L. resulted in enhanced drought and salt stress tolerance, mainly demonstrated by the transgenic plants exhibiting of increased germination rate, root length, survival rate, and relative water content under these stress conditions. Further investigation showed that transgenic plants also retained higher proline and soluble sugar contents, and lower reactive oxygen species and malonaldehyde contents. Moreover, overexpression of the TaWRKY10 regulated the expression of a series of stress related genes. Taken together, our results indicate that TaWRKY10 functions as a positive factor under drought and salt stresses by regulating the osmotic balance, ROS scavenging and transcription of stress related genes.

  8. Exogenous Melatonin Confers Cadmium Tolerance by Counterbalancing the Hydrogen Peroxide Homeostasis in Wheat Seedlings

    Directory of Open Access Journals (Sweden)

    Jun Ni

    2018-03-01

    Full Text Available Melatonin has emerged as a research highlight regarding its important role in regulating plant growth and the adaptation to the environmental stresses. In this study, we investigated how melatonin prevented the cadmium toxicity to wheat seedlings. The results demonstrated that cadmium induced the expression of melatonin biosynthesis-related genes and cause a significant increase of endogenous melatonin level. Melatonin treatment drastically alleviated the cadmium toxicity, resulting in increased plant height, biomass accumulation, and root growth. Cadmium and senescence treatment significantly increased the endogenous level of hydrogen peroxide, which was strictly counterbalanced by melatonin. Furthermore, melatonin treatment caused a significant increase of GSH (reduced glutathione content and the GSH/GSSG (oxidized glutathione ratio. The activities of two key antioxidant enzymes, ascorbate peroxidase (APX and superoxide dismutase (SOD, but not catalase (CAT and peroxidase (POD, were specifically improved by melatonin. Additionally, melatonin not only promoted the primary root growth, but also drastically enhanced the capacity of the seedling roots to degrade the exogenous hydrogen peroxide. These results suggested that melatonin played a key role in maintaining the hydrogen peroxide homeostasis, via regulation of the antioxidant systems. Conclusively, this study revealed a crucial protective role of melatonin in the regulation of cadmium resistance in wheat.

  9. Exogenous Melatonin Confers Cadmium Tolerance by Counterbalancing the Hydrogen Peroxide Homeostasis in Wheat Seedlings.

    Science.gov (United States)

    Ni, Jun; Wang, Qiaojian; Shah, Faheem Afzal; Liu, Wenbo; Wang, Dongdong; Huang, Shengwei; Fu, Songling; Wu, Lifang

    2018-03-30

    Melatonin has emerged as a research highlight regarding its important role in regulating plant growth and the adaptation to the environmental stresses. In this study, we investigated how melatonin prevented the cadmium toxicity to wheat seedlings. The results demonstrated that cadmium induced the expression of melatonin biosynthesis-related genes and cause a significant increase of endogenous melatonin level. Melatonin treatment drastically alleviated the cadmium toxicity, resulting in increased plant height, biomass accumulation, and root growth. Cadmium and senescence treatment significantly increased the endogenous level of hydrogen peroxide, which was strictly counterbalanced by melatonin. Furthermore, melatonin treatment caused a significant increase of GSH (reduced glutathione) content and the GSH/GSSG (oxidized glutathione) ratio. The activities of two key antioxidant enzymes, ascorbate peroxidase (APX) and superoxide dismutase (SOD), but not catalase (CAT) and peroxidase (POD), were specifically improved by melatonin. Additionally, melatonin not only promoted the primary root growth, but also drastically enhanced the capacity of the seedling roots to degrade the exogenous hydrogen peroxide. These results suggested that melatonin played a key role in maintaining the hydrogen peroxide homeostasis, via regulation of the antioxidant systems. Conclusively, this study revealed a crucial protective role of melatonin in the regulation of cadmium resistance in wheat.

  10. Oil palm EgCBF3 conferred stress tolerance in transgenic tomato plants through modulation of the ethylene signaling pathway.

    Science.gov (United States)

    Ebrahimi, Mortaza; Abdullah, Siti Nor Akmar; Abdul Aziz, Maheran; Namasivayam, Parameswari

    2016-09-01

    CBF/DREB1 is a group of transcription factors that are mainly involved in abiotic stress tolerance in plants. They belong to the AP2/ERF superfamily of plant-specific transcription factors. A gene encoding a new member of this group was isolated from ripening oil palm fruit and designated as EgCBF3. The oil palm fruit demonstrates the characteristics of a climacteric fruit like tomato, in which ethylene has a major impact on the ripening process. A transgenic approach was used for functional characterization of the EgCBF3, using tomato as the model plant. The effects of ectopic expression of EgCBF3 were analyzed based on expression profiling of the ethylene biosynthesis-related genes, anti-freeze proteins (AFPs), abiotic stress tolerance and plant growth and development. The EgCBF3 tomatoes demonstrated altered phenotypes compared to the wild type tomatoes. Delayed leaf senescence and flowering, increased chlorophyll content and abnormal flowering were the consequences of overexpression of EgCBF3 in the transgenic tomatoes. The EgCBF3 tomatoes demonstrated enhanced abiotic stress tolerance under in vitro conditions. Further, transcript levels of ethylene biosynthesis-related genes, including three SlACSs and two SlACOs, were altered in the transgenic plants' leaves and roots compared to that in the wild type tomato plant. Among the eight AFPs studied in the wounded leaves of the EgCBF3 tomato plants, transcript levels of SlOSM-L, SlNP24, SlPR5L and SlTSRF1 decreased, while expression of the other four, SlCHI3, SlPR1, SlPR-P2 and SlLAP2, were up-regulated. These findings indicate the possible functions of EgCBF3 in plant growth and development as a regulator of ethylene biosynthesis-related and AFP genes, and as a stimulator of abiotic stress tolerance. Copyright © 2016 Elsevier GmbH. All rights reserved.

  11. Enhanced tolerance and remediation of anthracene by transgenic tobacco plants expressing a fungal glutathione transferase gene

    Energy Technology Data Exchange (ETDEWEB)

    Dixit, Prachy; Mukherjee, Prasun K.; Sherkhane, Pramod D.; Kale, Sharad P. [Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Eapen, Susan, E-mail: eapenhome@yahoo.com [Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2011-08-15

    Highlights: {yields} Transgenic plants expressing a TvGST gene were tested for tolerance, uptake and degradation of anthracene. {yields} Transgenic plants were more tolerant to anthracene and take up more anthracene from soil and solutions compared to control plants. {yields} Using in vitro T{sub 1} seedlings, we showed that anthracene-a three fused benzene ring compound was phytodegraded to naphthalene derivatives, having two benzene rings. {yields} This is the first time that a transgenic plant was shown to have the potential to phytodegrade anthracene. - Abstract: Plants can be used for remediation of polyaromatic hydrocarbons, which are known to be a major concern for human health. Metabolism of xenobiotic compounds in plants occurs in three phases and glutathione transferases (GST) mediate phase II of xenobiotic transformation. Plants, although have GSTs, they are not very efficient for degradation of exogenous recalcitrant xenobiotics including polyaromatic hydrocarbons. Hence, heterologous expression of efficient GSTs in plants may improve their remediation and degradation potential of xenobiotics. In the present study, we investigated the potential of transgenic tobacco plants expressing a Trichoderma virens GST for tolerance, remediation and degradation of anthracene-a recalcitrant polyaromatic hydrocarbon. Transgenic plants with fungal GST showed enhanced tolerance to anthracene compared to control plants. Remediation of {sup 14}C uniformly labeled anthracene from solutions and soil by transgenic tobacco plants was higher compared to wild-type plants. Transgenic plants (T{sub 0} and T{sub 1}) degraded anthracene to naphthalene derivatives, while no such degradation was observed in wild-type plants. The present work has shown that in planta expression of a fungal GST in tobacco imparted enhanced tolerance as well as higher remediation potential of anthracene compared to wild-type plants.

  12. Enhanced tolerance and remediation of anthracene by transgenic tobacco plants expressing a fungal glutathione transferase gene

    International Nuclear Information System (INIS)

    Dixit, Prachy; Mukherjee, Prasun K.; Sherkhane, Pramod D.; Kale, Sharad P.; Eapen, Susan

    2011-01-01

    Highlights: → Transgenic plants expressing a TvGST gene were tested for tolerance, uptake and degradation of anthracene. → Transgenic plants were more tolerant to anthracene and take up more anthracene from soil and solutions compared to control plants. → Using in vitro T 1 seedlings, we showed that anthracene-a three fused benzene ring compound was phytodegraded to naphthalene derivatives, having two benzene rings. → This is the first time that a transgenic plant was shown to have the potential to phytodegrade anthracene. - Abstract: Plants can be used for remediation of polyaromatic hydrocarbons, which are known to be a major concern for human health. Metabolism of xenobiotic compounds in plants occurs in three phases and glutathione transferases (GST) mediate phase II of xenobiotic transformation. Plants, although have GSTs, they are not very efficient for degradation of exogenous recalcitrant xenobiotics including polyaromatic hydrocarbons. Hence, heterologous expression of efficient GSTs in plants may improve their remediation and degradation potential of xenobiotics. In the present study, we investigated the potential of transgenic tobacco plants expressing a Trichoderma virens GST for tolerance, remediation and degradation of anthracene-a recalcitrant polyaromatic hydrocarbon. Transgenic plants with fungal GST showed enhanced tolerance to anthracene compared to control plants. Remediation of 14 C uniformly labeled anthracene from solutions and soil by transgenic tobacco plants was higher compared to wild-type plants. Transgenic plants (T 0 and T 1 ) degraded anthracene to naphthalene derivatives, while no such degradation was observed in wild-type plants. The present work has shown that in planta expression of a fungal GST in tobacco imparted enhanced tolerance as well as higher remediation potential of anthracene compared to wild-type plants.

  13. The SbMT-2 gene from a halophyte confers abiotic stress tolerance and modulates ROS scavenging in transgenic tobacco.

    Directory of Open Access Journals (Sweden)

    Amit Kumar Chaturvedi

    Full Text Available Heavy metals are common pollutants of the coastal saline area and Salicornia brachiata an extreme halophyte is frequently exposed to various abiotic stresses including heavy metals. The SbMT-2 gene was cloned and transformed to tobacco for the functional validation. Transgenic tobacco lines (L2, L4, L6 and L13 showed significantly enhanced salt (NaCl, osmotic (PEG and metals (Zn++, Cu++ and Cd++ tolerance compared to WT plants. Transgenic lines did not show any morphological variation and had enhanced growth parameters viz. shoot length, root length, fresh weight and dry weight. High seed germination percentage, chlorophyll content, relative water content, electrolytic leakage and membrane stability index confirmed that transgenic lines performed better under salt (NaCl, osmotic (PEG and metals (Zn++, Cu++ and Cd++ stress conditions compared to WT plants. Proline, H2O2 and lipid peroxidation (MDA analyses suggested the role of SbMT-2 in cellular homeostasis and H2O2 detoxification. Furthermore in vivo localization of H2O2 and O2-; and elevated expression of key antioxidant enzyme encoding genes, SOD, POD and APX evident the possible role of SbMT-2 in ROS scavenging/detoxification mechanism. Transgenic lines showed accumulation of Cu++ and Cd++ in root while Zn++ in stem under stress condition. Under control (unstressed condition, Zn++ was accumulated more in root but accumulation of Zn++ in stem under stress condition suggested that SbMT-2 may involve in the selective translocation of Zn++ from root to stem. This observation was further supported by the up-regulation of zinc transporter encoding genes NtZIP1 and NtHMA-A under metal ion stress condition. The study suggested that SbMT-2 modulates ROS scavenging and is a potential candidate to be used for phytoremediation and imparting stress tolerance.

  14. The SbMT-2 gene from a halophyte confers abiotic stress tolerance and modulates ROS scavenging in transgenic tobacco.

    Science.gov (United States)

    Chaturvedi, Amit Kumar; Patel, Manish Kumar; Mishra, Avinash; Tiwari, Vivekanand; Jha, Bhavanath

    2014-01-01

    Heavy metals are common pollutants of the coastal saline area and Salicornia brachiata an extreme halophyte is frequently exposed to various abiotic stresses including heavy metals. The SbMT-2 gene was cloned and transformed to tobacco for the functional validation. Transgenic tobacco lines (L2, L4, L6 and L13) showed significantly enhanced salt (NaCl), osmotic (PEG) and metals (Zn++, Cu++ and Cd++) tolerance compared to WT plants. Transgenic lines did not show any morphological variation and had enhanced growth parameters viz. shoot length, root length, fresh weight and dry weight. High seed germination percentage, chlorophyll content, relative water content, electrolytic leakage and membrane stability index confirmed that transgenic lines performed better under salt (NaCl), osmotic (PEG) and metals (Zn++, Cu++ and Cd++) stress conditions compared to WT plants. Proline, H2O2 and lipid peroxidation (MDA) analyses suggested the role of SbMT-2 in cellular homeostasis and H2O2 detoxification. Furthermore in vivo localization of H2O2 and O2-; and elevated expression of key antioxidant enzyme encoding genes, SOD, POD and APX evident the possible role of SbMT-2 in ROS scavenging/detoxification mechanism. Transgenic lines showed accumulation of Cu++ and Cd++ in root while Zn++ in stem under stress condition. Under control (unstressed) condition, Zn++ was accumulated more in root but accumulation of Zn++ in stem under stress condition suggested that SbMT-2 may involve in the selective translocation of Zn++ from root to stem. This observation was further supported by the up-regulation of zinc transporter encoding genes NtZIP1 and NtHMA-A under metal ion stress condition. The study suggested that SbMT-2 modulates ROS scavenging and is a potential candidate to be used for phytoremediation and imparting stress tolerance.

  15. Phenotypic and genetic characteristics associated with Listeria monocytogenes food chain isolates displaying enhanced and diminished cold tolerance

    DEFF Research Database (Denmark)

    Hingston, P.; Chen, J.; Laing, C.

    between strains with varied cold tolerance. The objective of this study was to determine if Lm isolates with enhanced cold tolerance, exhibit other high risk characteristics that may add to their survival and/or pathogenicity. To accomplish this, 166 predominantly food/food plant Lm isolates were tested...... in brainheart infusion broth, for their ability to tolerate cold (4°C), salt (6% NaCl, 25°C), acid (pH 5, 25°C), and desiccation (33% RH, 20°C) stress. Isolates were considered tolerant or sensitive if they exhibited survival characteristics > or ... with a truncated version (n=47). Cold tolerant isolates were more likely to be tolerant to the other three stresses than intermediate and cold sensitive isolates. Similarly, cold sensitive isolates were more likely to be sensitive to the other stresses. Cold tolerant isolates had shorter (p=0.012) lag phases...

  16. Expression of TaWRKY44, a wheat WRKY gene, in transgenic tobacco confers multiple abiotic stress tolerances

    Directory of Open Access Journals (Sweden)

    Xiatian eWang

    2015-08-01

    Full Text Available The WRKY transcription factors have been reported to be involved in various plant physiological and biochemical processes. In this study, we successfully assembled ten unigenes from expressed sequence tags (ESTs of wheat and designated them as TaWRKY44–TaWRKY53, respectively. Among these genes, a subgroup I gene, TaWRKY44, was found to be upregulated by treatments with PEG6000, NaCl, 4°C, abscisic acid (ABA, H2O2 and gibberellin (GA. The TaWRKY44-GFP fusion protein was localized to the nucleus of onion epidermal cells, and TaWRKY44 was able to bind to the core DNA sequences of TTGACC and TTAACC in yeast. The N-terminal of TaWRKY44 showed transcriptional activation activity. Expression of TaWRKY44 in tobacco plants conferred drought and salt tolerance and transgenic tobacco exhibited a higher survival rate, relative water content (RWC, soluble sugar, proline and superoxide dismutase (SOD content, as well as higher activities of catalase (CAT and peroxidase (POD, but less ion leakage (IL, lower contents of malondialdehyde (MDA, and H2O2. In addition, expression of TaWRKY44 also increased the seed germination rate in the transgenic lines under osmotic stress conditions while exhibiting a lower H2O2 content and higher SOD, CAT and POD activities. Expression of TaWRKY44 upregulated the expression of some reactive oxygen species (ROS-related genes and stress-responsive genes in tobacco under osmotic stresses. These data demonstrate that TaWRKY44 may act as a positive regulator in drought/salt/osmotic stress responses by either efficient ROS elimination through direct or indirect activation of the cellular antioxidant systems or activation of stress-associated gene expression.

  17. Enhanced tolerance to stretch-induced performance degradation of stretchable MnO2-based supercapacitors.

    Science.gov (United States)

    Huang, Yan; Huang, Yang; Meng, Wenjun; Zhu, Minshen; Xue, Hongtao; Lee, Chun-Sing; Zhi, Chunyi

    2015-02-04

    The performance of many stretchable electronics, such as energy storage devices and strain sensors, is highly limited by the structural breakdown arising from the stretch imposed. In this article, we focus on a detailed study on materials matching between functional materials and their conductive substrate, as well as enhancement of the tolerance to stretch-induced performance degradation of stretchable supercapacitors, which are essential for the design of a stretchable device. It is revealed that, being widely utilized as the electrode material of the stretchable supercapacitor, metal oxides such as MnO2 nanosheets have serious strain-induced performance degradation due to their rigid structure. In comparison, with conducting polymers like a polypyrrole (PPy) film as the electrochemically active material, the performance of stretchable supercapacitors can be well preserved under strain. Therefore, a smart design is to combine PPy with MnO2 nanosheets to achieve enhanced tolerance to strain-induced performance degradation of MnO2-based supercapacitors, which is realized by fabricating an electrode of PPy-penetrated MnO2 nanosheets. The composite electrodes exhibit a remarkable enhanced tolerance to strain-induced performance degradation with well-preserved performance over 93% under strain. The detailed morphology and electrochemical impedance variations are investigated for the mechanism analyses. Our work presents a systematic investigation on the selection and matching of electrode materials for stretchable supercapacitors to achieve high performance and great tolerance to strain, which may guide the selection of functional materials and their substrate materials for the next-generation of stretchable electronics.

  18. 6th International Conference in Methodologies and intelligent Systems for Technology Enhanced Learning

    CERN Document Server

    Prieta, Fernando; Mascio, Tania; Gennari, Rosella; Rodríguez, Javier; Vittorini, Pierpaolo

    2016-01-01

    The 6th International Conference in Methodologies and intelligent Systems for Technology Enhanced Learning held in Seville (Spain) is host by the University of Seville from 1st to 3rd June, 2016. The 6th edition of this conference expands the topics of the evidence-based TEL workshops series in order to provide an open forum for discussing intelligent systems for TEL, their roots in novel learning theories, empirical methodologies for their design or evaluation, stand-alone solutions or web-based ones. It intends to bring together researchers and developers from industry, the education field and the academic world to report on the latest scientific research, technical advances and methodologies.

  19. Integrated phospholipidomics and transcriptomics analysis of Saccharomyces cerevisiae with enhanced tolerance to a mixture of acetic acid, furfural, and phenol

    Science.gov (United States)

    A mixture of acetic acid, furfural and phenol (AFP), three representative lignocellulose derived inhibitors, significantly inhibited the growth and bioethanol production of Saccharomyces cerevisiae. In order to uncover mechanisms behind the enhanced tolerance of an inhibitor-tolerant S.cerevisiae s...

  20. Enhanced development of dispositional tolerance to methadone by desipramine given together with methadone

    International Nuclear Information System (INIS)

    Liu, S.J.; Wang, R.I.H.

    1985-01-01

    Rats given 2-day oral administration of methadone (15 mg/kg, twice on day 1 and once on day 2) by gastric tube developed dispositional tolerance to methadone analgesia as demonstrated by a decrease in analgesic response and by an increase in methadone metabolism. The increased metabolism of methadone was evidenced by a decrease in brain concentration of 14 C-methadone and increases in the percentages of total 14 C in liver or urine as 14 C-water-soluble metabolites ( 14 C-WSM) after the rats were challenged with a test dose of 14 C-methadone. Two-day pretreatment with a combination of desipramine (DMI) (10 mg/kg, ip) and methadone (15 mg/kg, po) enhanced the development of dispositional tolerance to methadone analgesia which was evidenced by a greater decrease in the brain concentration of methadone and a greater increase in methadone metabolism as compared to those changes in rats pretreated with only methadone. Repeated treatment with DMI alone neither decreased the analgesic effect of methadone nor stimulated methadone metabolism. It is suggested that DMI given together with methadone promoted the induction of methadone metabolism in the liver by prolonging the enzyme-stimulating state of methadone, thus enhancing the development of dispositional tolerance to methadone. 20 references, 1 figure, 1 table

  1. Enhanced salt tolerance of transgenic poplar plants expressing a manganese superoxide dismutase from Tamarix androssowii.

    Science.gov (United States)

    Wang, Yu Cheng; Qu, Guan Zheng; Li, Hong Yan; Wu, Ying Jie; Wang, Chao; Liu, Gui Feng; Yang, Chuan Ping

    2010-02-01

    Superoxide dismutases (SODs) play important role in stress tolerance of plants. In this study, an MnSOD gene (TaMnSOD) from Tamarix androssowii, under the control of the CaMV35S promoter, was introduced into poplar (Populus davidiana x P. bolleana). The physiological parameters, including SOD activity, malondialdehyde (MDA) content, relative electrical conductivity (REC) and relative weight gain, of transgenic lines and wild type (WT) plants, were measured and compared. The results showed that SOD activity was enhanced in transgenic plants, and the MDA content and REC were significantly decreased compared to WT plants when exposed to NaCl stress. In addition, the relative weight gains of the transgenic plants were 8- to 23-fold of those observed for WT plants after NaCl stress for 30 days. The data showed that the SOD activities that increased in transgenic lines are 1.3-4-folds of that increased in the WT plant when exposed to NaCl stress. Our analysis showed that increases in SOD activities as low as 0.15-fold can also significantly enhance salt tolerance in transgenic plants, suggesting an important role of increased SOD activity in plant salt tolerance

  2. Overexpression of a bacterial mercury transporter MerT in Arabidopsis enhances mercury tolerance.

    Science.gov (United States)

    Xu, Sheng; Sun, Bin; Wang, Rong; He, Jia; Xia, Bing; Xue, Yong; Wang, Ren

    2017-08-19

    The phytoremediation by using of green plants in the removal of environmental pollutant is an environment friendly, green technology that is cost effective and energetically inexpensive. By using Agrobacterium-mediated gene transfer, we generated transgenic Arabidopsis plants ectopically expressing mercuric transport protein gene (merT) from Pseudomonas alcaligenes. Compared with wild-type (WT) plants, overexpressing PamerT in Arabidopsis enhanced the tolerance to HgCl 2 . Further results showed that the enhanced total activities or corresponding transcripts of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT) and guaiacol peroxidase (POD) were observed in transgenic Arabidopsis under HgCl 2 stress. These results were confirmed by the alleviation of oxidative damage, as indicated by the decrease of thiobarbituric acid reactive substances (TBARS) contents and reactive oxygen species (ROS) accumulation. In addition, localization analysis of PaMerT in Arabidopsis protoplast showed that it is likely to be associated with vacuole. In all, PamerT increased mercury (Hg) tolerance in transgenic Arabidopsis, and decreased production of Hg-induced ROS, thereby protecting plants from oxidative damage. The present study has provided further evidence that bacterial MerT plays an important role in the plant tolerance to HgCl 2 and in reducing the production of ROS induced by HgCl 2 . Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Glycinebetaine synthesizing transgenic potato plants exhibit enhanced tolerance to salt and cold stresses

    International Nuclear Information System (INIS)

    Ahmad, R.; Hussain, J.

    2014-01-01

    Abiotic stresses are the most important contributors towards low productivity of major food crops. Various attempts have been made to enhance abiotic stress tolerance of crop plants by classical breeding and genetic transformation. Genetic transformation with glycinebetaine (GB) synthesizing enzymes' gene(s) in naturally non accumulating plants has resulted in enhanced tolerance against variety of abiotic stresses. Present study was aimed to evaluate the performance of GB synthesizing transgenic potato plants against salt and cold stresses. Transgenic potato plants were challenged against salt and cold stresses at whole plant level. Transgenic lines were characterized to determine the transgene copy number. Different parameters like integrity, chlorophyll contents, tuber yield and vegetative biomass were studied to monitor the stress tolerance of transgenic potato plants. The results were compared with Non-transgenic (NT) plants and statistically analyzed to evaluate significant differences. Multi-copy insertion of expression cassette was found in both transgenic lines. Upon salt stress, transgenic plants maintained better growth as compared to NT plants. The tuber yield of transgenic plants was significantly greater than NT plants in salt stress. Transgenic plants showed improved membrane integrity against cold stress by depicting appreciably reduced ion leakage as compared to NT plants. Moreover, transgenic plants showed significantly less chlorophyll bleaching than NT plants upon cold stress. In addition, NT plants accumulated significantly less biomass, and yielded fewer tubers as compared to transgenic plants after cold stress treatment. The study will be a committed step for field evaluation of transgenic plants with the aim of commercialization. (author)

  4. Co-expression of G2-EPSPS and glyphosate acetyltransferase GAT genes conferring high tolerance to glyphosate in soybean

    OpenAIRE

    Guo, Bingfu; Guo, Yong; Hong, Huilong; Jin, Longguo; Zhang, Lijuan; Chang, Ru-Zhen; Lu, Wei; Lin, Min; Qiu, Li-Juan

    2015-01-01

    Glyphosate is a widely used non-selective herbicide with broad spectrum of weed control around the world. At present, most of the commercial glyphosate tolerant soybeans utilize glyphosate tolerant gene CP4-EPSPS or glyphosate acetyltransferase gene GAT separately. In this study, both glyphosate tolerant gene G2-EPSPS and glyphosate degraded gene GAT were co-transferred into soybean and transgenic plants showed high tolerance to glyphosate. Molecular analysis including PCR, Sothern blot, qRT-...

  5. Difference in root K+ retention ability and reduced sensitivity of K+-permeable channels to reactive oxygen species confer differential salt tolerance in three Brassica species.

    Science.gov (United States)

    Chakraborty, Koushik; Bose, Jayakumar; Shabala, Lana; Shabala, Sergey

    2016-08-01

    Brassica species are known to possess significant inter and intraspecies variability in salinity stress tolerance, but the cell-specific mechanisms conferring this difference remain elusive. In this work, the role and relative contribution of several key plasma membrane transporters to salinity stress tolerance were evaluated in three Brassica species (B. napus, B. juncea, and B. oleracea) using a range of electrophysiological assays. Initial root growth assay and viability staining revealed that B. napus was most tolerant amongst the three species, followed by B. juncea and B. oleracea At the mechanistic level, this difference was conferred by at least three complementary physiological mechanisms: (i) higher Na(+) extrusion ability from roots resulting from increased expression and activity of plasma membrane SOS1-like Na(+)/H(+) exchangers; (ii) better root K(+) retention ability resulting from stress-inducible activation of H(+)-ATPase and ability to maintain more negative membrane potential under saline conditions; and (iii) reduced sensitivity of B. napus root K(+)-permeable channels to reactive oxygen species (ROS). The last two mechanisms played the dominant role and conferred most of the differential salt sensitivity between species. Brassica napus plants were also more efficient in preventing the stress-induced increase in GORK transcript levels and up-regulation of expression of AKT1, HAK5, and HKT1 transporter genes. Taken together, our data provide the mechanistic explanation for differential salt stress sensitivity amongst these species and shed light on transcriptional and post-translational regulation of key ion transport systems involved in the maintenance of the root plasma membrane potential and cytosolic K/Na ratio as a key attribute for salt tolerance in Brassica species. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  6. Application of the Concept of Intrusion Tolerant System for Evaluating Cyber Security Enhancements

    International Nuclear Information System (INIS)

    Lee, Chanyoung; Seong, Poong Hyun

    2016-01-01

    One of the major problems is that nuclear industry is in very early stage in dealing with cyber security issues. It is because that cyber security has received less attention compared to other safety problems. In addition, late adoption of digital I and C systems has resulted in lower level of cyber security advancements in nuclear industry than ones in other industries. For the cyber security of NPP I and C systems, many regulatory documents, guides and standards were already published. These documents include cyber security plans, methods for cyber security assessments and comprehensive set of security controls. However, methods which can help assess how much security is improved if a specific security control is applied are not included in these documents. Hence, NPP I and C system designers may encounter difficulties when trying to apply security controls with limited structure and cost. In order to provide useful information about cyber security issues including cyber security enhancements, this paper suggests a framework to evaluate how much cyber security is improved when a specific cyber security enhancement is applied in NPPs. In order to provide useful information about cyber security issues including cyber security enhancements, this paper suggests a framework to evaluate how much cyber security is improved when a specific cyber security enhancement is applied in NPPs. The extent of cyber security improvement caused by security enhancement was defined as reduction ratio of the failure probability to secure the system from cyber-attack as Eq.1. The concept of 'intrusion tolerant system' was applied to not only prevent cyber-attacks but also limit the extent of damage in this study. For applying the concept of intrusion tolerant system to NPP, the event tree was constructed with some assumptions. Cyber security improvement caused by cyber security enhancement can be estimated as Eq.3. By comparing current system to the enhanced system, it is possible to

  7. Application of the Concept of Intrusion Tolerant System for Evaluating Cyber Security Enhancements

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chanyoung; Seong, Poong Hyun [KAIST, Daejeon (Korea, Republic of)

    2016-10-15

    One of the major problems is that nuclear industry is in very early stage in dealing with cyber security issues. It is because that cyber security has received less attention compared to other safety problems. In addition, late adoption of digital I and C systems has resulted in lower level of cyber security advancements in nuclear industry than ones in other industries. For the cyber security of NPP I and C systems, many regulatory documents, guides and standards were already published. These documents include cyber security plans, methods for cyber security assessments and comprehensive set of security controls. However, methods which can help assess how much security is improved if a specific security control is applied are not included in these documents. Hence, NPP I and C system designers may encounter difficulties when trying to apply security controls with limited structure and cost. In order to provide useful information about cyber security issues including cyber security enhancements, this paper suggests a framework to evaluate how much cyber security is improved when a specific cyber security enhancement is applied in NPPs. In order to provide useful information about cyber security issues including cyber security enhancements, this paper suggests a framework to evaluate how much cyber security is improved when a specific cyber security enhancement is applied in NPPs. The extent of cyber security improvement caused by security enhancement was defined as reduction ratio of the failure probability to secure the system from cyber-attack as Eq.1. The concept of 'intrusion tolerant system' was applied to not only prevent cyber-attacks but also limit the extent of damage in this study. For applying the concept of intrusion tolerant system to NPP, the event tree was constructed with some assumptions. Cyber security improvement caused by cyber security enhancement can be estimated as Eq.3. By comparing current system to the enhanced system, it is

  8. Plant Growth-Promoting Rhizobacteria Enhance Salinity Stress Tolerance in Okra through ROS-Scavenging Enzymes

    Directory of Open Access Journals (Sweden)

    Sheikh Hasna Habib

    2016-01-01

    Full Text Available Salinity is a major environmental stress that limits crop production worldwide. In this study, we characterized plant growth-promoting rhizobacteria (PGPR containing 1-aminocyclopropane-1-carboxylate (ACC deaminase and examined their effect on salinity stress tolerance in okra through the induction of ROS-scavenging enzyme activity. PGPR inoculated okra plants exhibited higher germination percentage, growth parameters, and chlorophyll content than control plants. Increased antioxidant enzyme activities (SOD, APX, and CAT and upregulation of ROS pathway genes (CAT, APX, GR, and DHAR were observed in PGPR inoculated okra plants under salinity stress. With some exceptions, inoculation with Enterobacter sp. UPMR18 had a significant influence on all tested parameters under salt stress, as compared to other treatments. Thus, the ACC deaminase-containing PGPR isolate Enterobacter sp. UPMR18 could be an effective bioresource for enhancing salt tolerance and growth of okra plants under salinity stress.

  9. Multiple cold resistance loci confer the high cold tolerance adaptation of Dongxiang wild rice (Oryza rufipogon) to its high-latitude habitat.

    Science.gov (United States)

    Mao, Donghai; Yu, Li; Chen, Dazhou; Li, Lanying; Zhu, Yuxing; Xiao, Yeqing; Zhang, Dechun; Chen, Caiyan

    2015-07-01

    Dongxiang wild rice is phylogenetically close to temperate japonica and contains multiple cold resistance loci conferring its adaptation to high-latitude habitat. Understanding the nature of adaptation in wild populations will benefit crop breeding in the development of climate-resilient crop varieties. Dongxiang wild rice (DXWR), the northernmost common wild rice known, possesses a high degree of cold tolerance and can survive overwintering in its native habitat. However, to date, it is still unclear how DXWR evolved to cope with low-temperature environment, resulting in limited application of DXWR in rice breeding programs. In this study, we carried out both QTL mapping and phylogenetic analysis to discern the genetic mechanism underlying the strong cold resistance. Through a combination of interval mapping and single locus analysis in two genetic populations, at least 13 QTLs for seedling cold tolerance were identified in DXWR. A phylogenetic study using both genome-wide InDel markers and markers associated with cold tolerance loci reveals that DXWR belongs to the Or-III group, which is most closely related to cold-tolerant Japonica rice rather than to the Indica cultivars that are predominant in the habitat where DXWR grows. Our study paves the way toward an understanding of the nature of adaptation to a northern habitat in O. rufipogon. The QTLs identified in DXWR in this study will be useful for molecular breeding of cold-tolerant rice.

  10. The Multifarious PGPR Serratia marcescens CDP-13 Augments Induced Systemic Resistance and Enhanced Salinity Tolerance of Wheat (Triticum aestivum L..

    Directory of Open Access Journals (Sweden)

    Rajnish Prakash Singh

    Full Text Available The present study demonstrates the plant growth promoting (PGP potential of a bacterial isolate CDP-13 isolated from 'Capparis decidua' plant, and its ability to protect plants from the deleterious effect of biotic and abiotic stressors. Based on 16S rRNA gene sequence analysis, the isolate was identified as Serratia marcescens. Among the PGP traits, the isolate was found to be positive for ACC deaminase activity, phosphate solubilization, production of siderophore, indole acetic acid production, nitrogen fixation, and ammonia production. CDP-13 showed growth at an increased salt (NaCl concentration of up to 6%, indicating its potential to survive and associate with plants growing in saline soil. The inoculation of S. marcescens enhanced the growth of wheat plant under salinity stress (150-200 mM. It significantly reduced inhibition of plant growth (15 to 85% caused by salt stressors. Application of CDP-13 also modulated concentration (20 to 75% of different osmoprotectants (proline, malondialdehyde, total soluble sugar, total protein content, and indole acetic acid in plants suggesting its role in enabling plants to tolerate salt stressors. In addition, bacterial inoculation also reduced the disease severity caused by fungal infection, which illustrated its ability to confer induced systemic resistance (ISR in host plants. Treatment of wheat plants with the test organism caused alteration in anti-oxidative enzymes activities (Superoxide dismutase, Catalase, and Peroxidase under various salinity levels, and therefore minimizes the salinity-induced oxidative damages to the plants. Colonization efficiency of strain CDP-13 was confirmed by CFU count, epi-fluorescence microscopy, and ERIC-PCR-based DNA fingerprinting approach. Hence, the study indicates that bacterium CDP-13 enhances plant growth, and has potential for the amelioration of salinity stress in wheat plants. Likewise, the results also provide insights into biotechnological approaches to

  11. Unwinding after high salinity stress: Pea DNA helicase 45 over- expression in tobacco confers high salinity tolerance without affecting yield (abstract)

    International Nuclear Information System (INIS)

    Tuteja, N.

    2005-01-01

    Soil salinity is an increasing threat for agriculture and is a major factor in reducing plant productivity; therefore, it is necessary to obtain salinity-tolerant varieties. A typical characteristic of soil salinity is the induction of multiple stress- inducible genes. Some of the genes encoding osmolytes, ion channels or enzymes are able to confer salinity-tolerant phenotypes when transferred to sensitive plants. As salinity stress affects the cellular gene-expression machinery, it is evident that molecules involved in nucleic acid processing including helicases, are likely to be affected as well. DNA helicases unwind duplex DNA and are involved in replication, repair, recombination and transcription while RNA helicases unfold the secondary structures in RNA and are involved in transcription, ribosome biogenesis and translation initiation. We have earlier reported the isolation of a pea DNA helicase 45 (PDH45) that exhibits striking homology with eIF-4A (Plant J. 24:219-230,2000). Here we report that PDH45 mRNA is induced in pea seedlings in response to high salt and its over- expression driven by a constitutive CAMV-355-promoter in tobacco plants confers salinity tolerance, thus suggesting a new pathway for manipulating stress tolerance in crop plants. The T0 transgenic plants showed high-levels of PDH45 protein in normal and stress conditions, as compared to wild type (WT) plants. The T0 transgenics also showed tolerance to high salinity as tested by a leaf disc senescence assay. The T1 transgenics were able to grow to maturity and set normal viable seeds under continuous salinity stress, without any reduction in plant yield, in terms of seed weight. Measurement of Na/sup +/ ions in different parts of the plant showed higher accumulation in the old leaves and negligible in seeds of T1 transgenic lines as compared with the WT plants. The possible mechanism of salinity tolerance will be discussed. Over-expression of PDH45 provides a possible example of the

  12. Enhancement of salinity tolerance in wheat through soil applied calcium carbide

    Directory of Open Access Journals (Sweden)

    Z. Ahmad

    2009-05-01

    Full Text Available Calcium carbide (CaC2 has been reported to increase growth and yield of crops under normal soil conditions. This study assessed its capacity to enhance salinity tolerance in wheat (Triticum aestivum L.; cv- 1076 under saline conditions. Three levels of salinity: 0, 7 and 12 dS m-1 were created using NaCl. Nitrogen, phosphorus and potassium were applied as ammonium sulphate and KH2PO4 at 50 and 25 mg kg-1 soil, respectively. The encapsulated calcium carbide (ECC at 45 mg kg-1 soil produced 1291.8 µmols of acetylene (C2H2 and 257.5 µmols of its product ethylene (C2H4 over a period of 80 days. The results of the pot study indicated that ECC increased the weight of spike, weight of grains per spike, length of spike, total water concentration, root/shoot ratio and relative leaf water content up to 17, 23, 22, 35, 33 and 3%, respectively, over the control. Contrary to this, salinity (at 12 dS m -1 decreased all these parameters up to 68, 60, 26, 30, 28 and 8%, respectively, compared to the control. These results indicate that ECC enhances salinity tolerance in wheat by improving uptake of nutrients through enhanced root growth, increased hydraulic conductivity and hormonal action of ethylene released by ECC. Total water concentration was positively correlated (0.73 with grains spike-1 at P ≤ 0.05

  13. Overexpression of AtEDT1/HDG11 in Chinese Kale (Brassica oleracea var. alboglabra) Enhances Drought and Osmotic Stress Tolerance.

    Science.gov (United States)

    Zhu, Zhangsheng; Sun, Binmei; Xu, Xiaoxia; Chen, Hao; Zou, Lifang; Chen, Guoju; Cao, Bihao; Chen, Changming; Lei, Jianjun

    2016-01-01

    Plants are constantly challenged by environmental stresses, including drought and high salinity. Improvement of drought and osmotic stress tolerance without yield decrease has been a great challenge in crop improvement. The Arabidopsis ENHANCED DROUGHT TOLERANCE1/HOMEODOMAIN GLABROUS11 (AtEDT1/HDG11), a protein of the class IV HD-Zip family, has been demonstrated to significantly improve drought tolerance in Arabidopsis, rice, and pepper. Here, we report that AtEDT1/HDG11 confers drought and osmotic stress tolerance in the Chinese kale. AtEDT1/HDG11-overexpression lines exhibit auxin-overproduction phenotypes, such as long hypocotyls, tall stems, more root hairs, and a larger root system architecture. Compared with the untransformed control, transgenic lines have significantly reduced stomatal density. In the leaves of transgenic Chinese kale plants, proline (Pro) content and reactive oxygen species-scavenging enzyme activity was significantly increased after drought and osmotic stress, particularly compared to wild kale. More importantly, AtEDT1/HDG11-overexpression leads to abscisic acid (ABA) hypersensitivity, resulting in ABA inhibitor germination and induced stomatal closure. Consistent with observed phenotypes, the expression levels of auxin, ABA, and stress-related genes were also altered under both normal and/or stress conditions. Further analysis showed that AtEDT1/HDG11, as a transcription factor, can target the auxin biosynthesis gene YUCC6 and ABA response genes ABI3 and ABI5. Collectively, our results provide a new insight into the role of AtEDT1/HDG11 in enhancing abiotic stress resistance through auxin- and ABA-mediated signaling response in Chinese kale.

  14. Overexpression of DgWRKY4 Enhances Salt Tolerance in Chrysanthemum Seedlings

    Directory of Open Access Journals (Sweden)

    Ke Wang

    2017-09-01

    Full Text Available High salinity seriously affects the production of chrysanthemum, so improving the salt tolerance of chrysanthemum becomes the focus and purpose of our research. The WRKY transcription factor (TF family is highly associated with a number of processes of abiotic stress responses. We isolated DgWRKY4 from Dendranthema grandiflorum, and a protein encoded by this new gene contains two highly conserved WRKY domains and two C2H2 zinc-finger motifs. Then, we functionally characterized that DgWRKY4 was induced by salt, and DgWRKY4 overexpression in chrysanthemum resulted in increased tolerance to high salt stress compared to wild-type (WT. Under salt stress, the transgenic chrysanthemum accumulated less malondialdehyde, hydrogen peroxide (H2O2, and superoxide anion (O2− than WT, accompanied by more proline, soluble sugar, and activities of antioxidant enzymes than WT; in addition, a stronger photosynthetic capacity and a series of up-regulated stress-related genes were also found in transgenic chrysanthemum. All results demonstrated that DgWRKY4 is a positive regulatory gene responding to salt stress, via advancing photosynthetic capacity, promoting the operation of reactive oxygen species-scavenging system, maintaining membrane stability, enhancing the osmotic adjustment, and up-regulating transcript levels of stress-related genes. So, DgWRKY4 can serve as a new candidate gene for salt-tolerant plant breeding.

  15. Overexpression of a Pathogenesis-Related Protein 10 Enhances Biotic and Abiotic Stress Tolerance in Rice

    Directory of Open Access Journals (Sweden)

    Jingni Wu

    2016-12-01

    Full Text Available Pathogenesis-related proteins play multiple roles in plant development and biotic and abiotic stress tolerance. Here, we characterize a rice defense related gene named “jasmonic acid inducible pathogenesis-related class 10” (JIOsPR10 to gain an insight into its functional properties. Semi-quantitative RT-PCR analysis showed up-regulation of JIOsPR10 under salt and drought stress conditions. Constitutive over-expression JIOsPR10 in rice promoted shoot and root development in transgenic plants, however, their productivity was unaltered. Further experiments exhibited that the transgenic plants showed reduced susceptibility to rice blast fungus, and enhanced salt and drought stress tolerance as compared to the wild type. A comparative proteomic profiling of wild type and transgenic plants showed that overexpression of JIOsPR10 led to the differential modulation of several proteins mainly related with oxidative stresses, carbohydrate metabolism, and plant defense. Taken together, our findings suggest that JIOsPR10 plays important roles in biotic and abiotic stresses tolerance probably by activation of stress related proteins.

  16. Enhanced water stress tolerance of transgenic maize plants over-expressing LEA Rab28 gene.

    Science.gov (United States)

    Amara, Imen; Capellades, Montserrat; Ludevid, M Dolors; Pagès, Montserrat; Goday, Adela

    2013-06-15

    Late Embryogenesis Abundant (LEA) proteins participate in plant stress responses and contribute to the acquisition of desiccation tolerance. In this report Rab28 LEA gene has been over-expressed in maize plants under a constitutive maize promoter. The expression of Rab28 transcripts led to the accumulation and stability of Rab28 protein in the transgenic plants. Native Rab28 protein is localized to nucleoli in wild type maize embryo cells; here we find by whole-mount immunocytochemistry that in root cells of Rab28 transgenic and wild-type plants the protein is also associated to nucleolar structures. Transgenic plants were tested for stress tolerance and resulted in sustained growth under polyethyleneglycol (PEG)-mediated dehydration compared to wild-type controls. Under osmotic stress transgenic seedlings showed increased leaf and root areas, higher relative water content (RWC), reduced chlorophyll loss and lower Malondialdehyde (MDA) production in relation to wild-type plants. Moreover, transgenic seeds exhibited higher germination rates than wild-type seeds under water deficit. Overall, our results highlight the presence of transgenic Rab28 protein in nucleolar structures and point to the potential of group 5 LEA Rab28 gene as candidate to enhance stress tolerance in maize plants. Copyright © 2013 Elsevier GmbH. All rights reserved.

  17. Development of Cr cold spray–coated fuel cladding with enhanced accident tolerance

    Directory of Open Access Journals (Sweden)

    Martin Ševeček

    2018-03-01

    Full Text Available Accident-tolerant fuels (ATFs are currently of high interest to researchers in the nuclear industry and in governmental and international organizations. One widely studied accident-tolerant fuel concept is multilayer cladding (also known as coated cladding. This concept is based on a traditional Zr-based alloy (Zircaloy-4, M5, E110, ZIRLO etc. serving as a substrate. Different protective materials are applied to the substrate surface by various techniques, thus enhancing the accident tolerance of the fuel. This study focuses on the results of testing of Zircaloy-4 coated with pure chromium metal using the cold spray (CS technique. In comparison with other deposition methods, e.g., Physical vapor deposition (PVD, laser coating, or Chemical vapor deposition techniques (CVD, the CS technique is more cost efficient due to lower energy consumption and high deposition rates, making it more suitable for industry-scale production. The Cr-coated samples were tested at different conditions (500°C steam, 1200°C steam, and Pressurized water reactor (PWR pressurization test and were precharacterized and postcharacterized by various techniques, such as scanning electron microscopy, Energy-dispersive X-ray spectroscopy (EDX, or nanoindentation; results are discussed. Results of the steady-state fuel performance simulations using the Bison code predicted the concept's feasibility. It is concluded that CS Cr coating has high potential benefits but requires further optimization and out-of-pile and in-pile testing. Keywords: Accident-Tolerant Fuel, Chromium, Cladding, Coating, Cold Spray, Nuclear Fuel

  18. Tolerance to quaternary ammonium compound disinfectants may enhance growth of Listeria monocytogenes in the food industry.

    Science.gov (United States)

    Møretrø, Trond; Schirmer, Bjørn C T; Heir, Even; Fagerlund, Annette; Hjemli, Pernille; Langsrud, Solveig

    2017-01-16

    The antibacterial effect of disinfectants is crucial for the control of Listeria monocytogenes in food processing environments. Tolerance of L. monocytogenes to sublethal levels of disinfectants based on quaternary ammonium compounds (QAC) is conferred by the resistance determinants qacH and bcrABC. The presence and distribution of these genes have been anticipated to have a role in the survival and growth of L. monocytogenes in food processing environments where QAC based disinfectants are in common use. In this study, a panel of 680 L. monocytogenes from nine Norwegian meat- and salmon processing plants were grouped into 36 MLVA profiles. The presence of qacH and bcrABC was determined in 101 isolates from the 26 most common MLVA profiles. Five MLVA profiles contained qacH and two contained bcrABC. Isolates with qacH and bcrABC showed increased tolerance to the QAC Benzalkonium chloride (BC), with minimal inhibitory concentrations (MICs) of 5-12, 10-13 and 100ppm). A sample with lower BC concentrations (14ppm of chain length C-12 and 2.7ppm of chain length C-14) inhibited growth of L. monocytogenes not containing bcrABC or qacH, compared to strains with these genes. The study has shown that L. monocytogenes harbouring the QAC resistance genes qacH and bcrABC are prevalent in the food industry and that residuals of QAC may be present in concentrations after sanitation in the industry that result in a growth advantage for bacteria with such resistance genes. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  19. Ectopically expressing MdPIP1;3, an aquaporin gene, increased fruit size and enhanced drought tolerance of transgenic tomatoes.

    Science.gov (United States)

    Wang, Lin; Li, Qing-Tian; Lei, Qiong; Feng, Chao; Zheng, Xiaodong; Zhou, Fangfang; Li, Lingzi; Liu, Xuan; Wang, Zhi; Kong, Jin

    2017-12-19

    Water deficit severely reduces apple growth and production, is detrimental to fruit quality and size. This problem is exacerbated as global warming is implicated in producing more severe drought stress. Thus water-efficiency has becomes the major target for apple breeding. A desired apple tree can absorb and transport water efficiently, which not only confers improved drought tolerance, but also guarantees fruit size for higher income returns. Aquaporins, as water channels, control water transportation across membranes and can regulate water flow by changing their amount and activity. The exploration of molecular mechanism of water efficiency and the gene wealth will pave a way for molecular breeding of drought tolerant apple tree. In the current study, we screened out a drought inducible aquaporin gene MdPIP1;3, which specifically enhanced its expression during fruit expansion in 'Fuji' apple (Malus domestica Borkh. cv. Red Fuji). It localized on plasma membranes and belonged to PIP1 subfamily. The tolerance to drought stress enhanced in transgenic tomato plants ectopically expressing MdPIP1;3, showing that the rate of losing water in isolated transgenic leaves was slower than wild type, and stomata of transgenic plants closed sensitively to respond to drought compared with wild type. Besides, length and diameter of transgenic tomato fruits increased faster than wild type, and in final, fruit sizes and fresh weights of transgenic tomatoes were bigger than wild type. Specially, in cell levels, fruit cell size from transgenic tomatoes was larger than wild type, showing that cell number per mm 2 in transgenic fruits was less than wild type. Altogether, ectopically expressing MdPIP1;3 enhanced drought tolerance of transgenic tomatoes partially via reduced water loss controlled by stomata closure in leaves. In addition, the transgenic tomato fruits are larger and heavier with larger cells via more efficient water transportation across membranes. Our research will

  20. Overexpression of snapdragon Delila (Del) gene in tobacco enhances anthocyanin accumulation and abiotic stress tolerance.

    Science.gov (United States)

    Naing, Aung Htay; Park, Kyeung Il; Ai, Trinh Ngoc; Chung, Mi Young; Han, Jeung Sul; Kang, Young-Wha; Lim, Ki Byung; Kim, Chang Kil

    2017-03-23

    Rosea1 (Ros1) and Delila (Del) co-expression controls anthocyanin accumulation in snapdragon flowers, while their overexpression in tomato strongly induces anthocyanin accumulation. However, little data exist on how Del expression alone influences anthocyanin accumulation. In tobacco (Nicotiana tabacum 'Xanthi'), Del expression enhanced leaf and flower anthocyanin production through regulating NtCHS, NtCHI, NtF3H, NtDFR, and NtANS transcript levels. Transgenic lines displayed different anthocyanin colors (e.g., pale red: T 0 -P, red: T 0 -R, and strong red: T 0 -S), resulting from varying levels of biosynthetic gene transcripts. Under salt stress, the T 2 generation had higher total polyphenol content, radical (DPPH, ABTS) scavenging activities, antioxidant-related gene expression, as well as overall greater salt and drought tolerance than wild type (WT). We propose that Del overexpression elevates transcript levels of anthocyanin biosynthetic and antioxidant-related genes, leading to enhanced anthocyanin production and antioxidant activity. The resultant increase of anthocyanin and antioxidant activity improves abiotic stress tolerance.

  1. Organic amendments enhance Pb tolerance and accumulation during micropropagation of Daphne jasminea.

    Science.gov (United States)

    Wiszniewska, Alina; Muszyńska, Ewa; Hanus-Fajerska, Ewa; Smoleń, Sylwester; Dziurka, Michał; Dziurka, Kinga

    2017-01-01

    The study investigated the effects of organic amendments: pineapple pulp (PP) and agar hydrolyzate (AH), on micropropagation and Pb bioaccumulation and tolerance in a woody shrub Daphne jasminea cultured in vitro. The amendments were analyzed for their content of carbohydrates, phenolic acids, and phytohormones and added at a dose of 10 mL L -1 to the medium containing 1.0 mM lead nitrate. Micropropagation coefficient increased by 10.2-16.6 % in PP and AH variants, respectively. Growth tolerance index increased by 22.9-31.8 % for the shoots and by 60.1-82.4 % for the roots. In the absence of Pb, the additives inhibited multiplication and growth of microplantlets. PP and AH facilitated Pb accumulation in plant organs, especially in the roots. PP enhanced bioconcentration factor and AH improved Pb translocation to the shoots. Adaptation to Pb was associated with increased accumulation of phenolics and higher radical scavenging activity. Medium supplementation, particularly with AH, enhanced antiradical activity of Pb-adapted lines but reduced the content of phenolic compounds. The study results indicated that supplementation with organic amendments may be beneficial in in vitro selection against lead toxicity.

  2. Enhancing bile tolerance improves survival and persistence of Bifidobacterium and Lactococcus in the murine gastrointestinal tract

    Directory of Open Access Journals (Sweden)

    Hill Colin

    2008-10-01

    Full Text Available Abstract Background The majority of commensal gastrointestinal bacteria used as probiotics are highly adapted to the specialised environment of the large bowel. However, unlike pathogenic bacteria; they are often inadequately equipped to endure the physicochemical stresses of gastrointestinal (GI delivery in the host. Herein we outline a patho-biotechnology strategy to improve gastric delivery and host adaptation of a probiotic strain Bifidobacterium breve UCC2003 and the generally regarded as safe (GRAS organism Lactococcus lactis NZ9000. Results In vitro bile tolerance of both strains was significantly enhanced (P Listeria monocytogenes bile resistance mechanism BilE. Strains harbouring bilE were also recovered at significantly higher levels (P n = 5, following oral inoculation. Furthermore, a B. breve strain expressing bilE demonstrated increased efficacy relative to the wild-type strain in reducing oral L. monocytogenes infection in mice. Conclusion Collectively the data indicates that bile tolerance can be enhanced in Bifidobacterium and Lactococcus species through rational genetic manipulation and that this can significantly improve delivery to and colonisation of the GI tract.

  3. Overexpression of Late Embryogenesis Abundant 14 enhances Arabidopsis salt stress tolerance

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Fengjuan, E-mail: jfj.5566@163.com; Qi, Shengdong, E-mail: zisexanwu@163.com; Li, Hui, E-mail: 332453593@qq.com; Liu, Pu, E-mail: banbaokezhan@163.com; Li, Pengcheng, E-mail: lpcsdau@163.com; Wu, Changai, E-mail: cawu@sdau.edu.cn; Zheng, Chengchao, E-mail: cczheng@sdau.edu.cn; Huang, Jinguang, E-mail: jghuang@sdau.edu.cn

    2014-11-28

    Highlights: • It is the first time to investigate the biological function of AtLEA14 in salt stress response. • AtLEA14 enhances the salt stress tolerance both in Arabidopsis and yeast. • AtLEA14 responses to salt stress by stabilizing AtPP2-B11, an E3 ligase, under normal or salt stress conditions. - Abstract: Late embryogenesis abundant (LEA) proteins are implicated in various abiotic stresses in higher plants. In this study, we identified a LEA protein from Arabidopsis thaliana, AtLEA14, which was ubiquitously expressed in different tissues and remarkably induced with increased duration of salt treatment. Subcellular distribution analysis demonstrated that AtLEA14 was mainly localized in the cytoplasm. Transgenic Arabidopsis and yeast overexpressing AtLEA14 all exhibited enhanced tolerance to high salinity. The transcripts of salt stress-responsive marker genes (COR15a, KIN1, RD29B and ERD10) were overactivated in AtLEA14 overexpressing lines compared with those in wild type plants under normal or salt stress conditions. In vivo and in vitro analysis showed that AtLEA14 could effectively stabilize AtPP2-B11, an important E3 ligase. These results suggested that AtLEA14 had important protective functions under salt stress conditions in Arabidopsis.

  4. Overexpression of Late Embryogenesis Abundant 14 enhances Arabidopsis salt stress tolerance

    International Nuclear Information System (INIS)

    Jia, Fengjuan; Qi, Shengdong; Li, Hui; Liu, Pu; Li, Pengcheng; Wu, Changai; Zheng, Chengchao; Huang, Jinguang

    2014-01-01

    Highlights: • It is the first time to investigate the biological function of AtLEA14 in salt stress response. • AtLEA14 enhances the salt stress tolerance both in Arabidopsis and yeast. • AtLEA14 responses to salt stress by stabilizing AtPP2-B11, an E3 ligase, under normal or salt stress conditions. - Abstract: Late embryogenesis abundant (LEA) proteins are implicated in various abiotic stresses in higher plants. In this study, we identified a LEA protein from Arabidopsis thaliana, AtLEA14, which was ubiquitously expressed in different tissues and remarkably induced with increased duration of salt treatment. Subcellular distribution analysis demonstrated that AtLEA14 was mainly localized in the cytoplasm. Transgenic Arabidopsis and yeast overexpressing AtLEA14 all exhibited enhanced tolerance to high salinity. The transcripts of salt stress-responsive marker genes (COR15a, KIN1, RD29B and ERD10) were overactivated in AtLEA14 overexpressing lines compared with those in wild type plants under normal or salt stress conditions. In vivo and in vitro analysis showed that AtLEA14 could effectively stabilize AtPP2-B11, an important E3 ligase. These results suggested that AtLEA14 had important protective functions under salt stress conditions in Arabidopsis

  5. Enhanced disease resistance and drought tolerance in transgenic rice plants overexpressing protein elicitors from Magnaporthe oryzae.

    Science.gov (United States)

    Wang, Zhenzhen; Han, Qiang; Zi, Qian; Lv, Shun; Qiu, Dewen; Zeng, Hongmei

    2017-01-01

    Exogenous application of the protein elicitors MoHrip1 and MoHrip2, which were isolated from the pathogenic fungus Magnaporthe oryzae (M. oryzae), was previously shown to induce a hypersensitive response in tobacco and to enhance resistance to rice blast. In this work, we successfully transformed rice with the mohrip1 and mohrip2 genes separately. The MoHrip1 and MoHrip2 transgenic rice plants displayed higher resistance to rice blast and stronger tolerance to drought stress than wild-type (WT) rice and the vector-control pCXUN rice. The expression of salicylic acid (SA)- and abscisic acid (ABA)-related genes was also increased, suggesting that these two elicitors may trigger SA signaling to protect the rice from damage during pathogen infection and regulate the ABA content to increase drought tolerance in transgenic rice. Trypan blue staining indicated that expressing MoHrip1 and MoHrip2 in rice plants inhibited hyphal growth of the rice blast fungus. Relative water content (RWC), water usage efficiency (WUE) and water loss rate (WLR) were measured to confirm the high capacity for water retention in transgenic rice. The MoHrip1 and MoHrip2 transgenic rice also exhibited enhanced agronomic traits such as increased plant height and tiller number.

  6. Ectopic overexpression of WsSGTL1, a sterol glucosyltransferase gene in Withania somnifera, promotes growth, enhances glycowithanolide and provides tolerance to abiotic and biotic stresses.

    Science.gov (United States)

    Saema, Syed; Rahman, Laiq Ur; Singh, Ruchi; Niranjan, Abhishek; Ahmad, Iffat Zareen; Misra, Pratibha

    2016-01-01

    Overexpression of sterol glycosyltransferase (SGTL1) gene of Withania somnifera showing its involvement in glycosylation of withanolide that leads to enhanced growth and tolerance to biotic and abiotic stresses. Withania somnifera is widely used in Ayurvedic medicines for over 3000 years due to its therapeutic properties. It contains a variety of glycosylated steroids called withanosides that possess neuroregenerative, adaptogenic, anticonvulsant, immunomodulatory and antioxidant activities. The WsSGTL1 gene specific for 3β-hydroxy position has a catalytic specificity to glycosylate withanolide and sterols. Glycosylation not only stabilizes the products but also alters their physiological activities and governs intracellular distribution. To understand the functional significance and potential of WsSGTL1 gene, transgenics of W. somnifera were generated using Agrobacterium tumefaciens-mediated transformation. Stable integration and overexpression of WsSGTL1 gene were confirmed by Southern blot analysis followed by quantitative real-time PCR. The WsGTL1 transgenic plants displayed number of alterations at phenotypic and metabolic level in comparison to wild-type plants which include: (1) early and enhanced growth with leaf expansion and increase in number of stomata; (2) increased production of glycowithanolide (majorly withanoside V) and campesterol, stigmasterol and sitosterol in glycosylated forms with reduced accumulation of withanolides (withaferin A, withanolide A and withanone); (3) tolerance towards biotic stress (100 % mortality of Spodoptera litura), improved survival capacity under abiotic stress (cold stress) and; (4) enhanced recovery capacity after cold stress, as indicated by better photosynthesis performance, chlorophyll, anthocyanin content and better quenching regulation of PSI and PSII. Our data demonstrate overexpression of WsSGTL1 gene which is responsible for increase in glycosylated withanolide and sterols, and confers better growth and

  7. The MerR-like regulator BrlR confers biofilm tolerance by activating multidrug efflux pumps in Pseudomonas aeruginosa biofilms.

    Science.gov (United States)

    Liao, Julie; Schurr, Michael J; Sauer, Karin

    2013-08-01

    A defining characteristic of biofilms is antibiotic tolerance that can be up to 1,000-fold greater than that of planktonic cells. In Pseudomonas aeruginosa, biofilm tolerance to antimicrobial agents requires the biofilm-specific MerR-type transcriptional regulator BrlR. However, the mechanism by which BrlR mediates biofilm tolerance has not been elucidated. Genome-wide transcriptional profiling indicated that brlR was required for maximal expression of genes associated with antibiotic resistance, in particular those encoding the multidrug efflux pumps MexAB-OprM and MexEF-OprN. Chromatin immunoprecipitation (ChIP) analysis revealed a direct regulation of these genes by BrlR, with DNA binding assays confirming BrlR binding to the promoter regions of the mexAB-oprM and mexEF-oprN operons. Quantitative reverse transcriptase PCR (qRT-PCR) analysis further indicated BrlR to be an activator of mexAB-oprM and mexEF-oprN gene expression. Moreover, immunoblot analysis confirmed increased MexA abundance in cells overexpressing brlR. Inactivation of both efflux pumps rendered biofilms significantly more susceptible to five different classes of antibiotics by affecting MIC but not the recalcitrance of biofilms to killing by bactericidal agents. Overexpression of either efflux pump in a ΔbrlR strain partly restored tolerance of ΔbrlR biofilms to antibiotics. Expression of brlR in mutant biofilms lacking both efflux pumps partly restored antimicrobial tolerance of biofilms to wild-type levels. Our results indicate that BrlR acts as an activator of multidrug efflux pumps to confer tolerance to P. aeruginosa biofilms and to resist the action of antimicrobial agents.

  8. Contrast-enhanced spectral mammography (CESM) and contrast enhanced MRI (CEMRI): Patient preferences and tolerance.

    Science.gov (United States)

    Hobbs, Max M; Taylor, Donna B; Buzynski, Sebastian; Peake, Rachel E

    2015-06-01

    Contrast-enhanced spectral mammography (CESM) may have similar diagnostic performance to Contrast-enhanced MRI (CEMRI) in the diagnosis and staging of breast cancer. To date, research has focused exclusively on diagnostic performance when comparing these two techniques. Patient experience is also an important factor when comparing and deciding on which of these modalities is preferable. The aim of this study is to compare patient experience of CESM against CEMRI during preoperative breast cancer staging. Forty-nine participants who underwent both CESM and CEMRI, as part of a larger trial, completed a Likert questionnaire about their preference for each modality according to the following criteria: comfort of breast compression, comfort of intravenous (IV) contrast injection, anxiety and overall preference. Participants also reported reasons for preferring one modality to the other. Quantitative data were analysed using a Wilcoxon sign-rank test and chi-squared test. Qualitative data are reported descriptively. A significantly higher overall preference towards CESM was demonstrated (n = 49, P < 0.001), with faster procedure time, greater comfort and lower noise level cited as the commonest reasons. Participants also reported significantly lower rates of anxiety during CESM compared with CEMRI (n = 36, P = 0.009). A significantly higher rate of comfort was reported during CEMRI for measures of breast compression (n = 49, P = 0.001) and the sensation of IV contrast injection (n = 49, P = 0.003). Our data suggest that overall, patients prefer the experience of CESM to CEMRI, adding support for the role of CESM as a possible alternative to CEMRI for breast cancer staging. © 2015 The Royal Australian and New Zealand College of Radiologists.

  9. Contrast-enhanced spectral mammography (CESM) and contrast enhanced MRI (CEMRI): Patient preferences and tolerance

    International Nuclear Information System (INIS)

    Hobbs, Max; Buzynski, Sebastian; Taylor, Donna B.; Peake, Rachel E.

    2015-01-01

    Contrast-enhanced spectral mammography (CESM) may have similar diagnostic performance to Contrast-enhanced MRI (CEMRI) in the diagnosis and staging of breast cancer. To date, research has focused exclusively on diagnostic performance when comparing these two techniques. Patient experience is also an important factor when comparing and deciding on which of these modalities is preferable. The aim of this study is to compare patient experience of CESM against CEMRI during preoperative breast cancer staging. Forty-nine participants who underwent both CESM and CEMRI, as part of a larger trial, completed a Likert questionnaire about their preference for each modality according to the following criteria: comfort of breast compression, comfort of intravenous (IV) contrast injection, anxiety and overall preference. Participants also reported reasons for preferring one modality to the other. Quantitative data were analysed using a Wilcoxon sign-rank test and chi-squared test. Qualitative data are reported descriptively. A significantly higher overall preference towards CESM was demonstrated (n = 49, P < 0.001), with faster procedure time, greater comfort and lower noise level cited as the commonest reasons. Participants also reported significantly lower rates of anxiety during CESM compared with CEMRI (n = 36, P = 0.009). A significantly higher rate of comfort was reported during CEMRI for measures of breast compression (n = 49, P = 0.001) and the sensation of IV contrast injection (n = 49, P = 0.003). Our data suggest that overall, patients prefer the experience of CESM to CEMRI, adding support for the role of CESM as a possible alternative to CEMRI for breast cancer staging.

  10. Mutations Enhancing Amino Acid Catabolism Confer a Growth Advantage in Stationary Phase

    Science.gov (United States)

    Zinser, Erik R.; Kolter, Roberto

    1999-01-01

    Starved cultures of Escherichia coli undergo successive rounds of population takeovers by mutants of increasing fitness. These mutants express the growth advantage in stationary phase (GASP) phenotype. Previous work identified the rpoS819 allele as a GASP mutation allowing cells to take over stationary-phase cultures after growth in rich media (M. M. Zambrano, D. A. Siegele, M. A. Almirón, A. Tormo, and R. Kolter, Science 259:1757–1760, 1993). Here we have identified three new GASP loci from an aged rpoS819 strain: sgaA, sgaB, and sgaC. Each locus is capable of conferring GASP on the rpoS819 parent, and they can provide successively higher fitnesses for the bacteria in the starved cultures. All four GASP mutations isolated thus far allow for faster growth on both individual and mixtures of amino acids. Each mutation confers a growth advantage on a different subset of amino acids, and these mutations act in concert to increase the overall catabolic capacity of the cell. We present a model whereby this enhanced ability to catabolize amino acids is responsible for the fitness gain during carbon starvation, as it may allow GASP mutants to outcompete the parental cells when growing on the amino acids released by dying cells. PMID:10482523

  11. Expression of cold and drought regulatory protein (CcCDR) of pigeonpea imparts enhanced tolerance to major abiotic stresses in transgenic rice plants.

    Science.gov (United States)

    Sunitha, Mellacheruvu; Srinath, Tamirisa; Reddy, Vudem Dashavantha; Rao, Khareedu Venkateswara

    2017-06-01

    Transgenic rice expressing pigeonpea Cc CDR conferred high-level tolerance to different abiotic stresses. The multiple stress tolerance observed in CcCDR -transgenic lines is attributed to the modulation of ABA-dependent and-independent signalling-pathway genes. Stable transgenic plants expressing Cajanus cajan cold and drought regulatory protein encoding gene (CcCDR), under the control of CaMV35S and rd29A promoters, have been generated in indica rice. Different transgenic lines of CcCDR, when subjected to drought, salt, and cold stresses, exhibited higher seed germination, seedling survival rates, shoot length, root length, and enhanced plant biomass when compared with the untransformed control plants. Furthermore, transgenic plants disclosed higher leaf chlorophyll content, proline, reducing sugars, SOD, and catalase activities, besides lower levels of MDA. Localization studies revealed that the CcCDR-GFP fusion protein was mainly present in the nucleus of transformed cells of rice. The CcCDR transgenics were found hypersensitive to abscisic acid (ABA) and showed reduced seed germination rates as compared to that of control plants. When the transgenic plants were exposed to drought and salt stresses at vegetative and reproductive stages, they revealed larger panicles and higher number of filled grains compared to the untransformed control plants. Under similar stress conditions, the expression levels of P5CS, bZIP, DREB, OsLEA3, and CIPK genes, involved in ABA-dependent and-independent signal transduction pathways, were found higher in the transgenic plants than the control plants. The overall results amply demonstrate that the transgenic rice expressing CcCDR bestows high-level tolerance to drought, salt, and cold stress conditions. Accordingly, the CcCDR might be deployed as a promising candidate gene for improving the multiple stress tolerance of diverse crop plants.

  12. Enhanced Boron Tolerance in Plants Mediated by Bidirectional Transport Through Plasma Membrane Intrinsic Proteins.

    Science.gov (United States)

    Mosa, Kareem A; Kumar, Kundan; Chhikara, Sudesh; Musante, Craig; White, Jason C; Dhankher, Om Parkash

    2016-02-23

    High boron (B) concentration is toxic to plants that limit plant productivity. Recent studies have shown the involvement of the members of major intrinsic protein (MIP) family in controlling B transport. Here, we have provided experimental evidences showing the bidirectional transport activity of rice OsPIP1;3 and OsPIP2;6. Boron transport ability of OsPIP1;3 and OsPIP2;6 were displayed in yeast HD9 mutant strain (∆fps1∆acr3∆ycf1) as a result of increased B sensitivity, influx and accumulation by OsPIP1;3, and rapid efflux activity by OsPIP2;6. RT-PCR analysis showed strong upregulation of OsPIP1;3 and OsPIP2;6 transcripts in roots by B toxicity. Transgenic Arabidopsis lines overexpressing OsPIP1;3 and OsPIP2;6 exhibited enhanced tolerance to B toxicity. Furthermore, B concentration was significantly increased after 2 and 3 hours of tracer boron ((10)B) treatment. Interestingly, a rapid efflux of (10)B from the roots of the transgenic plants was observed within 1 h of (10)B treatment. Boron tolerance in OsPIP1;3 and OsPIP2;6 lines was inhibited by aquaporin inhibitors, silver nitrate and sodium azide. Our data proved that OsPIP1;3 and OsPIP2;6 are indeed involved in both influx and efflux of boron transport. Manipulation of these PIPs could be highly useful in improving B tolerance in crops grown in high B containing soils.

  13. Immune suppressor factor confers stromal cell line with enhanced supporting activity for hematopoietic stem cells

    International Nuclear Information System (INIS)

    Nakajima, Hideaki; Shibata, Fumi; Fukuchi, Yumi; Goto-Koshino, Yuko; Ito, Miyuki; Urano, Atsushi; Nakahata, Tatsutoshi; Aburatani, Hiroyuki; Kitamura, Toshio

    2006-01-01

    Immune suppressor factor (ISF) is a subunit of the vacuolar ATPase proton pump. We earlier identified a short form of ISF (ShIF) as a stroma-derived factor that supports cytokine-independent growth of mutant Ba/F3 cells. Here, we report that ISF/ShIF supports self-renewal and expansion of primary hematopoietic stem cells (HSCs). Co-culture of murine bone marrow cells with a stromal cell line overexpressing ISF or ShIF (MS10/ISF or MS10/ShIF) not only enhanced their colony-forming activity and the numbers of long-term culture initiating cells, but also maintained the competitive repopulating activity of HSC. This stem cell supporting activity depended on the proton-transfer function of ISF/ShIF. Gene expression analysis of ISF/ShIF-transfected cell lines revealed down-regulation of secreted frizzled-related protein-1 and tissue inhibitor of metalloproteinase-3, and the restoration of their expressions in MS10/ISF cells partially reversed its enhanced LTC-IC supporting activity to a normal level. These results suggest that ISF/ShIF confers stromal cells with enhanced supporting activities for HSCs by modulating Wnt-activity and the extracellular matrix

  14. Enhancing tolerance of rice (Oryza sativa) to simulated acid rain by exogenous abscisic acid.

    Science.gov (United States)

    Wu, Xi; Liang, Chanjuan

    2017-02-01

    Abscisic acid (ABA) regulates much important plant physiological and biochemical processes and induces tolerance to different stresses. Here, we studied the regulation of exogenous ABA on adaptation of rice seedlings to simulated acid rain (SAR) stress by measuring biomass dry weight, stomatal conductance, net photosynthesis rate, nutrient elements, and endogenous hormones. The application of 10 μM ABA alleviated the SAR-induced inhibition on growth, stomatal conductance, net photosynthesis rate, and decreases in contents of nutrient (K, Mg, N, and P) and hormone (auxin, gibberellins, and zeatin). Moreover, 10 μM ABA could stimulate the Ca content as signaling molecules under SAR stress. Contrarily, the application of 100 μM ABA aggravated the SAR-induced inhibition on growth, stomatal conductance, net photosynthesis rate, and contents of nutrient and hormone. The results got after a 5-day recovery (without SAR) show that exogenous 10 μM ABA can promote self-restoration process in rice whereas 100 μM ABA hindered the restoration by increasing deficiency of nutrients and disturbing the balance of hormones. These results confirmed that exogenous ABA at proper concentration could enhance the tolerance of rice to SAR stress.

  15. Arbuscular Mycorrhizal Fungi Enhance Basil Tolerance to Salt Stress through Improved Physiological and Nutritional Status

    International Nuclear Information System (INIS)

    Salwa, A.; Abeer, H.; Alqarawi, A. A.; Abdullah, E.F.; Egamberdieva, D.

    2016-01-01

    Pot experiments were conducted to evaluate the influence of salinity on some physio-biochemical traits in sweet basil (Ocimum basilicum L.) cultivars with contrasting salt stress tolerance and to determine the role of arbuscular mycorrhizal fungi (AMF) in ameliorating the salt stress in plant. Salt stress (250 mM NaCl) reduced the colonization potential of AMF and inhibited photosynthetic pigments, chlorophyll and carotenoids in plant tissue. AMF inoculated plants contained higher level of chlorophyll pigments. Salt stressed plants showed increased lipid peroxidation, antioxidant enzyme activities like superoxide dismutase (SOD), ascorbate peroxidase (APX) and peroxidase (POD). Plants inoculated with AMF showed lower lipid peroxidation and enhanced antioxidant enzyme activities. Moreover, the content of lipids, proline, and soluble sugars in basil plants was improved with AMF inoculation. AMF inoculation reduced accumulation of Na+ and improved nutrient acquisition. In conclusion, AMF were capable to reduce oxidative stress via supporting of the antioxidant system. Salt tolerant cultivar showed higher antioxidant enzyme activity and accumulation of osmolytes. (author)

  16. Density functional theory study for the enhanced sulfur tolerance of Ni catalysts by surface alloying

    Science.gov (United States)

    Hwang, Bohyun; Kwon, Hyunguk; Ko, Jeonghyun; Kim, Byung-Kook; Han, Jeong Woo

    2018-01-01

    Sulfur compounds in fuels deactivate the surface of anode materials in solid oxide fuel cells (SOFCs), which adversely affect the long-term durability. To solve this issue, it is important to design new SOFC anode materials with high sulfur tolerance. Unfortunately, it is difficult to completely replace the traditional Ni anode owing to its outstanding reactivity with low cost. As an alternative, alloying Ni with transition metals is a practical strategy to enhance the sulfur resistance while taking advantage of Ni metal. Therefore, in this study, we examined the effects of transition metal (Cu, Rh, Pd, Ag, Pt, and Au) doping into a Ni catalyst on not only the adsorption of H2S, HS, S, and H but also H2S decomposition using density functional theory (DFT) calculations. The dopant metals were selected rationally by considering the stability of the Ni-based binary alloys. The interactions between sulfur atoms produced by H2S dissociation and the surface are weakened by the dopant metals at the topmost layer. In addition, the findings show that H2S dissociation can be suppressed by doping transition metals. It turns out that these effects are maximized in the Au-doped Ni catalyst. Our DFT results will provide useful insights into the design of sulfur-tolerant SOFC anode materials.

  17. Enhancement of Salinity Tolerance during Rice Seed Germination by Presoaking with Hemoglobin

    Directory of Open Access Journals (Sweden)

    Sheng Xu

    2011-04-01

    Full Text Available Salinity stress is an important environmental constraint limiting the productivity of many crops worldwide. In this report, experiments were conducted to investigate the effects of seed presoaking by bovine hemoglobin, an inducer of heme oxygenase-1 (HO-1, on salinity tolerance in rice (Oryza sativa plants. The results showed that different concentrations of the hemoglobin (0.01, 0.05, 0.2, 1.0, and 5.0 g/L differentially alleviated the inhibition of rice seed germination and thereafter seedling shoot growth caused by 100 mM NaCl stress, and the responses of 1.0 g/L hemoglobin was the most obvious. Further analyses showed that application of hemoglobin not only increased the HO-1 gene expression, but also differentially induced catalase (CAT, ascorbate peroxidase (APX, and superoxide dismutase (SOD activities or transcripts, thus decreasing the lipid peroxidation in germinating rice seeds subjected to salt stress. Compared with non-hemoglobin treatment, hemoglobin presoaking also increased the potassium (K to sodium (Na ratio both in the root and shoot parts after salinity stress. The effect is specific for HO-1 since the potent HO-1 inhibitor zinc protoporphyrin IX (ZnPPIX blocked the positive actions of hemoglobin on seed germination and seedling shoot growth. Overall, these results suggested that hemoglobin performs an advantageous role in enhancement of salinity tolerance during rice seed germination.

  18. International conference on challenges faced by technical and scientific support organizations in enhancing nuclear safety. Contributed papers and presentations

    International Nuclear Information System (INIS)

    2007-01-01

    Over the past two decades, the IAEA has conducted a series of major conferences that have addressed topical issues and strategies critical to nuclear safety for consideration by the world's nuclear regulators. More recently, the IAEA organized the International Conference on Effective Nuclear Regulatory Systems - Facing Safety and Security Challenges, held in Moscow in 2006. The Moscow conference was the first of its kind, because it brought together senior regulators of nuclear safety, radiation safety and security from around the world to discuss how to improve regulatory effectiveness with the objective of improving the protection of the public and the users of nuclear and radioactive material. The International Conference on Challenges Faced by Technical and Scientific Support Organizations in Enhancing Nuclear Safety was held in Aix-en-Provence, France, from 23 to 27 April 2007. This conference, again, was the first of its kind, because it was the first to address technical and scientific support organizations (TSOs), the role they play in supporting either the national regulatory bodies or the industry in making optimum safety decisions and the challenges they face in providing this support. This conference provided a forum for the TSOs to discuss these and other issues with the organizations to which they provide this support - that is, the regulators and the operators/industry - as well as with other stakeholders such as research organizations and public authorities. This conference can also be considered to have a link to the Moscow conference. The Moscow conference concluded that effective regulation of nuclear safety is vital for the safe use of nuclear energy and associated technologies, both now and in the future, and is an essential prerequisite for establishing an effective Global Nuclear Safety Regime. The Moscow conference also highlighted the importance of continued and improved international cooperation in the area of nuclear safety. These

  19. A chloroplast-localized and auxin-induced glutathione S-transferase from phreatophyte Prosopis juliflora confer drought tolerance on tobacco.

    Science.gov (United States)

    George, Suja; Venkataraman, Gayatri; Parida, Ajay

    2010-03-01

    Plant growth and productivity are adversely affected by various abiotic stress factors. In our previous study, we used Prosopis juliflora, a drought-tolerant tree species of Fabaceae, as a model plant system for mining genes functioning in abiotic stress tolerance. Large-scale random EST sequencing from a cDNA library obtained from drought-stressed leaves of 2-month-old P. juliflora plants resulted in identification of three different auxin-inducible glutathione S-transferases. In this paper, we report the cellular localization and the ability to confer drought tolerance in transgenic tobacco of one of these GSTs (PjGSTU1). PjGSTU1 was overexpressed in Escherichia coli and GST and GPX activities in total protein samples were assayed and compared with controls. The results indicated that PjGSTU1 protein forms a functional homo-dimer in recombinant bacteria with glutathione transferase as well as glutathione peroxidase activities. PjGSTU1 transgenic tobacco lines survived better under conditions of 15% PEG stress compared with control un-transformed plants. In vivo localization studies for PjGSTU1 using GFP fusion revealed protein localization in chloroplasts of transgenic plants. The peroxidase activity of PjGSTU1 and its localization in the chloroplast indicates a possible role for PjGSTU1 in ROS removal. Copyright 2009 Elsevier GmbH. All rights reserved.

  20. An evolutionary fitness enhancement conferred by the circadian system in cyanobacteria

    International Nuclear Information System (INIS)

    Ma, Peijun; Woelfle, Mark A.; Johnson, Carl Hirschie

    2013-01-01

    Circadian clocks are found in a wide variety of organisms from cyanobacteria to mammals. Many believe that the circadian clock system evolved as an adaption to the daily cycles in light and temperature driven by the rotation of the earth. Studies on the cyanobacterium, Synechococcus elongatus PCC 7942, have confirmed that the circadian clock in resonance with environmental cycles confers an adaptive advantage to cyanobacterial strains with different clock properties when grown in competition under light–dark cycles. The results thus far suggest that in a cyclic environment, the cyanobacterial strains whose free running periods are closest to the environmental period are the most fit and the strains lacking a functional circadian clock are at a competitive disadvantage relative to strains with a functional clock. In contrast, the circadian system provides little or no advantage to cyanobacteria grown in competition in constant light. To explain the potential mechanism of this clock-mediated enhancement in fitness in cyanobacteria, several models have been proposed; these include the limiting resource model, the diffusible inhibitor model and the cell-to-cell communication model. None of these models have been excluded by the currently available experimental data and the mechanistic basis of clock-mediated fitness enhancement remains elusive

  1. Chronic environmental stress enhances tolerance to seasonal gradual warming in marine mussels.

    Directory of Open Access Journals (Sweden)

    Ionan Marigómez

    Full Text Available In global climate change scenarios, seawater warming acts in concert with multiple stress sources, which may enhance the susceptibility of marine biota to thermal stress. Here, the responsiveness to seasonal gradual warming was investigated in temperate mussels from a chronically stressed population in comparison with a healthy one. Stressed and healthy mussels were subjected to gradual temperature elevation for 8 days (1°C per day; fall: 16-24°C, winter: 12-20°C, summer: 20-28°C and kept at elevated temperature for 3 weeks. Healthy mussels experienced thermal stress and entered the time-limited survival period in the fall, became acclimated in winter and exhibited sublethal damage in summer. In stressed mussels, thermal stress and subsequent health deterioration were elicited in the fall but no transition into the critical period of time-limited survival was observed. Stressed mussels did not become acclimated to 20°C in winter, when they experienced low-to-moderate thermal stress, and did not experience sublethal damage at 28°C in summer, showing instead signs of metabolic rate depression. Overall, although the thermal threshold was lowered in chronically stressed mussels, they exhibited enhanced tolerance to seasonal gradual warming, especially in summer. These results challenge current assumptions on the susceptibility of marine biota to the interactive effects of seawater warming and pollution.

  2. Transgenic rice expressing a codon-modified synthetic CP4-EPSPS confers tolerance to broad-spectrum herbicide, glyphosate.

    Science.gov (United States)

    Chhapekar, Sushil; Raghavendrarao, Sanagala; Pavan, Gadamchetty; Ramakrishna, Chopperla; Singh, Vivek Kumar; Phanindra, Mullapudi Lakshmi Venkata; Dhandapani, Gurusamy; Sreevathsa, Rohini; Ananda Kumar, Polumetla

    2015-05-01

    Highly tolerant herbicide-resistant transgenic rice was developed by expressing codon-modified synthetic CP4--EPSPS. The transformants could tolerate up to 1% commercial glyphosate and has the potential to be used for DSR (direct-seeded rice). Weed infestation is one of the major biotic stress factors that is responsible for yield loss in direct-seeded rice (DSR). Herbicide-resistant rice has potential to improve the efficiency of weed management under DSR. Hence, the popular indica rice cultivar IR64, was genetically modified using Agrobacterium-mediated transformation with a codon-optimized CP4-EPSPS (5-enolpyruvylshikimate-3-phosphate synthase) gene, with N-terminal chloroplast targeting peptide from Petunia hybrida. Integration of the transgenes in the selected rice plants was confirmed by Southern hybridization and expression by Northern and herbicide tolerance assays. Transgenic plants showed EPSPS enzyme activity even at high concentrations of glyphosate, compared to untransformed control plants. T0, T1 and T2 lines were tested by herbicide bioassay and it was confirmed that the transgenic rice could tolerate up to 1% of commercial Roundup, which is five times more in dose used to kill weeds under field condition. All together, the transgenic rice plants developed in the present study could be used efficiently to overcome weed menace.

  3. Unravelling chemical priming machinery in plants: the role of reactive oxygen-nitrogen-sulfur species in abiotic stress tolerance enhancement.

    Science.gov (United States)

    Antoniou, Chrystalla; Savvides, Andreas; Christou, Anastasis; Fotopoulos, Vasileios

    2016-10-01

    Abiotic stresses severely limit crop yield and their detrimental effects are aggravated by climate change. Chemical priming is an emerging field in crop stress management. The exogenous application of specific chemical agents before stress events results in tolerance enhancement and reduction of stress impacts on plant physiology and growth. However, the molecular mechanisms underlying the remarkable effects of chemical priming on plant physiology remain to be elucidated. Reactive oxygen, nitrogen and sulfur species (RONSS) are molecules playing a vital role in the stress acclimation of plants. When applied as priming agents, RONSS improve stress tolerance. This review summarizes the recent knowledge on the role of RONSS in cell signalling and gene regulation contributing to abiotic stress tolerance enhancement. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. A novel bHLH transcription factor PebHLH35 from Populus euphratica confers drought tolerance through regulating stomatal development, photosynthesis and growth in Arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Yan [College of Biological Sciences and Technology, National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing 100083 (China); Liaoning Forestry Vocational-Technical College, Shenyang 110101 (China); Wang, Congpeng; Han, Xiao; Tang, Sha; Liu, Sha [College of Biological Sciences and Technology, National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing 100083 (China); Xia, Xinli, E-mail: xiaxl@bjfu.edu.cn [College of Biological Sciences and Technology, National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing 100083 (China); Yin, Weilun, E-mail: yinwl@bjfu.edu.cn [College of Biological Sciences and Technology, National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing 100083 (China)

    2014-07-18

    Highlights: • PebHLH35 is firstly cloned from Populus euphratica and characterized its functions. • PebHLH35 is important for earlier seedling establishment and vegetative growth. • PebHLH35 enhances tolerance to drought by regulating growth. • PebHLH35 enhances tolerance to drought by regulating stomatal development. • PebHLH35 enhances tolerance to drought by regulating photosynthesis and transpiration. - Abstract: Plant basic helix-loop-helix (bHLH) transcription factors (TFs) are involved in a variety of physiological processes including the regulation of plant responses to various abiotic stresses. However, few drought-responsive bHLH family members in Populus have been reported. In this study, a novel bHLH gene (PebHLH35) was cloned from Populus euphratica. Expression analysis in P. euphratica revealed that PebHLH35 was induced by drought and abscisic acid. Subcellular localization studies using a PebHLH35-GFP fusion showed that the protein was localized to the nucleus. Ectopic overexpression of PebHLH35 in Arabidopsis resulted in a longer primary root, more leaves, and a greater leaf area under well-watered conditions compared with vector control plants. Notably, PebHLH35 overexpression lines showed enhanced tolerance to water-deficit stress. This finding was supported by anatomical and physiological analyses, which revealed a reduced stomatal density, stomatal aperture, transpiration rate, and water loss, and a higher chlorophyll content and photosynthetic rate. Our results suggest that PebHLH35 functions as a positive regulator of drought stress responses by regulating stomatal density, stomatal aperture, photosynthesis and growth.

  5. A novel bHLH transcription factor PebHLH35 from Populus euphratica confers drought tolerance through regulating stomatal development, photosynthesis and growth in Arabidopsis

    International Nuclear Information System (INIS)

    Dong, Yan; Wang, Congpeng; Han, Xiao; Tang, Sha; Liu, Sha; Xia, Xinli; Yin, Weilun

    2014-01-01

    Highlights: • PebHLH35 is firstly cloned from Populus euphratica and characterized its functions. • PebHLH35 is important for earlier seedling establishment and vegetative growth. • PebHLH35 enhances tolerance to drought by regulating growth. • PebHLH35 enhances tolerance to drought by regulating stomatal development. • PebHLH35 enhances tolerance to drought by regulating photosynthesis and transpiration. - Abstract: Plant basic helix-loop-helix (bHLH) transcription factors (TFs) are involved in a variety of physiological processes including the regulation of plant responses to various abiotic stresses. However, few drought-responsive bHLH family members in Populus have been reported. In this study, a novel bHLH gene (PebHLH35) was cloned from Populus euphratica. Expression analysis in P. euphratica revealed that PebHLH35 was induced by drought and abscisic acid. Subcellular localization studies using a PebHLH35-GFP fusion showed that the protein was localized to the nucleus. Ectopic overexpression of PebHLH35 in Arabidopsis resulted in a longer primary root, more leaves, and a greater leaf area under well-watered conditions compared with vector control plants. Notably, PebHLH35 overexpression lines showed enhanced tolerance to water-deficit stress. This finding was supported by anatomical and physiological analyses, which revealed a reduced stomatal density, stomatal aperture, transpiration rate, and water loss, and a higher chlorophyll content and photosynthetic rate. Our results suggest that PebHLH35 functions as a positive regulator of drought stress responses by regulating stomatal density, stomatal aperture, photosynthesis and growth

  6. Overexpression of Rat Neurons Nitric Oxide Synthase in Rice Enhances Drought and Salt Tolerance.

    Directory of Open Access Journals (Sweden)

    Wei Cai

    Full Text Available Nitric oxide (NO has been shown to play an important role in the plant response to biotic and abiotic stresses in Arabidopsis mutants with lower or higher levels of endogenous NO. The exogenous application of NO donors or scavengers has also suggested an important role for NO in plant defense against environmental stress. In this study, rice plants under drought and high salinity conditions showed increased nitric oxide synthase (NOS activity and NO levels. Overexpression of rat neuronal NO synthase (nNOS in rice increased both NOS activity and NO accumulation, resulting in improved tolerance of the transgenic plants to both drought and salt stresses. nNOS-overexpressing plants exhibited stronger water-holding capability, higher proline accumulation, less lipid peroxidation and reduced electrolyte leakage under drought and salt conditions than wild rice. Moreover, nNOS-overexpressing plants accumulated less H2O2, due to the observed up-regulation of OsCATA, OsCATB and OsPOX1. In agreement, the activities of CAT and POX were higher in transgenic rice than wild type. Additionally, the expression of six tested stress-responsive genes including OsDREB2A, OsDREB2B, OsSNAC1, OsSNAC2, OsLEA3 and OsRD29A, in nNOS-overexpressing plants was higher than that in the wild type under drought and high salinity conditions. Taken together, our results suggest that nNOS overexpression suppresses the stress-enhanced electrolyte leakage, lipid peroxidation and H2O2 accumulation, and promotes proline accumulation and the expression of stress-responsive genes under stress conditions, thereby promoting increased tolerance to drought and salt stresses.

  7. Vacuolar iron transporter BnMEB2 is involved in enhancing iron tolerance of Brassica napus

    Directory of Open Access Journals (Sweden)

    Wei Zhu

    2016-09-01

    Full Text Available Iron toxicity is a major nutrient disorder that severely affects crop development and yield. Vacuolar detoxification of metal stress is an important strategy for plants to survive and adapt to this adverse environment. Vacuolar iron transporter (VIT members are involved in this process and play essential roles in iron storage and transport. In this study, a rapeseed VIT gene BnMEB2 (BnaC07g30170D was identified. BnMEB2 is a homolog to Arabidopsis MEB2 (At5g24290 and acts as a detoxifier in vacuolar sequestration of divalent metal. Transient expression analysis revealed that BnMEB2 was localized to the vacuolar membrane. Q-PCR detection showed a high expression of BnMEB2 in mature (60-day-old leaves and could be obviously induced by exogenous iron stress in both roots and leaves. Over-expressed BnMEB2 in both Arabidopsis wild type and meb2 mutant seedlings resulted in greatly improved iron tolerability with no significant changes in the expression level of other vacuolar iron transporter genes. The mutant meb2 grew slowly and its root hair elongation was inhibited under high iron concentration condition while BnMEB2 over-expressed transgenic plants of the mutant restored the phenotypes with apparently higher iron storage in roots and dramatically increased iron content in the whole plant. Taken together, these results suggested that BnMEB2 was a VIT gene in rapeseed which was necessary for safe storage and vacuole detoxification function of excess iron to enhance the tolerance of iron toxicity. This research sheds light on a potentially new strategy for attenuating hazardous metal stress from environment and improving iron biofortification in Brassicaceae crops.

  8. 9th International Bielefeld Conference 2009: Upgrading the eLibrary: Enhanced Information Services Driven by Technology and Economics

    Directory of Open Access Journals (Sweden)

    Almuth Gastinger

    2009-10-01

    Full Text Available Thisarticle reports on the 9th International Bielefeld Conference ‘Upgrading the eLibrary: Enhanced Information Services Driven by Technology and Economics’, 3-5 February 2009, in Bielefeld, Germany. The conference focused on future challenges for libraries regarding the development of information services and infrastructures that meet the changing needs of scholarly communication, collaboration (e-science and publication (open access as well as new requirements regarding teaching and learning (virtual learning spaces. In addition attention was paid to economic conditions and strategic positioning of libraries as a general framework for information services.

  9. Enhanced glucose tolerance in pancreatic-derived factor (PANDER knockout C57BL/6 mice

    Directory of Open Access Journals (Sweden)

    Shari L. Moak

    2014-11-01

    Full Text Available Pancreatic-derived factor (PANDER; also known as FAM3B is a uniquely structured protein strongly expressed within and secreted from the endocrine pancreas. PANDER has been hypothesized to regulate fasting and fed glucose homeostasis, hepatic lipogenesis and insulin signaling, and to serve a potential role in the onset or progression of type 2 diabetes (T2D. Despite having potentially pivotal pleiotropic roles in glycemic regulation and T2D, there has been limited generation of stable animal models for the investigation of PANDER function, and there are no models on well-established genetic murine backgrounds for T2D. Our aim was to generate an enhanced murine model to further elucidate the biological function of PANDER. Therefore, a pure-bred PANDER knockout C57BL/6 (PANKO-C57 model was created and phenotypically characterized with respect to glycemic regulation and hepatic insulin signaling. The PANKO-C57 model exhibited an enhanced metabolic phenotype, particularly with regard to enhanced glucose tolerance. Male PANKO-C57 mice displayed decreased fasting plasma insulin and C-peptide levels, whereas leptin levels were increased as compared with matched C57BL/6J wild-type mice. Despite similar peripheral insulin sensitivity between both groups, hepatic insulin signaling was significantly increased during fasting conditions, as demonstrated by increased phosphorylation of hepatic PKB/Akt and AMPK, along with mature SREBP-1 expression. Insulin stimulation of PANKO-C57 mice resulted in increased hepatic triglyceride and glycogen content as compared with wild-type C57BL/6 mice. In summary, the PANKO-C57 mouse represents a suitable model for the investigation of PANDER in multiple metabolic states and provides an additional tool to elucidate the biological function and potential role in T2D.

  10. Evaluations of Mo-alloy for light water reactor fuel cladding to enhance accident tolerance

    Directory of Open Access Journals (Sweden)

    Cheng Bo

    2016-01-01

    Full Text Available Molybdenum based alloy is selected as a candidate to enhance tolerance of fuel to severe loss of coolant accidents due to its high melting temperature of ∼2600 °C and ability to maintain sufficient mechanical strength at temperatures exceeding 1200 °C. An outer layer of either a Zr-alloy or Al-containing stainless steel is designed to provide corrosion resistance under normal operation and oxidation resistance in steam exceeding 1000 °C for 24 hours under severe loss of coolant accidents. Due to its higher neutron absorption cross-sections, the Mo-alloy cladding is designed to be less than half the thickness of the current Zr-alloy cladding. A feasibility study has been undertaken to demonstrate (1 fabricability of long, thin wall Mo-alloy tubes, (2 formability of a protective outer coating, (3 weldability of Mo tube to endcaps, (4 corrosion resistance in autoclaves with simulated LWR coolant, (5 oxidation resistance to steam at 1000–1500 °C, and (6 sufficient axial and diametral strength and ductility. High purity Mo as well as Mo + La2O3 ODS alloy have been successfully fabricated into ∼2-meter long tubes for the feasibility study. Preliminary results are encouraging, and hence rodlets with Mo-alloy cladding containing fuel pellets have been under preparation for irradiation at the Advanced Test Reactor (ATR in Idaho National Laboratory. Additional efforts are underway to enhance the Mo cladding mechanical properties via process optimization. Oxidation tests to temperatures up to 1500 °C, and burst and creep tests up to 1000 °C are also underway. In addition, some Mo disks in close contact with UO2 from a previous irradiation program (to >100 GWd/MTU at the Halden Reactor have been subjected to post-irradiation examination to evaluate the chemical compatibility of Mo with irradiated UO2 and fission products. This paper will provide an update on results from the feasibility study and discuss the attributes of the

  11. Characterization of pbt genes conferring increased Pb(2+) and Cd(2+) tolerance upon Achromobacter xylosoxidans A8

    Czech Academy of Sciences Publication Activity Database

    Hložková, K.; Šuman, J.; Strnad, Hynek; Ruml, T.; Pačes, Václav; Kotrba, P.

    2013-01-01

    Roč. 164, č. 10 (2013), s. 1009-1018 ISSN 1769-7123 R&D Projects: GA MŠk(CZ) 1M0520 Grant - others:GA ČR(CZ) GAP504/11/0484 Program:GA Institutional support: RVO:68378050 Keywords : Achromobacter xylosoxidans * metal tolerance * lead * cadmium * zinc * P1-type ATPase * MerR family * transcriptional control Subject RIV: EB - Genetics ; Molecular Biology

  12. Overexpression of a modiifed AM79 aroA gene in transgenic maize confers high tolerance to glyphosate

    Institute of Scientific and Technical Information of China (English)

    REN Zhen-jing; CAO Gao-yi; ZHANG Yu-wen; LIU Yan; LIU Yun-jun

    2015-01-01

    It has previously been shown that a bacterial 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) encoding gene AM79 aroA can be a candidate gene to develop glyphosate-tolerant transgenic crops (Cao et al. 2012). In this study, AM79 aroA was redesigned using the plant biased codons and eliminating the motifs which would lead to the instability of mRNA, to create a synthetic gene that would be expressed highly in plant cel s. The redesigned and artiifcial y synthesized gene, named as mAM79, was cloned into plant expression vector pM3301UbiSpAM79, where mAM79 is fused with signal peptide sequence of pea rib-1,5-bisphospate carboxylase (rbcS) smal subunit and control ed by ubiquitin promoter. The plasmid was transformed into maize (Zea mays) immature embryos using Agrobacterium-mediated transformation method. Total 74 regenerated plants were obtained and PCR analysis showed that these transgenic plants had the integration of mAM79. Southern blot analysis was performed on the genomic DNA from four transgenic lines, and the result showed that one or two copies of mAM79 were integrated into maize genome. RT-PCR analysis result indicated that mAM79 was highly transcribed in transgenic maize plants. When sprayed with glyphosate, transgenic maize line AM85 and AM72 could tolerate 4-fold of commercial usage of glyphosate;however, al the non-transgenic maize plants were kil ed by glyphosate. The results in this study conifrmed that mAM79 could be used to develop glyphosate-tolerant maize, and the obtained transgenic maize lines could be used for the breeding of glyphosate-tolerant maize.

  13. Overexpression of EcbHLH57 Transcription Factor from Eleusine coracana L. in Tobacco Confers Tolerance to Salt, Oxidative and Drought Stress.

    Directory of Open Access Journals (Sweden)

    K C Babitha

    Full Text Available Basic helix-loop-helix (bHLH transcription factors constitute one of the largest families in plants and are known to be involved in various developmental processes and stress tolerance. We report the characterization of a stress responsive bHLH transcription factor from stress adapted species finger millet which is homologous to OsbHLH57 and designated as EcbHLH57. The full length sequence of EcbHLH57 consisted of 256 amino acids with a conserved bHLH domain followed by leucine repeats. In finger millet, EcbHLH57 transcripts were induced by ABA, NaCl, PEG, methyl viologen (MV treatments and drought stress. Overexpression of EcbHLH57 in tobacco significantly increased the tolerance to salinity and drought stress with improved root growth. Transgenic plants showed higher photosynthetic rate and stomatal conductance under drought stress that resulted in higher biomass. Under long-term salinity stress, the transgenic plants accumulated higher seed weight/pod and pod number. The transgenic plants were also tolerant to oxidative stress and showed less accumulation of H202 and MDA levels. The overexpression of EcbHLH57 enhanced the expression of stress responsive genes such as LEA14, rd29A, rd29B, SOD, APX, ADH1, HSP70 and also PP2C and hence improved tolerance to diverse stresses.

  14. Durum wheat dehydrin (DHN-5) confers salinity tolerance to transgenic Arabidopsis plants through the regulation of proline metabolism and ROS scavenging system.

    Science.gov (United States)

    Saibi, Walid; Feki, Kaouthar; Ben Mahmoud, Rihem; Brini, Faiçal

    2015-11-01

    The wheat dehydrin (DHN-5) gives birth to salinity tolerance to transgenic Arabidopsis plants by the regulation of proline metabolism and the ROS scavenging system. Dehydrins (DHNs) are involved in plant abiotic stress tolerance. In this study, we reported that salt tolerance of transgenic Arabidopsis plants overexpressing durum wheat dehydrin (DHN-5) was closely related to the activation of the proline metabolism enzyme (P5CS) and some antioxidant biocatalysts. Indeed, DHN-5 improved P5CS activity in the transgenic plants generating a significant proline accumulation. Moreover, salt tolerance of Arabidopsis transgenic plants was accompanied by an excellent activation of antioxidant enzymes like catalase (CAT), superoxide dismutase (SOD) and peroxide dismutase (POD) and generation of a lower level of hydrogen peroxide (H2O2) in leaves compared to the wild-type plants. The enzyme activities were enhanced in these transgenic plants in the presence of exogenous proline. Nevertheless, proline accumulation was slightly reduced in transgenic plants promoting chlorophyll levels. All these results suggest the crucial role of DHN-5 in response to salt stress through the activation of enzymes implicated in proline metabolism and in ROS scavenging enzymes.

  15. DsSWEET17, a Tonoplast-Localized Sugar Transporter from Dianthus spiculifolius, Affects Sugar Metabolism and Confers Multiple Stress Tolerance in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Aimin Zhou

    2018-05-01

    Full Text Available Plant SWEETs (Sugars Will Eventually be Exported Transporters affect the growth of plants by regulating the transport of sugar from source to sink and its intracellular transport between different organelles. In this study, DsSWEET17 from Dianthus spiculifolius was identified and characterized. Real-time quantitative PCR analysis revealed that the expression of DsSWEET17 was affected by exogenous application of fructose and glucose as well as under salt, osmotic, and oxidation stress. Colocalization experiments showed that the DsSWEET17-GFP (green fluorescent protein fusion protein was localized to the FM4-64-labeled tonoplasts in Arabidopsis. Compared to the wild type, the transgenic Arabidopsis seedlings overexpressing DsSWEET17 had longer roots, greater fresh weight, and a faster root growth upon exogenous application of fructose. Furthermore, transgenic Arabidopsis seedlings had significantly higher fructose accumulation than was observed for the wild-type seedlings. The analysis of root length revealed that transgenic Arabidopsis had higher tolerance to salt, osmotic, and oxidative stresses. Taken together, our results suggest that DsSWEET17 may be a tonoplast sugar transporter, and its overexpression affects sugar metabolism and confers multiple stress tolerance in Arabidopsis.

  16. DsSWEET17, a Tonoplast-Localized Sugar Transporter from Dianthus spiculifolius, Affects Sugar Metabolism and Confers Multiple Stress Tolerance in Arabidopsis.

    Science.gov (United States)

    Zhou, Aimin; Ma, Hongping; Feng, Shuang; Gong, Shufang; Wang, Jingang

    2018-05-24

    Plant SWEETs (Sugars Will Eventually be Exported Transporters) affect the growth of plants by regulating the transport of sugar from source to sink and its intracellular transport between different organelles. In this study, DsSWEET17 from Dianthus spiculifolius was identified and characterized. Real-time quantitative PCR analysis revealed that the expression of DsSWEET17 was affected by exogenous application of fructose and glucose as well as under salt, osmotic, and oxidation stress. Colocalization experiments showed that the DsSWEET17-GFP (green fluorescent protein) fusion protein was localized to the FM4-64-labeled tonoplasts in Arabidopsis . Compared to the wild type, the transgenic Arabidopsis seedlings overexpressing DsSWEET17 had longer roots, greater fresh weight, and a faster root growth upon exogenous application of fructose. Furthermore, transgenic Arabidopsis seedlings had significantly higher fructose accumulation than was observed for the wild-type seedlings. The analysis of root length revealed that transgenic Arabidopsis had higher tolerance to salt, osmotic, and oxidative stresses. Taken together, our results suggest that DsSWEET17 may be a tonoplast sugar transporter, and its overexpression affects sugar metabolism and confers multiple stress tolerance in Arabidopsis .

  17. Knock-out of Arabidopsis AtNHX4 gene enhances tolerance to salt stress

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hong-Tao; Liu, Hua; Gao, Xiao-Shu [Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032 (China); Zhang, Hongxia, E-mail: hxzhang@sippe.ac.cn [Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032 (China)

    2009-05-08

    AtNHX4 belongs to the monovalent cation:proton antiporter-1 (CPA1) family in Arabidopsis. Several members of this family have been shown to be critical for plant responses to abiotic stress, but little is known on the biological functions of AtNHX4. Here, we provide the evidence that AtNHX4 plays important roles in Arabidopsis responses to salt stress. Expression of AtNHX4 was responsive to salt stress and abscisic acid. Experiments with CFP-AtNHX4 fusion protein indicated that AtNHX4 is vacuolar localized. The nhx4 mutant showed enhanced tolerance to salt stress, and lower Na{sup +} content under high NaCl stress compared with wild-type plants. Furthermore, heterologous expression of AtNHX4 in Escherichia coli BL21 rendered the transformants hypersensitive to NaCl. Deletion of the hydrophilic C-terminus of AtNHX4 dramatically increased the hypersensitivity of transformants, indicating that AtNHX4 may function in Na{sup +} homeostasis in plant cell, and its C-terminus plays a role in regulating the AtNHX4 activity.

  18. Plant Growth Promoting Rhizobacteria and Silicon Synergistically Enhance Salinity Tolerance of Mung Bean

    KAUST Repository

    Mahmood, Sajid; Daur, Ihsanullah; Al-Solaimani, Samir G.; Ahmad, Shakeel; Madkour, Mohamed H.; Yasir, Muhammad; Hirt, Heribert; Ali, Shawkat; Ali, Zahir

    2016-01-01

    The present study explored the eco-friendly approach of utilizing plant-growth-promoting rhizobacteria (PGPR) inoculation and foliar application of silicon (Si) to improve the physiology, growth, and yield of mung bean under saline conditions. We isolated 18 promising PGPR from natural saline soil in Saudi Arabia, and screened them for plant-growth-promoting activities. Two effective strains were selected from the screening trial, and were identified as Enterobacter cloacae and Bacillus drentensis using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry and 16S rRNA gene sequencing techniques, respectively. Subsequently, in a 2-year mung bean field trial, using a randomized complete block design with a split-split plot arrangement, we evaluated the two PGPR strains and two Si levels (1 and 2 kg ha−1), in comparison with control treatments, under three different saline irrigation conditions (3.12, 5.46, and 7.81 dS m−1). The results indicated that salt stress substantially reduced stomatal conductance, transpiration rate, relative water content (RWC), total chlorophyll content, chlorophyll a, chlorophyll b, carotenoid content, plant height, leaf area, dry biomass, seed yield, and salt tolerance index. The PGPR strains and Si levels independently improved all the aforementioned parameters. Furthermore, the combined application of the B. drentensis strain with 2 kg Si ha−1 resulted in the greatest enhancement of mung bean physiology, growth, and yield. Overall, the results of this study provide important information for the benefit of the agricultural industry.

  19. Plant Growth Promoting Rhizobacteria and Silicon Synergistically Enhance Salinity Tolerance of Mung Bean

    KAUST Repository

    Mahmood, Sajid

    2016-06-17

    The present study explored the eco-friendly approach of utilizing plant-growth-promoting rhizobacteria (PGPR) inoculation and foliar application of silicon (Si) to improve the physiology, growth, and yield of mung bean under saline conditions. We isolated 18 promising PGPR from natural saline soil in Saudi Arabia, and screened them for plant-growth-promoting activities. Two effective strains were selected from the screening trial, and were identified as Enterobacter cloacae and Bacillus drentensis using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry and 16S rRNA gene sequencing techniques, respectively. Subsequently, in a 2-year mung bean field trial, using a randomized complete block design with a split-split plot arrangement, we evaluated the two PGPR strains and two Si levels (1 and 2 kg ha−1), in comparison with control treatments, under three different saline irrigation conditions (3.12, 5.46, and 7.81 dS m−1). The results indicated that salt stress substantially reduced stomatal conductance, transpiration rate, relative water content (RWC), total chlorophyll content, chlorophyll a, chlorophyll b, carotenoid content, plant height, leaf area, dry biomass, seed yield, and salt tolerance index. The PGPR strains and Si levels independently improved all the aforementioned parameters. Furthermore, the combined application of the B. drentensis strain with 2 kg Si ha−1 resulted in the greatest enhancement of mung bean physiology, growth, and yield. Overall, the results of this study provide important information for the benefit of the agricultural industry.

  20. Knock-out of Arabidopsis AtNHX4 gene enhances tolerance to salt stress

    International Nuclear Information System (INIS)

    Li, Hong-Tao; Liu, Hua; Gao, Xiao-Shu; Zhang, Hongxia

    2009-01-01

    AtNHX4 belongs to the monovalent cation:proton antiporter-1 (CPA1) family in Arabidopsis. Several members of this family have been shown to be critical for plant responses to abiotic stress, but little is known on the biological functions of AtNHX4. Here, we provide the evidence that AtNHX4 plays important roles in Arabidopsis responses to salt stress. Expression of AtNHX4 was responsive to salt stress and abscisic acid. Experiments with CFP-AtNHX4 fusion protein indicated that AtNHX4 is vacuolar localized. The nhx4 mutant showed enhanced tolerance to salt stress, and lower Na + content under high NaCl stress compared with wild-type plants. Furthermore, heterologous expression of AtNHX4 in Escherichia coli BL21 rendered the transformants hypersensitive to NaCl. Deletion of the hydrophilic C-terminus of AtNHX4 dramatically increased the hypersensitivity of transformants, indicating that AtNHX4 may function in Na + homeostasis in plant cell, and its C-terminus plays a role in regulating the AtNHX4 activity.

  1. Enhanced radiation tolerance of ultrafine grained Fe–Cr–Ni alloy

    International Nuclear Information System (INIS)

    Sun, C.; Yu, K.Y.; Lee, J.H.; Liu, Y.; Wang, H.; Shao, L.; Maloy, S.A.; Hartwig, K.T.; Zhang, X.

    2012-01-01

    Highlights: ► Ultrafine grained Fe-Cr-Ni alloy was processed by equal channel angular pressing technique. ► The overall Helium bubble density and dislocation loop density were reduced by grain refinement. ► The ultrafine grained microstructure alleviated radiation-induced hardening. - Abstract: The evolutions of microstructure and mechanical properties of Fe–14Cr–16Ni (wt.%) alloy subjected to Helium ion irradiations were investigated. Equal channel angular pressing (ECAP) process was used to significantly reduce the average grain size from 700 μm to 400 nm. At a peak fluence level of 5.5 displacement per atom (dpa), helium bubbles, 0.5–2 nm in diameter, were observed in both coarse-grained (CG) and ultrafine grained (UFG) alloy. The density of He bubbles, dislocation loops, as well as radiation hardening were reduced in the UFG Fe–Cr–Ni alloy comparing to those in its CG counterpart. The results imply that radiation tolerance in bulk metals can be effectively enhanced by refinement of microstructures.

  2. Hydrogen sulfide interacts with calcium signaling to enhance the chromium tolerance in Setaria italica.

    Science.gov (United States)

    Fang, Huihui; Jing, Tao; Liu, Zhiqiang; Zhang, Liping; Jin, Zhuping; Pei, Yanxi

    2014-12-01

    The oscillation of intracellular calcium (Ca(2+)) concentration is a primary event in numerous biological processes in plants, including stress response. Hydrogen sulfide (H2S), an emerging gasotransmitter, was found to have positive effects in plants responding to chromium (Cr(6+)) stress through interacting with Ca(2+) signaling. While Ca(2+) resemblances H2S in mediating biotic and abiotic stresses, crosstalk between the two pathways remains unclear. In this study, Ca(2+) signaling interacted with H2S to produce a complex physiological response, which enhanced the Cr(6+) tolerance in foxtail millet (Setaria italica). Results indicate that Cr(6+) stress activated endogenous H2S synthesis as well as Ca(2+) signaling. Moreover, toxic symptoms caused by Cr(6+) stress were strongly moderated by 50μM H2S and 20mM Ca(2+). Conversely, treatments with H2S synthesis inhibitor and Ca(2+) chelators prior to Cr(6+)-exposure aggravated these toxic symptoms. Interestingly, Ca(2+) upregulated expression of two important factors in metal metabolism, MT3A and PCS, which participated in the biosynthesis of heavy metal chelators, in a H2S-dependent manner to cope with Cr(6+) stress. These findings also suggest that the H2S dependent pathway is a component of the Ca(2+) activating antioxidant system and H2S partially contributes Ca(2+)-activating antioxidant system. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Bacillus amyloliquefaciens Confers Tolerance to Various Abiotic Stresses and Modulates Plant Response to Phytohormones through Osmoprotection and Gene Expression Regulation in Rice

    Directory of Open Access Journals (Sweden)

    Shalini Tiwari

    2017-08-01

    Full Text Available Being sessile in nature, plants have to withstand various adverse environmental stress conditions including both biotic and abiotic stresses. Comparatively, abiotic stresses such as drought, salinity, high temperature, and cold pose major threat to agriculture by negatively impacting plant growth and yield worldwide. Rice is one of the most widely consumed staple cereals across the globe, the production and productivity of which is also severely affected by different abiotic stresses. Therefore, several crop improvement programs are directed toward developing stress tolerant rice cultivars either through marker assisted breeding or transgenic technology. Alternatively, some known rhizospheric competent bacteria are also known to improve plant growth during abiotic stresses. A plant growth promoting rhizobacteria (PGPR, Bacillus amyloliquefaciens NBRI-SN13 (SN13 was previously reported by our lab to confer salt stress tolerance to rice seedlings. However, the present study investigates the role of SN13 in ameliorating various abiotic stresses such as salt, drought, desiccation, heat, cold, and freezing on a popular rice cv. Saryu-52 under hydroponic growth conditions. Apart from this, seedlings were also exogenously supplied with abscisic acid (ABA, salicylic acid (SA, jasmonic acid (JA and ethephon (ET to study the role of SN13 in phytohormone-induced stress tolerance as well as its role in abiotic and biotic stress cross-talk. All abiotic stresses and phytohormone treatments significantly affected various physiological and biochemical parameters like membrane integrity and osmolyte accumulation. SN13 also positively modulated stress-responsive gene expressions under various abiotic stresses and phytohormone treatments suggesting its multifaceted role in cross-talk among stresses and phytohormones in response to PGPR. To the best of our knowledge, this is the first report on detailed analysis of plant growth promotion and stress alleviation by a

  4. CbRCI35, a cold responsive peroxidase from Capsella bursa-pastoris regulates reactive oxygen species homeostasis and enhances cold tolerance in tobacco

    Directory of Open Access Journals (Sweden)

    Juan Lin

    2016-10-01

    Full Text Available Low temperature affects gene regulatory networks and alters cellular metabolism to inhibit plant growth. Peroxidases are widely distributed in plants and play a large role in adjusting and controlling reactive oxygen species (ROS homeostasis in response to abiotic stresses such as low temperature. The Rare Cold-Inducible 35 gene from Capsella bursa-pastoris (CbRCI35 belongs to the type III peroxidase family and has been reported to be a cold responsive gene in plants. Here we performed an expressional characterization of CbRCI35 under cold and ionic liquid treatments. The promoter of CbRCI35 was also cloned and its activity was examined using the GUS reporter system. CbRCI35 protein was localized in the cytoplasm according to sequence prediction and GFP fusion assay. Heterologous expression tests revealed that CbRCI35 conferred enhanced resistance to low temperature and activated endogenous cold responsive signaling in tobacco. Furthermore, in the normal condition the ROS accumulation was moderately enhanced while after chilling exposure superoxide dismutase (SOD activity was increased in CbRCI53 transgenic plants. The ROS metabolism related genes expression was altered accordingly. We conclude that CbRCI35 modulates ROS homeostasis and contributes to cold tolerance in plants.

  5. Overexpression of WsSGTL1 Gene of Withania somnifera Enhances Salt Tolerance, Heat Tolerance and Cold Acclimation Ability in Transgenic Arabidopsis Plants

    Science.gov (United States)

    Mishra, Manoj K.; Chaturvedi, Pankaj; Singh, Ruchi; Singh, Gaurav; Sharma, Lokendra K.; Pandey, Vibha; Kumari, Nishi; Misra, Pratibha

    2013-01-01

    Background Sterol glycosyltrnasferases (SGT) are enzymes that glycosylate sterols which play important role in plant adaptation to stress and are medicinally important in plants like Withania somnifera. The present study aims to find the role of WsSGTL1 which is a sterol glycosyltransferase from W. somnifera, in plant’s adaptation to abiotic stress. Methodology The WsSGTL1 gene was transformed in Arabidopsis thaliana through Agrobacterium mediated transformation, using the binary vector pBI121, by floral dip method. The phenotypic and physiological parameters like germination, root length, shoot weight, relative electrolyte conductivity, MDA content, SOD levels, relative electrolyte leakage and chlorophyll measurements were compared between transgenic and wild type Arabidopsis plants under different abiotic stresses - salt, heat and cold. Biochemical analysis was done by HPLC-TLC and radiolabelled enzyme assay. The promoter of the WsSGTL1 gene was cloned by using Genome Walker kit (Clontech, USA) and the 3D structures were predicted by using Discovery Studio Ver. 2.5. Results The WsSGTL1 transgenic plants were confirmed to be single copy by Southern and homozygous by segregation analysis. As compared to WT, the transgenic plants showed better germination, salt tolerance, heat and cold tolerance. The level of the transgene WsSGTL1 was elevated in heat, cold and salt stress along with other marker genes such as HSP70, HSP90, RD29, SOS3 and LEA4-5. Biochemical analysis showed the formation of sterol glycosides and increase in enzyme activity. When the promoter of WsSGTL1 gene was cloned from W. somnifera and sequenced, it contained stress responsive elements. Bioinformatics analysis of the 3D structure of the WsSGTL1 protein showed functional similarity with sterol glycosyltransferase AtSGT of A. thaliana. Conclusions Transformation of WsSGTL1 gene in A. thaliana conferred abiotic stress tolerance. The promoter of the gene in W.somnifera was found to have stress

  6. The fifth international conference on microbial enhanced oil recovery and related biotechnology for solving environmental problems: 1995 Conference proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Bryant, R. [ed.

    1995-12-31

    This volume contains 41 papers covering the following topics: field trials of microbial enhanced recovery of oil; control and treatment of sour crudes and natural gas with microorganisms; bioremediation of hydrocarbon contamination in soils; microbial plugging processes; microbial waste water treatment; the use of microorganisms as biological indicators of oils; and characterization and behavior of microbial systems. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  7. A Rice Immunophilin Gene, OsFKBP16-3, Confers Tolerance to Environmental Stress in Arabidopsis and Rice

    Directory of Open Access Journals (Sweden)

    Jun Cheul Ahn

    2013-03-01

    Full Text Available The putative thylakoid lumen immunophilin, FKBP16-3, has not yet been characterized, although this protein is known to be regulated by thioredoxin and possesses a well-conserved CxxxC motif in photosynthetic organisms. Here, we characterized rice OsFKBP16-3 and examined the role of this gene in the regulation of abiotic stress in plants. FKBP16-3s are well conserved in eukaryotic photosynthetic organisms, including the presence of a unique disulfide-forming CxxxC motif in their N-terminal regions. OsFKBP16-3 was mainly expressed in rice leaf tissues and was upregulated by various abiotic stresses, including salt, drought, high light, hydrogen peroxide, heat and methyl viologen. The chloroplast localization of OsFKBP16-3-GFP was confirmed through the transient expression of OsFKBP16-3 in Nicotiana benthamiana leaves. Transgenic Arabidopsis and transgenic rice plants that constitutively expressed OsFKBP16-3 exhibited increased tolerance to salinity, drought and oxidative stresses, but showed no change in growth or phenotype, compared with vector control plants, when grown under non-stressed conditions. This is the first report to demonstrate the potential role of FKBP16-3 in the environmental stress response, which may be regulated by a redox relay process in the thylakoid lumen, suggesting that artificial regulation of FKBP16-3 expression is a candidate for stress-tolerant crop breeding.

  8. Overexpression of Arabidopsis NADPH-dependent thioredoxin reductase C (AtNTRC) confers freezing and cold shock tolerance to plants

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Jeong Chan [National Institute of Ecology, 1210 Geumgang-ro, Maseo-myeon, Seocheon-gun 325-813 (Korea, Republic of); Lee, Sangmin [Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon (Korea, Republic of); Shin, Su Young [National Institute of Ecology, 1210 Geumgang-ro, Maseo-myeon, Seocheon-gun 325-813 (Korea, Republic of); Chae, Ho Byoung; Jung, Young Jun [Division of Applied Life Science - BK21+ program, PMBBRC, Gyeongsang National University, Jinju (Korea, Republic of); Jung, Hyun Suk [Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon (Korea, Republic of); Lee, Kyun Oh [Division of Applied Life Science - BK21+ program, PMBBRC, Gyeongsang National University, Jinju (Korea, Republic of); Lee, Jung Ro, E-mail: leejr73@nie.re.kr [National Institute of Ecology, 1210 Geumgang-ro, Maseo-myeon, Seocheon-gun 325-813 (Korea, Republic of); Department of Biochemistry and Biophysics, Texas A& M University, College Station, TX (United States); Lee, Sang Yeol, E-mail: sylee@gnu.ac.kr [Division of Applied Life Science - BK21+ program, PMBBRC, Gyeongsang National University, Jinju (Korea, Republic of)

    2015-08-07

    Overexpression of AtNTRC (AtNTRC{sup OE}) in Arabidopsis thaliana led to a freezing and cold stress tolerance, whereas a knockout mutant (atntrc) showed a stress-sensitive phenotype. Biochemical analyses showed that the recombinant AtNTRC proteins exhibited a cryoprotective activity for malate dehydrogenase and lactic dehydrogenase. Furthermore, conclusive evidence of its interaction with nucleic acids in vitro is provided here on the basis of gel shift and electron microscopy analysis. Recombinant AtNTRC efficiently protected RNA and DNA from RNase A and metal catalyzed oxidation damage, respectively. The C-terminal thioredoxin domain is required for the nucleic acid–protein complex formation. From these results, it can be hypothesized that AtNTRC, which is known to be an electron donor of peroxiredoxin, contributes the stability of macromolecules under cold stress. - Highlights: • AtNTRC has a cryoprotective activity in vitro. • Overexpression of AtNTRC increases tolerance to freezing and cold shock stresses. • Thioredoxin domain of AtNTRC protects nucleic acids in vitro. • AtNTRC inhibits protein aggregation under freezing stress in vitro.

  9. Overexpression of Arabidopsis NADPH-dependent thioredoxin reductase C (AtNTRC) confers freezing and cold shock tolerance to plants

    International Nuclear Information System (INIS)

    Moon, Jeong Chan; Lee, Sangmin; Shin, Su Young; Chae, Ho Byoung; Jung, Young Jun; Jung, Hyun Suk; Lee, Kyun Oh; Lee, Jung Ro; Lee, Sang Yeol

    2015-01-01

    Overexpression of AtNTRC (AtNTRC OE ) in Arabidopsis thaliana led to a freezing and cold stress tolerance, whereas a knockout mutant (atntrc) showed a stress-sensitive phenotype. Biochemical analyses showed that the recombinant AtNTRC proteins exhibited a cryoprotective activity for malate dehydrogenase and lactic dehydrogenase. Furthermore, conclusive evidence of its interaction with nucleic acids in vitro is provided here on the basis of gel shift and electron microscopy analysis. Recombinant AtNTRC efficiently protected RNA and DNA from RNase A and metal catalyzed oxidation damage, respectively. The C-terminal thioredoxin domain is required for the nucleic acid–protein complex formation. From these results, it can be hypothesized that AtNTRC, which is known to be an electron donor of peroxiredoxin, contributes the stability of macromolecules under cold stress. - Highlights: • AtNTRC has a cryoprotective activity in vitro. • Overexpression of AtNTRC increases tolerance to freezing and cold shock stresses. • Thioredoxin domain of AtNTRC protects nucleic acids in vitro. • AtNTRC inhibits protein aggregation under freezing stress in vitro

  10. The maize CorA/MRS2/MGT-type Mg transporter, ZmMGT10, responses to magnesium deficiency and confers low magnesium tolerance in transgenic Arabidopsis.

    Science.gov (United States)

    Li, Hongyou; Wang, Ning; Ding, Jianzhou; Liu, Chan; Du, Hanmei; Huang, Kaifeng; Cao, Moju; Lu, Yanli; Gao, Shibin; Zhang, Suzhi

    2017-10-01

    ZmMGT10 was specifically expressed in maize roots and induced by a deficiency of magnesium. Overexpression of ZmMGT10 restored growth deficiency of the Salmonella typhimurium MM281 strain and enhanced the tolerance in Arabidopsis to stress induced by low magnesium levels by increasing uptake of Mg 2+ via roots. CorA/MRS2/MGT-type Mg 2+ transporters play a significant role in maintaining magnesium (Mg) homeostasis in plants. Although the maize CorA/MRS2/MGT family comprises of 12 members, currently no member has been functionally characterized. Here, we report the isolation and functional characterization of ZmMGT10 from the maize MRS2/MGT gene family. ZmMGT10 has a typical structure feature which includes two conserved TMs near the C-terminal end and an altered AMN tripeptide motif. The high sequence similarity and close phylogenetic relationship indicates that ZmMGT10 is probably the counterpart of Arabidopsis AtMGT6. The complementation of the Salmonella typhimurium mutated MM281 strain indicates that ZmMGT10 possesses the ability to transport Mg 2+ . ZmMGT10 was specifically expressed in the plant roots and it can be stimulated by a deficiency of Mg. Transgenic Arabidopsis plants which overexpressed ZmMGT10 grew more vigorously than wild-type plants under low Mg conditions, exhibited by longer root length, higher plant fresh weight and chlorophyll content, suggesting ZmMGT10 was essential for plant growth and development under low Mg conditions. Further investigations found that high accumulation of Mg 2+ occurred in transgenic plants attributed to improved Mg 2+ uptake and thereby enhanced tolerance to Mg deficiency. Results from this investigation illustrate that ZmMGT10 is a Mg transporter of maize which can enhance the tolerance to Mg deficient conditions by improving Mg 2+ uptake in the transgenic plants of Arabidopsis.

  11. Salicylic acid and methyl jasmonate enhance drought tolerance in chamomile plants

    Directory of Open Access Journals (Sweden)

    Nazarli Hossein

    2014-04-01

    Full Text Available Introduction: The dried flowers of chamomile contain many terpenoids and flavonoids contributing to its medicinal properties. Salicylic acid (SA and methyl jasmonate (MeJA have antioxidant properties and function as direct radical scavengers. Two Matricaria chamomilla cultivars (Bodgold and Hungary breed seeds were used in this study to investigate the effects of exogenous application of SA and MeJA on protection against drought stress as well as on changes of malone dialdehyde (MDA and electrolyte leakage index (ELI, and the fluctuation of proline and soluble sugars content in the leaves under drought stress. Methods: The experiment was conducted in a factorial design based on randomized complete blocks with three replicates. Chamomile plants were treated by two levels of drought stress as well as two different levels of MeJA (i.e., 0.0 and 100 μM and SA (i.e., 0.0 and 0.5 mM solutions. Results: There was a dramatic drought induced increase in the MDA content (128% and ELI (49% in the leaves. Deleterious effect of drought stress was more severe in untreated plants than in treated ones. Treatments with SA and MeJA significantly improved drought tolerance in chamomile plants. These treatments effectively maintained membrane integrity, thereby retarding electrolyte leakage and membrane lipid peroxidation (MDA. Treatments with SA and MeJA were also effective in enhancing the antioxidant concentrations of proline and soluble sugars. Conclusion: The production of these antioxidants could have been part of a defence system against drought damage, reducing MDA and ELI and maintaining membrane stability.

  12. Stress-inducible expression of an F-box gene TaFBA1 from wheat enhanced the drought tolerance in transgenic tobacco plants without impacting growth and development

    Directory of Open Access Journals (Sweden)

    Xiangzhu Kong

    2016-09-01

    Full Text Available E3 ligase plays an important role in the response to many environment stresses in plants. In our previous study, constitutive overexpression of an F-box protein gene TaFBA1 driven by 35S promoter improved the drought tolerance in transgenic tobacco plants, but the growth and development in transgenic plants was altered in normal conditions. In this study, we used stress-inducible promoter RD29A instead of 35S promoter, as a results, the stress-inducible transgenic tobacco plants exhibit a similar phenotype with WT plants. However, the drought tolerance of the transgenic plants with stress-inducible expressed TaFBA1 was enhanced. The improved drought tolerance of transgenic plants was indicated by their higher seed germination rate and survival rate, greater biomass and photosynthesis than those of WT under water stress, which may be related to their greater water retention capability and osmotic adjustment. Moreover, the transgenic plants accumulated less reactive oxygen species (ROS, kept lower MDA content and membrane leakage under water stress, which may be related to their higher levels of antioxidant enzyme activity and upregulated gene expression of some antioxidant enzymes. These results suggest that stress induced expression of TaFBA1 confers drought tolerance via the improved water retention and antioxidative compete abilibty. Meanwhile, this stress-inducible expression strategy by RD29A promoter can minimize the unexpectable effects by 35S constitutive promoter on phenotypes of the transgenic plants.

  13. Stress-Inducible Expression of an F-box Gene TaFBA1 from Wheat Enhanced the Drought Tolerance in Transgenic Tobacco Plants without Impacting Growth and Development.

    Science.gov (United States)

    Kong, Xiangzhu; Zhou, Shumei; Yin, Suhong; Zhao, Zhongxian; Han, Yangyang; Wang, Wei

    2016-01-01

    E3 ligase plays an important role in the response to many environment stresses in plants. In our previous study, constitutive overexpression of an F-box protein gene TaFBA1 driven by 35S promoter improved the drought tolerance in transgenic tobacco plants, but the growth and development in transgenic plants was altered in normal conditions. In this study, we used stress-inducible promoter RD29A instead of 35S promoter, as a results, the stress-inducible transgenic tobacco plants exhibit a similar phenotype with wild type (WT) plants. However, the drought tolerance of the transgenic plants with stress-inducible expressed TaFBA1 was enhanced. The improved drought tolerance of transgenic plants was indicated by their higher seed germination rate and survival rate, greater biomass and photosynthesis than those of WT under water stress, which may be related to their greater water retention capability and osmotic adjustment. Moreover, the transgenic plants accumulated less reactive oxygen species, kept lower MDA content and membrane leakage under water stress, which may be related to their higher levels of antioxidant enzyme activity and upregulated gene expression of some antioxidant enzymes. These results suggest that stress induced expression of TaFBA1 confers drought tolerance via the improved water retention and antioxidative compete ability. Meanwhile, this stress-inducible expression strategy by RD29A promoter can minimize the unexpectable effects by 35S constitutive promoter on phenotypes of the transgenic plants.

  14. Overexpression of a maize plasma membrane intrinsic protein ZmPIP1;1 confers drought and salt tolerance in Arabidopsis.

    Science.gov (United States)

    Zhou, Lian; Zhou, Jing; Xiong, Yuhan; Liu, Chaoxian; Wang, Jiuguang; Wang, Guoqiang; Cai, Yilin

    2018-01-01

    Drought and salt stress are major abiotic stress that inhibit plants growth and development, here we report a plasma membrane intrinsic protein ZmPIP1;1 from maize and identified its function in drought and salt tolerance in Arabidopsis. ZmPIP1;1 was localized to the plasma membrane and endoplasmic reticulum in maize protoplasts. Treatment with PEG or NaCl resulted in induced expression of ZmPIP1;1 in root and leaves. Constitutive overexpression of ZmPIP1;1 in transgenic Arabidopsis plants resulted in enhanced drought and salt stress tolerance compared to wild type. A number of stress responsive genes involved in cellular osmoprotection in ZmPIP1;1 overexpression plants were up-regulated under drought or salt condition. ZmPIP1;1 overexpression plants showed higher activities of reactive oxygen species (ROS) scavenging enzymes such as catalase and superoxide dismutase, lower contents of stress-induced ROS such as superoxide, hydrogen peroxide and malondialdehyde, and higher levels of proline under drought and salt stress than did wild type. ZmPIP1;1 may play a role in drought and salt stress tolerance by inducing of stress responsive genes and increasing of ROS scavenging enzymes activities, and could provide a valuable gene for further plant breeding.

  15. Overexpression of OLE1 enhances stress tolerance and constitutively activates the MAPK HOG pathway in Saccharomyces cerevisiae.

    Science.gov (United States)

    Nasution, Olviyani; Lee, Young Mi; Kim, Eunjung; Lee, Yeji; Kim, Wankee; Choi, Wonja

    2017-03-01

    OLE1 of Saccharomyces cerevisiae encodes the sole and essential Δ-9 desaturase catalyzing the conversion of saturated to unsaturated fatty acids. Upon ectopic overexpression of OLE1 in S. cerevisiae, significant increases in the membrane oleic acid content were observed. OLE1-overexpressing strains displayed enhanced tolerance to various stresses, better proton efflux, lower membrane permeability, and lessened internal hydrogen peroxide content. The OLE1-mediated enhanced stress tolerance was considerably diminished upon deletion of HOG1, which encodes the mitogen-activated protein kinase (MAPK) Hog1 of the high osmolarity glycerol (HOG) pathway. Furthermore, OLE1 overexpression constitutively activated Hog1, which remained in the cytoplasm. Hog1 activation was accomplished through the MAPK kinase kinase (MAPKKK) Ssk2, but not Ste11 and Ssk22, the other MAPKKKs of the HOG pathway. Despite its cytoplasmic location, activated Hog1 was able to activate the expression of its canonical targets, including CTT1, HSP12, and STL1, and further, the cAMP and stress response elements present in the promoter. OLE1 overexpression neither caused nor relieved endoplasmic reticulum stress. Individually or in combination, the physiological and molecular changes caused by OLE1 overexpression may contribute to enhanced tolerance to various types of stress. Biotechnol. Bioeng. 2017;114: 620-631. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  16. Dietary Fiber and Bacterial SCFA Enhance Oral Tolerance and Protect against Food Allergy through Diverse Cellular Pathways.

    Science.gov (United States)

    Tan, Jian; McKenzie, Craig; Vuillermin, Peter J; Goverse, Gera; Vinuesa, Carola G; Mebius, Reina E; Macia, Laurence; Mackay, Charles R

    2016-06-21

    The incidence of food allergies in western countries has increased dramatically in recent decades. Tolerance to food antigens relies on mucosal CD103(+) dendritic cells (DCs), which promote differentiation of regulatory T (Treg) cells. We show that high-fiber feeding in mice improved oral tolerance and protected from food allergy. High-fiber feeding reshaped gut microbial ecology and increased the release of short-chain fatty acids (SCFAs), particularly acetate and butyrate. High-fiber feeding enhanced oral tolerance and protected against food allergy by enhancing retinal dehydrogenase activity in CD103(+) DC. This protection depended on vitamin A in the diet. This feeding regimen also boosted IgA production and enhanced T follicular helper and mucosal germinal center responses. Mice lacking GPR43 or GPR109A, receptors for SCFAs, showed exacerbated food allergy and fewer CD103(+) DCs. Dietary elements, including fiber and vitamin A, therefore regulate numerous protective pathways in the gastrointestinal tract, necessary for immune non-responsiveness to food antigens. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  17. Expression of an Arabidopsis molybdenum cofactor sulphurase gene in soybean enhances drought tolerance and increases yield under field conditions.

    Science.gov (United States)

    Li, Yajun; Zhang, Jiachang; Zhang, Juan; Hao, Ling; Hua, Jinping; Duan, Liusheng; Zhang, Mingcai; Li, Zhaohu

    2013-08-01

    LOS5/ABA3 gene encoding molybdenum cofactor sulphurase is involved in aldehyde oxidase (AO) activity in Arabidopsis, which indirectly regulates ABA biosynthesis and increased stress tolerance. Here, we used a constitutive super promoter to drive LOS5/ABA3 overexpression in soybean (Glycine max L.) to enhance drought tolerance in growth chamber and field conditions. Expression of LOS5/ABA3 was up-regulated by drought stress, which led to increasing AO activity and then a notable increase in ABA accumulation. Transgenic soybean under drought stress had reduced water loss by decreased stomatal aperture size and transpiration rate, which alleviated leaf wilting and maintained higher relative water content. Exposed to drought stress, transgenic soybean exhibited reduced cell membrane damage by reducing electrolyte leakage and production of malondialdehyde and promoting proline accumulation and antioxidant enzyme activities. Also, overexpression of LOS5/ABA3 enhanced expression of stress-up-regulated genes. Furthermore, the seed yield of transgenic plants is at least 21% higher than that of wide-type plants under drought stress conditions in the field. These data suggest that overexpression of LOS5/ABA3 could improve drought tolerance in transgenic soybean via enhanced ABA accumulation, which could activate expression of stress-up-regulated genes and cause a series of physiological and biochemical resistant responses. © 2013 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  18. Dietary Fiber and Bacterial SCFA Enhance Oral Tolerance and Protect against Food Allergy through Diverse Cellular Pathways

    Directory of Open Access Journals (Sweden)

    Jian Tan

    2016-06-01

    Full Text Available The incidence of food allergies in western countries has increased dramatically in recent decades. Tolerance to food antigens relies on mucosal CD103+ dendritic cells (DCs, which promote differentiation of regulatory T (Treg cells. We show that high-fiber feeding in mice improved oral tolerance and protected from food allergy. High-fiber feeding reshaped gut microbial ecology and increased the release of short-chain fatty acids (SCFAs, particularly acetate and butyrate. High-fiber feeding enhanced oral tolerance and protected against food allergy by enhancing retinal dehydrogenase activity in CD103+ DC. This protection depended on vitamin A in the diet. This feeding regimen also boosted IgA production and enhanced T follicular helper and mucosal germinal center responses. Mice lacking GPR43 or GPR109A, receptors for SCFAs, showed exacerbated food allergy and fewer CD103+ DCs. Dietary elements, including fiber and vitamin A, therefore regulate numerous protective pathways in the gastrointestinal tract, necessary for immune non-responsiveness to food antigens.

  19. Overexpression of persimmon DkXTH1 enhanced tolerance to abiotic stress and delayed fruit softening in transgenic plants.

    Science.gov (United States)

    Han, Ye; Han, Shoukun; Ban, Qiuyan; He, Yiheng; Jin, Mijing; Rao, Jingping

    2017-04-01

    DkXTH1 promoted cell elongation and more strength to maintain structural integrity by involving in cell wall assembly, thus enhanced tolerance to abiotic stress with broader phenotype in transgenic plants. Xyloglucan endotransglucosylase/hydrolase (XTH) is thought to play a key role in cell wall modifications by cleaving and re-joining xyloglucan, and participates in the diverse physiological processes. DkXTH1 was found to peak in immature expanding persimmon fruit, and its higher expression level exhibited along with firmer fruit during storage. In the present study, transgenic Arabidopsis and tomato plants were generated with DkXTH1 constitutively expressed. Overexpression of DkXTH1 enhanced tolerance to salt, ABA and drought stresses in transgenic Arabidopsis plants with respect to root and leaf growth, and survival. Transgenic tomatoes collected at the mature green stage, presented delayed fruit softening coupled with postponed color change, a later and lower ethylene peak, and higher firmness in comparison with the wild-type tomatoes during storage. Furthermore, broader leaves and tomato fruit with larger diameter were gained in transgenic Arabidopsis and tomato, respectively. Most importantly, transgenic plants exhibited more large and irregular cells with higher density of cell wall and intercellular spaces, resulting from the overactivity of XET enzymes involving in cell wall assembly. We suggest that DkXTH1 expression resulted in cells with more strength and thickness to maintain structural integrity, and thus enhanced tolerance to abiotic stress and delayed fruit softening in transgenic plants.

  20. Over-expression of a NAC 67 transcription factor from finger millet (Eleusine coracana L.) confers tolerance against salinity and drought stress in rice.

    Science.gov (United States)

    Rahman, Hifzur; Ramanathan, Valarmathi; Nallathambi, Jagedeeshselvam; Duraialagaraja, Sudhakar; Muthurajan, Raveendran

    2016-05-11

    NAC proteins (NAM (No apical meristem), ATAF (Arabidopsis transcription activation factor) and CUC (cup-shaped cotyledon)) are plant-specific transcription factors reported to be involved in regulating growth, development and stress responses. Salinity responsive transcriptome profiling in a set of contrasting finger millet genotypes through RNA-sequencing resulted in the identification of a NAC homolog (EcNAC 67) exhibiting differential salinity responsive expression pattern. Full length cDNA of EcNAC67 was isolated, characterized and validated for its role in abiotic stress tolerance through agrobacterium mediated genetic transformation in a rice cultivar ASD16. Bioinformatics analysis of putative NAC transcription factor (TF) isolated from a salinity tolerant finger millet showed its genetic relatedness to NAC67 family TFs in related cereals. Putative transgenic lines of rice over-expressing EcNAC67 were generated through Agrobacterium mediated transformation and presence/integration of transgene was confirmed through PCR and southern hybridization analysis. Transgenic rice plants harboring EcNAC67 showed enhanced tolerance against drought and salinity under greenhouse conditions. Transgenic rice plants were found to possess higher root and shoot biomass during stress and showed better revival ability upon relief from salinity stress. Upon drought stress, transgenic lines were found to maintain higher relative water content and lesser reduction in grain yield when compared to non-transgenic ASD16 plants. Drought induced spikelet sterility was found to be much lower in the transgenic lines than the non-transgenic ASD16. Results revealed the significant role of EcNAC67 in modulating responses against dehydration stress in rice. No detectable abnormalities in the phenotypic traits were observed in the transgenic plants under normal growth conditions. Results indicate that EcNAC67 can be used as a novel source for engineering tolerance against drought and salinity

  1. The Antirrhinum AmDEL gene enhances flavonoids accumulation and salt and drought tolerance in transgenic Arabidopsis.

    Science.gov (United States)

    Wang, Feibing; Zhu, Hong; Kong, Weili; Peng, Rihe; Liu, Qingchang; Yao, Quanhong

    2016-07-01

    A basic helix-loop-helix (bHLH) transcription factor gene from Antirrhinum, AmDEL , increases flavonoids accumulation and enhances salt and drought tolerance via up-regulating flavonoid biosynthesis, proline biosynthesis and ROS scavenging genes in transgenic Arabidopsis. In plants, transcriptional regulation is the most important tools for increasing flavonoid biosynthesis. The AmDEL gene, as a basic helix-loop-helix transcription factor gene from Antirrhinum, has been shown to increase flavonoids accumulation in tomato. However, its role in tolerance to abiotic stresses has not yet been investigated. In this study, the codon-optimized AmDEL gene was chemically synthesized. Subcellular localization analysis in onion epidermal cells indicated that AmDEL protein was localized to the nucleus. Expression analysis in yeast showed that the full length of AmDEL exhibited transcriptional activation. Overexpression of AmDEL significantly increased flavonoids accumulation and enhanced salt and drought tolerance in transgenic Arabidopsis plants. Real-time quantitative PCR analysis showed that overexpression of AmDEL resulted in the up-regulation of genes involved in flavonoid biosynthesis, proline biosynthesis and ROS scavenging under salt and drought stresses. Meanwhile, Western blot and enzymatic analyses showed that the activities of phenylalanine ammonia lyase, chalcone isomerase, dihydroflavonol reductase, pyrroline-5-carboxylate synthase, superoxide dismutase and peroxidase were also increased. Further components analyses indicated that the significant increase of proline and relative water content and the significant reduction of H2O2 and malonaldehyde content were observed under salt and drought stresses. In addition, the rates of electrolyte leakage and water loss were reduced in transgenic plants. These findings imply functions of AmDEL in accumulation of flavonoids and tolerance to salt and drought stresses. The AmDEL gene has the potential to be used to increase

  2. MhYTP1 and MhYTP2 from Apple Confer Tolerance to Multiple Abiotic Stresses in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Na Wang

    2017-08-01

    Full Text Available The first YTH domain-containing RNA binding protein (YTP was found in rat, where it was related to oxidative stress. Unlike characterizations in yeast and animals, functions of plant YTPs are less clear. Malus hupehensis (Pamp. Rehd. YTP1 and YTP2 (MhYTP1 and MhYTP2 are known to be active in leaf senescence and fruit ripening. However, no research has been published about their roles in stress responses. Here, we investigate the stress-related functions of MhYTP1 and MhYTP2 in Arabidopsis thaliana. Both of the two genes participated in salicylic acid (SA, jasmonic acid (JA, and abscisic acid (ABA signaling and play roles in plant responses to oxidative stress, chilling, high temperature, high salinity, and mannitol induced physiological drought stress. Moreover, MhYTP1 plays leading roles in SA and ABA signaling, and MhYTP2 plays leading roles in JA signaling and oxidative stress responses. These results will fill a gap in our knowledge about plant YTPs and stress responses and provide a foundation for future attempts to improve stress tolerance in apple.

  3. Role of the durum wheat dehydrin in the function of proteases conferring salinity tolerance in Arabidopsis thaliana transgenic lines.

    Science.gov (United States)

    Saibi, Walid; Zouari, Nabil; Masmoudi, Khaled; Brini, Faiçal

    2016-04-01

    Dehydrins are claimed to stabilize macromolecules against freezing damage, dehydration, ionic or osmotic stresses, thermal stress and re-folding yield. However, their precise function remains unknown. In this context, we report the behavior of protease activities in dehydrin transgenic Arabidopsis lines against the wild type plant under salt stress (100mM NaCl). Indeed, proteases play key roles in plants, maintaining strict protein quality control and degrading specific sets of proteins in response to diverse environmental and developmental stimuli. We proved that durum wheat DHN-5 modulates the activity of some proteases, summarized on the promotion of the Cysteinyl protease and the decrease of the Aspartyl protease activity. This fact is also upgraded in salt stress conditions. We conclude that the dehydrin transgenic context encodes salinity tolerance in transgenic lines through the modulation of the interaction not only at transcriptional level but also at protein level and also with the impact of salt stress as an endogenous and exogenous effector on some biocatalysts like proteases. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Overexpression of the tonoplast aquaporin AtTIP5;1 conferred tolerance to boron toxicity in Arabidopsis.

    Science.gov (United States)

    Pang, Yongqi; Li, Lijuan; Ren, Fei; Lu, Pingli; Wei, Pengcheng; Cai, Jinghui; Xin, Lingguo; Zhang, Juan; Chen, Jia; Wang, Xuechen

    2010-06-01

    Boron (B) toxicity to plants is responsible for low crop productivity in many regions of the world. Here we report a novel and effective means to alleviate the B toxicity to plants under high B circumstance. Functional characterization of AtTIP5;1, an aquaporin gene, revealed that overexpression of AtTIP5;1 (OxAtTIP5;1) in Arabidopsis significantly increased its tolerance to high B toxicity. Compared to wild-type plants, OxAtTIP5;1 plants exhibited longer hypocotyls, accelerated development, increased silique production under high B treatments. GUS staining and quantitative RT-PCR (qRT-PCR) results demonstrated that the expression of AtTIP5;1 was induced by high B concentration treatment. Subcellular localization analysis revealed that the AtTIP5;1-GFP fusion protein was localized on the tonoplast membrane, which was consistent with the prediction based on bioinformatics. Taken together, our results suggest that AtTIP5;1 is involved in B transport pathway possibly via vacuolar compartmentation for B, and that overexpression of AtTIP5;1 in plants may provide an effective way to overcome the problem resulting from high B concentration toxicity. Copyright 2010 Institute of Genetics and Developmental Biology and the Genetics Society of China. Published by Elsevier Ltd. All rights reserved.

  5. GhWRKY25, a group I WRKY gene from cotton, confers differential tolerance to abiotic and biotic stresses in transgenic Nicotiana benthamiana.

    Science.gov (United States)

    Liu, Xiufang; Song, Yunzhi; Xing, Fangyu; Wang, Ning; Wen, Fujiang; Zhu, Changxiang

    2016-09-01

    WRKY transcription factors are involved in various processes, ranging from plant growth to abiotic and biotic stress responses. Group I WRKY members have been rarely reported compared with group II or III members, particularly in cotton (Gossypium hirsutum). In this study, a group I WRKY gene, namely, GhWRKY25, was cloned from cotton and characterized. Expression analysis revealed that GhWRKY25 can be induced or deduced by the treatments of abiotic stresses and multiple defense-related signaling molecules. Overexpression of GhWRKY25 in Nicotiana benthamiana reduced plant tolerance to drought stress but enhanced tolerance to salt stress. Moreover, more MDA and ROS accumulated in transgenic plants after drought treatment with lower activities of SOD, POD, and CAT. Our study further demonstrated that GhWRKY25 overexpression in plants enhanced sensitivity to the fungal pathogen Botrytis cinerea by reducing the expression of SA or ET signaling related genes and inducing the expression of genes involved in the JA signaling pathway. These results indicated that GhWRKY25 plays negative or positive roles in response to abiotic stresses, and the reduced pathogen resistance may be related to the crosstalk of the SA and JA/ET signaling pathways.

  6. Phase 1A Final Report for the AREVA Team Enhanced Accident Tolerant Fuels Concepts

    Energy Technology Data Exchange (ETDEWEB)

    Morrell, Mike E. [AREVA Federal Services LLC, Charlotte, NC (United States)

    2015-03-19

    In response to the Department of Energy (DOE) funded initiative to develop and deploy lead fuel assemblies (LFAs) of Enhanced Accident Tolerant Fuel (EATF) into a US reactor within 10 years, AREVA put together a team to develop promising technologies for improved fuel performance during off normal operations. This team consisted of the University of Florida (UF) and the University of Wisconsin (UW), Savannah River National Laboratory (SRNL), Duke Energy and Tennessee Valley Authority (TVA). This team brought broad experience and expertise to bear on EATF development. AREVA has been designing; manufacturing and testing nuclear fuel for over 50 years and is one of the 3 large international companies supplying fuel to the nuclear industry. The university and National Laboratory team members brought expertise in nuclear fuel concepts and materials development. Duke and TVA brought practical utility operating experience. This report documents the results from the initial “discovery phase” where the team explored options for EATF concepts that provide enhanced accident tolerance for both Design Basis (DB) and Beyond Design Basis Events (BDB). The main driver for the concepts under development were that they could be implemented in a 10 year time frame and be economically viable and acceptable to the nuclear fuel marketplace. The economics of fuel design make this DOE funded project very important to the nuclear industry. Even incremental changes to an existing fuel design can cost in the range of $100M to implement through to LFAs. If this money is invested evenly over 10 years then it can take the fuel vendor several decades after the start of the project to recover their initial investment and reach a breakeven point on the initial investment. Step or radical changes to a fuel assembly design can cost upwards of $500M and will take even longer for the fuel vendor to recover their investment. With the projected lifetimes of the current generation of nuclear power

  7. A late embryogenesis abundant protein HVA1 regulated by an inducible promoter enhances root growth and abiotic stress tolerance in rice without yield penalty.

    Science.gov (United States)

    Chen, Yi-Shih; Lo, Shuen-Fang; Sun, Peng-Kai; Lu, Chung-An; Ho, Tuan-Hua D; Yu, Su-May

    2015-01-01

    Regulation of root architecture is essential for maintaining plant growth under adverse environment. A synthetic abscisic acid (ABA)/stress-inducible promoter was designed to control the expression of a late embryogenesis abundant protein (HVA1) in transgenic rice. The background of HVA1 is low but highly inducible by ABA, salt, dehydration and cold. HVA1 was highly accumulated in root apical meristem (RAM) and lateral root primordia (LRP) after ABA/stress treatments, leading to enhanced root system expansion. Water-use efficiency (WUE) and biomass also increased in transgenic rice, likely due to the maintenance of normal cell functions and metabolic activities conferred by HVA1 which is capable of stabilizing proteins, under osmotic stress. HVA1 promotes lateral root (LR) initiation, elongation and emergence and primary root (PR) elongation via an auxin-dependent process, particularly by intensifying asymmetrical accumulation of auxin in LRP founder cells and RAM, even under ABA/stress-suppressive conditions. We demonstrate a successful application of an inducible promoter in regulating the spatial and temporal expression of HVA1 for improving root architecture and multiple stress tolerance without yield penalty. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  8. Overexpression of rice thaumatin-like protein (Ostlp gene in transgenic cassava results in enhanced tolerance to Colletotrichum gloeosporioides f. sp. manihotis

    Directory of Open Access Journals (Sweden)

    Patroba Odeny Ojola

    2018-06-01

    Full Text Available Cassava (Manihot esculenta Crantz is the most important staple food for more than 300 million people in Africa, and anthracnose disease caused by Colletotrichum gloeosporioides f. sp. manihotis is the most destructive fungal disease affecting cassava production in sub-Saharan Africa. The main objective of this study was to improve anthracnose resistance in cassava through genetic engineering. Transgenic cassava plants harbouring rice thaumatin-like protein (Ostlp gene, driven by the constitutive CaMV35S promoter, were generated using Agrobacterium-mediated transformation of friable embryogenic calli (FEC of cultivar TMS 60444. Molecular analysis confirmed the presence, integration, copy number of the transgene all the independent transgenic events. Semi-quantitative RT-PCR confirmed high expression levels of Ostlp in six transgenic lines tested. The antifungal activity of the transgene against Colletotrichum gloeosporioides pathogen was evaluated using the leaves and stem cuttings bioassay. The results demonstrated significantly delayed disease development and reduced size of necrotic lesions in leaves and stem cuttings of all transgenic lines compared to the leaves and stem cuttingss of non-transgenic control plants. Therefore, constitutive overexpression of rice thaumatin-like protein in transgenic cassava confers enhanced tolerance to the fungal pathogen C. gloeosporioides f. sp. manihotis. These results can therefore serve as an initial step towards genetic engineering of farmer-preffered cassava cultivars for resistance to anthracnose disease. Keywords: Colletotrichum gloeosporioides f. sp. manihotis, Thaumatin-like protein, Transgenic cassava

  9. Enhanced drought-tolerance in the homoploid hybrid species Pinus densata: implication for its habitat divergence from two progenitors.

    Science.gov (United States)

    Ma, Fei; Zhao, Changming; Milne, Richard; Ji, Mingfei; Chen, Litong; Liu, Jianquan

    2010-01-01

    The homoploid hybrid species Pinus densata is restricted to alpine habitats that exceed the altitude range of its two parental species, Pinus tabulaeformis and Pinus yunnanensis. Alpine habitats usually generate cold-induced water stress in plants. To understand the ecological differentiation between these three species, we examined their physiological responses to drought stress. Potted seedlings of three species were subjected to low, mild, moderate and severe water stress in an automatic-controlled glasshouse. Fifteen indicators of fitness were measured for each species in each treatment, and most of these decreased as drought increased. Pinus densata exhibited higher fitness than both parental species in terms of total dry mass production (TDM) and long-term water use efficiency (WUE(L)) across all treatments; several other ecophysiological traits were also extreme but not across every treatment, and not always in the highest stress treatment. These results indicate that extreme characters that have become well fixed in P. densata, confer a faster seedling growth rate and more efficient water use, which in turn should confer increased drought tolerance. These traits of P. densata likely promoted its ecological separation from its parental species and facilitated its successful colonization and establishment in high-altitude habitats.

  10. Genotypes Associated with Listeria monocytogenes Isolates Displaying Impaired or Enhanced Tolerances to Cold, Salt, Acid, or Desiccation Stress

    Science.gov (United States)

    Hingston, Patricia; Chen, Jessica; Dhillon, Bhavjinder K.; Laing, Chad; Bertelli, Claire; Gannon, Victor; Tasara, Taurai; Allen, Kevin; Brinkman, Fiona S. L.; Truelstrup Hansen, Lisbeth; Wang, Siyun

    2017-01-01

    sequencing of L. monocytogenes isolates in combination with stress tolerance profiling, will enhance the ability to identify genetic elements associated with higher risk strains. PMID:28337186

  11. Plant nuclear factor Y (NF-Y) B subunits confer drought tolerance and lead to improved corn yields on water-limited acres.

    Science.gov (United States)

    Nelson, Donald E; Repetti, Peter P; Adams, Tom R; Creelman, Robert A; Wu, Jingrui; Warner, David C; Anstrom, Don C; Bensen, Robert J; Castiglioni, Paolo P; Donnarummo, Meghan G; Hinchey, Brendan S; Kumimoto, Roderick W; Maszle, Don R; Canales, Roger D; Krolikowski, Katherine A; Dotson, Stanton B; Gutterson, Neal; Ratcliffe, Oliver J; Heard, Jacqueline E

    2007-10-16

    Commercially improved crop performance under drought conditions has been challenging because of the complexity of the trait and the multitude of factors that influence yield. Here we report the results of a functional genomics approach that identified a transcription factor from the nuclear factor Y (NF-Y) family, AtNF-YB1, which acts through a previously undescribed mechanism to confer improved performance in Arabidopsis under drought conditions. An orthologous maize transcription factor, ZmNF-YB2, is shown to have an equivalent activity. Under water-limited conditions, transgenic maize plants with increased ZmNF-YB2 expression show tolerance to drought based on the responses of a number of stress-related parameters, including chlorophyll content, stomatal conductance, leaf temperature, reduced wilting, and maintenance of photosynthesis. These stress adaptations contribute to a grain yield advantage to maize under water-limited environments. The application of this technology has the potential to significantly impact maize production systems that experience drought.

  12. Overexpression of Arachis hypogaea AREB1 Gene Enhances Drought Tolerance by Modulating ROS Scavenging and Maintaining Endogenous ABA Content

    Directory of Open Access Journals (Sweden)

    Ling Li

    2013-06-01

    Full Text Available AhAREB1 (Arachis hypogaea Abscisic-acid Response Element Binding Protein 1 is a member of the basic domain leucine zipper (bZIP-type transcription factor in peanut. Previously, we found that expression of AhAREB1 was specifically induced by abscisic acid (ABA, dehydration and drought. To understand the drought defense mechanism regulated by AhAREB1, transgenic Arabidopsis overexpressing AhAREB1 was conducted in wild-type (WT, and a complementation experiment was employed to ABA non-sensitivity mutant abi5 (abscisic acid-insensitive 5. Constitutive expression of AhAREB1 confers water stress tolerance and is highly sensitive to exogenous ABA. Microarray and further real-time PCR analysis revealed that drought stress, reactive oxygen species (ROS scavenging, ABA synthesis/metabolism-related genes and others were regulated in transgenic Arabidopsis overexpressing AhAREB1. Accordingly, low level of ROS, but higher ABA content was detected in the transgenic Arabidopsis plants’ overexpression of AhAREB1. Taken together, it was concluded that AhAREB1 modulates ROS accumulation and endogenous ABA level to improve drought tolerance in transgenic Arabidopsis.

  13. Exogenous application of hydrogen sulfide donor sodium hydrosulfide enhanced multiple abiotic stress tolerance in bermudagrass (Cynodon dactylon (L). Pers.).

    Science.gov (United States)

    Shi, Haitao; Ye, Tiantian; Chan, Zhulong

    2013-10-01

    As a gaseous molecule, hydrogen sulfide (H2S) has been recently found to be involved in plant responses to multiple abiotic stress. In this study, salt (150 and 300 mM NaCl), osmotic (15% and 30% PEG6000) and cold (4 °C) stress treatments induced accumulation of endogenous H2S level, indicating that H2S might play a role in bermudagrass responses to salt, osmotic and cold stresses. Exogenous application of H2S donor (sodium hydrosulfide, NaHS) conferred improved salt, osmotic and freezing stress tolerances in bermudagrass, which were evidenced by decreased electrolyte leakage and increased survival rate under stress conditions. Additionally, NaHS treatment alleviated the reactive oxygen species (ROS) burst and cell damage induced by abiotic stress, via modulating metabolisms of several antioxidant enzymes [catalase (CAT), peroxidase (POD) and GR (glutathione reductase)] and non-enzymatic glutathione antioxidant pool and redox state. Moreover, exogenous NaHS treatment led to accumulation of osmolytes (proline, sucrose and soluble total sugars) in stressed bermudagrass plants. Taken together, all these data indicated the protective roles of H2S in bermudagrass responses to salt, osmotic and freezing stresses, via activation of the antioxidant response and osmolyte accumulation. These findings might be applicable to grass and crop engineering to improve abiotic stress tolerance. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  14. Adaptive evolution of Saccharomyces cerevisiae with enhanced ethanol tolerance for Chinese rice wine fermentation.

    Science.gov (United States)

    Chen, Shuang; Xu, Yan

    2014-08-01

    High tolerance towards ethanol is a desirable property for the Saccharomyces cerevisiae strains used in the alcoholic beverage industry. To improve the ethanol tolerance of an industrial Chinese rice wine yeast, a sequential batch fermentation strategy was used to adaptively evolve a chemically mutagenized Chinese rice wine G85 strain. The high level of ethanol produced under Chinese rice wine-like fermentation conditions was used as the selective pressure. After adaptive evolution of approximately 200 generations, mutant G85X-8 was isolated and shown to have markedly increased ethanol tolerance. The evolved strain also showed higher osmotic and temperature tolerances than the parental strain. Laboratory Chinese rice wine fermentation showed that the evolved G85X-8 strain was able to catabolize sugars more completely than the parental G85 strain. A higher level of yeast cell activity was found in the fermentation mash produced by the evolved strain, but the aroma profiles were similar between the evolved and parental strains. The improved ethanol tolerance in the evolved strain might be ascribed to the altered fatty acids composition of the cell membrane and higher intracellular trehalose concentrations. These results suggest that adaptive evolution is an efficient approach for the non-recombinant modification of industrial yeast strains.

  15. Functional FRIGIDA allele enhances drought tolerance by regulating the P5CS1 pathway in Arabidopsis thaliana.

    Science.gov (United States)

    Chen, Qian; Zheng, Yan; Luo, Landi; Yang, Yongping; Hu, Xiangyang; Kong, Xiangxiang

    2018-01-01

    Flowering at the right time is important for the reproductive success of plants and their response to environmental stress. In Arabidopsis, a major determinant of natural variation in flowering time is FRIGIDA (FRI). In the present study, we show that overexpression of the functional FRIGIDA gene in wild-type Col background (ColFRI) positively enhances the drought tolerance by activating P5CS1 expression and promoting proline accumulation during water stress. Furthermore, no significant changes in FRI gene and protein expression levels were observed with drought treatment, whereas P5CS1 protein expression significantly increased. In contrast, vernalization treatment efficiently reduced P5CS1 expression levels and resulted in a decrease in drought tolerance in the ColFRI plants. The flc mutants with a functional FRI background also relieved FRI-mediated activation of P5CS1 during drought tolerance. Taken together, our findings reveal the novel function of FRI in enhancing drought resistance through its downstream P5CS1 pathway during water-deficit stress, which is dependent on its target, the FLC gene. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Diagnostic accuracy and tolerability of contrast enhanced CT colonoscopy in symptomatic patients with increased risk for colorectal cancer

    International Nuclear Information System (INIS)

    Ozsunar, Yelda; Coskun, Guelten; Delibas, Naciye; Uz, Burcin; Yuekselen, Vahit

    2009-01-01

    Objective: We compared the accuracy and tolerability of intravenous contrast enhanced spiral computed tomography colonography (CTC) and optical colonoscopy (OC) for the detection of colorectal neoplasia in symptomatic patients for colorectal neoplasia. Methods: A prospective study was performed in 48 patients with symptomatic patients with increased risk for colorectal cancer. Spiral CTC was performed in supine and prone positions after colonic cleansing. The axial, 2D MPR and virtual endoluminal views were analyzed. Results of spiral CTC were compared with OC which was done within 15 days. The psychometric tolerance test was asked to be performed for both CTC and colonoscopy after the procedure. Results: Ten lesions in 9 of 48 patients were found in CTC and confirmed with OC. Two masses and eight polyps, consisted of 1 tubulovillous, 1 tubular, 2 villous adenoma, 4 adenomatous polyp, 4 adenocarcinoma, were identified. Lesion prevalence was 21%. Sensitivity, specificity, accuracy, positive and negative predictive values were found 100%, 87%, 89%, 67% and 100%, respectively. Psychometric tolerance test showed that CTC significantly more comfortable comparing with OC (p = 0.00). CTC was the preferred method in 37% while OC was preferred in 6% of patients. In both techniques, the most unpleasant part was bowel cleansing. Conclusion: Contrast enhanced CTC is a highly accurate method in detecting colorectal lesions. Since the technique was found to be more comfortable and less time consuming compare to OE, it may be preferable in management of symptomatic patients with increased risk for colorectal cancer.

  17. A novel cold-inducible zinc finger protein from soybean, SCOF-1, enhances cold tolerance in transgenic plants.

    Science.gov (United States)

    Kim, J C; Lee, S H; Cheong, Y H; Yoo, C M; Lee, S I; Chun, H J; Yun, D J; Hong, J C; Lee, S Y; Lim, C O; Cho, M J

    2001-02-01

    Cold stress on plants induces changes in the transcription of cold response genes. A cDNA clone encoding C2H2-type zinc finger protein, SCOF-1, was isolated from soybean. The transcription of SCOF-1 is specifically induced by low temperature and abscisic acid (ABA) but not by dehydration or high salinity. Constitutive overexpression of SCOF-1 induced cold-regulated (COR) gene expression and enhanced cold tolerance of non-acclimated transgenic Arabidopsis and tobacco plants. SCOF-1 localized to the nucleus but did not bind directly to either C-repeat/dehydration (CRT/DRE) or ABA responsive element (ABRE), cis-acting DNA regulatory elements present in COR gene promoters. However, SCOF-1 greatly enhanced the DNA binding activity of SGBF-1, a soybean G-box binding bZIP transcription factor, to ABRE in vitro. SCOF-1 also interacted with SGBF-1 in a yeast two-hybrid system. The SGBF-1 transactivated the beta-glucuronidase reporter gene driven by the ABRE element in Arabidopsis leaf protoplasts. Furthermore, the SCOF-1 enhanced ABRE-dependent gene expression mediated by SGBF-1. These results suggest that SCOF-1 may function as a positive regulator of COR gene expression mediated by ABRE via protein-protein interaction, which in turn enhances cold tolerance of plants.

  18. Limited uptake, translocation and enhanced metabolic degradation contribute to glyphosate tolerance in Mucuna pruriens var. utilis plants.

    Science.gov (United States)

    Rojano-Delgado, Antonia María; Cruz-Hipolito, Hugo; De Prado, Rafael; Luque de Castro, María Dolores; Franco, Antonio Rodríguez

    2012-01-01

    Velvet bean (Mucuna pruriens, Fabaceae) plants exhibits an innate, very high resistance (i.e., tolerance) to glyphosate similar to that of plants which have acquired resistance to this herbicide as a trait. We analyzed the uptake of [(14)C]-glyphosate by leaves and its translocation to meristematic tissues, and used scanning electron micrographs to further analyze the cuticle and 3D capillary electrophoresis to investigate a putative metabolism capable of degrading the herbicide. Velvet bean exhibited limited uptake of glyphosate and impaired translocation of the compound to meristematic tissues. Also, for the first time in a higher plant, two concurrent pathways capable of degrading glyphosate to AMPA, Pi, glyoxylate, sarcosine and formaldehyde as end products were identified. Based on the results, the innate tolerance of velvet bean to glyphosate is possibly a result of the combined action of the previous three traits, namely: limited uptake, impaired translocation and enhanced degradation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Tolerance for audiovisual asynchrony is enhanced by the spectrotemporal fidelity of the speaker's mouth movements and speech.

    Science.gov (United States)

    Shahin, Antoine J; Shen, Stanley; Kerlin, Jess R

    2017-01-01

    We examined the relationship between tolerance for audiovisual onset asynchrony (AVOA) and the spectrotemporal fidelity of the spoken words and the speaker's mouth movements. In two experiments that only varied in the temporal order of sensory modality, visual speech leading (exp1) or lagging (exp2) acoustic speech, participants watched intact and blurred videos of a speaker uttering trisyllabic words and nonwords that were noise vocoded with 4-, 8-, 16-, and 32-channels. They judged whether the speaker's mouth movements and the speech sounds were in-sync or out-of-sync . Individuals perceived synchrony (tolerated AVOA) on more trials when the acoustic speech was more speech-like (8 channels and higher vs. 4 channels), and when visual speech was intact than blurred (exp1 only). These findings suggest that enhanced spectrotemporal fidelity of the audiovisual (AV) signal prompts the brain to widen the window of integration promoting the fusion of temporally distant AV percepts.

  20. Enhanced cadmium accumulation and tolerance in transgenic tobacco overexpressing rice metal tolerance protein gene OsMTP1 is promising for phytoremediation.

    Science.gov (United States)

    Das, Natasha; Bhattacharya, Surajit; Maiti, Mrinal K

    2016-08-01

    One of the most grievous heavy metal pollutants in the environment is cadmium (Cd), which is not only responsible for the crop yield loss owing to its phytotoxicity, but also for the human health hazards as the toxic elements usually accumulate in the consumable parts of crop plants. In the present study, we aimed to isolate and functionally characterize the OsMTP1 gene from indica rice (Oryza sativa L. cv. IR64) to study its potential application for efficient phytoremediation of Cd. The 1257 bp coding DNA sequence (CDS) of OsMTP1 encodes a ∼46 kDa protein belonging to the cation diffusion facilitator (CDF) or metal tolerance/transport protein (MTP) family. The OsMTP1 transcript in rice plant was found to respond during external Cd stress. Heterologous expression of OsMTP1 in tobacco resulted in the reduction of Cd stress-induced phytotoxic effects, including growth inhibition, lipid peroxidation, and cell death. Compared to untransformed control, the transgenic tobacco plants showed enhanced vacuolar thiol content, indicating vacuolar localization of the sequestered Cd. The transgenic tobacco plants exhibited significantly higher biomass growth (2.2-2.8-folds) and hyperaccumulation of Cd (1.96-2.22-folds) compared to untransformed control under Cd exposure. The transgenic plants also showed moderate tolerance and accumulation of arsenic (As) upon exogenous As stress, signifying broad substrate specificity of OsMTP1. Together, findings of our research suggest that the transgenic tobacco plants overexpressing OsMTP1 with its hyperaccumulating activity and increased growth rate could be useful for future phytoremediation applications to clean up the Cd-contaminated soil. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  1. Expression of a monothiol glutaredoxin, AtGRXS17, in tomato (Solanum lycopersicum) enhances drought tolerance

    Science.gov (United States)

    Abiotic stresses are a major factor limiting crop growth and productivity. Our previous studies revealed that Arabidopsis thaliana glutaredoxin S17 (AtGRXS17) has conserved functions in plant tolerance to heat and chilling stress in tomato. Here, we report that ectopic expression of AtGRXS17 in toma...

  2. Pretreatment of seed with H2O2 enhances drought tolerance of ...

    African Journals Online (AJOL)

    Drought is an important environmental constraint limiting the productivity of many crops worldwide. Seedling tolerance to drought is crucial for crop growth and development through the whole season under water-limited condition. Experiments were conducted to investigate the effects of seed pretreatment by hydrogen ...

  3. TaSK5, an abiotic stress-inducible GSK3/shaggy-like kinase from wheat, confers salt and drought tolerance in transgenic Arabidopsis.

    Science.gov (United States)

    Christov, Nikolai Kirilov; Christova, Petya Koeva; Kato, Hideki; Liu, Yuelin; Sasaki, Kentaro; Imai, Ryozo

    2014-11-01

    A novel cold-inducible GSK3/shaggy-like kinase, TaSK5, was isolated from winter wheat using a macroarray-based differential screening approach. TaSK5 showed high similarity to Arabidopsis subgroup I GSK3/shaggy-like kinases ASK-alpha, AtSK-gamma and ASK-epsilon. RNA gel blot analyses revealed TaSK5 induction by cold and NaCl treatments and to a lesser extent by drought treatment. TaSK5 functionally complemented the cold- and salt-sensitive phenotypes of a yeast GSK3/shaggy-like kinase mutant, △mck1. Transgenic Arabidopsis plants overexpressing TaSK5 cDNA showed enhanced tolerance to salt and drought stresses. By contrast, the tolerance of the transgenic plants to freezing stress was not altered. Microarray analysis revealed that a number of abiotic stress-inducible genes were constitutively induced in the transgenic Arabidopsis plants, suggesting that TaSK5 may function in a novel signal transduction pathway that appears to be unrelated to DREB1/CBF regulon and may involve crosstalk between abiotic and hormonal signals. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  4. Melatonin confers plant tolerance against cadmium stress via the decrease of cadmium accumulation and reestablishment of microRNA-mediated redox homeostasis.

    Science.gov (United States)

    Gu, Quan; Chen, Ziping; Yu, Xiuli; Cui, Weiti; Pan, Jincheng; Zhao, Gan; Xu, Sheng; Wang, Ren; Shen, Wenbiao

    2017-08-01

    Although melatonin-alleviated cadmium (Cd) toxicity both in animals and plants have been well studied, little is known about its regulatory mechanisms in plants. Here, we discovered that Cd stress stimulated the production of endogenous melatonin in alfalfa seedling root tissues. The pretreatment with exogenous melatonin not only increased melatonin content, but also alleviated Cd-induced seedling growth inhibition. The melatonin-rich transgenic Arabidopsis plants overexpressing alfalfa SNAT (a melatonin synthetic gene) exhibited more tolerance than wild-type plants under Cd conditions. Cd content was also reduced in root tissues. In comparison with Cd stress alone, ABC transporter and PCR2 transcripts in alfalfa seedlings, PDR8 and HMA4 in Arabidopsis, were up-regulated by melatonin. By contrast, Nramp6 transcripts were down-regulated. Changes in above transporters were correlated with the less accumulation of Cd. Additionally Cd-triggered redox imbalance was improved by melatonin. These could be supported by the changes of the Cu/Zn Superoxide Dismutase gene regulated by miR398a and miR398b. Histochemical staining, laser scanning confocal microscope, and H 2 O 2 contents analyses showed the similar tendencies. Taking together, we clearly suggested that melatonin enhanced Cd tolerance via decreasing cadmium accumulation and reestablishing the microRNAs-mediated redox homeostasis. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Conference summaries

    International Nuclear Information System (INIS)

    1988-01-01

    This volume contains conference summaries of the 28. annual conference of the Canadian Nuclear Association, and the 9. annual conference of the Canadian Nuclear Society. Topics of discussion include: power reactors; fuel cycles; nuclear power and public understanding; future trends; applications of nuclear technology; CANDU reactors; operational enhancements; design of small reactors; accident behaviour in fuel channels; fuel storage and waste management; reactor commissioning/decommissioning; nuclear safety experiments and modelling; the next generation reactors; advances in nuclear engineering education in Canada; safety of small reactors; current position and improvements of fuel channels; current issues in nuclear safety; and radiation applications - medical and industrial

  6. Castasterone confers copper stress tolerance by regulating antioxidant enzyme responses, antioxidants, and amino acid balance in B. juncea seedlings.

    Science.gov (United States)

    Yadav, Poonam; Kaur, Ravdeep; Kanwar, Mukesh Kumar; Sharma, Anket; Verma, Vinod; Sirhindi, Geetika; Bhardwaj, Renu

    2018-01-01

    The aim of the present study was to explore the effect of exogenous application of castasterone (CS) on physiologic and biochemical responses in Brassica juncea seedlings under copper (Cu) stress. Seeds were pre-soaked in different concentrations of CS and grown for 7 days under various levels of Cu. The exposure of B. juncea to higher levels of Cu led to decrease of morphologic parameters, with partial recovery of length and fresh weight in the CS pre-treated seedlings. Metal content was high in both roots and shoots under Cu exposure while the CS pre-treatment reduced the metal uptake. Accumulation of hydrogen peroxide (H 2 O 2 ) and superoxide anion radical (O 2 - ) were chosen as stress biomarker and higher levels of H 2 O 2 (88.89%) and O 2 - (62.11%) showed the oxidative stress in metal treated B. juncea seedlings, however, CS pre-treatment reduced ROS accumulation in Cu-exposed seedlings. The Cu exposures lead to enhance the plant's enzymatic and non-enzymatic antioxidant system. It was observed that enzymatic activities of ascorbate peroxidase (APOX), dehydroascorbate reductase (DHAR), and glutathione reductase (GR), glutathione perxoidase (GPOX) and gultrathione-s-transferase increased while activity of monodehydroascorbate reductase (MDHAR) decreased under Cu stress. The pre-treatment with CS positively affected the activities of enzymes. RT-PCR analysis showed that mRNA transcript levels were correlated with total enzymatic activity of DHAR, GR, GST and GSH. Increase in the gene expression of DHAR (1.85 folds), GR (3.24 folds), GST-1 (2.00 folds) and GSH-S (3.18 folds) was noticed with CS pre-treatment. Overall, the present study shows that Cu exposure induced severe oxidative stress in B. juncea plants and exogenous application of CS improved antioxidative defense system by modulating the ascorbate-glutathione cycle and amino acid metabolism. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Overexpression of GsZFP1 enhances salt and drought tolerance in transgenic alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Tang, Lili; Cai, Hua; Ji, Wei; Luo, Xiao; Wang, Zhenyu; Wu, Jing; Wang, Xuedong; Cui, Lin; Wang, Yang; Zhu, Yanming; Bai, Xi

    2013-10-01

    GsZFP1 encodes a Cys2/His2-type zinc-finger protein. In our previous study, when GsZFP1 was heterologously expressed in Arabidopsis, the transgenic Arabidopsis plants exhibited enhanced drought and cold tolerance. However, it is still unknown whether GsZFP1 is also involved in salt stress. GsZFP1 is from the wild legume Glycine soja. Therefore, the aims of this study were to further elucidate the functions of the GsZFP1 gene under salt and drought stress in the forage legume alfalfa and to investigate its biochemical and physiological functions under these stress conditions. Our data showed that overexpression of GsZFP1 in alfalfa resulted in enhanced salt tolerance. Under high salinity stress, greater relative membrane permeability and malondialdehyde (MDA) content were observed and more free proline and soluble sugars accumulated in transgenic alfalfa than in the wild-type (WT) plants; in addition, the transgenic lines accumulated less Na(+) and more K(+) in both the shoots and roots. Overexpression of GsZFP1 also enhanced the drought tolerance of alfalfa. The fold-inductions of stress-responsive marker gene expression, including MtCOR47, MtRAB18, MtP5CS, and MtRD2, were greater in transgenic alfalfa than those of WT under drought stress conditions. In conclusion, the transgenic alfalfa plants generated in this study could be used for farming in salt-affected as well as arid and semi-arid areas. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  8. Enhanced salt stress tolerance in transgenic potato plants expressing IbMYB1, a sweet potato transcription factor.

    Science.gov (United States)

    Cheng, Yu-Jie; Kim, Myoung-Duck; Deng, Xi-Ping; Kwak, Sang-Soo; Chen, Wei

    2013-12-01

    IbMYB1, a transcription factor (TF) for R2R3-type MYB TFs, is a key regulator of anthocyanin biosynthesis during storage of sweet potatoes. Anthocyanins provide important antioxidants of nutritional value to humans, and also protect plants from oxidative stress. This study aimed to increase transgenic potatoes' (Solanum tuberosum cv. LongShu No.3) tolerance to environmental stress and enhance their nutritional value. Transgenic potato plants expressing IbMYB1 genes under the control of an oxidative stress-inducible peroxidase (SWPA2) promoter (referred to as SM plants) were successfully generated through Agrobacterium-mediated transformation. Two representative transgenic SM5 and SM12 lines were evaluated for enhanced tolerance to salinity, UV-B rays, and drought conditions. Following treatment of 100 mM NaCl, seedlings of SM5 and SM12 lines showed less root damage and more shoot growth than control lines expressing only an empty vector. Transgenic potato plants in pots treated with 400 mM NaCl showed high amounts of secondary metabolites, including phenols, anthocyanins, and flavonoids, compared with control plants. After treatment of 400 mM NaCl, transgenic potato plants also showed high DDPH radical scavenging activity and high PS II photochemical efficiency compared with the control line. Furthermore, following treatment of NaCl, UV-B, and drought stress, the expression levels of IbMYB1 and several structural genes in the flavonoid biosynthesis such as CHS, DFR, and ANS in transgenic plants were found to be correlated with plant phenotype. The results suggest that enhanced IbMYB1 expression affects secondary metabolism, which leads to improved tolerance ability in transgenic potatoes.

  9. An iterative method applied to optimize the design of PIN photodiodes for enhanced radiation tolerance and maximum light response

    International Nuclear Information System (INIS)

    Cedola, A.P.; Cappelletti, M.A.; Casas, G.; Peltzer y Blanca, E.L.

    2011-01-01

    An iterative method based on numerical simulations was developed to enhance the proton radiation tolerance and the responsivity of Si PIN photodiodes. The method allows to calculate the optimal values of the intrinsic layer thickness and the incident light wavelength, in function of the light intensity and the maximum proton fluence to be supported by the device. These results minimize the effects of radiation on the total reverse current of the photodiode and maximize its response to light. The implementation of the method is useful in the design of devices whose operation point should not suffer variations due to radiation.

  10. Naturally evolved enhanced Cd tolerance of Dianthus carthusianorum L. is not related to accumulation of thiol peptides and organic acids.

    Science.gov (United States)

    Wójcik, Małgorzata; Dresler, Sławomir; Plak, Andrzej; Tukiendorf, Anna

    2015-05-01

    Two contrasting ecotypes of Dianthus carthusianorum L., metallicolous (M) and nonmetallicolous (NM), were cultivated in hydroponics at 0-50 μM Cd for 14 days to compare their Cd accumulation, sensitivity and tolerance mechanisms. While both ecotypes contained similar concentrations of Cd in the shoots and roots, the M ecotype was more Cd-tolerant (as measured by fresh weight production and root and leaf viability). Both ecotypes accumulated phytochelatins (PCs) in response to Cd with a higher amount thereof found in the NM ecotype. Concentrations of PCs remained unchanged with increasing Cd concentrations in the root tissues, but their content in the shoots increased. The addition of L-buthionine-sulfoximine (BSO) diminished glutathione (GSH) accumulation and arrested PC production, which increased the sensitivity to Cd of the NM, but not M ecotype. Organic acids (malate and citrate) as well as proline accumulation did not change significantly after Cd exposition and was at the same level in both ecotypes. The enhanced Cd tolerance of the M ecotype of D. carthusianorum cannot be explained in terms of restricted Cd uptake and differential production of PCs, organic acids or proline; some other mechanisms must be involved in its adaptation to the high Cd content in the environment.

  11. BoALMT1, an Al-Induced Malate Transporter in Cabbage, Enhances Aluminum Tolerance in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    2018-01-01

    Full Text Available Aluminum (Al is present in approximately 50% of the arable land worldwide and is regarded as the main limiting factor of crop yield on acidic soil. Al-induced root malate efflux plays an important role in the Al tolerance of plants. Here, the aluminum induced malate transporter BoALMT1 (KF322104 was cloned from cabbage (Brassica oleracea. BoALMT1 showed higher expression in roots than in shoots. The expression of BoALMT1 was specifically induced by Al treatment, but not the trivalent cations lanthanum (La, cadmium (Cd, zinc (Zn, or copper (Cu. Subcellular localization studies were performed in onion epidermal cells and revealed that BoALMT1 was localized at the plasma membrane. Scanning Ion-selective Electrode Technique was used to analyze H+ flux. Xenopus oocytes and Arabidopsis thaliana expressing BoALMT1 excreted more H+ under Al treatment. Overexpressing BoALMT1 in transgenic Arabidopsis resulted in enhanced Al tolerance and increased malate secretion. The results suggested that BoALMT1 functions as an Al-resistant gene and encodes a malate transporter. Expressing BoALMT1 in Xenopus oocytes or A. thaliana indicated that BoALMT1 could increase malate secretion and H+ efflux to resist Al tolerance.

  12. Arbuscular mycorrhizal fungi enhance the copper tolerance of Tagetes patula through the sorption and barrier mechanisms of intraradical hyphae.

    Science.gov (United States)

    Zhou, Xishi; Fu, Lei; Xia, Yan; Zheng, Luqing; Chen, Chen; Shen, Zhenguo; Chen, Yahua

    2017-07-19

    Arbuscular mycorrhizal fungi (AMF) are widespread soil fungi that can form endosymbiotic structures with the root systems of most plants and can improve the tolerance of host plants to heavy metals. In the present study, we investigated the effects of AMF (Glomus coronatum) inoculation on the tolerance of Tagetes patula L. to Cu. Almost all of the non-mycorrhizal plants exposed to 100 μM Cu died after 3 d, whereas phytotoxicity was only observed in mycorrhizal plants that were exposed to Cu concentrations greater than 100 μM. Analysing the dynamic accumulation of Cu indicated that, after 7 d of Cu exposure, less Cu was absorbed or accumulated by mycorrhizal plants than by control plants, and significantly less Cu was translocated to the shoots. Meanwhile, analysing the root morphology, the integrity of the root plasma membranes, the photosynthesis rate, and the content of essential elements of plants growing in cultures with 50 μM Cu revealed that AMF inoculation markedly alleviated the toxic effects of Cu stress on root system activity, photosynthesis rate, and mineral nutrient accumulation. In addition, to understand the Cu allocation, an energy spectrum analysis of Cu content at the transverse section of root tips was conducted and subsequently provided direct evidence that intraradical hyphae at the root endodermis could selectively immobilise large amounts of Cu. Indeed, the sorption and barrier mechanisms of AMF hyphae reduce Cu toxicity in the roots of T. patula and eventually enhance the plants' Cu tolerance.

  13. Reduced Tonoplast Fast-Activating and Slow-Activating Channel Activity Is Essential for Conferring Salinity Tolerance in a Facultative Halophyte, Quinoa1[C][W][OA

    Science.gov (United States)

    Bonales-Alatorre, Edgar; Shabala, Sergey; Chen, Zhong-Hua; Pottosin, Igor

    2013-01-01

    Halophyte species implement a “salt-including” strategy, sequestering significant amounts of Na+ to cell vacuoles. This requires a reduction of passive Na+ leak from the vacuole. In this work, we used quinoa (Chenopodium quinoa) to investigate the ability of halophytes to regulate Na+-permeable slow-activating (SV) and fast-activating (FV) tonoplast channels, linking it with Na+ accumulation in mesophyll cells and salt bladders as well as leaf photosynthetic efficiency under salt stress. Our data indicate that young leaves rely on Na+ exclusion to salt bladders, whereas old ones, possessing far fewer salt bladders, depend almost exclusively on Na+ sequestration to mesophyll vacuoles. Moreover, although old leaves accumulate more Na+, this does not compromise their leaf photochemistry. FV and SV channels are slightly more permeable for K+ than for Na+, and vacuoles in young leaves express less FV current and with a density unchanged in plants subjected to high (400 mm NaCl) salinity. In old leaves, with an intrinsically lower density of the FV current, FV channel density decreases about 2-fold in plants grown under high salinity. In contrast, intrinsic activity of SV channels in vacuoles from young leaves is unchanged under salt stress. In vacuoles of old leaves, however, it is 2- and 7-fold lower in older compared with young leaves in control- and salt-grown plants, respectively. We conclude that the negative control of SV and FV tonoplast channel activity in old leaves reduces Na+ leak, thus enabling efficient sequestration of Na+ to their vacuoles. This enables optimal photosynthetic performance, conferring salinity tolerance in quinoa species. PMID:23624857

  14. Cyanobacteria-mediated phenylpropanoids and phytohormones in rice (Oryza sativa) enhance plant growth and stress tolerance.

    Science.gov (United States)

    Singh, Dhananjaya P; Prabha, Ratna; Yandigeri, Mahesh S; Arora, Dilip K

    2011-11-01

    Phenylpropanoids, flavonoids and plant growth regulators in rice (Oryza sativa) variety (UPR 1823) inoculated with different cyanobacterial strains namely Anabaena oryzae, Anabaena doliolum, Phormidium fragile, Calothrix geitonos, Hapalosiphon intricatus, Aulosira fertilissima, Tolypothrix tenuis, Oscillatoria acuta and Plectonema boryanum were quantified using HPLC in pot conditions after 15 and 30 days. Qualitative analysis of the induced compounds using reverse phase HPLC and further confirmation with LC-MS/MS showed consistent accumulation of phenolic acids (gallic, gentisic, caffeic, chlorogenic and ferulic acids), flavonoids (rutin and quercetin) and phytohormones (indole acetic acid and indole butyric acid) in rice leaves. Plant growth promotion (shoot, root length and biomass) was positively correlated with total protein and chlorophyll content of leaves. Enzyme activity of peroxidase and phenylalanine ammonia lyase and total phenolic content was fairly high in rice leaves inoculated with O. acuta and P. boryanum after 30 days. Differential systemic accumulation of phenylpropanoids in plant leaves led us to conclude that cyanobacterial inoculation correlates positively with plant growth promotion and stress tolerance in rice. Furthermore, the study helped in deciphering possible mechanisms underlying plant growth promotion and stress tolerance in rice following cyanobacterial inoculation and indicated the less explored avenue of cyanobacterial colonization in stress tolerance against abiotic stress.

  15. A Mutated Yeast Strain with Enhanced Ethanol Production Efficiency and Stress Tolerance

    Directory of Open Access Journals (Sweden)

    Naghmeh Hemmati1*, David A. Lightfoot1,2, and Ahmed Fakhoury3

    2012-05-01

    Full Text Available One of the strategies to improve and optimize bio-ethanolproduction from new feed stocks is to develop new strainsof Saccharomyces cerevisiae with tolerance to stresses. Themain objectives here were to; generate S. cerevisiae mutantstolerant to high ethanol concentrations; test for their abilityto ferment maize starch; and partially characterize the mutationsresponsible for the new phenotypes. A combinationof mutagenesis, selection and cross-stress protection methodswere used. EMS (ethyl methanesulfonate was used tomutagenize one S. cerevisiae strain. The mutagenized yeaststrain was exposed to high concentrations of ethanol andtolerant mutants were isolated. Mutants showed improvedethanol yield (0.02-0.03 g/g of maize and fermentation efficiency(3-5%. Finally, AFLP (Amplified Fragment LengthPolymorphism was performed to identify polymorphisms inthe mutants that might underlie the strains ethanol tolerance.The best performing mutant isolate had four altered genetranscripts encoding; an arginine uptake and canavanine resistanceprotein (CAN1; mitochondrial membrane proteins(SLS1; a putative membrane glycoprotein (VTH1; and cytochromeC oxidase (COX6; EC 1.9.3.1 among about 1,000tested. It was concluded these mutations might underlie theimproved ethanol production efficiency and stress tolerance.

  16. A Nucleocytoplasmic Shuttling Protein in Oxidative Stress Tolerance

    Energy Technology Data Exchange (ETDEWEB)

    Ow, David W.; Song, Wen

    2003-03-26

    Plants for effective extraction of toxic metals and radionuclides must tolerate oxidative stress. To identify genes that enhance oxidative stress tolerance, an S. pombe cDNA expression plasmid library was screened for the ability to yield hypertolerant colonies. Here, we report on the properties of one gene that confers hypertolerance to cadmium and oxidizing chemicals. This gene appears to be conserved in other organisms as homologous genes are found in human, mouse, fruitfly and Arabidopsis. The fruitfly and Arabidopsis genes likewise enhance oxidative stress tolerance in fission yeast. During oxidative stress, the amount of mRNA does not change, but protein fusions to GFP relocate from the cytoplasm to the nucleus. The same pattern is observed with the Arabidopsis homologue-GFP fusion protein. This behavior suggests a signaling role in oxidative stress tolerance and these conserved proteins may be targets for engineering stress tolerant plants for phytoremediation.

  17. Over-expression of VvWRKY1 in grapevines induces expression of jasmonic acid pathway-related genes and confers higher tolerance to the downy mildew.

    Directory of Open Access Journals (Sweden)

    Chloé Marchive

    Full Text Available Most WRKY transcription factors activate expression of defence genes in a salicylic acid- and/or jasmonic acid-dependent signalling pathway. We previously identified a WRKY gene, VvWRKY1, which is able to enhance tolerance to fungal pathogens when it is overexpressed in tobacco. The present work analyzes the effects of VvWRKY1 overexpression in grapevine. Microarray analysis showed that genes encoding defence-related proteins were up-regulated in the leaves of transgenic 35S::VvWRKY1 grapevines. Quantitative RT-PCR analysis confirmed that three genes putatively involved in jasmonic acid signalling pathway were overexpressed in the transgenic grapes. The ability of VvWRKY1 to trans-activate the promoters of these genes was demonstrated by transient expression in grape protoplasts. The resistance to the causal agent of downy mildew, Plasmopara viticola, was enhanced in the transgenic plants. These results show that VvWRKY1 can increase resistance of grapevine against the downy mildew through transcriptional reprogramming leading to activation of the jasmonic acid signalling pathway.

  18. Overexpression of Pyrabactin Resistance-Like Abscisic Acid Receptors Enhances Drought, Osmotic, and Cold Tolerance in Transgenic Poplars

    Directory of Open Access Journals (Sweden)

    Jingling Yu

    2017-10-01

    Full Text Available Abscisic acid (ABA has been known participate in a wider range of adaptive responses to diverse environmental abiotic stresses such as drought, osmosis, and low temperatures. ABA signaling is initiated by its receptors PYR/PYL/RCARs, a type of soluble proteins with a conserved START domain which can bind ABA and trigger the downstream pathway. Previously, we discovered that poplar (Populus trichocarpa genome encodes 14 PYR/PYL/RCAR orthologs (PtPYRLs, and two of them, PtPYRL1 and PtPYRL5 have been functionally characterized to positively regulate drought tolerance. However, the physiological function of these ABA receptors in poplar remains uncharacterized. Here, we generated transgenic poplar plants overexpressing PtPYRL1 and PtPYRL5 and found that they exhibited more vigorous growth and produced greater biomass when exposed to drought stress. The improved drought tolerance was positively correlated with the key physiological responses dictated by the ABA signaling pathway, including increase in stomatal closure and decrease in leaf water loss. Further analyses revealed that overexpression lines showed improved capacity in scavenging reactive oxygen species and enhanced the activation of antioxidant enzymes under drought stress. Moreover, overexpression of PtPYRL1 or PtPYRL5 significantly increased the poplar resistance to osmotic and cold stresses. In summary, our results suggest that constitutive expression of PtPYRL1 and PtPYRL5 significantly enhances the resistance to drought, osmotic and cold stresses by positively regulating ABA signaling in poplar.

  19. Melatonin enhances cold tolerance in drought-primed wild-type and abscisic acid-deficient mutant barley.

    Science.gov (United States)

    Li, Xiangnan; Tan, Dun-Xian; Jiang, Dong; Liu, Fulai

    2016-10-01

    Melatonin is involved in multiple plant developmental processes and various stress responses. To explore the roles of melatonin played as well as its association with abscisic acid (ABA) in a process of drought priming-induced cold tolerance (DPICT), a wild-type barley and its ABA-deficient mutant Az34 counterpart were selected for comparison, in which the effects of melatonin application (either foliarly or rhizospherically) and/or drought priming on the cold tolerance of both types of barleys were systematically investigated. It was demonstrated that the early drought priming induced an increase of endogenous melatonin production, which is not ABA dependent. In addition, exogenously applied melatonin resulted in higher ABA concentration in the drought-primed plants than in the nonprimed plants when exposed to cold stress, indicating that ABA responded in a drought-dependent manner. The interplay of melatonin and ABA leads to plants maintaining better water status. Drought priming-induced melatonin accumulation enhanced the antioxidant capacity in both chloroplasts and mitochondria, which sustained the photosynthetic electron transport in photosynthetic apparatus of the plants under cold stress. These results suggest that the exogenous melatonin application enhances the DPICT by modulating subcellular antioxidant systems and ABA levels in barley. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Over-expression of histone H3K4 demethylase gene JMJ15 enhances salt tolerance in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Yuan eShen

    2014-06-01

    Full Text Available Histone H3 lysine 4 trimethylation (H3K4me3 has been shown to be involved in stress-responsive gene expression and gene priming in plants. However, the role of H3K4me3 resetting in the processes is not clear. In this work we studied the expression and function of Arabidopsis H3K4 demethylase gene JMJ15. We show that the expression of JMJ15 was relatively low and was limited to a number of tissues during vegetative growth but was higher in young floral organs. Over-expression of the gene in gain-of-function mutants reduced the plant height with accumulation of lignin in stems, while the loss-of-function mutation did not produce any visible phenotype. The gain-of-function mutants showed enhanced salt tolerance, whereas the loss-of-function mutant was more sensitive to salt compared to the wild type. Transcriptomic analysis revealed that over-expression of JMJ15 down-regulated many genes which are preferentially marked by H3K4me3 and H3K4me2. Many of the down-regulated genes encode transcription regulators involved in stress responses. The data suggest that increased JMJ15 levels may regulate the gene expression program that enhances stress tolerance.

  1. Enhancement of thermo-stability and product tolerance of Pseudomonas putida nitrile hydratase by fusing with self-assembling peptide.

    Science.gov (United States)

    Liu, Yi; Cui, Wenjing; Liu, Zhongmei; Cui, Youtian; Xia, Yuanyuan; Kobayashi, Michihiko; Zhou, Zhemin

    2014-09-01

    Self-assembling amphipathic peptides (SAPs) are the peptides that can spontaneously assemble into ordered nanostructures. It has been reported that the attachment of SAPs to the N- or C-terminus of an enzyme can benefit the thermo-stability of the enzyme. Here, we discovered that the thermo-stability and product tolerance of nitrile hydratase (NHase) were enhanced by fusing with two of the SAPs (EAK16 and ELK16). When the ELK16 was fused to the N-terminus of β-subunit, the resultant NHase (SAP-NHase-2) became an active inclusion body; EAK16 fused NHase in the N-terminus of β-subunit (SAP-NHase-1) and ELK16 fused NHase in the C-terminus of β-subunit (SAP-NHase-10) did not affect NHase solubility. Compared with the deactivation of the wild-type NHase after 30 min incubation at 50°C, SAP-NHase-1, SAP-NHase-2 and SAP-NHase-10 retained 45%, 30% and 50% activity; after treatment in the buffer containing 10% acrylamide, the wild-type retained 30% activity, while SAP-NHase-1, SAP-NHase-2 and SAP-NHase-10 retained 52%, 42% and 55% activity. These SAP-NHases with enhanced thermo-stability and product tolerance would be helpful for further industrial applications of the NHase. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  2. Enhancing the methanol tolerance of platinum nanoparticles for the cathode reaction of direct methanol fuel cells through a geometric design.

    Science.gov (United States)

    Feng, Yan; Ye, Feng; Liu, Hui; Yang, Jun

    2015-11-18

    Mastery over the structure of nanoparticles might be an effective way to enhance their performance for a given application. Herein we demonstrate the design of cage-bell nanostructures to enhance the methanol tolerance of platinum (Pt) nanoparticles while remaining their catalytic activity for oxygen reduction reaction. This strategy starts with the synthesis of core-shell-shell nanoparticles with Pt and silver (Ag) residing respectively in the core and inner shell regions, which are then agitated with saturated sodium chloride (NaCl) solution to eliminate the Ag component from the inner shell region, leading to the formation of bimetallic nanoparticles with a cage-bell structure, defined as a movable Pt core enclosed by a metal shell with nano-channels, which exhibit superior methanol-tolerant property in catalyzing oxygen reduction reaction due to the different diffusion behaviour of methanol and oxygen in the porous metal shell of cage-bell structured nanoparticles. In particular, the use of remarkably inexpensive chemical agent (NaCl) to promote the formation of cage-bell structured particles containing a wide spectrum of metal shells highlights its engineering merit to produce highly selective electrocatalysts on a large scale for the cathode reaction of direct methanol fuel cells.

  3. Enhancement of naphthalene tolerance in transgenic Arabidopsis plants overexpressing the ferredoxin-like protein (ADI1) from rice.

    Science.gov (United States)

    Fu, Xiao-Yan; Zhu, Bo; Han, Hong-Juan; Zhao, Wei; Tian, Yong-Sheng; Peng, Ri-He; Yao, Quan-Hong

    2016-01-01

    The ADI1 Arabidopsis plants enhanced tolerance and degradation efficiency to naphthalene and had great potential for phytoremediation of naphthalene in the plant material before composting or harvesting and removal. Naphthalene is a global environmental concern, because this substance is assumed to contribute considerably to human cancer risk. Cleaning up naphthalene contamination in the environment is crucial. Phytoremediation is an efficient technology to clean up contaminants. However, no gene that can efficiently degrade exogenous recalcitrant naphthalene in plants has yet been discovered. Ferredoxin (Fd) is a key player of biological electron transfer reaction in the PAH degradation process. The biochemical pathway for bacterial degradation of naphthalene has been well investigated. In this study, a rice gene, ADI1, which codes for a putative photosynthetic-type Fd, has been transformed into Arabidopsis thaliana. The transgenic Arabidopsis plants enhanced tolerance and degradation efficiency of naphthalene. Compared with wild-type plants, transgenic plants assimilated naphthalene from the culture media faster and removed more of this substance. When taken together, our findings suggest that breeding plants with overexpressed ADI1 gene is an effective strategy to degrade naphthalene in the environment.

  4. RNA interference of GhPEPC2 enhanced seed oil accumulation and salt tolerance in Upland cotton.

    Science.gov (United States)

    Zhao, Yanpeng; Huang, Yi; Wang, Yumei; Cui, Yupeng; Liu, Zhengjie; Hua, Jinping

    2018-06-01

    Phosphoenolpyruvate carboxylase (PEPCase) mainly produces oxaloacetic acid for tricarboxylic acid (TCA) cycle. Here we reported that GhPEPC2 silencing with PEPC2-RNAi vector could regulate oil and protein accumulation in cottonseeds. In GhPEPC2 transgenic plants, PEPCase activities in immature embryos were significantly reduced, and the oil content in seed kernel was increased 7.3 percentages, whereas total proteins decreased 5.65 percentages. Compared to wild type, agronomical traits of transgenic plant were obviously unaffected. Furthermore, gene expression profile of GhPEPC2 transgenic seeds were investigated using RNA-seq, most lipid synthesis related genes were up-regulated, but amino acid metabolic related genes were down-regulated. In addition, the GhPEPC2 transgenic cotton seedlings were stressed using sodium salts at seedling stage, and the salt tolerance was significantly enhanced. Our observations of GhPEPC2 in cotton would shade light on understanding the regulation of oil content, protein accumulation and salt tolerance enhancement in other plants. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Silicon enhanced salt tolerance by improving the root water uptake and decreasing the ion toxicity in cucumber

    Directory of Open Access Journals (Sweden)

    Shiwen eWang

    2015-09-01

    Full Text Available Although the effects of silicon application on enhancing plant salt tolerance have been widely investigated, the underlying mechanism has remained unclear. In this study, seedlings of cucumber, a medium silicon accumulator plant, grown in 0.83 mM silicon solution for two weeks were exposed to 65 mM NaCl solution for another one week. The dry weight and shoot/root ratio were reduced by salt stress, but silicon application significantly alleviated these decreases. The chlorophyll concentration, net photosynthetic rate, transpiration rate and leaf water content were higher in plants treated with silicon than in untreated plants under salt stress conditions. Further investigation showed that salt stress decreased root hydraulic conductance (Lp, but that silicon application moderated this salt-induced decrease in Lp. The higher Lp in silicon-treated plants may account for the superior plant water balance. Moreover, silicon application significantly decreased Na+ concentration in the leaves while increasing K+ concentration. Simultaneously, both free and conjugated types of polyamines were maintained at high levels in silicon-treated plants, suggesting that polyamines may be involved in the ion toxicity. Our results indicate that silicon enhances the salt tolerance of cucumber through improving plant water balance by increasing the Lp and reducing Na+ content by increasing polyamine accumulation.

  6. Overexpression of miR529a confers enhanced resistance to oxidative stress in rice (Oryza sativa L.).

    Science.gov (United States)

    Yue, Erkui; Liu, Zhen; Li, Chao; Li, Yu; Liu, Qiuxiang; Xu, Jian-Hong

    2017-07-01

    Overexpressing miR529a can enhance oxidative stress resistance by targeting OsSPL2 and OsSPL14 genes that can regulate the expression of their downstream SOD and POD related genes. MicroRNAs are involved in the regulation of plant developmental and physiological processes, and their expression can be altered when plants suffered environment stresses, including salt, oxidative, drought and Cadmium. The expression of microRNA529 (miR529) can be induced under oxidative stress. However, its biological function under abiotic stress responses is still unclear. In this study, miR529a was overexpressed to investigate the function of miR529a under oxidative stress in rice. Our results demonstrated that the expression of miR529a can be induced by exogenous H 2 O 2 , and overexpressing miR529a can increase plant tolerance to high level of H 2 O 2 , resulting in increased seed germination rate, root tip cell viability, reduced leaf rolling rate and chlorophyll retention. The expression of oxidative stress responsive genes and the activities of superoxide dismutase (SOD) and peroxidase (POD) were increased in miR529a overexpression plant, which could help to reduce redundant reactive oxygen species (ROS). Furthermore, only OsSPL2 and OsSPL14 were targeted by miR529a in rice seedlings, repressing their expression in miR529aOE plants could lead to strengthen plant tolerance to oxidation stress. Our study provided the evidence that overexpression of miR529a could strengthen oxidation resistance, and its target genes OsSPL2 and OsSPL14 were responsible for oxidative tolerance, implied the manipulation of miR529a and its target genes regulation on H 2 O 2 related response genes could improve oxidative stress tolerance in rice.

  7. Physiological Mechanism of Enhancing Salt Stress Tolerance of Perennial Ryegrass by 24-Epibrassinolide

    Directory of Open Access Journals (Sweden)

    Wenli Wu

    2017-06-01

    Full Text Available Brassinosteroids (BR regulate plant tolerance to salt stress but the mechanisms underlying are not fully understood. This study was to investigate physiological mechanisms of 24-epibrassinolide (EBR's impact on salt stress tolerance in perennial ryegrass (Lolium perenne L. The grass seedlings were treated with EBR at 0, 10, and 100 nM, and subjected to salt stress (250 mM NaCl. The grass irrigated with regular water without EBR served as the control. Salt stress increased leaf electrolyte leakage (EL, malondialdehyde (MDA, and reduced photosynthetic rate (Pn. Exogenous EBR reduced EL and MDA, increased Pn, chlorophyll content, and stomatal conductance (gs. The EBR applications also alleviated decline of superoxide dismutase (SOD and catalase (CAT and ascorbate peroxidase (APX activity when compared to salt treatment alone. Salt stress increased leaf abscisic acid (ABA and gibberellin A4 (GA4 content but reduced indole-3-acetic acid (IAA, zeatin riboside (ZR, isopentenyl adenosine (iPA, and salicylic acid (SA. Exogenous EBR at 10 nm and 100 nM increased ABA, and iPA content under salt stress. The EBR treatment at 100 nM also increased leaf IAA, ZR, JA, and SA. In addition, EBR treatments increased leaf proline and ions (K+, Mg2+, and Ca2+ content, and reduced Na+/K+ in leaf tissues. The results of this study suggest that EBR treatment may improve salt stress tolerance by increasing the level of selected hormones and antioxidant enzyme (SOD and CAT activity, promoting accumulation of proline and ions (K+, Ca2+, and Mg2+ in perennial ryegrass.

  8. Overexpression of Nictaba-Like Lectin Genes from Glycine max Confers Tolerance towards Pseudomonas syringae Infection, Aphid Infestation and Salt Stress in Transgenic Arabidopsis Plants

    Directory of Open Access Journals (Sweden)

    Sofie Van Holle

    2016-10-01

    Full Text Available Plants have evolved a sophisticated immune system that allows them to recognize invading pathogens by specialized receptors. Carbohydrate-binding proteins or lectins are part of this immune system and especially the lectins that reside in the nucleocytoplasmic compartment are known to be implicated in biotic and abiotic stress responses. The class of Nictaba-like lectins (NLL groups all proteins with homology to the tobacco (Nicotiana tabacum lectin, known as a stress-inducible lectin. Here we focus on two Nictaba homologs from soybean (Glycine max, referred to as GmNLL1 and GmNLL2. Confocal laser scanning microscopy of fusion constructs with the green fluorescent protein either transiently expressed in Nicotiana benthamiana leaves or stably transformed in tobacco BY-2 suspension cells revealed a nucleocytoplasmic localization for the GmNLLs under study. RT-qPCR analysis of the transcript levels for the Nictaba-like lectins in soybean demonstrated that the genes are expressed in several tissues throughout the development of the plant. Furthermore, it was shown that salt treatment, Phytophthora sojae infection and Aphis glycines infestation trigger the expression of particular NLL genes. Stress experiments with Arabidopsis lines overexpressing the NLLs from soybean yielded an enhanced tolerance of the plant towards bacterial infection (Pseudomonas syringae, insect infestation (Myzus persicae and salinity. Our data showed a better performance of the transgenic lines compared to wild type plants, indicating that the NLLs from soybean are implicated in the stress response. These data can help to further elucidate the physiological importance of the Nictaba-like lectins from soybean, which can ultimately lead to the design of crop plants with a better tolerance to changing environmental conditions.

  9. Increased biomass, seed yield and stress tolerance is conferred in Arabidopsis by a novel enzyme from the resurrection grass Sporobolus stapfianus that glycosylates the strigolactone analogue GR24.

    Directory of Open Access Journals (Sweden)

    Sharmin Islam

    Full Text Available Isolation of gene transcripts from desiccated leaf tissues of the resurrection grass, Sporobolus stapfianus, resulted in the identification of a gene, SDG8i, encoding a Group 1 glycosyltransferase (UGT. Here, we examine the effects of introducing this gene, under control of the CaMV35S promoter, into the model plant Arabidopsis thaliana. Results show that Arabidopsis plants constitutively over-expressing SDG8i exhibit enhanced growth, reduced senescence, cold tolerance and a substantial improvement in protoplasmic drought tolerance. We hypothesise that expression of SDG8i in Arabidopsis negatively affects the bioactivity of metabolite/s that mediate/s environmentally-induced repression of cell division and expansion, both during normal development and in response to stress. The phenotype of transgenic plants over-expressing SDG8i suggests modulation in activities of both growth- and stress-related hormones. Plants overexpressing the UGT show evidence of elevated auxin levels, with the enzyme acting downstream of ABA to reduce drought-induced senescence. Analysis of the in vitro activity of the UGT recombinant protein product demonstrates that SDG8i can glycosylate the synthetic strigolactone analogue GR24, evoking a link with strigolactone-related processes in vivo. The large improvements observed in survival of transgenic Arabidopsis plants under cold-, salt- and drought-stress, as well as the substantial increases in growth rate and seed yield under non-stress conditions, indicates that overexpression of SDG8i in crop plants may provide a novel means of increasing plant productivity.

  10. Tolerance of image enhancement brightness and contrast in lateral cephalometric digital radiography for Steiner analysis

    Science.gov (United States)

    Rianti, R. A.; Priaminiarti, M.; Syahraini, S. I.

    2017-08-01

    Image enhancement brightness and contrast can be adjusted on lateral cephalometric digital radiographs to improve image quality and anatomic landmarks for measurement by Steiner analysis. To determine the limit value for adjustments of image enhancement brightness and contrast in lateral cephalometric digital radiography for Steiner analysis. Image enhancement brightness and contrast were adjusted on 100 lateral cephalometric radiography in 10-point increments (-30, -20, -10, 0, +10, +20, +30). Steiner analysis measurements were then performed by two observers. Reliabilities were tested by the Interclass Correlation Coefficient (ICC) and significance tested by ANOVA or the Kruskal Wallis test. No significant differences were detected in lateral cephalometric analysis measurements following adjustment of the image enhancement brightness and contrast. The limit value of adjustments of the image enhancement brightness and contrast associated with incremental 10-point changes (-30, -20, -10, 0, +10, +20, +30) does not affect the results of Steiner analysis.

  11. Fault-tolerant computing systems

    International Nuclear Information System (INIS)

    Dal Cin, M.; Hohl, W.

    1991-01-01

    Tests, Diagnosis and Fault Treatment were chosen as the guiding themes of the conference. However, the scope of the conference included reliability, availability, safety and security issues in software and hardware systems as well. The sessions were organized for the conference which was completed by an industrial presentation: Keynote Address, Reconfiguration and Recover, System Level Diagnosis, Voting and Agreement, Testing, Fault-Tolerant Circuits, Array Testing, Modelling, Applied Fault Tolerance, Fault-Tolerant Arrays and Systems, Interconnection Networks, Fault-Tolerant Software. One paper has been indexed separately in the database. (orig./HP)

  12. Tetraploid Rangpur lime rootstock increases drought tolerance via enhanced constitutive root abscisic acid production.

    Science.gov (United States)

    Allario, Thierry; Brumos, Javier; Colmenero-Flores, Jose M; Iglesias, Domingo J; Pina, Jose A; Navarro, Luis; Talon, Manuel; Ollitrault, Patrick; Morillon, Raphaël

    2013-04-01

    Whole-genome duplication, or polyploidy, is common in many plant species and often leads to better adaptation to adverse environmental condition. However, little is known about the physiological and molecular determinants underlying adaptation. We examined the drought tolerance in diploid (2x) and autotetraploid (4x) clones of Rangpur lime (Citrus limonia) rootstocks grafted with 2x Valencia Delta sweet orange (Citrus sinensis) scions, named V/2xRL and V/4xRL, respectively. Physiological experiments to study root-shoot communication associated with gene expression studies in roots and leaves were performed. V/4xRL was much more tolerant to water deficit than V/2xRL. Gene expression analysis in leaves and roots showed that more genes related to the response to water stress were differentially expressed in V/2xRL than in V/4xRL. Prior to the stress, when comparing V/4xRL to V/2xRL, V/4xRL leaves had lower stomatal conductance and greater abscisic acid (ABA) content. In roots, ABA content was higher in V/4xRL and was associated to a greater expression of drought responsive genes, including CsNCED1, a pivotal regulatory gene of ABA biosynthesis. We conclude that tetraploidy modifies the expression of genes in Rangpur lime citrus roots to regulate long-distance ABA signalling and adaptation to stress. © 2012 Blackwell Publishing Ltd.

  13. [Analysis of structural characteristics of alpha-tubulins in plants with enhanced cold tolerance].

    Science.gov (United States)

    Nyporko, A Iu; Demchuk, O N; Blium, Ia B

    2003-01-01

    The uniqueness of the point substitutions in the sequences of two alpha-tubulin isotypes from psychrophilic alga Chloromonas that can determine the increased cold tolerance of this alga was analyzed. The comparison of all known amino acid sequences of plant alpha-tubulins enabled to ascertain that only M268-->V replacement is unique and may have a significant influence on spatial structure of plant alpha-tubulins. Modeling of molecular surfaces of alpha-tubulins from Chloromonas, Chalmydomonas reinhardtii and goose grass Eleusine indica showed that insertion of the amino acid replacement M268-->V into the sequence of goose grace tubulin led to the likening of this protein surface to the surface of native alpha-tubulin from Chloromonas. Alteration of local hydrophobic properties of alpha-tubulin molecular surface in interdimeric contact zone as a result of the mentioned replacement was shown that may play important role in increasing the level of cold resistance of microtubules. The crucial role of amino acid residue in 268 position for forming the interdimeric contact surface of alpha-tubulin molecule was revealed. The assumption is made about the importance of replacements at this position for plant tolerance to abiotic factors of different nature (cold, herbicides).

  14. Determination of the Effects of Nutrient sources on Enhancement of Crop Tolerance to Bean Root Rot and Bean Stem Maggot in Western Kenya

    International Nuclear Information System (INIS)

    Otsyula, R.M.; Nderitu, J.H.

    1999-01-01

    Field bean phaseolus vulgaris tolerance to root rot (BRR) and bean stem maggot (BSM) is enhanced by improvement of soil nutrients. Organic and inorganic sources of soil nutrients were evaluated in this study to determine their effects on crop tolerance to BRR and BSM. Three variety of GLP 585 susceptible to BRR and BSM; GLP X92 tolerant to BRR and BSM; and KK-8 resistant to BRR and BSM were used. The study was conducted in farmer's field with high level of BRR and BSM over three seasons in a split plot design. Nutrient sources were laid down in main plots while varieties were in subplots. KK-8 gave the highest plant survival and yield over the seasons. GLP 585 had the lowest mean yield and plant survival. Crop tolerance was greatly improved by application of DAP as applied as nutrient sources and varieties for crop tolerance were identified

  15. Enhanced Predictive Capability of a 1-Hour Oral Glucose Tolerance Test

    DEFF Research Database (Denmark)

    Pareek, Manan; Bhatt, Deepak L; Nielsen, Mette L

    2018-01-01

    OBJECTIVE: To examine whether the 1-h blood glucose measurement would be a more suitable screening tool for assessing the risk of diabetes and its complications than the 2-h measurement. RESEARCH DESIGN AND METHODS: We conducted a prospective population-based cohort study of 4,867 men, randomly...... selected from prespecified birth cohorts between 1921 and 1949, who underwent an oral glucose tolerance test with blood glucose measurements at 0, 1, and 2 h. Subjects were followed for up to 39 years, with registry-based recording of events. Discriminative abilities of elevated 1-h (≥8.6 mmol/L) versus 2......-h (≥7.8 mmol/L) glucose for predicting incident type 2 diabetes, vascular complications, and mortality were compared using Kaplan-Meier analysis, Cox proportional hazards regression, and net reclassification improvement. RESULTS: Median age was 48 years (interquartile range [IQR] 48-49). During...

  16. Aromatically enhanced pear distillates from blanquilla and conference varieties using a packed column.

    Science.gov (United States)

    Arrieta-Garay, Yanine; García-Llobodanin, Laura; Pérez-Correa, José Ricardo; López-Vázquez, Cristina; Orriols, Ignacio; López, Francisco

    2013-05-22

    Pear distillates are generally produced from the Bartlett variety because of its rich aroma. In this study, a chemical and sensorial comparative examination of pear distillates from the three main varieties grown in Spain (Bartlett, Blanquilla, and Conference) using two distillation systems (copper Charentais alembic and packed column) was undertaken. Volatile compounds were identified by gas chromatography to differentiate the spirits according to pear variety and distillation method. The Bartlett distillates from both distillation systems possessed higher ethyl ester and acetate and lower cis-3-hexen-1-ol and 1-hexanol concentrations. Despite these differences, a sensory analysis panel could distinguish only the Bartlett alembic distillate from the alembic distillates of the other varieties. In contrast, the panel rated the packed-column distillates equally. Therefore, less aromatic pear varieties can be used to produce distillates with aromatic characteristics similar to those of the Bartlett variety if a suitable distillation process is used.

  17. A Nucleus-localized Long Non-Coding RNA Enhances Drought and Salt Stress Tolerance

    KAUST Repository

    Qin, Tao

    2017-09-09

    Long non-coding RNAs (lncRNAs) affect gene expression through a wide range of mechanisms and are considered as important regulators in many essential biological processes. A large number of lncRNA transcripts have been predicted or identified in plants in recent years. However, the biological functions for most of them are still unknown. In this study, we identified an Arabidopsis thaliana lncRNA, Drought induced RNA (DRIR), as a novel positive regulator of plant response to drought and salt stress. DRIR was expressed at a low level under non-stress conditions but can be significantly activated by drought and salt stress as well as by abscisic acid (ABA) treatment. We identified a T-DNA insertion mutant, drirD, which had higher expression of the DRIR gene than the wild type plants. The drirD mutant exhibits increased tolerance to drought and salt stress. Overexpressing DRIR in Arabidopsis also increased tolerance to drought and salt stress of the transgenic plants. The drirD mutant and the overexpressing seedlings are more sensitive to ABA than the wild type in stomata closure and seedling growth. Genome-wide transcriptome analysis demonstrated that the expression of a large number of genes was altered in drirD and the overexpressing plants. These include genes involved in ABA signaling, water transport and other stress-relief processes. Our study reveals a mechanism whereby DRIR regulates plant response to abiotic stress by modulating the expression of a series of genes involved in stress response.

  18. Conference on microbiological processes useful in enhanced oil recovery. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1979-10-01

    Six formal presentations were made at the meeting, followed by four workshops dealing with specific topics: bioengineering, reservoir ecology and environment, transformations, and bioproducts. All were related to microbial enhancement of oil recovery. (DLC)

  19. ThNAC13, a NAC Transcription Factor from Tamarix hispida, Confers Salt and Osmotic Stress Tolerance to Transgenic Tamarix and Arabidopsis

    Science.gov (United States)

    Wang, Liuqiang; Li, Zhen; Lu, Mengzhu; Wang, Yucheng

    2017-01-01

    NAC (NAM, ATAF1/2, and CUC2) proteins play critical roles in many plant biological processes and environmental stress. However, NAC proteins from Tamarix hispida have not been functionally characterized. Here, we studied a NAC gene from T. hispida, ThNAC13, in response to salt and osmotic stresses. ThNAC13 is a nuclear protein with a C-terminal transactivation domain. ThNAC13 can bind to NAC recognized sites and calmodulin-binding NAC (CBNAC) binding element. Overexpression of ThNAC13 in Arabidopsis improved seed germination rate and increased root growth and fresh weight gain under salt or osmotic stress. Transgenic T. hispida plants transiently overexpressing ThNAC13 and with RNAi-silenced ThNAC13 were generated for gain- and loss-of-function experiments. Following exposure to salt or osmotic stress, overexpression of ThNAC13 induced superoxide dismutase (SOD) and peroxidase (POD) activities, chlorophyll and proline contents; decreased the reactive oxygen species (ROS) and malondialdehyde levels; and reduced electrolyte leakage rates in both transgenic Tamarix and Arabidopsis plants. In contrast, RNAi-silenced ThNAC13 showed the opposite results in transgenic Tamarix. Furthermore, ThNAC13 induced the expression of SODs and PODs in transgenic Arabidopsis. These results suggest that ThNAC13 improves salt and osmotic tolerance by enhancing the ROS-scavenging capability and adjusting osmotic potential. PMID:28491072

  20. ThNAC13, a NAC Transcription Factor from Tamarix hispida, Confers Salt and Osmotic Stress Tolerance to Transgenic Tamarix and Arabidopsis

    Directory of Open Access Journals (Sweden)

    Mengzhu Lu

    2017-04-01

    Full Text Available NAC (NAM, ATAF1/2, and CUC2 proteins play critical roles in many plant biological processes and environmental stress. However, NAC proteins from Tamarix hispida have not been functionally characterized. Here, we studied a NAC gene from T. hispida, ThNAC13, in response to salt and osmotic stresses. ThNAC13 is a nuclear protein with a C-terminal transactivation domain. ThNAC13 can bind to NAC recognized sites and calmodulin-binding NAC (CBNAC binding element. Overexpression of ThNAC13 in Arabidopsis improved seed germination rate and increased root growth and fresh weight gain under salt or osmotic stress. Transgenic T. hispida plants transiently overexpressing ThNAC13 and with RNAi-silenced ThNAC13 were generated for gain- and loss-of-function experiments. Following exposure to salt or osmotic stress, overexpression of ThNAC13 induced superoxide dismutase (SOD and peroxidase (POD activities, chlorophyll and proline contents; decreased the reactive oxygen species (ROS and malondialdehyde levels; and reduced electrolyte leakage rates in both transgenic Tamarix and Arabidopsis plants. In contrast, RNAi-silenced ThNAC13 showed the opposite results in transgenic Tamarix. Furthermore, ThNAC13 induced the expression of SODs and PODs in transgenic Arabidopsis. These results suggest that ThNAC13 improves salt and osmotic tolerance by enhancing the ROS-scavenging capability and adjusting osmotic potential.

  1. Mining Halophytes for Plant Growth-Promoting Halotolerant Bacteria to Enhance the Salinity Tolerance of Non-halophytic Crops

    Directory of Open Access Journals (Sweden)

    Hassan Etesami

    2018-02-01

    Full Text Available Salinity stress is one of the major abiotic stresses limiting crop production in arid and semi-arid regions. Interest is increasing in the application of PGPRs (plant growth promoting rhizobacteria to ameliorate stresses such as salinity stress in crop production. The identification of salt-tolerant, or halophilic, PGPRs has the potential to promote saline soil-based agriculture. Halophytes are a useful reservoir of halotolerant bacteria with plant growth-promoting capabilities. Here, we review recent studies on the use of halophilic PGPRs to stimulate plant growth and increase the tolerance of non-halophytic crops to salinity. These studies illustrate that halophilic PGPRs from the rhizosphere of halophytic species can be effective bio-inoculants for promoting the production of non-halophytic species in saline soils. These studies support the viability of bioinoculation with halophilic PGPRs as a strategy for the sustainable enhancement of non-halophytic crop growth. The potential of this strategy is discussed within the context of ensuring sustainable food production for a world with an increasing population and continuing climate change. We also explore future research needs for using halotolerant PGPRs under salinity stress.

  2. Xenobiotics enhance laccase activity in alkali-tolerant γ-proteobacterium JB.

    Science.gov (United States)

    Singh, Gursharan; Batish, Mona; Sharma, Prince; Capalash, Neena

    2009-01-01

    Various genotoxic textile dyes, xenobiotics, substrates (10 µM) and agrochemicals (100 µg/ml) were tested for enhancement of alkalophilic laccase activity in γ-proteobacterium JB. Neutral Red, Indigo Carmine, Naphthol Base Bordears and Sulphast Ruby dyes increased the activity by 3.7, 2.7, 2.6 and 2.3 fold respectively. Xenobiotics/substrates like p-toluidine, 8-hydroxyquinoline and anthracine increased it by 3.4, 2.8 and 2.3 fold respectively. Atrazine and trycyclozole pesticides enhanced the activity by 1.95 and 1.5 fold respectively.

  3. Periodic 48 h feed withdrawal improves glucose tolerance in growing pigs by enhancing adipogenesis and lipogenesis

    Directory of Open Access Journals (Sweden)

    Mir Priya S

    2012-02-01

    Full Text Available Abstract Background Adipocyte numbers and peroxisome proliferators activated receptorγ (PPARγ expression of retroperitoneal tissue increased while area under the curve (AUC during the glucose tolerance test (GTT was reduced in rats subjected to certain feed withdrawal (FW regimens. Thus, using pigs as the experimental model, the hypothesis that FW regimens influence glucose tolerance by influencing fat cell function was evaluated with the objective of determining the effect of a single (FWx1; at age of 19 wk for 48 h or periodic, multiple (FWx4; 24 h FW at 7 and 11 wk of age and 48 h FW at 15 and 19 wk of age FW on AUC of glucose and insulin during the GTT relative to pigs that did not experience FW (Control. Methods Growth, body composition, adipocyte numbers, PPARγ expression, lipogenic potential as glucose uptake into fat of adipocytes of varying diameter in omental (OM and subcutaneous (SQ fat as affected by FW regimens were determined in pigs initiated into the study at 5 wk of age and fed the same diet, ad libitum. Results Blood glucose concentrations for prior to and 120 min post glucose meal tended to be lower (p = 0.105 and 0.097, respectively in pigs in FW treatments. In OM fat; cell numbers, glucose Universal14C [U14C] incorporation into fat and rate of incorporation per 104 cells was greatest for cells with diameters of 90-119 μm. Pigs undergoing FWx4 tended to have greater (p = 0.0685; by 191% number of adipocytes, increased (p = 0.0234 glucose U14C incorporation into adipocytes and greater (p = 0.0872 rate of glucose uptake into cells of 119-150 μm diameter than of cells from control or FWx1 pigs. Subcutaneous adipocyte numbers in 22-60 and 61-90 μm diameter ranges from pigs in FWx1 tended to be greater (p = 0.08 and 0.06, respectively than for those in FWx4 treatment, yet PPARγ expression and total cell number were not affected by treatment. Conclusions Results suggest that FW regimens influence fat cell function or

  4. Layout techniques to enhance the radiation tolerance of standard CMOS technologies demonstrated on a pixel detector readout chip

    CERN Document Server

    Snoeys, W; Burns, M; Campbell, M; Cantatore, E; Carrer, N; Casagrande, L; Cavagnoli, A; Dachs, C; Di Liberto, S; Formenti, F; Giraldo, A; Heijne, Erik H M; Jarron, Pierre; Letheren, M F; Marchioro, A; Martinengo, P; Meddi, F; Mikulec, B; Morando, M; Morel, M; Noah, E; Paccagnella, A; Ropotar, I; Saladino, S; Sansen, Willy; Santopietro, F; Scarlassara, F; Segato, G F; Signe, P M; Soramel, F; Vannucci, Luigi; Vleugels, K

    2000-01-01

    A new pixel readout prototype has been developed at CERN for high- energy physics applications. This full mixed mode circuit has been implemented in a commercial 0.5 mu m CMOS technology. Its radiation tolerance has been enhanced by designing all NMOS transistors in enclosed geometry and introducing guardrings wherever necessary. The technique is explained and its effectiveness demonstrated on various irradiation measurements on individual transistors and on the prototype. Circuit performance started to degrade only after a total dose of 600 krad-1.7 Mrad depending on the type of radiation. 10 keV X-rays, /sup 60/Co gamma-rays, 6.5 MeV protons, and minimum ionizing particles were used. Implications of this layout approach on the circuit design and perspectives for even deeper submicron technologies are discussed. (20 refs).

  5. TaNAC29, a NAC transcription factor from wheat, enhances salt and drought tolerance in transgenic Arabidopsis.

    Science.gov (United States)

    Huang, Quanjun; Wang, Yan; Li, Bin; Chang, Junli; Chen, Mingjie; Li, Kexiu; Yang, Guangxiao; He, Guangyuan

    2015-11-04

    NAC (NAM, ATAF, and CUC) transcription factors play important roles in plant biological processes, including phytohormone homeostasis, plant development, and in responses to various environmental stresses. TaNAC29 was introduced into Arabidopsis using the Agrobacterium tumefaciens-mediated floral dipping method. TaNAC29-overexpression plants were subjected to salt and drought stresses for examining gene functions. To investigate tolerant mechanisms involved in the salt and drought responses, expression of related marker genes analyses were conducted, and related physiological indices were also measured. Expressions of genes were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). A novel NAC transcription factor gene, designated TaNAC29, was isolated from bread wheat (Triticum aestivum). Sequence alignment suggested that TaNAC29 might be located on chromosome 2BS. TaNAC29 was localized to the nucleus in wheat protoplasts, and proved to have transcriptional activation activities in yeast. TaNAC29 was expressed at a higher level in the leaves, and expression levels were much higher in senescent leaves, indicating that TaNAC29 might be involved in the senescence process. TaNAC29 transcripts were increased following treatments with salt, PEG6000, H2O2, and abscisic acid (ABA). To examine TaNAC29 function, transgenic Arabidopsis plants overexpressing TaNAC29 were generated. Germination and root length assays of transgenic plants demonstrated that TaNAC29 overexpression plants had enhanced tolerances to high salinity and dehydration, and exhibited an ABA-hypersensitive response. When grown in the greenhouse, TaNAC29-overexpression plants showed the same tolerance response to salt and drought stresses at both the vegetative and reproductive period, and had delayed bolting and flowering in the reproductive period. Moreover, TaNAC29 overexpression plants accumulated lesser malondialdehyde (MDA), H2O2, while had higher superoxide dismutase (SOD) and

  6. Reprogramming of murine macrophages through TLR2 confers viral resistance via TRAF3-mediated, enhanced interferon production.

    Directory of Open Access Journals (Sweden)

    Darren J Perkins

    Full Text Available The cell surface/endosomal Toll-like Receptors (TLRs are instrumental in initiating immune responses to both bacteria and viruses. With the exception of TLR2, all TLRs and cytosolic RIG-I-like receptors (RLRs with known virus-derived ligands induce type I interferons (IFNs in macrophages or dendritic cells. Herein, we report that prior ligation of TLR2, an event previously shown to induce "homo" or "hetero" tolerance, strongly "primes" macrophages for increased Type I IFN production in response to subsequent TLR/RLR signaling. This occurs by increasing activation of the transcription factor, IFN Regulatory Factor-3 (IRF-3 that, in turn, leads to enhanced induction of IFN-β, while expression of other pro-inflammatory genes are suppressed (tolerized. In vitro or in vivo "priming" of murine macrophages with TLR2 ligands increase virus-mediated IFN induction and resistance to infection. This priming effect of TLR2 is mediated by the selective upregulation of the K63 ubiquitin ligase, TRAF3. Thus, we provide a mechanistic explanation for the observed antiviral actions of MyD88-dependent TLR2 and further define the role of TRAF3 in viral innate immunity.

  7. Impact of Methyl Jasmonate on Enhancing Chilling Tolerance of Cucumber (Cucumis sativus L. Seedlings

    Directory of Open Access Journals (Sweden)

    F. Saydpour

    2016-12-01

    Full Text Available Cucumber is a warm season crop that suffers from chilling injury at temperatures below 10°C. In recent years, jasmonates have been used for reduction of chilling injuries in plants. An experiment was, therefore, conducted to test whether methyl jasmonate (MeJA application at various concentrations (0, 0.05, 0.1 and 0.15 mM through seed soaking or foliar spray would protect cucumber seedlings, subjected to chilling stress. Results showed that MeJA application decreased chilling index, ion leakage, malondialdehyde content and hydrogen peroxide free radical and increased growth parameters, proline contents, chlorophylls contents and antioxidant activity. Although, seed soaking method provided better protection compared to foliar spray method, the highest cold tolerance was obtained with 0.15mM MeJA application in both application methods that caused low level of chilling index (1.67, malondialdehyde content (0.11 nm g-1 FW, hydrogen peroxide free radical (0.22 nm g-1 FW and ion leakage (32.87%. In general, it may be concluded that MeJA could be used effectively to protect cucumber seedling from damaging effects of chilling stress at the early stages of growth.

  8. Enhancing water stress tolerance improves fitness in biological control strains of Lactobacillus plantarum in plant environments.

    Science.gov (United States)

    Daranas, Núria; Badosa, Esther; Francés, Jesús; Montesinos, Emilio; Bonaterra, Anna

    2018-01-01

    Lactobacillus plantarum strains PM411 and TC92 can efficiently control bacterial plant diseases, but their fitness on the plant surface is limited under unfavourable low relative humidity (RH) conditions. To increase tolerance of these strains to water stress, an adaptive strategy was used consisting of hyperosmotic and acidic conditions during growth. Adapted cells had higher survival rates under desiccation than non-adapted cells. Transcript levels and patterns of general stress-related genes increased immediately after the combined-stress adaptation treatment, and remained unaltered or repressed during the desiccation challenge. However, there were differences between strains in the transcription patterns that were in agreement with a better performance of adapted cells of PM411 than TC92 in plant surfaces under low RH environmental conditions. The combined-stress adaptation treatment increased the survival of PM411 cells consistently in different plant hosts in the greenhouse and under field conditions. Stress-adapted cells of PM411 had similar biocontrol potential against bacterial plant pathogens than non-adapted cells, but with less variability within experiments.

  9. Enhancing water stress tolerance improves fitness in biological control strains of Lactobacillus plantarum in plant environments.

    Directory of Open Access Journals (Sweden)

    Núria Daranas

    Full Text Available Lactobacillus plantarum strains PM411 and TC92 can efficiently control bacterial plant diseases, but their fitness on the plant surface is limited under unfavourable low relative humidity (RH conditions. To increase tolerance of these strains to water stress, an adaptive strategy was used consisting of hyperosmotic and acidic conditions during growth. Adapted cells had higher survival rates under desiccation than non-adapted cells. Transcript levels and patterns of general stress-related genes increased immediately after the combined-stress adaptation treatment, and remained unaltered or repressed during the desiccation challenge. However, there were differences between strains in the transcription patterns that were in agreement with a better performance of adapted cells of PM411 than TC92 in plant surfaces under low RH environmental conditions. The combined-stress adaptation treatment increased the survival of PM411 cells consistently in different plant hosts in the greenhouse and under field conditions. Stress-adapted cells of PM411 had similar biocontrol potential against bacterial plant pathogens than non-adapted cells, but with less variability within experiments.

  10. Soybean Salt Tolerance 1 (GmST1) Reduces ROS Production, Enhances ABA Sensitivity, and Abiotic Stress Tolerance in Arabidopsis thaliana.

    Science.gov (United States)

    Ren, Shuxin; Lyle, Chimera; Jiang, Guo-Liang; Penumala, Abhishek

    2016-01-01

    Abiotic stresses, including high soil salinity, significantly reduce crop production worldwide. Salt tolerance in plants is a complex trait and is regulated by multiple mechanisms. Understanding the mechanisms and dissecting the components on their regulatory pathways will provide new insights, leading to novel strategies for the improvement of salt tolerance in agricultural and economic crops of importance. Here we report that soybean salt tolerance 1, named GmST1, exhibited strong tolerance to salt stress in the Arabidopsis transgenic lines. The GmST1-overexpressed Arabidopsis also increased sensitivity to ABA and decreased production of reactive oxygen species under salt stress. In addition, GmST1 significantly improved drought tolerance in Arabidopsis transgenic lines. GmST1 belongs to a 3-prime part of Glyma.03g171600 gene in the current version of soybean genome sequence annotation. However, comparative reverse transcription-polymerase chain reaction analysis around Glyma.03g171600 genomic region confirmed that GmST1 might serve as an intact gene in soybean leaf tissues. Unlike Glyma.03g171600 which was not expressed in leaves, GmST1 was strongly induced by salt treatment in the leaf tissues. By promoter analysis, a TATA box was detected to be positioned close to GmST1 start codon and a putative ABRE and a DRE cis-acting elements were identified at about 1 kb upstream of GmST1 gene. The data also indicated that GmST1-transgenic lines survived under drought stress and showed a significantly lower water loss than non-transgenic lines. In summary, our results suggest that overexpression of GmST1 significantly improves Arabidopsis tolerance to both salt and drought stresses and the gene may be a potential candidate for genetic engineering of salt- and drought-tolerant crops.

  11. Soybean salt tolerance 1 (GmST1 reduces ROS production, enhances ABA sensitivity and abiotic stress tolerance in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Shuxin eRen

    2016-04-01

    Full Text Available Abiotic stresses, including high soil salinity, significantly reduce crop production worldwide. Salt tolerance in plants is a complex trait and is regulated by multiple mechanisms. Understanding the mechanisms and dissecting the components on their regulatory pathways will provide new insights, leading to novel strategies for the improvement of salt tolerance in agricultural and economic crops of importance. Here we report that soybean salt tolerance 1, named GmST1, exhibited strong tolerance to salt stress in the Arabidopsis transgenic lines. The GmST1-overexpressed Arabidopsis also increased sensitivity to ABA and decreased production of reactive oxygen species (ROS under salt stress. In addition, GmST1 significantly improved drought tolerance in Arabidopsis transgenic lines. GmST1 belongs to a 3-prime part of Glyma.03g171600 gene in the current version of soybean genome sequence annotation. However, comparative RT-PCR analysis around Glyma.03g171600 genomic region confirmed that GmST1 might serve as an intact gene in soybean leaf tissues. Unlike Glyma.03g171600 which was not expressed in leaves, GmST1 was strongly induced by salt treatment in the leaf tissues. By promoter analysis, a TATA box was detected to be positioned close to GmST1 start codon and a putative ABRE and a DRE cis-acting elements were identified at about 1kb upstream of GmST1 gene. The data also indicated that GmST1-transgenic lines survived under drought stress and showed a significantly lower water loss than non-transgenic lines. In summary, our results suggest that overexpression of GmST1 significantly improves Arabidopsis tolerance to both salt and drought stresses and the gene may be a potential candidate for genetic engineering of salt- and drought-tolerant crops.

  12. A Novel G-Protein-Coupled Receptors Gene from Upland Cotton Enhances Salt Stress Tolerance in Transgenic Arabidopsis.

    Science.gov (United States)

    Lu, Pu; Magwanga, Richard Odongo; Lu, Hejun; Kirungu, Joy Nyangasi; Wei, Yangyang; Dong, Qi; Wang, Xingxing; Cai, Xiaoyan; Zhou, Zhongli; Wang, Kunbo; Liu, Fang

    2018-04-12

    Plants have developed a number of survival strategies which are significant for enhancing their adaptation to various biotic and abiotic stress factors. At the transcriptome level, G-protein-coupled receptors (GPCRs) are of great significance, enabling the plants to detect a wide range of endogenous and exogenous signals which are employed by the plants in regulating various responses in development and adaptation. In this research work, we carried out genome-wide analysis of target of Myb1 ( TOM1 ), a member of the GPCR gene family. The functional role of TOM1 in salt stress tolerance was studied using a transgenic Arabidopsis plants over-expressing the gene. By the use of the functional domain PF06454, we obtained 16 TOM genes members in Gossypium hirsutum , 9 in Gossypium arboreum , and 11 in Gossypium raimondii . The genes had varying physiochemical properties, and it is significant to note that all the grand average of hydropathy (GRAVY) values were less than one, indicating that all are hydrophobic in nature. In all the genes analysed here, both the exonic and intronic regions were found. The expression level of Gh_A07G0747 (GhTOM) was significantly high in the transgenic lines as compared to the wild type; a similar trend in expression was observed in all the salt-related genes tested in this study. The study in epidermal cells confirmed the localization of the protein coded by the gene TOM1 in the plasma membrane. Analysis of anti-oxidant enzymes showed higher concentrations of antioxidants in transgenic lines and relatively lower levels of oxidant substances such as H₂O₂. The low malondialdehyde (MDA) level in transgenic lines indicated that the transgenic lines had relatively low level of oxidative damage compared to the wild types. The results obtained indicate that Gh_A07G0747 (GhTOM) can be a putative target gene for enhancing salt stress tolerance in plants and could be exploited in the future for the development of salt stress-tolerant cotton

  13. A Novel G-Protein-Coupled Receptors Gene from Upland Cotton Enhances Salt Stress Tolerance in Transgenic Arabidopsis

    Directory of Open Access Journals (Sweden)

    Pu Lu

    2018-04-01

    Full Text Available Plants have developed a number of survival strategies which are significant for enhancing their adaptation to various biotic and abiotic stress factors. At the transcriptome level, G-protein-coupled receptors (GPCRs are of great significance, enabling the plants to detect a wide range of endogenous and exogenous signals which are employed by the plants in regulating various responses in development and adaptation. In this research work, we carried out genome-wide analysis of target of Myb1 (TOM1, a member of the GPCR gene family. The functional role of TOM1 in salt stress tolerance was studied using a transgenic Arabidopsis plants over-expressing the gene. By the use of the functional domain PF06454, we obtained 16 TOM genes members in Gossypium hirsutum, 9 in Gossypium arboreum, and 11 in Gossypium raimondii. The genes had varying physiochemical properties, and it is significant to note that all the grand average of hydropathy (GRAVY values were less than one, indicating that all are hydrophobic in nature. In all the genes analysed here, both the exonic and intronic regions were found. The expression level of Gh_A07G0747 (GhTOM was significantly high in the transgenic lines as compared to the wild type; a similar trend in expression was observed in all the salt-related genes tested in this study. The study in epidermal cells confirmed the localization of the protein coded by the gene TOM1 in the plasma membrane. Analysis of anti-oxidant enzymes showed higher concentrations of antioxidants in transgenic lines and relatively lower levels of oxidant substances such as H2O2. The low malondialdehyde (MDA level in transgenic lines indicated that the transgenic lines had relatively low level of oxidative damage compared to the wild types. The results obtained indicate that Gh_A07G0747 (GhTOM can be a putative target gene for enhancing salt stress tolerance in plants and could be exploited in the future for the development of salt stress-tolerant

  14. RSK2-induced stress tolerance enhances cell survival signals mediated by inhibition of GSK3β activity

    International Nuclear Information System (INIS)

    Lee, Cheol-Jung; Lee, Mee-Hyun; Lee, Ji-Young; Song, Ji Hong; Lee, Hye Suk; Cho, Yong-Yeon

    2013-01-01

    Highlights: •We demonstrated a novel function of RSK2 in stress tolerance. •RSK2 deficiency enhanced apoptosis by calcium stress. •RSK2-mediated GSK3β phosphorylation at serine 9 increased calcium-induced stress tolerance. •Calcium stress-induced apoptosis inhibited by adding back of RSK2 into RSK2 −/− MEFs. -- Abstract: Our previous studies demonstrated that RSK2 plays a key role in cell proliferation and transformation induced by tumor promoters such as epidermal growth factor (EGF) in mouse and human skin cells. However, no direct evidence has been found regarding the relationship of RSK2 and cell survival. In this study, we found that RSK2 interacted and phosphorylated GSK3β at Ser9. Notably, GSK3β phosphorylation at Ser9 was suppressed in RSK2 −/− MEFs compared with RSK2 +/+ MEFs by stimulation of EGF and calcium ionophore A23187, a cellular calcium stressor. In proliferation, we found that RSK2 deficiency suppressed cell proliferation compared with RSK2 +/+ MEFs. In contrast, GSK3β −/− MEFs induced the cell proliferation compared with GSK3β +/+ MEFs. Importantly, RSK2 −/− MEFs were induced severe cellular morphology change by A23187 and enhanced G1/G0 and sub-G1 accumulation of the cell cycle phase compared with RSK2 +/+ MEFs. The sub-G1 induction in RSK2 −/− MEFs by A23187 was correlated with increase of cytochrome c release, caspase-3 cleavage and apoptotic DNA fragmentation compared with RSK2 +/+ MEFs. Notably, return back of RSK2 into RSK2 −/− MEFs restored A23187-induced morphological change, and decreased apoptosis, apoptotic DNA fragmentation and caspase-3 induction compared with RSK2 −/− /mock MEFs. Taken together, our results demonstrated that RSK2 plays an important role in stress-tolerance and cell survival, resulting in cell proliferation and cancer development

  15. First Toronto Conference on Database Users. Systems that Enhance User Performance.

    Science.gov (United States)

    Doszkocs, Tamas E.; Toliver, David

    1987-01-01

    The first of two papers discusses natural language searching as a user performance enhancement tool, focusing on artificial intelligence applications for information retrieval and problems with natural language processing. The second presents a conceptual framework for further development and future design of front ends to online bibliographic…

  16. Overexpression of snapdragon Delila (Del) gene in tobacco enhances anthocyanin accumulation and abiotic stress tolerance

    OpenAIRE

    Naing, Aung Htay; Park, Kyeung Il; Ai, Trinh Ngoc; Chung, Mi Young; Han, Jeung Sul; Kang, Young-Wha; Lim, Ki Byung; Kim, Chang Kil

    2017-01-01

    Background Rosea1 (Ros1) and Delila (Del) co-expression controls anthocyanin accumulation in snapdragon flowers, while their overexpression in tomato strongly induces anthocyanin accumulation. However, little data exist on how Del expression alone influences anthocyanin accumulation. Results In tobacco (Nicotiana tabacum ?Xanthi?), Del expression enhanced leaf and flower anthocyanin production through regulating NtCHS, NtCHI, NtF3H, NtDFR, and NtANS transcript levels. Transgenic lines display...

  17. Arbuscular mycorrhizal association enhances drought tolerance potential of promising bioenergy grass (Saccharum arundinaceum retz.).

    Science.gov (United States)

    Mirshad, P P; Puthur, Jos T

    2016-07-01

    The influence of arbuscular mycorrhizal fungi (AMF) (Glomus spp.) on some physiological and biochemical characteristics of bioenergy grass Saccharum arundinaceum subjected to drought stress was studied. The symbiotic association of Glomus spp. was established with S. arundinaceum, a potential bioenergy grass as evident from the increase in percentage of root infection and distribution frequency of vesicles when compared with non-arbuscular mycorrhizal plants. AMF-treated plants exhibited an enhanced accumulation of osmolytes such as sugars and proline and also increased protein content under drought. AMF association significantly increased the accumulation of non-enzymatic antioxidants like phenols, ascorbate and glutathione as well as enhanced the activities of antioxidant enzymes such as SOD (superoxide dismutase), APX (ascorbate peroxidase) and GPX (guaiacol peroxidase) resulting in reduced lipid peroxidation in S. arundinaceum. AMF symbiosis also ameliorated the drought-induced reduction of total chlorophyll content and activities of photosystem I and II. The maximum quantum efficiency of PS II (F v/F m) and potential photochemical efficiency (F v/F o) were higher in AMF plants as compared to non-AMF plants under drought stress. These results indicate that AMF association alleviate drought stress in S. arundinaceum by the accumulation of osmolytes and non-enzymatic antioxidants and enhanced activities of antioxidant enzymes, and hence, the photosynthetic efficiency is improved resulting in increased biomass production. AMF association with energy grasses also improves the acclimatization of S. arundinaceum for growing in marginal lands of drought-affected soils.

  18. 47{sup th} Annual conference on nuclear technology (AMNT 2016). Key topics / Outstanding know-how and sustainable innovations - enhanced safety and operation excellence

    Energy Technology Data Exchange (ETDEWEB)

    Raetzke, Christian [CONLAR - Consulting on Nuclear Law, Licensing and Regulation, Leipzig (Germany); Fischer, Erwin [PreussenElektra GmbH, Hannover (Germany). Management Board; Mohrbach, Ludger [VGB PowerTech e.V., Essen (Germany). Competence Center ' ' Nuclear Power Plants' '

    2016-08-15

    Summary report on the Key Topics ''Outstanding Know-How and Sustainable Innovations'' and ''Enhanced Safety and Operation Excellence'' of the 47{sup th} Annual Conference on Nuclear Technology (AMNT 2016) held in Hamburg, 10 to 12 May 2016. Other Sessions of AMNT 2016 will be covered in further issues of atw.

  19. Enhancing Near Zero Volt Storage Tolerance of Lithium-ion Batteries

    Science.gov (United States)

    Crompton, Kyle R.

    discharge measurements were performed and show that double layer capacitance likely plays a major role in determining the behavior of electrode potentials during near zero volt storage. To further the viability of the anode pre-lithiation method in LiCoO2/MCMB cells, stabilization coatings on the cathode materials are being investigated to increase the tolerance of the cathode to the low potentials it may experience during near zero volt storage of an RLE lithium ion cell. Results show that an AlPO4 coating prevents cation exhange in the cathode crystal structure and substantially increases the cathode's resilience to low electrochemical potentials. Investigations into applying anode pre-lithiation to cells utilizing LiNiCoAlO2 (NCA) cathodes have also been initiated and found to maintain the anode potential below the copper dissolution potential during near zero volt storage. RLE NCA/MCMB cells showed strong recharge performance and improved rate capability retention over a conventional NCA/MCMB cell after ten, 3-day near zero volt storage periods. Scale up of reversible lithium management to NCA/MCMB x3450 pouch cells was achieved using bath lithium addition and rendered a cell that retained 100% of its discharge performance after a 14 day period at near zero volts under fixed load. The near zero volt storage tolerance of lithium ion cells utilizing an advanced, high energy density lithium rich cathode material (0.49Li2MnO3˙0.51LiNi 0.37Co0.24Mn0.39O2 or HE5050) has also been studied and found to be high at room temperature without the need for anode pre-lithiation. HE5050/MCMB cells maintained 100% of their discharge capacity after five, 3-day and five, 7-day near zero volt storage periods at room temperature. HE5050/MCMB also maintained 99% of their discharge capacity after two, 3-day near zero volt storage periods at 40°C. The high first cycle loss and lower intercalation potential of the HE5050 cathode lead to the anode potential remaining <2.8 V vs. Li/Li+ during

  20. The potyviral suppressor of RNA silencing confers enhanced resistance to multiple pathogens

    International Nuclear Information System (INIS)

    Pruss, Gail J.; Lawrence, Christopher B.; Bass, Troy; Li Qingshun Q.; Bowman, Lewis H.; Vance, Vicki

    2004-01-01

    Helper component-protease (HC-Pro) is a plant viral suppressor of RNA silencing, and transgenic tobacco expressing HC-Pro has increased susceptibility to a broad range of viral pathogens. Here we report that these plants also exhibit enhanced resistance to unrelated heterologous pathogens. Tobacco mosaic virus (TMV) infection of HC-Pro-expressing plants carrying the N resistance gene results in fewer and smaller lesions compared to controls without HC-Pro. The resistance to TMV is compromised but not eliminated by expression of nahG, which prevents accumulation of salicylic acid (SA), an important defense signaling molecule. HC-Pro-expressing plants are also more resistant to tomato black ring nepovirus (TBRV) and to the oomycete Peronospora tabacina. Enhanced TBRV resistance is SA-independent, whereas the response to P. tabacina is associated with early induction of markers characteristic of SA-dependent defense. Thus, a plant viral suppressor of RNA silencing enhances resistance to multiple pathogens via both SA-dependent and SA-independent mechanisms

  1. The potyviral suppressor of RNA silencing confers enhanced resistance to multiple pathogens.

    Science.gov (United States)

    Pruss, Gail J; Lawrence, Christopher B; Bass, Troy; Li, Qingshun Q; Bowman, Lewis H; Vance, Vicki

    2004-03-01

    Helper component-protease (HC-Pro) is a plant viral suppressor of RNA silencing, and transgenic tobacco expressing HC-Pro has increased susceptibility to a broad range of viral pathogens. Here we report that these plants also exhibit enhanced resistance to unrelated heterologous pathogens. Tobacco mosaic virus (TMV) infection of HC-Pro-expressing plants carrying the N resistance gene results in fewer and smaller lesions compared to controls without HC-Pro. The resistance to TMV is compromised but not eliminated by expression of nahG, which prevents accumulation of salicylic acid (SA), an important defense signaling molecule. HC-Pro-expressing plants are also more resistant to tomato black ring nepovirus (TBRV) and to the oomycete Peronospora tabacina. Enhanced TBRV resistance is SA-independent, whereas the response to P. tabacina is associated with early induction of markers characteristic of SA-dependent defense. Thus, a plant viral suppressor of RNA silencing enhances resistance to multiple pathogens via both SA-dependent and SA-independent mechanisms.

  2. A booster vaccine expressing a latency-associated antigen augments BCG induced immunity and confers enhanced protection against tuberculosis.

    Directory of Open Access Journals (Sweden)

    Bappaditya Dey

    Full Text Available BACKGROUND: In spite of a consistent protection against tuberculosis (TB in children, Mycobacterium bovis Bacille Calmette-Guerin (BCG fails to provide adequate protection against the disease in adults as well as against reactivation of latent infections or exogenous reinfections. It has been speculated that failure to generate adequate memory T cell response, elicitation of inadequate immune response against latency-associated antigens and inability to impart long-term immunity against M. tuberculosis infections are some of the key factors responsible for the limited efficiency of BCG in controlling TB. METHODS/PRINCIPAL FINDINGS: In this study, we evaluated the ability of a DNA vaccine expressing α-crystallin--a key latency antigen of M. tuberculosis to boost the BCG induced immunity. 'BCG prime-DNA boost' regimen (B/D confers robust protection in guinea pigs along with a reduced pathology in comparison to BCG vaccination (1.37 log(10 and 1.96 log(10 fewer bacilli in lungs and spleen, respectively; p<0.01. In addition, B/D regimen also confers enhanced protection in mice. Further, we show that B/D immunization in mice results in a heightened frequency of PPD and antigen specific multi-functional CD4 T cells (3(+ simultaneously producing interferon (IFNγ, tumor necrosis factor (TNFα and interleukin (IL2. CONCLUSIONS/SIGNIFICANCE: These results clearly indicate the superiority of α-crystallin based B/D regimen over BCG. Our study, also demonstrates that protection against TB is predictable by an increased frequency of 3(+ Th1 cells with superior effector functions. We anticipate that this study would significantly contribute towards the development of superior booster vaccines for BCG vaccinated individuals. In addition, this regimen can also be expected to reduce the risk of developing active TB due to reactivation of latent infection.

  3. Sfp-type PPTase inactivation promotes bacterial biofilm formation and ability to enhance wheat drought tolerance

    Directory of Open Access Journals (Sweden)

    Salme eTimmusk

    2015-05-01

    Full Text Available Paenibacillus polymyxa is a common soil bacterium with broad range of practical applications. An important group of secondary metabolites in P. polymyxa are nonribosomal peptide and polyketide derived metabolites (NRP/PK. Modular nonribosomal peptide synthetases catalyse main steps in the biosynthesis of the complex secondary metabolites. Here we report on the inactivation of an A26 sfp-type phosphopantetheinyl transferase. The inactivation of the gene resulted in loss of NRP/PK production. In contrast to the former Bacillus spp. model the mutant strain compared to wild type showed greatly enhanced biofilm formation ability. Its biofilm promotion is directly mediated by NRP/PK, as exogenous addition of the wild type metabolite extracts restores its biofilm formation level. Wheat inoculation with bacteria that had lost their sfp-type PPTase gene resulted in two times higher plant survival and about three times increased biomass under severe drought stress compared to wild type.

  4. Tetraploidy Enhances Boron-Excess Tolerance in Carrizo Citrange (Citrus sinensis L. Osb. × Poncirus trifoliata L. Raf.).

    Science.gov (United States)

    Ruiz, Marta; Quiñones, Ana; Martínez-Alcántara, Belén; Aleza, Pablo; Morillon, Raphaël; Navarro, Luis; Primo-Millo, Eduardo; Martínez-Cuenca, Mary-Rus

    2016-01-01

    Tetraploidy modifies root anatomy which may lead to differentiated capacity to uptake and transport mineral elements. This work provides insights into physiological and molecular characters involved in boron (B) toxicity responses in diploid (2x) and tetraploid (4x) plants of Carrizo citrange (Citrus sinensis L. Osb. × Poncirus trifoliata L. Raf.), a widely used citrus rootstock. With B excess, 2x plants accumulated more B in leaves than 4x plants, which accounted for their higher B uptake and root-to-shoot transport rates. Ploidy did not modify the expression of membrane transporters NIP5 and BOR1 in roots. The cellular allocation of B excess differed between ploidy levels in the soluble fraction, which was lower in 4x leaves, while cell wall-linked B was similar in 2x and 4x genotypes. This correlates with the increased damage and stunted growth recorded in the 2x plants. The 4x roots were found to have fewer root tips, shorter specific root length, longer diameter, thicker exodermis and earlier tissue maturation in root tips, where the Casparian strip was detected at a shorter distance from the root apex than in the 2x roots. The results presented herein suggest that the root anatomical characters of the 4x plants play a key role in their lower B uptake capacity and root-to-shoot transport. Tetraploidy enhances B excess tolerance in citrange CarrizoExpression of NIP5 and BOR1 transporters and cell wall-bounded B are similar between ploidiesB tolerance is attributed to root anatomical modifications induced by genome duplicationThe rootstock 4x citrange carrizo may prevent citrus trees from B excess.

  5. H(2 enhances arabidopsis salt tolerance by manipulating ZAT10/12-mediated antioxidant defence and controlling sodium exclusion.

    Directory of Open Access Journals (Sweden)

    Yanjie Xie

    Full Text Available BACKGROUND: The metabolism of hydrogen gas (H(2 in bacteria and algae has been extensively studied for the interesting of developing H(2-based fuel. Recently, H(2 is recognized as a therapeutic antioxidant and activates several signalling pathways in clinical trials. However, underlying physiological roles and mechanisms of H(2 in plants as well as its signalling cascade remain unknown. METHODOLOGY/PRINCIPAL FINDINGS: In this report, histochemical, molecular, immunological and genetic approaches were applied to characterize the participation of H(2 in enhancing Arabidopsis salt tolerance. An increase of endogenous H(2 release was observed 6 hr after exposure to 150 mM NaCl. Arabidopsis pretreated with 50% H(2-saturated liquid medium, mimicking the induction of endogenous H(2 release when subsequently exposed to NaCl, effectively decreased salinity-induced growth inhibition. Further results showed that H(2 pretreatment modulated genes/proteins of zinc-finger transcription factor ZAT10/12 and related antioxidant defence enzymes, thus significantly counteracting the NaCl-induced reactive oxygen species (ROS overproduction and lipid peroxidation. Additionally, H(2 pretreatment maintained ion homeostasis by regulating the antiporters and H(+ pump responsible for Na(+ exclusion (in particular and compartmentation. Genetic evidence suggested that SOS1 and cAPX1 might be the target genes of H(2 signalling. CONCLUSIONS: Overall, our findings indicate that H(2 acts as a novel and cytoprotective regulator in coupling ZAT10/12-mediated antioxidant defence and maintenance of ion homeostasis in the improvement of Arabidopsis salt tolerance.

  6. Expression of chickpea CIPK25 enhances root growth and tolerance to dehydration and salt stress in transgenic tobacco

    Directory of Open Access Journals (Sweden)

    Mukesh Kumar Meena

    2015-09-01

    Full Text Available Calcium signaling plays an important role in adaptation and developmental processes in plants and animals. A class of calcium sensors, known as Calcineurin B-like (CBL proteins sense specific temporal changes in cytosolic Ca2+ concentration and regulate activities of a group of ser/thr protein kinases called CBL-interacting protein kinases (CIPKs. Although a number of CIPKs have been shown to play crucial roles in the regulation of stress signaling, no study on the function of CIPK25 or its orthologues has been reported so far. In the present study, an orthologue of Arabidopsis CIPK25 was cloned from chickpea (Cicer arietinum. CaCIPK25 gene expression in chickpea increased upon salt, dehydration, and different hormonal treatments. CaCIPK25 gene showed differential tissue-specific expression. 5'-upstream activation sequence (5'-UAS of the gene and its different truncated versions were fused to a reporter gene and studied in Arabidopsis to identify promoter regions directing its tissue-specific expression. Replacement of a conserved threonine residue with an aspartic acid at its catalytic site increased the kinase activity of CaCIPK25 by 2.5-fold. Transgenic tobacco plants overexpressing full-length and the high active versions of CaCIPK25 displayed a differential germination period and longer root length in comparison to the control plants. Expression of CaCIPK25 and its high active form differentially increased salt and water-deficit tolerance demonstrated by improved growth and reduced leaf chlorosis suggesting that the kinase activity of CaCIPK25 was required for these functions. Expressions of the abiotic stress marker genes were enhanced in the CaCIPK25-expressing tobacco plants. Our results suggested that CaCIPK25 functions in root development and abiotic stress tolerance.

  7. Ectopic Expression of JcWRKY Confers Enhanced Resistance in Transgenic Tobacco Against Macrophomina phaseolina.

    Science.gov (United States)

    Agarwal, Parinita; Patel, Khantika; Agarwal, Pradeep K

    2018-04-01

    Plants possess an innate immune system comprising of a complex network of closely regulated defense responses involving differential gene expression mediated by transcription factors (TFs). The WRKYs comprise of an important plant-specific TF family, which is involved in regulation of biotic and abiotic defenses. The overexpression of JcWRKY resulted in improved resistance in transgenic tobacco against Macrophomina phaseolina. The production of reactive oxygen species (ROS) and its detoxification through antioxidative system in the transgenics facilitates defense against Macrophomina. The enhanced catalase activity on Macrophomina infection limits the spread of infection. The transcript expression of antioxidative enzymes gene (CAT and SOD) and salicylic acid (SA) biosynthetic gene ICS1 showed upregulation during Macrophomina infection and combinatorial stress. The enhanced transcript of pathogenesis-related genes PR-1 indicates the accumulation of SA during different stresses. The PR-2 and PR-5 highlight the activation of defense responses comprising of activation of hydrolytic cleavage of glucanases and thaumatin-like proteins causing disruption of fungal cells. The ROS homeostasis in coordination with signaling molecules regulate the defense responses and inhibit fungal growth.

  8. Salicylic acid confers enhanced resistance to Glomerella leaf spot in apple.

    Science.gov (United States)

    Zhang, Ying; Shi, Xiangpeng; Li, Baohua; Zhang, Qingming; Liang, Wenxing; Wang, Caixia

    2016-09-01

    Glomerella leaf spot (GLS) caused by Glomerella cingulata is a newly emergent disease that results in severe defoliation and fruit spots in apple. Currently, there are no effective means to control this disease except for the traditional fungicide sprays. Induced resistance by elicitors against pathogens infection is a widely accepted eco-friendly strategy. In the present study, we investigated whether exogenous application of salicylic acid (SA) could improve resistance to GLS in a highly susceptible apple cultivar (Malus domestica Borkh. cv. 'Gala') and the underlying mechanisms. The results showed that pretreatment with SA, at 0.1-1.0 mM, induced strong resistance against GLS in 'Gala' apple leaves, with SA treated leaves showing significant reduction in lesion numbers and disease index. Concurrent with the enhanced disease resistance, SA treatment markedly increased the total antioxidant capacity (T-AOC) and defence-related enzyme activities, including catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), phenylalanine ammonia-lyase (PAL) and polyphenol oxidase (PPO). As expected, SA treatment also induced the expression levels of five pathogenesis-related (PR) genes including PR1, PR5, PR8, Chitinase and β-1,3-glucanase. Furthermore, the most pronounced and/or rapid increase was observed in leaves treated with SA and subsequently inoculated with G. cingulata compared to the treatment with SA or inoculation with the pathogen. Together, these results suggest that exogenous SA triggered increase in reactive oxygen species levels and the antioxidant system might be responsible for enhanced resistance against G. cingulata in 'Gala' apple leaves. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  9. Enhanced photosynthetic capacity and antioxidant potential mediate brassinosteriod-induced phenanthrene stress tolerance in tomato

    International Nuclear Information System (INIS)

    Ahammed, Golam Jalal; Li, Xin; Xia, Xiao-Jian; Shi, Kai; Zhou, Yan-Hong; Yu, Jing-Quan

    2015-01-01

    Photosynthesis, the basal manufacturing process in the earth is habitually restricted by airborne micropollutants such as phenanthrene (PHE). Here, we show that 24-epibrassinolide (EBR), a bioactive plant steroid is able to keep higher photosynthetic capacity consistently for a long period under a shoot-imposed PHE stress in tomato. EBR-promoted photosynthetic capacity and efficiency eventually resulted in a 37.5% increase of biomass under PHE stress. As primary response, transcripts of antioxidant genes were remarkably induced by EBR in PHE-treated plants. Activities of antioxidant and detoxification enzymes were also enhanced by EBR. Notably, EBR-induced higher antioxidant potential was associated with reduced levels of H 2 O 2 and O 2 · — , resulting in a 32.7% decrease of content of malondialdehyde in the end of experiment and relatively healthy chloroplast ultrastructure in EBR + PHE treatment compared with PHE alone. These results indicate that EBR alleviates shoot-imposed PHE phytotoxicity by maintaining a consistently higher photosynthetic capacity and antioxidant potential in tomato. - Highlights: • PHE mist spray gradually inhibits photosynthesis and eventually reduces biomass. • EBR maintains a consistently higher photosynthesis even under PHE stress. • EBR upregulates expression of antioxidant genes as initial response to PHE stress. • EBR reduces oxidative stress by constantly activating strong antioxidant potential. • EBR-induced efficient neutralization of ROS protects chloroplast ultrastructure. - 24-epibrassinolide protects tomato plants from airborne phenanthrene-induced damages by maintaining a consistently higher photosynthetic capacity and antioxidant potential

  10. Expression of multiple resistance genes enhances tolerance to environmental stressors in transgenic poplar (Populus × euramericana 'Guariento'.

    Directory of Open Access Journals (Sweden)

    Xiaohua Su

    Full Text Available Commercial and non-commercial plants face a variety of environmental stressors that often cannot be controlled. In this study, transgenic hybrid poplar (Populus × euramericana 'Guariento' harboring five effector genes (vgb, SacB, JERF36, BtCry3A and OC-I were subjected to drought, salinity, waterlogging and insect stressors in greenhouse or laboratory conditions. Field trials were also conducted to investigate long-term effects of transgenic trees on insects and salt tolerance in the transformants. In greenhouse studies, two transgenic lines D5-20 and D5-21 showed improved growth, as evidenced by greater height and basal diameter increments and total biomass relative to the control plants after drought or salt stress treatments. The improved tolerance to drought and salt was primarily attributed to greater instantaneous water use efficiency (WUEi in the transgenic trees. The chlorophyll concentrations tended to be higher in the transgenic lines under drought or saline conditions. Transformed trees in drought conditions accumulated more fructan and proline and had increased Fv/Fm ratios (maximum quantum yield of photosystem II under waterlogging stress. Insect-feeding assays in the laboratory revealed a higher total mortality rate and lower exuviation index of leaf beetle [Plagiodera versicolora (Laicharting] larvae fed with D5-21 leaves, suggesting enhanced insect resistance in the transgenic poplar. In field trials, the dominance of targeted insects on 2-year-old D5-21 transgenic trees was substantially lower than that of the controls, indicating enhanced resistance to Coleoptera. The average height and DBH (diameter at breast height of 2.5-year-old transgenic trees growing in naturally saline soil were 3.80% and 4.12% greater than those of the control trees, but these increases were not significant. These results suggested that multiple stress-resistance properties in important crop tree species could be simultaneously improved, although

  11. Enhanced tolerability of the 5-hydroxytryptophane challenge test combined with granisetron.

    Science.gov (United States)

    Jacobs, G E; Kamerling, I M C; de Kam, M L; Derijk, R H; van Pelt, J; Zitman, F G; van Gerven, J M A

    2010-01-01

    A recently developed oral serotonergic challenge test consisting of 5-Hydroxytryptophane (5-HTP, 200 mg) combined with carbidopa (CBD, 100 mg + 50 mg) exhibited dose-related neuroendocrine responsiveness and predictable pharmacokinetics. However, its applicability is limited by nausea and vomiting. A randomized, double-blind, placebo-controlled, four-way crossover trial was performed in 12 healthy male volunteers. The 5-HTP/CBD-challenge was combined with two oral anti-emetics (granisetron, 2 mg or domperidone, 10 mg) to investigate its reliability when side-effects are suppressed. The neuroendocrine response (serum cortisol and prolactin), the side-effect profile [Visual Analogue Scale Nausea (VAS)] and vomiting subjects per treatment were the main outcome measures. Compared to 5-HTP/CBD/placebo, 5-HTP/CBD/ granisetron had no impact on cortisol [% change with 95% confidence interval: -7.1% (18.9; 6.5)] or prolactin levels [-9.6% (-25.1; 9.1)]; 5-HTP/CBD/domperidone increased cortisol [+13.0% (-4.2; 33.4)], and increased prolactin extensively [+336.8% (245.7; 451.9)]. Compared to placebo, VAS Nausea increased non-significantly with granisetron [+7.6 mm (-1.3; 16.5)], as opposed to domperidone [+16.2 mm (7.2; 25.2)] and 5-HTP/CBD/placebo [+14.7 mm (5.5; 23.8)]. No subjects vomited with granisetron, compared to two subjects treated with 5-HTP/CBD/placebo and five subjects with domperidone. Compared with 5-HTP/CBD/placebo, granisetron addition decreased C(max) of 5-HTP statistically significantly different (from 1483 to 1272 ng/ml) without influencing AUC(0- infinity). Addition of granisetron to the combined 5-HTP/CBD challenge suppresses nausea and vomiting without influencing the neuroendocrine response or pharmacokinetics, enhancing its clinical applicability in future psychiatric research and drug development.

  12. A bHLH gene from Tamarix hispida improves abiotic stress tolerance by enhancing osmotic potential and decreasing reactive oxygen species accumulation.

    Science.gov (United States)

    Ji, Xiaoyu; Nie, Xianguang; Liu, Yujia; Zheng, Lei; Zhao, Huimin; Zhang, Bing; Huo, Lin; Wang, Yucheng

    2016-02-01

    Basic helix-loop-helix (bHLH) leucine-zipper transcription factors play important roles in abiotic stress responses. However, their specific roles in abiotic stress tolerance are not fully known. Here, we functionally characterized a bHLH gene, ThbHLH1, from Tamarix hispida in abiotic stress tolerance. ThbHLH1 specifically binds to G-box motif with the sequence of 'CACGTG'. Transiently transfected T. hispida plantlets with transiently overexpressed ThbHLH1 and RNAi-silenced ThbHLH1 were generated for gain- and loss-of-function analysis. Transgenic Arabidopsis thaliana lines overexpressing ThbHLH1 were generated to confirm the gain- and loss-of-function analysis. Overexpression of ThbHLH1 significantly elevates glycine betaine and proline levels, increases Ca(2+) concentration and enhances peroxidase (POD) and superoxide dismutase (SOD) activities to decrease reactive oxygen species (ROS) accumulation. Additionally, ThbHLH1 regulates the expression of the genes including P5CS, BADH, CaM, POD and SOD, to activate the above physiological changes, and also induces the expression of stress tolerance-related genes LEAs and HSPs. These data suggest that ThbHLH1 induces the expression of stress tolerance-related genes to improve abiotic stress tolerance by increasing osmotic potential, improving ROS scavenging capability and enhancing second messenger in stress signaling cascades. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. AZIN1 RNA editing confers cancer stemness and enhances oncogenic potential in colorectal cancer.

    Science.gov (United States)

    Shigeyasu, Kunitoshi; Okugawa, Yoshinaga; Toden, Shusuke; Miyoshi, Jinsei; Toiyama, Yuji; Nagasaka, Takeshi; Takahashi, Naoki; Kusunoki, Masato; Takayama, Tetsuji; Yamada, Yasuhide; Fujiwara, Toshiyoshi; Chen, Leilei; Goel, Ajay

    2018-06-21

    Adenosine-to-inosine (A-to-I) RNA editing, a process mediated by adenosine deaminases that act on the RNA (ADAR) gene family, is a recently discovered epigenetic modification dysregulated in human cancers. However, the clinical significance and the functional role of RNA editing in colorectal cancer (CRC) remain unclear. We have systematically and comprehensively investigated the significance of the expression status of ADAR1 and of the RNA editing levels of antizyme inhibitor 1 (AZIN1), one of the most frequently edited genes in cancers, in 392 colorectal tissues from multiple independent CRC patient cohorts. Both ADAR1 expression and AZIN1 RNA editing levels were significantly elevated in CRC tissues when compared with corresponding normal mucosa. High levels of AZIN1 RNA editing emerged as a prognostic factor for overall survival and disease-free survival and were an independent risk factor for lymph node and distant metastasis. Furthermore, elevated AZIN1 editing identified high-risk stage II CRC patients. Mechanistically, edited AZIN1 enhances stemness and appears to drive the metastatic processes. We have demonstrated that edited AZIN1 functions as an oncogene and a potential therapeutic target in CRC. Moreover, AZIN1 RNA editing status could be used as a clinically relevant prognostic indicator in CRC patients.

  14. Deep rooting conferred by DEEPER ROOTING 1 enhances rice yield in paddy fields.

    Science.gov (United States)

    Arai-Sanoh, Yumiko; Takai, Toshiyuki; Yoshinaga, Satoshi; Nakano, Hiroshi; Kojima, Mikiko; Sakakibara, Hitoshi; Kondo, Motohiko; Uga, Yusaku

    2014-07-03

    To clarify the effect of deep rooting on grain yield in rice (Oryza sativa L.) in an irrigated paddy field with or without fertilizer, we used the shallow-rooting IR64 and the deep-rooting Dro1-NIL (a near-isogenic line homozygous for the Kinandang Patong allele of DEEPER ROOTING 1 (DRO1) in the IR64 genetic background). Although total root length was similar in both lines, more roots were distributed within the lower soil layer of the paddy field in Dro1-NIL than in IR64, irrespective of fertilizer treatment. At maturity, Dro1-NIL showed approximately 10% higher grain yield than IR64, irrespective of fertilizer treatment. Higher grain yield of Dro1-NIL was mainly due to the increased 1000-kernel weight and increased percentage of ripened grains, which resulted in a higher harvest index. After heading, the uptake of nitrogen from soil and leaf nitrogen concentration were higher in Dro1-NIL than in IR64. At the mid-grain-filling stage, Dro1-NIL maintained higher cytokinin fluxes from roots to shoots than IR64. These results suggest that deep rooting by DRO1 enhances nitrogen uptake and cytokinin fluxes at late stages, resulting in better grain filling in Dro1-NIL in a paddy field in this study.

  15. Productivity of sodic soils can be enhanced through the use of salt tolerant rice varieties and proper agronomic practices.

    Science.gov (United States)

    Singh, Y P; Mishra, V K; Singh, Sudhanshu; Sharma, D K; Singh, D; Singh, U S; Singh, R K; Haefele, S M; Ismail, A M

    2016-04-01

    Regaining the agricultural potential of sodic soils in the Indo-Gangetic plains necessitates the development of suitable salt tolerant rice varieties to provide an entry for other affordable agronomic and soil manipulation measures. Thus selection of high yielding rice varieties across a range of sodic soils is central. Evaluation of breeding lines through on-station and on-farm farmers' participatory varietal selection (FPVS) resulted in the identification of a short duration (110-115 days), high yielding and disease resistant salt-tolerant rice genotype 'CSR-89IR-8', which was later released as 'CSR43' in 2011. Several agronomic traits coupled with good grain quality and market value contributed to commercialization and quick adoption of this variety in the sodic areas of the Indo-Gangetic plains of eastern India. Management practices required for rice production in salt affected soils are evidently different from those in normal soils and practices for a short duration salt tolerant variety differ from those for medium to long duration varieties. Experiments were conducted at the Indian Council of Agricultural Research-Central Soil Salinity Research Institute (ICAR-CSSRI), Regional Research Station, Lucknow, Uttar Pradesh, India during 2011 and 2013 wet seasons, to test the hypothesis that combining matching management practices (Mmp) with an improved genotype would enhance productivity and profitability of rice in sodic soils. Mmp were developed on-station by optimizing existing best management practices (Bmp) recommended for the region to match the requirements of CSR43. The results revealed that transplanting 4 seedlings hill -1 at a spacing of 15 × 20 cm produced significantly higher yield over other treatments. The highest additional net gain was US$ 3.3 at 90 kg ha -1  N, and the lowest was US$ 0.4 at 150 kg ha -1  N. Above 150 kg ha -1 , the additional net gain became negative, indicating decreasing returns from additional N. Hence, 150

  16. Label-free direct surface-enhanced Raman scattering (SERS) of nucleic acids (Conference Presentation)

    Science.gov (United States)

    Guerrini, Luca; Morla-Folch, Judit; Gisbert-Quilis, Patricia; Xie, Hainan; Alvarez-Puebla, Ramon

    2016-03-01

    Recently, plasmonic-based biosensing has experienced an unprecedented level of attention, with a particular focus on the nucleic acid detection, offering efficient solutions to engineer simple, fast, highly sensitive sensing platforms while overcoming important limitations of PCR and microarray techniques. In the broad field of plasmonics, surface-enhanced Raman scattering (SERS) spectroscopy has arisen as a powerful analytical tool for detection and structural characterization of biomolecules. Today applications of SERS to nucleic acid analysis largely rely on indirect strategies, which have been demonstrated very effective for pure sensing purposes but completely dismiss the exquisite structural information provided by the direct acquisition of the biomolecular vibrational fingerprint. Contrarily, direct label-free SERS of nucleic acid shows an outstanding potential in terms of chemical-specific information which, however, remained largely unexpressed mainly because of the inherent poor spectral reproducibility and/or limited sensitivity. To address these limitations, we developed a fast and affordable high-throughput screening direct SERS method for gaining detailed genomic information on nucleic acids (DNA and RNA) and for the characterization and quantitative recognition of DNA interactions with exogenous agents. The simple strategy relies on the electrostatic adhesion of DNA/RNA onto positively-charged silver colloids that promotes the nanoparticle aggregation into stable clusters yielding intense and reproducible SERS spectra at picogram level (i.e. the analysis can be performed without the necessity of amplification steps thus providing realistic direct information of the nucleic acid in its native state). We anticipate this method to gain a vast impact and set of applications in different fields, including medical diagnostics, genomic screening, drug discovery, forensic science and even molecular electronics.

  17. From photoluminescence to thermal emission: Thermally-enhanced PL (TEPL) for efficient PV (Conference Presentation)

    Science.gov (United States)

    Manor, Assaf; Kruger, Nimrod; Martin, Leopoldo L.; Rotschild, Carmel

    2016-09-01

    The Shockley-Queisser efficiency limit of 40% for single-junction photovoltaic (PV) cells is mainly caused by the heat dissipation accompanying the process of electro-chemical potential generation. Concepts such as solar thermo-photovoltaics (STPV) aim to harvest this heat loss by the use of a primary absorber which acts as a mediator between the sun and the PV, spectrally shaping the light impinging on the cell. However, this approach is challenging to realize due to the high operating temperatures of above 2000K required in order to generate high thermal emission fluxes. After over thirty years of STPV research, the record conversion efficiency for STPV device stands at 3.2% for 1285K operating temperature. In contrast, we recently demonstrated how thermally-enhanced photoluminescence (TEPL) is an optical heat-pump, in which photoluminescence is thermally blue-shifted upon heating while the number of emitted photons is conserved. This process generates energetic photon-rates which are comparable to thermal emission in significantly reduced temperatures, opening the way for a TEPL based energy converter. In such a device, a photoluminescent low bandgap absorber replaces the STPV thermal absorber. The thermalization heat induces a temperature rise and a blue-shifted emission, which is efficiently harvested by a higher bandgap PV. We show that such an approach can yield ideal efficiencies of 70% at 1140K, and realistic efficiencies of almost 50% at moderate concentration levels. As an experimental proof-of-concept, we demonstrate 1.4% efficient TEPL energy conversion of an Nd3+ system coupled to a GaAs cell, at 600K.

  18. Practical considerations for solar energy thermally enhanced photo-luminescence (TEPL) (Conference Presentation)

    Science.gov (United States)

    Kruger, Nimrod; Manor, Assaf; Kurtulik, Matej; Sabapathy, Tamilarasan; Rotschild, Carmel

    2017-04-01

    While single-junction photovoltaics (PV's) are considered limited in conversion efficiency according to the Shockley-Queisser limit, concepts such as solar thermo-photovoltaics aim to harness lost heat and overcome this barrier. We claim the novel concept of Thermally Enhanced Photoluminescence (TEPL) as an easier route to achieve this goal. Here we present a practical TEPL device where a thermally insulated photo-luminescent (PL) absorber, acts as a mediator between a photovoltaic cell and the sun. This high temperature absorber emits blue-shifted PL at constant flux, then coupled to a high band gap PV cell. This scheme promotes PV conversion efficiencies, under ideal conditions, higher than 62% at temperatures lower than 1300K. Moreover, for a PV and absorber band-gaps of 1.45eV (GaAs PV's) and 1.1eV respectively, under practical conditions, solar concentration of 1000 suns, and moderate thermal insulation; the conversion efficiencies potentially exceed 46%. Some of these practical conditions belong to the realm of optical design; including high photon recycling (PR) and absorber external quantum efficiency (EQE). High EQE values, a product of the internal QE of the active PL materials and the extraction efficiency of each photon (determined by the absorber geometry and interfaces), have successfully been reached by experts in laser cooling technology. PR is the part of emitted low energy photons (in relation to the PV band-gap) that are reabsorbed and consequently reemitted with above band-gap energies. PV back-reflector reflectivity, also successfully achieved by those who design the cutting edge high efficiency PV cells, plays a major role here.

  19. The enhancement of tolerance to salt and cold stresses by modifying the redox state and salicylic acid content via the cytosolic malate dehydrogenase gene in transgenic apple plants.

    Science.gov (United States)

    Wang, Qing-Jie; Sun, Hong; Dong, Qing-Long; Sun, Tian-Yu; Jin, Zhong-Xin; Hao, Yu-Jin; Yao, Yu-Xin

    2016-10-01

    In this study, we characterized the role of an apple cytosolic malate dehydrogenase gene (MdcyMDH) in the tolerance to salt and cold stresses and investigated its regulation mechanism in stress tolerance. The MdcyMDH transcript was induced by mild cold and salt treatments, and MdcyMDH-overexpressing apple plants possessed improved cold and salt tolerance compared to wild-type (WT) plants. A digital gene expression tag profiling analysis revealed that MdcyMDH overexpression largely altered some biological processes, including hormone signal transduction, photosynthesis, citrate cycle and oxidation-reduction. Further experiments verified that MdcyMDH overexpression modified the mitochondrial and chloroplast metabolisms and elevated the level of reducing power, primarily caused by increased ascorbate and glutathione, as well as the increased ratios of ascorbate/dehydroascorbate and glutathione/glutathione disulphide, under normal and especially stress conditions. Concurrently, the transgenic plants produced a high H2 O2 content, but a low O2·- production rate was observed compared to the WT plants. On the other hand, the transgenic plants accumulated more free and total salicylic acid (SA) than the WT plants under normal and stress conditions. Taken together, MdcyMDH conferred the transgenic apple plants a higher stress tolerance by producing more reductive redox states and increasing the SA level; MdcyMDH could serve as a target gene to genetically engineer salt- and cold-tolerant trees. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  20. Preliminary Results on FeCrAl Alloys in the As-received and Welded State Designed to Have Enhanced Weldability and Radiation Tolerance

    International Nuclear Information System (INIS)

    Field, Kevin G.; Gussev, Maxim N.; Hu, Xunxiang; Yamamoto, Yukinori

    2015-01-01

    The present report summarizes and discusses the recent results on developing a modern, nuclear grade FeCrAl alloy designed to have enhanced radiation tolerance and weldability. The alloys used for these investigations are modern FeCrAl alloys based on a Fe-13Cr-5Al-2Mo-0.2Si-0.05Y alloy (in wt.%, designated C35M). Development efforts have focused on assessing the influence of chemistry and microstructure on the fabricability and performance of these newly developed alloys. Specific focus was made to assess the weldability, thermal stability, and radiation tolerance.

  1. Preliminary Results on FeCrAl Alloys in the As-received and Welded State Designed to Have Enhanced Weldability and Radiation Tolerance

    Energy Technology Data Exchange (ETDEWEB)

    Field, Kevin G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gussev, Maxim N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hu, Xunxiang [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Yamamoto, Yukinori [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-30

    The present report summarizes and discusses the recent results on developing a modern, nuclear grade FeCrAl alloy designed to have enhanced radiation tolerance and weldability. The alloys used for these investigations are modern FeCrAl alloys based on a Fe-13Cr-5Al-2Mo-0.2Si-0.05Y alloy (in wt.%, designated C35M). Development efforts have focused on assessing the influence of chemistry and microstructure on the fabricability and performance of these newly developed alloys. Specific focus was made to assess the weldability, thermal stability, and radiation tolerance.

  2. CmWRKY1 Enhances the Dehydration Tolerance of Chrysanthemum through the Regulation of ABA-Associated Genes.

    Directory of Open Access Journals (Sweden)

    Qingqing Fan

    Full Text Available WRKY transcription factors serve as antagonistic or synergistic regulators in a variety of abiotic stress responses in plants. Here, we show that CmWRKY1, a member of the group IIb WRKY family isolated from Chrysanthemum morifolium, exhibits no transcriptional activation in yeast cells. The subcellular localization examination showed that CmWRKY1 localizes to the nucleus in vivo. Furthermore, CmWRKY1-overexpressing transgenic lines exhibit enhanced dehydration tolerance in response to polyethylene glycol (PEG treatment compared with wild-type plants. We further confirmed that the transgenic plants exhibit suppressed expression levels of genes negatively regulated by ABA, such as PP2C, ABI1 and ABI2, and activated expression levels of genes positively regulated by ABA, such as PYL2, SnRK2.2, ABF4, MYB2, RAB18, and DREB1A. Taken together, our results indicate that CmWRKY1 plays an important role in the response to drought in chrysanthemum through an ABA-mediated pathway.

  3. In-plane current-driven spin-orbit torque switching in perpendicularly magnetized films with enhanced thermal tolerance

    International Nuclear Information System (INIS)

    Wu, Di; Yu, Guoqiang; Shao, Qiming; Li, Xiang; Wong, Kin L.; Wang, Kang L.; Wu, Hao; Han, Xiufeng; Zhang, Zongzhi; Khalili Amiri, Pedram

    2016-01-01

    We study spin-orbit-torque (SOT)-driven magnetization switching in perpendicularly magnetized Ta/Mo/Co_4_0Fe_4_0B_2_0 (CoFeB)/MgO films. The thermal tolerance of the perpendicular magnetic anisotropy (PMA) is enhanced, and the films sustain the PMA at annealing temperatures of up to 430 °C, due to the ultra-thin Mo layer inserted between the Ta and CoFeB layers. More importantly, the Mo insertion layer also allows for the transmission of the spin current generated in the Ta layer due to spin Hall effect, which generates a damping-like SOT and is able to switch the perpendicular magnetization. When the Ta layer is replaced by a Pt layer, i.e., in a Pt/Mo/CoFeB/MgO multilayer, the direction of the SOT-induced damping-like effective field becomes opposite because of the opposite sign of spin Hall angle in Pt, which indicates that the SOT-driven switching is dominated by the spin current generated in the Ta or Pt layer rather than the Mo layer. Quantitative characterization through harmonic measurements reveals that the large SOT effective field is preserved for high annealing temperatures. This work provides a route to applying SOT in devices requiring high temperature processing steps during the back-end-of-line processes.

  4. Delaying chloroplast turnover increases water-deficit stress tolerance through the enhancement of nitrogen assimilation in rice.

    Science.gov (United States)

    Sade, Nir; Umnajkitikorn, Kamolchanok; Rubio Wilhelmi, Maria Del Mar; Wright, Matthew; Wang, Songhu; Blumwald, Eduardo

    2018-02-12

    Abiotic stress-induced senescence in crops is a process particularly affecting the photosynthetic apparatus, decreasing photosynthetic activity and inducing chloroplast degradation. A pathway for stress-induced chloroplast degradation that involves the CHLOROPLAST VESICULATION (CV) gene was characterized in rice (Oryza sativa) plants. OsCV expression was up-regulated with the age of the plants and when plants were exposed to water-deficit conditions. The down-regulation of OsCV expression contributed to the maintenance of the chloroplast integrity under stress. OsCV-silenced plants displayed enhanced source fitness (i.e. carbon and nitrogen assimilation) and photorespiration, leading to water-deficit stress tolerance. Co-immunoprecipitation, intracellular co-localization, and bimolecular fluorescence demonstrated the in vivo interaction between OsCV and chloroplastic glutamine synthetase (OsGS2), affecting source-sink relationships of the plants under stress. Our results would indicate that the OsCV-mediated chloroplast degradation pathway is involved in the regulation of nitrogen assimilation during stress-induced plant senescence. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  5. Enhancement in ionic liquid tolerance of cellulase immobilized on PEGylated graphene oxide nanosheets: Application in saccharification of lignocellulose.

    Science.gov (United States)

    Xu, Jiaxing; Sheng, Zhenhuan; Wang, Xinfeng; Liu, Xiaoyan; Xia, Jun; Xiong, Peng; He, Bingfang

    2016-01-01

    The objective of the present work was to improve ionic liquid (IL) tolerance of cellulase based on the exploration of functional nanoscale carriers for potential application in lignocellulosic biorefinery. PEGylated graphene oxide (GO) composite was successfully fabricated by chemical binding of 4-arm-PEG-NH2 and GO and applied to the immobilization of cellulase. The PEGylated GO-Cellulase retained 61% of the initial activity in 25% (w/v) 1-butyl-3-methylimidazolium chloride ([Bmim][Cl]) while free cellulase only retained 2%. The IL stability was enhanced more than 30 times. The relatively minor change in Km value (from 2.7 to 3.2mgmL(-1)) after the immobilization suggested that PEGylated GO-Cellulase was capable of closely mimicking the performance of free enzyme. After treating rice straw with [Bmim][Cl] and dilution to a final IL concentration of 15% (w/v), the slurry was directly hydrolyzed using PEGylated GO-Cellulase without IL removing and a high hydrolysis rate of 87% was achieved. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. The Expression of Millettia pinnata Chalcone Isomerase in Saccharomyces cerevisiae Salt-Sensitive Mutants Enhances Salt-Tolerance

    Directory of Open Access Journals (Sweden)

    Baiqu Huang

    2013-04-01

    Full Text Available The present study demonstrates a new Millettia pinnata chalcone isomerase (MpCHI whose transcription level in leaf was confirmed to be enhanced after being treated by seawater or NaCl (500 mM via transcriptome sequencing and Real-Time Quantitative Reverse Transcription PCR (QRT-PCR analyses. Its full length cDNA (666 bp was obtained by 3'-end and 5'-end Rapid Amplification of cDNA Ends (RACE. The analysis via NCBI BLAST indicates that both aminoacid sequence and nucleotide sequence of the MpCHI clone share high homology with other leguminous CHIs (73%–86%. Evolutionarily, the phylogenic analysis further revealed that the MpCHI is a close relative of leguminous CHIs. The MpCHI protein consists of 221 aminoacid (23.64 KDa, whose peptide length, amino acid residues of substrate-binding site and reactive site are very similar to other leguminous CHIs reported previously. Two pYES2-MpCHI transformed salt-sensitive Saccharomyces cerevisiae mutants (Δnha1 and Δnhx1 showed improved salt-tolerance significantly compared to pYES2-vector transformed yeast mutants, suggesting the MpCHI or the flavonoid biosynthesis pathway could regulate the resistance to salt stress in M. pinnata.

  7. The expression of Millettia pinnata chalcone isomerase in Saccharomyces cerevisiae salt-sensitive mutants enhances salt-tolerance.

    Science.gov (United States)

    Wang, Hui; Hu, Tangjin; Huang, Jianzi; Lu, Xiang; Huang, Baiqu; Zheng, Yizhi

    2013-04-24

    The present study demonstrates a new Millettia pinnata chalcone isomerase (MpCHI) whose transcription level in leaf was confirmed to be enhanced after being treated by seawater or NaCl (500 mM) via transcriptome sequencing and Real-Time Quantitative Reverse Transcription PCR (QRT-PCR) analyses. Its full length cDNA (666 bp) was obtained by 3'-end and 5'-end Rapid Amplification of cDNA Ends (RACE). The analysis via NCBI BLAST indicates that both aminoacid sequence and nucleotide sequence of the MpCHI clone share high homology with other leguminous CHIs (73%-86%). Evolutionarily, the phylogenic analysis further revealed that the MpCHI is a close relative of leguminous CHIs. The MpCHI protein consists of 221 aminoacid (23.64 KDa), whose peptide length, amino acid residues of substrate-binding site and reactive site are very similar to other leguminous CHIs reported previously. Two pYES2-MpCHI transformed salt-sensitive Saccharomyces cerevisiae mutants (Δnha1 and Δnhx1) showed improved salt-tolerance significantly compared to pYES2-vector transformed yeast mutants, suggesting the MpCHI or the flavonoid biosynthesis pathway could regulate the resistance to salt stress in M. pinnata.

  8. The novel wheat transcription factor TaNAC47 enhances multiple abiotic stress tolerances in transgenic plants

    Directory of Open Access Journals (Sweden)

    Li Na eZhang

    2016-01-01

    Full Text Available NAC transcription factors play diverse roles in plant development and responses to abiotic stresses. However, the biological roles of NAC family members in wheat are not well understood. Here, we reported the isolation and functional characterization of a novel wheat TaNAC47 gene. TaNAC47 encoded protein, localizing in the nucleus, is able to bind to the ABRE cis-element and transactivate transcription in yeast, suggesting that it likely functions as a transcriptional activator. We also showed that TaNAC47 is differentially expressed in different tissues, and its expression was induced by the stress treatments of salt, cold, polyethylene glycol (PEG and exogenous abscisic acid (ABA. Furthermore, overexpression of TaNAC47 in Arabidopsis resulted in ABA hypersensitivity and enhancing tolerance of transgenic plants to drought, salt and freezing stresses. Strikingly, overexpression of TaNAC47 was found to activate the expression of downstream genes and change several physiological indices that may enable transgenic plants to overcome unfavorable environments. Taken together, these results uncovered an important role of wheat TaNAC47 gene in response to ABA and abiotic stresses.

  9. Alpha-ketoglutarate enhances freeze-thaw tolerance and prevents carbohydrate-induced cell death of the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Bayliak, Maria M; Hrynkiv, Olha V; Knyhynytska, Roksolana V; Lushchak, Volodymyr I

    2018-01-01

    Stress resistance and fermentative capability are important quality characteristics of baker's yeast. In the present study, we examined protective effects of exogenous alpha-ketoglutarate (AKG), an intermediate of the tricarboxylic acid cycle and amino acid metabolism, against freeze-thaw and carbohydrate-induced stresses in the yeast Saccharomyces cerevisiae. Growth on AKG-supplemented medium prevented a loss of viability and improved fermentative capacity of yeast cells after freeze-thaw treatment. The cells grown in the presence of AKG had higher levels of amino acids (e.g., proline), higher metabolic activity and total antioxidant capacity, and higher activities of catalase, NADP-dependent glutamate dehydrogenase and glutamine synthase compared to control ones. Both synthesis of amino acids and enhancement of antioxidant system capacity could be involved in AKG-improved freeze-thaw tolerance in S. cerevisiae. Cell viability dramatically decreased under incubation of stationary-phase yeast cells in 2% glucose or fructose solutions (in the absence of the other nutrients) as compared with incubation in distilled water or in 10 mM AKG solution. The decrease in cell viability was accompanied by acidification of the medium, and decrease in cellular respiration, aconitase activity, and levels of total protein and free amino acids. The supplementation with 10 mM AKG effectively prevented carbohydrate-induced yeast death. Protective mechanisms of AKG could be associated with the intensification of respiration and prevention of decreasing protein level as well as with direct antioxidant AKG action.

  10. The Novel Wheat Transcription Factor TaNAC47 Enhances Multiple Abiotic Stress Tolerances in Transgenic Plants.

    Science.gov (United States)

    Zhang, Lina; Zhang, Lichao; Xia, Chuan; Zhao, Guangyao; Jia, Jizeng; Kong, Xiuying

    2015-01-01

    NAC transcription factors play diverse roles in plant development and responses to abiotic stresses. However, the biological roles of NAC family members in wheat are not well understood. Here, we reported the isolation and functional characterization of a novel wheat TaNAC47 gene. TaNAC47 encoded protein, localizing in the nucleus, is able to bind to the ABRE cis-element and transactivate transcription in yeast, suggesting that it likely functions as a transcriptional activator. We also showed that TaNAC47 is differentially expressed in different tissues, and its expression was induced by the stress treatments of salt, cold, polyethylene glycol and exogenous abscisic acid. Furthermore, overexpression of TaNAC47 in Arabidopsis resulted in ABA hypersensitivity and enhancing tolerance of transgenic plants to drought, salt, and freezing stresses. Strikingly, overexpression of TaNAC47 was found to activate the expression of downstream genes and change several physiological indices that may enable transgenic plants to overcome unfavorable environments. Taken together, these results uncovered an important role of wheat TaNAC47 gene in response to ABA and abiotic stresses.

  11. Transgenerational inheritance of modified DNA methylation patterns and enhanced tolerance induced by heavy metal stress in rice (Oryza sativa L.).

    Science.gov (United States)

    Ou, Xiufang; Zhang, Yunhong; Xu, Chunming; Lin, Xiuyun; Zang, Qi; Zhuang, Tingting; Jiang, Lili; von Wettstein, Diter; Liu, Bao

    2012-01-01

    DNA methylation is sensitive and responsive to stressful environmental conditions. Nonetheless, the extent to which condition-induced somatic methylation modifications can impose transgenerational effects remains to be fully understood. Even less is known about the biological relevance of the induced epigenetic changes for potentially altered well-being of the organismal progenies regarding adaptation to the specific condition their progenitors experienced. We analyzed DNA methylation pattern by gel-blotting at genomic loci representing transposable elements and protein-coding genes in leaf-tissue of heavy metal-treated rice (Oryza sativa) plants (S0), and its three successive organismal generations. We assessed expression of putative genes involved in establishing and/or maintaining DNA methylation patterns by reverse transcription (RT)-PCR. We measured growth of the stressed plants and their unstressed progenies vs. the control plants. We found (1) relative to control, DNA methylation patterns were modified in leaf-tissue of the immediately treated plants, and the modifications were exclusively confined to CHG hypomethylation; (2) the CHG-demethylated states were heritable via both maternal and paternal germline, albeit often accompanying further hypomethylation; (3) altered expression of genes encoding for DNA methyltransferases, DNA glycosylase and SWI/SNF chromatin remodeling factor (DDM1) were induced by the stress; (4) progenies of the stressed plants exhibited enhanced tolerance to the same stress their progenitor experienced, and this transgenerational inheritance of the effect of condition accompanying heritability of modified methylation patterns. Our findings suggest that stressful environmental condition can produce transgenerational epigenetic modifications. Progenies of stressed plants may develop enhanced adaptability to the condition, and this acquired trait is inheritable and accord with transmission of the epigenetic modifications. We suggest

  12. Genotypes Associated with Listeria monocytogenes Isolates Displaying Impaired or Enhanced Tolerances to Cold, Salt, Acid, or Desiccation Stress

    DEFF Research Database (Denmark)

    Hingston, Patricia A.; Chen, Jessica; Dhillon, Bhavjinder K

    2017-01-01

    elements. A whole genome single-nucleotide-variants phylogeny revealed sporadic distribution of tolerant isolates and closely related sensitive and tolerant isolates, highlighting that minor genetic differences can influence the stress tolerance of L. monocytogenes. Specifically, a number of cold......The human pathogen Listeria monocytogenes is a large concern in the food industry where its continuous detection in food products has caused a string of recalls in North America and Europe. Most recognized for its ability to grow in foods during refrigerated storage, L. monocytogenes can also...... tolerate several other food-related stresses with some strains possessing higher levels of tolerances than others. The objective of this study was to use a combination of phenotypic analyses and whole genome sequencing to elucidate potential relationships between L. monocytogenes genotypes and food...

  13. Potential application of metabolic engineering to tune the production of compatible solutes for enhancing tolerance of crop plants to salinity/drought (abstract)

    International Nuclear Information System (INIS)

    Sharmila, P.; Saradhi, P.P.

    2005-01-01

    Essential need to develop genotypes of crop plants that can substantially withstand salinity and drought with little yield losses is being increasingly felt, as the cultivable agricultural lands is increasingly being exposed to these stresses. In-spite of gains in productivity, conventional plant breeding methods have their limitations either due to limited gene pool or due to species barrier for gene transfer. Modern molecular tools have paved ways for identification of genes imparting abiotic stress tolerance in unrelated species/organisms and to transfer the selected genes into desirable crop plant species by conquering the incompatibility barriers. In fact, now genetic engineering has been widely realized to be in important tool for developing abiotic stress tolerant crop plants. Abiotic stress tolerance is a complex phenomenon involving simultaneous expression of a number of genes coupled with an interaction of varying weather variables and crop phonology. However, in order to tackle the issue, successful attempts have been made in identifying genes enhancing abiotic stress tolerance. The genes for biosynthesis of various compatible solutes (viz., mtlD for mannitol: P5CS or P5CSF129A for proline; coda/cox or belA/beIB for glycinebetaine' lpsl for trehalose; PINOI for inositol) have been demonstrated to enhance abiotic stress tolerance of plants. We have isolated the codA gene (Accession number AY589052) for choline oxidase from an Indian strain of Arthrobacter sp. from IMTECH (Chandigarh) and the mtlD genes from local strains of E. coli (accession number A Y523630) and halobacterium sp. (Accession number A Y52363 1). We have enhanced the tolerance of Brassica juncea to salt, drought and low temperature stresses by introducing the codA gene from Arthrobacter globiformis using Agrobacterium tumefaciens mediated transformation. Presenting our research team is busy developing genotypes of chickpea black gram, peanut and sorghum besides mustard with enhanced

  14. Constitutive expression of CaPLA1 conferred enhanced growth and grain yield in transgenic rice plants.

    Science.gov (United States)

    Park, Ki Youl; Kim, Eun Yu; Seo, Young Sam; Kim, Woo Taek

    2016-03-01

    Phospholipids are not only important components of cell membranes, but participate in diverse processes in higher plants. In this study, we generated Capsicum annuum phospholipiase A1 (CaPLA1) overexpressing transgenic rice (Oryza sativa L.) plants under the control of the maize ubiquitin promoter. The T4 CaPLA1-overexpressing rice plants (Ubi:CaPLA1) had a higher root:shoot mass ratio than the wild-type plants in the vegetative stage. Leaf epidermal cells from transgenic plants had more cells than wild-type plants. Genes that code for cyclin and lipid metabolic enzymes were up-regulated in the transgenic lines. When grown under typical paddy field conditions, the transgenic plants produced more tillers, longer panicles and more branches per panicle than the wild-type plants, all of which resulted in greater grain yield. Microarray analysis suggests that gene expressions that are related with cell proliferation, lipid metabolism, and redox state were widely altered in CaPLA1-overexpressing transgenic rice plants. Ubi:CaPLA1 plants had a reduced membrane peroxidation state, as determined by malondialdehyde and conjugated diene levels and higher peroxidase activity than wild-type rice plants. Furthermore, three isoprenoid synthetic genes encoding terpenoid synthase, hydroxysteroid dehydrogenase and 3-hydroxy-3-methyl-glutaryl-CoA reductase were up-regulated in CaPLA1-overexpressing plants. We suggest that constitutive expression of CaPLA1 conferred increased grain yield with enhanced growth in transgenic rice plants by alteration of gene activities related with cell proliferation, lipid metabolism, membrane peroxidation state and isoprenoid biosynthesis.

  15. Development of salt tolerant plants through genetic engineering (abstract)

    International Nuclear Information System (INIS)

    Mukhtar, Z.; Khan, S.A.; Zafar, Y.

    2005-01-01

    Salinity stress is one of the most serious factors limiting the productivity of agricultural crops. Genetic engineering provides a useful tool for tailoring plants with enhanced salt tolerance characteristics. Many organisms have evolved mechanisms to survive and grow under such extreme environments. These organisms provide us with a useful source of genes which can be used to improve salt tolerance in plants. The present study aims at identification and cloning of useful halo tolerance conferring genes from fungi and plants and to develop salt tolerant transgenic plants. Here we describe the cloning and use of HSR1 gene (a yeast transcription factor known to confer salt tolerance) and Na/sup +//H/sup +/ antiporter gene AtNHX1 (3016 bp) from Arabidopsis thaliana, and transformation of tobacco with HSR1 and AtNHX1 genes through Agrobacterium method. A number of transgenic tobacco plants were regenerated from leaf explants transformed with Agrobacterium tumefaciens (LBA4404) having HSR1 and AtNHX1 genes by leaf disc method. The putative transgenic plants were analyzed by PCR and dot blot analysis. Screening of these transgenic plants at different salinity levels is in progress which will help identify the suitable plant lines and thus the promising genes which can be further exploited to engineer salt tolerant crop plants. (author)

  16. Boron Supply Enhances Aluminum Tolerance in Root Border Cells of Pea (Pisum sativum by Interacting with Cell Wall Pectins

    Directory of Open Access Journals (Sweden)

    Xue Wen Li

    2017-05-01

    Full Text Available Aluminum (Al toxicity is the primary factor limiting crop growth in acidic soils. Boron (B alleviates Al toxicity in plants, which is mainly considered to be due to the formation of Rhamnogalacturonan II-B (RGII-B complexes, which helps to stabilize the cytoskeleton. It is unclear yet whether this is due to the increasing of net negative charges and/or further mechanisms. Kinetics of Al accumulation and adsorption were investigated using entire cells, cell wall and pectin of root border cells (RBCs of pea (Pisum sativum, to reveal the mechanism of B in interacting with alkali-soluble and chelator-soluble pectin for an increased Al tolerance in RBCs. The results show that B could rescue RBCs from Al-induced cell death by accumulating more Al in the cell wall, predominately in alkali-soluble pectin. Boron also promotes Al3+ adsorption and inhibits Al3+ desorption from alkali-soluble pectin. Thus, more Al3+ is immobilized within the alkali-soluble pectin fraction and less in the chelator-soluble pectin, rendering Al3+ less mobile. Boron induces an increase of RG-II (KDO,2-keto-3-deoxyoctonic acid content for forming more borate-RGII complexes, and the decrease of pectin methyl-esterification, thus creates more negative charges to immobilize Al3+ in cell wall pectin. The study provides evidence that abundant B supply enhances the immobilization of Al in alkali-soluble pectin, thus most likely reducing the entry of Al3+ into the symplast from the surroundings.

  17. CEA studies on advanced nuclear fuel claddings for enhanced accident tolerant LWRs fuel (LOCA and beyond LOCA conditions)

    International Nuclear Information System (INIS)

    Brachet, J.C.; Lorrette, C.; Michaux, A.; Sauder, C.; Idarraga-Trujillo, I.; Le Saux, M.; Le Flem, M.; Schuster, F.; Billard, A.; Monsifrot, E.; Torres, E.; Rebillat, F.; Bischoff, J.; Ambard, A.

    2015-01-01

    This paper gives an overview of CEA studies on advanced nuclear fuel claddings for enhanced Accident Tolerant LWR Fuel in collaboration with industrial partners AREVA and EDF. Two potential solutions were investigated: chromium coated zirconium based claddings and SiC/SiC composite claddings with a metallic liner. Concerning the first solution, the optimization of chromium coatings on Zircaloy-4 substrate has been performed. Thus, it has been demonstrated that, due in particular to their slower oxidation rate, a significant additional 'grace period( can be obtained on high temperature oxidized coated claddings in comparison to the conventional uncoated ones, regarding their residual PQ (Post-Quench) ductility and their ability to survive to the final water quenching in LOCA and, to some extent, beyond LOCA conditions. Concerning the second solution, the innovative 'sandwich' SiC/SiC cladding concept is introduced. Initially designed for the next generation of nuclear reactors, it can be adapted to obtain high safety performance for LWRs in LOCA conditions. The key findings of this work highlight the low sensitivity of SiC/SiC composites under the explored steam oxidation conditions. No signification degradation of the mechanical properties of CVI-HNI SiC/SiC specimen is particularly acknowledged for relatively long duration (beyond 100 h at 1200 Celsius degrees). Despite these very positive preliminary results, significant studies and developments are still necessary to close the technology gap. Qualification for nuclear application requires substantial irradiation testing, additional characterization and the definition of design rules applicable to such a structure. The use of a SiC-based fuel cladding shows promise for the highest temperature accident conditions but remains a long term perspective

  18. Enhancing E. coli tolerance towards oxidative stress via engineering its global regulator cAMP receptor protein (CRP.

    Directory of Open Access Journals (Sweden)

    Souvik Basak

    Full Text Available Oxidative damage to microbial hosts often occurs under stressful conditions during bioprocessing. Classical strain engineering approaches are usually both time-consuming and labor intensive. Here, we aim to improve E. coli performance under oxidative stress via engineering its global regulator cAMP receptor protein (CRP, which can directly or indirectly regulate redox-sensing regulators SoxR and OxyR, and other ~400 genes in E. coli. Error-prone PCR technique was employed to introduce modifications to CRP, and three mutants (OM1~OM3 were identified with improved tolerance via H(2O(2 enrichment selection. The best mutant OM3 could grow in 12 mM H(2O(2 with the growth rate of 0.6 h(-1, whereas the growth of wild type was completely inhibited at this H(2O(2 concentration. OM3 also elicited enhanced thermotolerance at 48°C as well as resistance against cumene hydroperoxide. The investigation about intracellular reactive oxygen species (ROS, which determines cell viability, indicated that the accumulation of ROS in OM3 was always lower than in WT with or without H(2O(2 treatment. Genome-wide DNA microarray analysis has shown not only CRP-regulated genes have demonstrated great transcriptional level changes (up to 8.9-fold, but also RpoS- and OxyR-regulated genes (up to 7.7-fold. qRT-PCR data and enzyme activity assay suggested that catalase (katE could be a major antioxidant enzyme in OM3 instead of alkyl hydroperoxide reductase or superoxide dismutase. To our knowledge, this is the first work on improving E. coli oxidative stress resistance by reframing its transcription machinery through its native global regulator. The positive outcome of this approach may suggest that engineering CRP can be successfully implemented as an efficient strain engineering alternative for E. coli.

  19. Cell-associated flagella enhance the protection conferred by mucosally-administered attenuated Salmonella Paratyphi A vaccines.

    Directory of Open Access Journals (Sweden)

    Orit Gat

    2011-11-01

    Full Text Available Antibiotic-resistant Salmonella enterica serovar Paratyphi A, the agent of paratyphoid A fever, poses an emerging public health dilemma in endemic areas of Asia and among travelers, as there is no licensed vaccine. Integral to our efforts to develop a S. Paratyphi A vaccine, we addressed the role of flagella as a potential protective antigen by comparing cell-associated flagella with exported flagellin subunits expressed by attenuated strains.S. Paratyphi A strain ATCC 9150 was first deleted for the chromosomal guaBA locus, creating CVD 1901. Further chromosomal deletions in fliD (CVD 1901D or flgK (CVD 1901K were then engineered, resulting in the export of unpolymerized FliC, without impairing its overall expression. The virulence of the resulting isogenic strains was examined using a novel mouse LD(50 model to accommodate the human-host restricted S. Paratyphi A. The immunogenicity of the attenuated strains was then tested using a mouse intranasal model, followed by intraperitoneal challenge with wildtype ATCC 9150.Mucosal (intranasal immunization of mice with strain CVD 1901 expressing cell-associated flagella conferred superior protection (vaccine efficacy [VE], 90% against a lethal intraperitoneal challenge, compared with the flagellin monomer-exporting mutants CVD 1901K (30% VE or CVD 1901D (47% VE. The superior protection induced by CVD 1901 with its cell-attached flagella was associated with an increased IgG2a:IgG1 ratio of FliC-specific antibodies with enhanced opsonophagocytic capacity.Our results clearly suggest that enhanced anti-FliC antibody-mediated clearance of S. Paratyphi A by phagocytic cells, induced by vaccines expressing cell-associated rather than exported FliC, might be contributing to the vaccine-induced protection from S. Paratyphi A challenge in vivo. We speculate that an excess of IgG1 anti-FliC antibodies induced by the exported FliC may compete with the IgG2a subtype and block binding to specific phagocyte Fc

  20. Isolation of butanol- and isobutanol-tolerant bacteria and physiological characterization of their butanol tolerance.

    Science.gov (United States)

    Kanno, Manabu; Katayama, Taiki; Tamaki, Hideyuki; Mitani, Yasuo; Meng, Xian-Ying; Hori, Tomoyuki; Narihiro, Takashi; Morita, Naoki; Hoshino, Tamotsu; Yumoto, Isao; Kimura, Nobutada; Hanada, Satoshi; Kamagata, Yoichi

    2013-11-01

    Despite their importance as a biofuel production platform, only a very limited number of butanol-tolerant bacteria have been identified thus far. Here, we extensively explored butanol- and isobutanol-tolerant bacteria from various environmental samples. A total of 16 aerobic and anaerobic bacteria that could tolerate greater than 2.0% (vol/vol) butanol and isobutanol were isolated. A 16S rRNA gene sequencing analysis revealed that the isolates were phylogenetically distributed over at least nine genera: Bacillus, Lysinibacillus, Rummeliibacillus, Brevibacillus, Coprothermobacter, Caloribacterium, Enterococcus, Hydrogenoanaerobacterium, and Cellulosimicrobium, within the phyla Firmicutes and Actinobacteria. Ten of the isolates were phylogenetically distinct from previously identified butanol-tolerant bacteria. Two relatively highly butanol-tolerant strains CM4A (aerobe) and GK12 (obligate anaerobe) were characterized further. Both strains changed their membrane fatty acid composition in response to butanol exposure, i.e., CM4A and GK12 exhibited increased saturated and cyclopropane fatty acids (CFAs) and long-chain fatty acids, respectively, which may serve to maintain membrane fluidity. The gene (cfa) encoding CFA synthase was cloned from strain CM4A and expressed in Escherichia coli. The recombinant E. coli showed relatively higher butanol and isobutanol tolerance than E. coli without the cfa gene, suggesting that cfa can confer solvent tolerance. The exposure of strain GK12 to butanol by consecutive passages even enhanced the growth rate, indicating that yet-unknown mechanisms may also contribute to solvent tolerance. Taken together, the results demonstrate that a wide variety of butanol- and isobutanol-tolerant bacteria that can grow in 2.0% butanol exist in the environment and have various strategies to maintain structural integrity against detrimental solvents.

  1. The assembly of metals chelation by thiols and vacuolar compartmentalization conferred increased tolerance to and accumulation of cadmium and arsenic in transgenic Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Guo, Jiangbo; Xu, Wenzhong; Ma, Mi

    2012-01-01

    Highlights: ► Simultaneous transformation of AsPCS1 and ScYCF1 into Arabidopsis thaliana which is sensitive to heavy metals, leads to transgenic plants tolerant to Arsenic and cadmium. ► Dual-gene transgenic Arabidopsis showed higher accumulation of Arsenic and cadmium than single and non-transgenic plants. ► Our results proved that improved thiol peptides synthesis and vacuolar compartmentation in plant dramatically boosted the survival rates of plants when exposed to heavy metals. ► A new strategy for efficient phytoremediation of heavy metals by stacking genes transformation in plants was developed in this article. - Abstract: Transgenic Arabidopsis thaliana were developed to increase tolerance for and accumulation of heavy metals and metalloids by simultaneous overexpression of AsPCS1 and YCF1 (derived from garlic and baker's yeast) based on the fact that chelation of metals and vacuolar compartmentalization are the main strategies for heavy metals/metalloids detoxification and tolerance in plants. Dual-gene transgenic lines had the longest roots and the highest accumulation of Cd and As than single-gene transgenic lines and wildtype. When grown on cadmium or arsenic (arsenite/arsenate), Dual-gene transgenic lines accumulated over 2–10 folds cadmium/arsenite and 2–3 folds arsenate than wild type or plants expressing AsPCS1 or YCF1 alone. Such stacking modified genes involved in chelation of toxic metals and vacuolar compartmentalization represents a highly promising new tool for use in phytoremediation efforts.

  2. The assembly of metals chelation by thiols and vacuolar compartmentalization conferred increased tolerance to and accumulation of cadmium and arsenic in transgenic Arabidopsis thaliana

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Jiangbo [Key Laboratory of Plant Resources, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093 (China); Inner Mongolia Key Laboratory of Biomass-Energy Conversion, The Institute of Bioengineering and Technology, Inner Mongolia University of Science and Technology, Baotou 040100 (China); Xu, Wenzhong [Key Laboratory of Plant Resources, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093 (China); Ma, Mi, E-mail: mami@ibcas.ac.cn [Key Laboratory of Plant Resources, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093 (China)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer Simultaneous transformation of AsPCS1 and ScYCF1 into Arabidopsis thaliana which is sensitive to heavy metals, leads to transgenic plants tolerant to Arsenic and cadmium. Black-Right-Pointing-Pointer Dual-gene transgenic Arabidopsis showed higher accumulation of Arsenic and cadmium than single and non-transgenic plants. Black-Right-Pointing-Pointer Our results proved that improved thiol peptides synthesis and vacuolar compartmentation in plant dramatically boosted the survival rates of plants when exposed to heavy metals. Black-Right-Pointing-Pointer A new strategy for efficient phytoremediation of heavy metals by stacking genes transformation in plants was developed in this article. - Abstract: Transgenic Arabidopsis thaliana were developed to increase tolerance for and accumulation of heavy metals and metalloids by simultaneous overexpression of AsPCS1 and YCF1 (derived from garlic and baker's yeast) based on the fact that chelation of metals and vacuolar compartmentalization are the main strategies for heavy metals/metalloids detoxification and tolerance in plants. Dual-gene transgenic lines had the longest roots and the highest accumulation of Cd and As than single-gene transgenic lines and wildtype. When grown on cadmium or arsenic (arsenite/arsenate), Dual-gene transgenic lines accumulated over 2-10 folds cadmium/arsenite and 2-3 folds arsenate than wild type or plants expressing AsPCS1 or YCF1 alone. Such stacking modified genes involved in chelation of toxic metals and vacuolar compartmentalization represents a highly promising new tool for use in phytoremediation efforts.

  3. Disruption of AtWNK8 Enhances Tolerance of Arabidopsis to Salt and Osmotic Stresses via Modulating Proline Content and Activities of Catalase and Peroxidase

    Directory of Open Access Journals (Sweden)

    Hong Liao

    2013-03-01

    Full Text Available With no lysine kinases (WNKs play important roles in plant growth and development. However, its role in salt and osmotic stress tolerance is unclear. Here, we report that AtWNK8 is mainly expressed in primary root, hypocotyl, stamen and pistil and is induced by NaCl and sorbitol treatment. Compared to the wild-type, the T-DNA knock-out wnk8 mutant was more tolerant to severe salinity and osmotic stresses, as indicated by 27% and 198% more fresh weight in the NaCl and sorbitol treatment, respectively. The wnk8 mutant also accumulated 1.43-fold more proline than the wild-type in the sorbitol treatment. Under NaCl and sorbitol stresses, catalase (CAT activity in wnk8 mutant was 1.92- and 3.7-times of that in Col-0, respectively. Similarly, under salt and osmotic stress conditions, peroxidase (POD activities in wnk8 mutant were 1.81- and 1.58-times of that in Col-0, respectively. Taken together, we revealed that maintaining higher CAT and POD activities might be one of the reasons that the disruption of AtWNK8 enhances the tolerance to salt stress, and accumulating more proline and higher activities of CAT and POD might result in the higher tolerance of WNK8 to osmotic stress.

  4. Safety evaluation of the phosphinothricin acetyltransferase proteins encoded by the pat and bar sequences that confer tolerance to glufosinate-ammonium herbicide in transgenic plants.

    Science.gov (United States)

    Hérouet, Corinne; Esdaile, David J; Mallyon, Bryan A; Debruyne, Eric; Schulz, Arno; Currier, Thomas; Hendrickx, Koen; van der Klis, Robert-Jan; Rouan, Dominique

    2005-03-01

    Transgenic plant varieties, which are tolerant to glufosinate-ammonium, were developed. The herbicide tolerance is based upon the presence of either the bar or the pat gene, which encode for two homologous phosphinothricin acetyltransferases (PAT), in the plant genome. Based on both a review of published literature and experimental studies, the safety assessment reviews the first step of a two-step-approach for the evaluation of the safety of the proteins expressed in plants. It can be used to support the safety of food or feed products derived from any crop that contains and expresses these PAT proteins. The safety evaluation supports the conclusion that the genes and the donor microorganisms (Streptomyces) are innocuous. The PAT enzymes are highly specific and do not possess the characteristics associated with food toxins or allergens, i.e., they have no sequence homology with any known allergens or toxins, they have no N-glycosylation sites, they are rapidly degraded in gastric and intestinal fluids, and they are devoid of adverse effects in mice after intravenous administration at a high dose level. In conclusion, there is a reasonable certainty of no harm resulting from the inclusion of the PAT proteins in human food or in animal feed.

  5. The wheat NHX antiporter gene TaNHX2 confers salt tolerance in transgenic alfalfa by increasing the retention capacity of intracellular potassium.

    Science.gov (United States)

    Zhang, Yan-Min; Zhang, Hong-Mei; Liu, Zi-Hui; Li, Hui-Cong; Guo, Xiu-Lin; Li, Guo-Liang

    2015-02-01

    Previous studies have shown that TaNHX2 transgenic alfalfa (Medicago sativa L.) accumulated more K(+) and less Na(+) in leaves than did the wild-type plants. To investigate whether the increased K(+) accumulation in transgenic plants is attributed to TaNHX2 gene expression and whether the compartmentalization of Na(+) into vacuoles or the intracellular compartmentalization of potassium is the critical mechanism for TaNHX2-dependent salt tolerance in transgenic alfalfa, aerated hydroponic culture was performed under three different stress conditions: control condition (0.1 mM Na(+) and 6 mM K(+) inside culture solution), K(+)-sufficient salt stress (100 mM NaCl and 6 mM K(+)) and K(+)-insufficient salt stress (100 mM NaCl and 0.1 mM K(+)). The transgenic alfalfa plants had lower K(+) efflux through specific K(+) channels and higher K(+) absorption through high-affinity K(+) transporters than did the wild-type plants. Therefore, the transgenic plants had greater K(+) contents and [K(+)]/[Na(+)] ratios in leaf tissue and cell sap. The intracellular compartmentalization of potassium is critical for TaNHX2-induced salt tolerance in transgenic alfalfa.

  6. A novel vacuolar membrane H+-ATPase c subunit gene (ThVHAc1) from Tamarix hispida confers tolerance to several abiotic stresses in Saccharomyces cerevisiae.

    Science.gov (United States)

    Gao, Caiqiu; Wang, Yucheng; Jiang, Bo; Liu, Guifeng; Yu, Lili; Wei, Zhigang; Yang, Chuanping

    2011-02-01

    Plant vacuolar H(+)-ATPase (V-ATPase) plays an important role in response to different adverse environmental conditions. In the present study, we cloned and characterized a V-ATPase c subunit gene (ThVHAc1) from Tamarix hispida. The deduced ThVHAc1 amino acid sequence lacks a signal peptide and ThVHAc1 is a highly hydrophobic protein with four transmembrane regions. A transient expression assay showed that the ThVHAc1-GFP fusion protein is expressed on onion epidermal endomembrane cells. Real-time RT-PCR demonstrated that ThVHAc1 gene expression was induced by NaCl, NaHCO(3), PEG and CdCl(2) stress in T. hispida roots, stems and leaves. Exogenous application of abscisic acid (ABA) also stimulated ThVHAc1 transcript levels in the absence of stress, suggesting that ThVHAc1 is involved in ABA-dependent stress signaling pathway. Furthermore, the transgenic yeast expressing ThVHAc1 increased salt, drought, ultraviolet (UV), oxidative, heavy metal, cold and high temperature tolerance. Our results suggested that the ThVHAc1 gene from T. hispida serves a stress tolerance role in the species.

  7. Ectopic over-expression of peroxisomal ascorbate peroxidase (SbpAPX) gene confers salt stress tolerance in transgenic peanut (Arachis hypogaea).

    Science.gov (United States)

    Singh, Natwar; Mishra, Avinash; Jha, Bhavanath

    2014-08-15

    Peroxisomal ascorbate peroxidase gene (SbpAPX) of an extreme halophyte Salicornia brachiata imparts abiotic stress endurance and plays a key role in the protection against oxidative stress. The cloned SbpAPX gene was transformed to local variety of peanut and about 100 transgenic plants were developed using optimized in vitro regeneration and Agrobacterium mediated genetic transformation method. The T0 transgenic plants were confirmed for the gene integration; grown under controlled condition in containment green house facility; seeds were harvested and T1 plants were raised. Transgenic plants (T1) were further confirmed by PCR using gene specific primers and histochemical GUS assay. About 40 transgenic plants (T1) were selected randomly and subjected for salt stress tolerance study. Transgenic plants remained green however non-transgenic plants showed bleaching and yellowish leaves under salt stress conditions. Under stress condition, transgenic plants continued normal growth and completed their life cycle. Transgenic peanut plants exhibited adequate tolerance under salt stress condition and thus could be explored for the cultivation in salt affected areas for the sustainable agriculture. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. A cold-induced myo-inositol transporter-like gene confers tolerance to multiple abiotic stresses in transgenic tobacco plants.

    Science.gov (United States)

    Sambe, Mame Abdou Nahr; He, Xueying; Tu, Qinghua; Guo, Zhenfei

    2015-03-01

    A full length cDNA encoding a myo-inositol transporter-like protein, named as MfINT-like, was cloned from Medicago sativa subsp. falcata (herein falcata), a species with greater cold tolerance than alfalfa (M. sativa subsp. sativa). MfINT-like is located on plasma membranes. MfINT-like transcript was induced 2-4 h after exogenous myo-inositol treatment, 24-96 h with cold, and 96 h by salinity. Given that myo-inositol accumulates higher in falcata after 24 h of cold treatment, myo-inositol is proposed to be involved in cold-induced expression of MfINT-like. Higher levels of myo-inositol was observed in leaves of transgenic tobacco plants overexpressing MfINT-like than the wild-type but not in the roots of plants grown on myo-inositol containing medium, suggesting that transgenic plants had higher myo-inositol transport activity than the wild-type. Transgenic plants survived better to freezing temperature, and had lower ion leakage and higher maximal photochemical efficiency of photosystem II (Fv /Fm ) after chilling treatment. In addition, greater plant fresh weight was observed in transgenic plants as compared with the wild-type when plants were grown under drought or salinity stress. The results suggest that MfINT-like mediated transport of myo-inositol is associated with plant tolerance to abiotic stresses. © 2014 Scandinavian Plant Physiology Society.

  9. Overexpression of a PLDα1 gene from Setaria italica enhances the sensitivity of Arabidopsis to abscisic acid and improves its drought tolerance.

    Science.gov (United States)

    Peng, Yunling; Zhang, Jinpeng; Cao, Gaoyi; Xie, Yuanhong; Liu, Xihui; Lu, Minhui; Wang, Guoying

    2010-07-01

    Phospholipase D (PLD) plays an important role in various physiological processes in plants, including drought tolerance. Here, we report the cloning and characterization of the full-length cDNA of PLDalpha1 from foxtail millet, which is a cereal crop with high water use efficiency. The expression pattern of the SiPLDalpha1 gene in foxtail millet revealed that it is up-regulated under dehydration, ABA and NaCl treatments. Heterologous overexpression of SiPLDalpha1 in Arabidopsis can significantly enhance their sensitivity to ABA, NaCl and mannitol during post-germination growth. Under water deprivation, overexpression of SiPLDalpha1 in Arabidopsis resulted in significantly enhanced tolerance to drought stress, displaying higher biomass and RWC, lower ion leakage and higher survival percentages than the wild type. Further analysis indicated that transgenic plants showed increased transcription of the stress-related genes, RD29A, RD29B, RAB18 and RD22, and the ABA-related genes, ABI1 and NCED3 under dehydration conditions. These results demonstrate that SiPLDalpha1 is involved in plant stress signal transduction, especially in the ABA signaling pathway. Moreover, no obvious adverse effects on growth and development in the 35S::SiPLDalpha1 transgenic plants implied that SiPLDalpha1 is a good candidate gene for improving crop drought tolerance.

  10. Acclimatization to high-variance habitats does not enhance physiological tolerance of two key Caribbean corals to future temperature and pH.

    Science.gov (United States)

    Camp, Emma F; Smith, David J; Evenhuis, Chris; Enochs, Ian; Manzello, Derek; Woodcock, Stephen; Suggett, David J

    2016-05-25

    Corals are acclimatized to populate dynamic habitats that neighbour coral reefs. Habitats such as seagrass beds exhibit broad diel changes in temperature and pH that routinely expose corals to conditions predicted for reefs over the next 50-100 years. However, whether such acclimatization effectively enhances physiological tolerance to, and hence provides refuge against, future climate scenarios remains unknown. Also, whether corals living in low-variance habitats can tolerate present-day high-variance conditions remains untested. We experimentally examined how pH and temperature predicted for the year 2100 affects the growth and physiology of two dominant Caribbean corals (Acropora palmata and Porites astreoides) native to habitats with intrinsically low (outer-reef terrace, LV) and/or high (neighbouring seagrass, HV) environmental variance. Under present-day temperature and pH, growth and metabolic rates (calcification, respiration and photosynthesis) were unchanged for HV versus LV populations. Superimposing future climate scenarios onto the HV and LV conditions did not result in any enhanced tolerance to colonies native to HV. Calcification rates were always lower for elevated temperature and/or reduced pH. Together, these results suggest that seagrass habitats may not serve as refugia against climate change if the magnitude of future temperature and pH changes is equivalent to neighbouring reef habitats. © 2016 The Author(s).

  11. Overexpression of heat stress-responsive TaMBF1c, a wheat (Triticum aestivum L.) Multiprotein Bridging Factor, confers heat tolerance in both yeast and rice.

    Science.gov (United States)

    Qin, Dandan; Wang, Fei; Geng, Xiaoli; Zhang, Liyuan; Yao, Yingyin; Ni, Zhongfu; Peng, Huiru; Sun, Qixin

    2015-01-01

    Previously, we found an ethylene-responsive transcriptional co-activator, which was significantly induced by heat stress (HS) in both thermo-sensitive and thermo-tolerant wheat. The corresponding ORF was isolated from wheat, and named TaMBF1c (Multiprotein Bridging Factor1c). The deduced amino acid sequence revealed the presence of conserved MBF1 and helix-turn-helix domains at the N- and C-terminus, respectively, which were highly similar to rice ERTCA (Ethylene Response Transcriptional Co-Activator) and Arabidopsis MBF1c. The promoter region of TaMBF1c contained three heat shock elements (HSEs) and other stress-responsive elements. There was no detectable mRNA of TaMBF1c under control conditions, but the transcript was rapidly and significantly induced by heat stress not only at the seedling stage, but also at the flowering stage. It was also slightly induced by drought and H2O2 stresses, as well as by application of the ethylene synthesis precursor ACC, but not, however, by circadian rhythm, salt, ABA or MeJA treatments. Under normal temperatures, TaMBF1c-eGFP protein showed predominant nuclear localization with some levels of cytosol localization in the bombarded onion epidermal cells, but it was mainly detected in the nucleus with almost no eGFP signals in cytosol when the bombarded onion cells were cultured under high temperature conditions. Overexpression of TaMBF1c in yeast imparted tolerance to heat stress compared to cells expressing the vector alone. Most importantly, transgenic rice plants engineered to overexpress TaMBF1c showed higher thermotolerance than control plants at both seedling and reproductive stages. In addition, transcript levels of six Heat Shock Protein and two Trehalose Phosphate Synthase genes were higher in TaMBF1c transgenic lines than in wild-type rice upon heat treatment. Collectively, the present data suggest that TaMBF1c plays a pivotal role in plant thermotolerance and holds promising possibilities for improving heat tolerance

  12. A new player in the biorefineries field: phasin PhaP enhances tolerance to solvents and boosts ethanol and 1,3-propanediol synthesis in Escherichia coli

    DEFF Research Database (Denmark)

    Mezzina, Mariela P.; Álvarez, Daniela; Egoburo, Diego

    2017-01-01

    The microbial production of biofuels and other added-value chemicals is often limited by the intrinsic toxicity of these compounds. Phasin PhaP from the soil bacterium Azotobacter sp. strain FA8 is a polyhydroxyalkanoate granule-associated protein that protects recombinant Escherichia coli against...... as a strategy to increase tolerance to several biotechnologically relevant chemicals. PhaP was observed to enhance bacterial fitness in the presence of biofuels, such as ethanol and butanol, and to other chemicals, such as 1,3-propanediol. The effect of PhaP was also studied in a groELS mutant strain, in which...... and chemicals production.Importance. This work has both basic and applied aspects. Our results demonstrate that a phasin with chaperone-like properties can increase bacterial tolerance to several biochemicals, providing further evidence of the diverse properties of these proteins. Additionally, both the Pha...

  13. An extracytoplasmic function sigma factor cotranscribed with its cognate anti-sigma factor confers tolerance to NaCl, ethanol and methylene blue in Azospirillum brasilense Sp7.

    Science.gov (United States)

    Mishra, Mukti Nath; Kumar, Santosh; Gupta, Namrata; Kaur, Simarjot; Gupta, Ankush; Tripathi, Anil K

    2011-04-01

    Azospirillum brasilense, a plant-growth-promoting rhizobacterium, is exposed to changes in its abiotic environment, including fluctuations in temperature, salinity, osmolarity, oxygen concentration and nutrient concentration, in the rhizosphere and in the soil. Since extra-cytoplasmic function (ECF) sigma factors play an important role in stress adaptation, we analysed the role of ECF sigma factor (also known as RpoE or σ(E)) in abiotic stress tolerance in A. brasilense. An in-frame rpoE deletion mutant of A. brasilense Sp7 was carotenoidless and slow-growing, and was sensitive to salt, ethanol and methylene blue stress. Expression of rpoE in the rpoE deletion mutant complemented the defects in growth, carotenoid biosynthesis and sensitivity to different stresses. Based on data from reverse transcriptase-PCR, a two-hybrid assay and a pull-down assay, we present evidence that rpoE is cotranscribed with chrR and the proteins synthesized from these two overlapping genes interact with each other. Identification of the transcription start site by 5' rapid amplification of cDNA ends showed that the rpoE-chrR operon was transcribed by two promoters. The proximal promoter was less active than the distal promoter, whose consensus sequence was characteristic of RpoE-dependent promoters found in alphaproteobacteria. Whereas the proximal promoter was RpoE-independent and constitutively expressed, the distal promoter was RpoE-dependent and strongly induced in response to stationary phase and elevated levels of ethanol, salt, heat and methylene blue. This study shows the involvement of RpoE in controlling carotenoid synthesis as well as in tolerance to some abiotic stresses in A. brasilense, which might be critical in the adaptation, survival and proliferation of this rhizobacterium in the soil and rhizosphere under stressful conditions.

  14. IL-6 Inhibits Upregulation of Membrane-Bound TGF-β 1 on CD4+ T Cells and Blocking IL-6 Enhances Oral Tolerance.

    Science.gov (United States)

    Kuhn, Chantal; Rezende, Rafael Machado; M'Hamdi, Hanane; da Cunha, Andre Pires; Weiner, Howard L

    2017-02-01

    Oral administration of Ag induces regulatory T cells that express latent membrane-bound TGF-β (latency-associated peptide [LAP]) and have been shown to play an important role in the induction of oral tolerance. We developed an in vitro model to study modulation of LAP + on CD4 + T cells. The combination of anti-CD3 mAb, anti-CD28 mAb, and recombinant IL-2 induced expression of LAP on naive CD4 + T cells, independent of Foxp3 or exogenous TGF-β. In vitro generated CD4 + LAP + Foxp3 - T cells were suppressive in vitro, inhibiting proliferation of naive CD4 + T cells and IL-17A secretion by Th17 cells. Assessing the impact of different cytokines and neutralizing Abs against cytokines, we found that LAP induction was decreased in the presence of IL-6 and IL-21, and to a lesser extent by IL-4 and TNF-α. IL-6 abrogated the in vitro induction of CD4 + LAP + T cells by STAT3-dependent inhibition of Lrrc32 (glycoprotein A repetitions predominant [GARP]), the adapter protein that tethers TGF-β to the membrane. Oral tolerance induction was enhanced in mice lacking expression of IL-6R by CD4 + T cells and by treatment of wild-type mice with neutralizing anti-IL-6 mAb. These results suggest that proinflammatory cytokines interfere with oral tolerance induction and that blocking the IL-6 pathway is a potential strategy for enhancing oral tolerance in the setting of autoimmune and inflammatory diseases. Copyright © 2017 by The American Association of Immunologists, Inc.

  15. IL-6 inhibits upregulation of membrane-bound TGF-beta 1 on CD4+ T cells and blocking IL-6 enhances oral tolerance

    Science.gov (United States)

    Kuhn, Chantal; Rezende, Rafael Machado; M'Hamdi, Hanane; da Cunha, Andre Pires; Weiner, Howard L.

    2016-01-01

    Oral administration of antigen induces regulatory T cells that express latent membrane-bound TGF-beta (LAP) and that have been shown to play an important role in the induction of oral tolerance. We developed an in vitro model to study modulation of LAP+ on CD4+ T cells. The combination of anti-CD3 mAb, anti-CD28 mAb and recombinant IL-2 induced expression of LAP on naïve CD4+ T cells, independent of FoxP3 or exogenous TGF-β. In vitro generated CD4+LAP+FoxP3− T cells were suppressive in vitro, inhibiting proliferation of naïve CD4+ T cells and IL-17A secretion by Th17 cells. Assessing the impact of different cytokines and neutralizing antibodies against cytokines we found that LAP induction was decreased in the presence of IL-6 and IL-21, and to a lesser extent by IL-4 and TNFα. IL-6 abrogated the in vitro induction of CD4+LAP+ T cells by STAT3 dependent inhibition of Lrrc32 (GARP), the adapter protein that tethers TGF-beta to the membrane. Oral tolerance induction was enhanced in mice lacking expression of IL-6R by CD4+ T cells and by treatment of wild-type mice with neutralizing anti-IL-6 mAb. These results suggest that pro-inflammatory cytokines interfere with oral tolerance induction and that blocking the IL-6 pathway is a potential strategy for enhancing oral tolerance in the setting of autoimmune and inflammatory diseases. PMID:28039301

  16. CYCLOXYDIM-TOLERANT MAIZE – BREEDERS STANDPOINT

    Directory of Open Access Journals (Sweden)

    G. Bekavac

    2008-09-01

    Full Text Available Cycloxydim-Tolerant Maize (CTM was developed by researches at the University of Minnesota. CTM plants were regenerated from tissue culture selected for callus growth in the presence of cycloxydim, and the resulting plants were shown to contain a nuclear mutation, expressed as a single, partially dominant gene (known as Acc1 that conferred tolerance to the herbicide. Cycloxydim is a systemic herbicide for post emergence application in dicot crops to selectively control grass weeds. Corn, like most grasses is susceptible to cycloxydim due to inhibited acetyl-coenzyimeA carboxylaze enzyme activity. There are two key benefits of this technology: first, cycloxydim applications in CTM hybrids can be delayed until the weed spectrum and population density exceed agro-economic threshold; second, cycloxydim can be applied at either stage of plant development with no effect on basic agronomic traits, compared to non treated plants. Nevertheless, this type of tolerance requires 2 genes to be fully effective, i.e. gene must be present in both inbred parents to provide complete tolerance in the resulting hybrid. Such type of tolerance doubles the chances for yield drag and doubles the number of inbred conversions needed. This also limits germplasm integration and increases time lag in developing hybrids. Despite these difficulties, many seed companies introduce tolerance to cycloxydim into their commercial inbreds, and many of them have already commercialized CTM hybrids. Finally, it came as a logical question what is more important – hybrid performance or new trait? Critical to the success of this technology has been yield performance of CTM hybrids. At the same time, performance and herbicide tolerance do not exclude each other and can surely co-exist. To be accepted, this coexistence must secure high profitability to corn producers. However, CTM hybrids will not replace conventional ones on a large scale, but could be used as a specific tool, or could

  17. Oxygation enhances growth, gas exchange and salt tolerance of vegetable soybean and cotton in a saline vertisol.

    Science.gov (United States)

    Bhattarai, Surya P; Midmore, David J

    2009-07-01

    Impacts of salinity become severe when the soil is deficient in oxygen. Oxygation (using aerated water for subsurface drip irrigation of crop) could minimize the impact of salinity on plants under oxygen-limiting soil environments. Pot experiments were conducted to evaluate the effects of oxygation (12% air volume/volume of water) on vegetable soybean (moderately salt tolerant) and cotton (salt tolerant) in a salinized vertisol at 2, 8, 14, 20 dS/m EC(e). In vegetable soybean, oxygation increased above ground biomass yield and water use efficiency (WUE) by 13% and 22%, respectively, compared with the control. Higher yield with oxygation was accompanied by greater plant height and stem diameter and reduced specific leaf area and leaf Na+ and Cl- concentrations. In cotton, oxygation increased lint yield and WUE by 18% and 16%, respectively, compared with the control, and was accompanied by greater canopy light interception, plant height and stem diameter. Oxygation also led to a greater rate of photosynthesis, higher relative water content in the leaf, reduced crop water stress index and lower leaf water potential. It did not, however, affect leaf Na+ or Cl- concentration. Oxygation invariably increased, whereas salinity reduced the K+ : Na+ ratio in the leaves of both species. Oxygation improved yield and WUE performance of salt tolerant and moderately tolerant crops under saline soil environments, and this may have a significant impact for irrigated agriculture where saline soils pose constraints to crop production.

  18. A SNARE-Like Superfamily Protein SbSLSP from the Halophyte Salicornia brachiata Confers Salt and Drought Tolerance by Maintaining Membrane Stability, K(+)/Na(+) Ratio, and Antioxidant Machinery.

    Science.gov (United States)

    Singh, Dinkar; Yadav, Narendra Singh; Tiwari, Vivekanand; Agarwal, Pradeep K; Jha, Bhavanath

    2016-01-01

    About 1000 salt-responsive ESTs were identified from an extreme halophyte Salicornia brachiata. Among these, a novel salt-inducible gene SbSLSP (Salicornia brachiata SNARE-like superfamily protein), showed up-regulation upon salinity and dehydration stress. The presence of cis-regulatory motifs related to abiotic stress in the putative promoter region supports our finding that SbSLSP gene is inducible by abiotic stress. The SbSLSP protein showed a high sequence identity to hypothetical/uncharacterized proteins from Beta vulgaris, Spinacia oleracea, Eucalyptus grandis, and Prunus persica and with SNARE-like superfamily proteins from Zostera marina and Arabidopsis thaliana. Bioinformatics analysis predicted a clathrin adaptor complex small-chain domain and N-myristoylation site in the SbSLSP protein. Subcellular localization studies indicated that the SbSLSP protein is mainly localized in the plasma membrane. Using transgenic tobacco lines, we establish that overexpression of SbSLSP resulted in elevated tolerance to salt and drought stress. The improved tolerance was confirmed by alterations in a range of physiological parameters, including high germination and survival rate, higher leaf chlorophyll contents, and reduced accumulation of Na(+) ion and reactive oxygen species (ROS). Furthermore, overexpressing lines also showed lower water loss, higher cell membrane stability, and increased accumulation of proline and ROS-scavenging enzymes. Overexpression of SbSLSP also enhanced the transcript levels of ROS-scavenging and signaling enzyme genes. This study is the first investigation of the function of the SbSLSP gene as a novel determinant of salinity/drought tolerance. The results suggest that SbSLSP could be a potential candidate to increase salinity and drought tolerance in crop plants for sustainable agriculture in semi-arid saline soil.

  19. A SNARE-like superfamily protein SbSLSP from the halophyte Salicornia brachiata confers salt and drought tolerance by maintaining membrane stability, K+/Na+ ratio, and antioxidant machinery

    Directory of Open Access Journals (Sweden)

    Dinkar eSingh

    2016-06-01

    Full Text Available About 1000 salt-responsive ESTs were identified from an extreme halophyte Salicornia brachiata. Among these, a novel salt-inducible gene SbSLSP, (Salicornia brachiata SNARE-like superfamily protein showed up-regulation upon salinity and dehydration stress. The presence of cis-regulatory motifs related to abiotic stress in the putative promoter region supports our finding that SbSLSP gene is inducible by abiotic stress. The SbSLSP protein showed a high sequence identity to hypothetical/uncharacterised proteins from Beta vulgaris, Spinacia oleracea, Eucalyptus grandis and Prunus persica and with SNARE-like superfamily proteins from Zostera marina and Arabidopsis thaliana. Bioinformatics analysis predicted a clathrin adaptor complex small-chain domain and N-myristoylation site in the SbSLSP protein. Subcellular localisation studies indicated that the SbSLSP protein is mainly localised in the plasma membrane. Using transgenic tobacco lines, we establish that overexpression of SbSLSP resulted in elevated tolerance to salt and drought stress. The improved tolerance was confirmed by alterations in a range of physiological parameters, including high germination and survival rate, higher leaf chlorophyll contents, and reduced accumulation of Na+ ion and reactive oxygen species (ROS. Furthermore, overexpressing lines also showed lower water loss, higher cell membrane stability and increased accumulation of proline and ROS-scavenging enzymes. Overexpression of SbSLSP also enhanced the transcript levels of ROS-scavenging and signalling enzyme genes. This study is the first investigation of the function of the SbSLSP gene as a novel determinant of salinity/drought tolerance. The results suggest that SbSLSP could be a potential candidate to increase salinity and drought tolerance in crop plants for sustainable agriculture in semi-arid saline soil.

  20. Overexpression of wheat ferritin gene TaFER-5B enhances tolerance to heat stress and other abiotic stresses associated with the ROS scavenging.

    Science.gov (United States)

    Zang, Xinshan; Geng, Xiaoli; Wang, Fei; Liu, Zhenshan; Zhang, Liyuan; Zhao, Yue; Tian, Xuejun; Ni, Zhongfu; Yao, Yingyin; Xin, Mingming; Hu, Zhaorong; Sun, Qixin; Peng, Huiru

    2017-01-14

    The yield of wheat (Triticum aestivum L.), an important crop, is adversely affected by heat stress in many regions of the world. However, the molecular mechanisms underlying thermotolerance are largely unknown. A novel ferritin gene, TaFER, was identified from our previous heat stress-responsive transcriptome analysis of a heat-tolerant wheat cultivar (TAM107). TaFER was mapped to chromosome 5B and named TaFER-5B. Expression pattern analysis revealed that TaFER-5B was induced by heat, polyethylene glycol (PEG), H 2 O 2 and Fe-ethylenediaminedi(o-hydroxyphenylacetic) acid (Fe-EDDHA). To confirm the function of TaFER-5B in wheat, TaFER-5B was transformed into the wheat cultivar Jimai5265 (JM5265), and the transgenic plants exhibited enhanced thermotolerance. To examine whether the function of ferritin from mono- and dico-species is conserved, TaFER-5B was transformed into Arabidopsis, and overexpression of TaFER-5B functionally complemented the heat stress-sensitive phenotype of a ferritin-lacking mutant of Arabidopsis. Moreover, TaFER-5B is essential for protecting cells against heat stress associated with protecting cells against ROS. In addition, TaFER-5B overexpression also enhanced drought, oxidative and excess iron stress tolerance associated with the ROS scavenging. Finally, TaFER-5B transgenic Arabidopsis and wheat plants exhibited improved leaf iron content. Our results suggest that TaFER-5B plays an important role in enhancing tolerance to heat stress and other abiotic stresses associated with the ROS scavenging.

  1. A Novel Sugar Transporter from Dianthus spiculifolius, DsSWEET12, Affects Sugar Metabolism and Confers Osmotic and Oxidative Stress Tolerance in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Aimin Zhou

    2018-02-01

    Full Text Available Plant SWEETs (sugars will eventually be exported transporters play a role in plant growth and plant response to biotic and abiotic stresses. In the present study, DsSWEET12 from Dianthus spiculifolius was identified and characterized. Real-time quantitative PCR analysis revealed that DsSWEET12 expression was induced by sucrose starvation, mannitol, and hydrogen peroxide. Colocalization experiment showed that the DsSWEET12-GFP fusion protein was localized to the plasma membrane, which was labeled with FM4-64 dye, in Arabidopsis and suspension cells of D. spiculifolius. Compared to wild type plants, transgenic Arabidopsis seedlings overexpressing DsSWEET12 have longer roots and have a greater fresh weight, which depends on sucrose content. Furthermore, a relative root length analysis showed that transgenic Arabidopsis showed higher tolerance to osmotic and oxidative stresses. Finally, a sugar content analysis showed that the sucrose content in transgenic Arabidopsis was less than that in the wild type, while fructose and glucose contents were higher than those in the wild type. Taken together, our results suggest that DsSWEET12 plays an important role in seedling growth and plant response to osmotic and oxidative stress in Arabidopsis by influencing sugar metabolism.

  2. A Novel Sugar Transporter from Dianthus spiculifolius, DsSWEET12, Affects Sugar Metabolism and Confers Osmotic and Oxidative Stress Tolerance in Arabidopsis.

    Science.gov (United States)

    Zhou, Aimin; Ma, Hongping; Feng, Shuang; Gong, Shufang; Wang, Jingang

    2018-02-07

    Plant SWEETs (sugars will eventually be exported transporters) play a role in plant growth and plant response to biotic and abiotic stresses. In the present study, DsSWEET12 from Dianthus spiculifolius was identified and characterized. Real-time quantitative PCR analysis revealed that DsSWEET12 expression was induced by sucrose starvation, mannitol, and hydrogen peroxide. Colocalization experiment showed that the DsSWEET12-GFP fusion protein was localized to the plasma membrane, which was labeled with FM4-64 dye, in Arabidopsis and suspension cells of D. spiculifolius . Compared to wild type plants, transgenic Arabidopsis seedlings overexpressing DsSWEET12 have longer roots and have a greater fresh weight, which depends on sucrose content. Furthermore, a relative root length analysis showed that transgenic Arabidopsis showed higher tolerance to osmotic and oxidative stresses. Finally, a sugar content analysis showed that the sucrose content in transgenic Arabidopsis was less than that in the wild type, while fructose and glucose contents were higher than those in the wild type. Taken together, our results suggest that DsSWEET12 plays an important role in seedling growth and plant response to osmotic and oxidative stress in Arabidopsis by influencing sugar metabolism.

  3. MTAP deletion confers enhanced dependency on the PRMT5 arginine methyltransferase in cancer cells | Office of Cancer Genomics

    Science.gov (United States)

    The discovery of cancer dependencies has the potential to inform therapeutic strategies and to identify putative drug targets. Integrating data from comprehensive genomic profiling of cancer cell lines and from functional characterization of cancer cell dependencies, we discovered that loss of the enzyme methylthioadenosine phosphorylase (MTAP) confers a selective dependence on protein arginine methyltransferase 5 (PRMT5) and its binding partner WDR77. MTAP is frequently lost due to its proximity to the commonly deleted tumor suppressor gene, CDKN2A.

  4. Simple one-pot synthesis of platinum-palladium nanoflowers with enhanced catalytic activity and methanol-tolerance for oxygen reduction in acid media

    International Nuclear Information System (INIS)

    Zheng, Jie-Ning; He, Li-Li; Chen, Fang-Yi; Wang, Ai-Jun; Xue, Meng-Wei; Feng, Jiu-Ju

    2014-01-01

    Graphical abstract: PtPd nanoflowers were fabricated by one-pot solvothermal co-reduction method in oleylamine system, which exhibited the improved electrocatalytic activity and higher methanol tolerance for oxygen reduction, compared with commercial Pt and Pd black catalysts. - Highlights: • Bimetallic alloyed PtPd nanoflowers are prepared by a simple one-pot solvothermal co-reduction method. • PtPd nanoflowers display high catalytic performance for ORR dominated by a four-electron pathway. • PtPd nanoflowers show good methanol tolerance for ORR. - Abstract: In this work, bimetallic alloyed platinum-palladium (PtPd) nanoflowers are fabricated by one-pot solvothermal co-reduction of Pt (II) acetylacetonate and Pd (II) acetylacetonate in oleylamine system. The as-prepared nanostructures show the enhanced electrocatalytic activity for oxygen reduction reaction (ORR), dominated by a four-electron pathway based on the Koutecky-Levich plots, mainly owing to the inhibition of the formation of Pt–OH ad via the downshift of d-band center for Pt. Meanwhile, PtPd nanoflowers display good methanol tolerance and improved stability for ORR. The chronoamperometry test reveals that the current of PtPd nanoflowers remains 45.9% of its original value within 6000 s, much higher than those of commercial Pt (36.7%) and Pd (32.2%) black catalysts. Therefore, PtPd nanoflowers with unique interconnected structures can be used as a promising cathode catalyst in direct methanol fuel cells

  5. The grapevine VvWRKY2 gene enhances salt and osmotic stress tolerance in transgenic Nicotiana tabacum.

    Science.gov (United States)

    Mzid, Rim; Zorrig, Walid; Ben Ayed, Rayda; Ben Hamed, Karim; Ayadi, Mariem; Damak, Yosra; Lauvergeat, Virginie; Hanana, Mohsen

    2018-06-01

    Our study aims to assess the implication of WRKY transcription factor in the molecular mechanisms of grapevine adaptation to salt and water stresses. In this respect, a full-length VvWRKY2 cDNA, isolated from a Vitis vinifera grape berry cDNA library, was constitutively over-expressed in Nicotiana tabacum seedlings. Our results showed that transgenic tobacco plants exhibited higher seed germination rates and better growth, under both salt and osmotic stress treatments, when compared to wild type plants. Furthermore, our analyses demonstrated that, under stress conditions, transgenic plants accumulated more osmolytes, such as soluble sugars and free proline, while no changes were observed regarding electrolyte leakage, H 2 O 2 , and malondialdehyde contents. The improvement of osmotic adjustment may be an important mechanism underlying the role of VvWRKY 2 in promoting tolerance and adaptation to abiotic stresses. Principal component analysis of our results highlighted a clear partition of plant response to stress. On the other hand, we observed a significant adaptation behaviour response for transgenic lines under stress. Taken together, all our findings suggest that over-expression of VvWRKY2 gene has a compelling role in abiotic stress tolerance and, therefore, would provide a useful strategy to promote abiotic stress tolerance in grape via molecular-assisted breeding and/or new biotechnology tools.

  6. A CBL-Interacting Protein Kinase TaCIPK2 Confers Drought Tolerance in Transgenic Tobacco Plants through Regulating the Stomatal Movement.

    Science.gov (United States)

    Wang, Yan; Sun, Tao; Li, Tingting; Wang, Meng; Yang, Guangxiao; He, Guangyuan

    2016-01-01

    In plants, the CBL-CIPK signaling pathways play key roles in the response to abiotic stresses. However, functional studies of CIPKs in the important staple crop wheat are very rare. In this study, we identified a CIPK gene from wheat, designated TaCIPK2. Expression analysis results showed that TaCIPK2 could be up-regulated in wheat leaves by polyethylene glycol, abscisic acid and H2O2 treatments. Subcellular localization analyses revealed that TaCIPK2 was present in whole wheat epidermal cells. A yeast two-hybrid assay indicated that TaCIPK2 interacted with TaCBL1, 2, 3 and 4 in vitro. Transgenic tobacco plants over-expressing TaCIPK2 exhibited increased drought tolerance, indicated by a larger proportion of green cotyledons and higher survival rates under the osmotic and drought stress conditions compared with control plants. Additionally, physiological index analyses revealed that the transgenic tobacco plants had lower water loss rates and ion leakage, accumulated less malondialdehyde and H2O2, and had higher catalase and superoxide dismutase activities than the control plants. The transgenic plants also exhibited faster stomatal closure following exposure to osmotic stress conditions. The seed germination rates and stomatal aperture of TaCIPK2-overexpressing tobacco plants decreased after exogenous abscisic acid treatment was applied, implying that the transgenic tobacco plants were more sensitive to exogenous abscisic acid than the control plants. Our results indicate that TaCIPK2 plays a positive regulatory role in drought stress responses in transgenic tobacco plants.

  7. Overexpression of a Plasma Membrane-Localized SbSRP-Like Protein Enhances Salinity and Osmotic Stress Tolerance in Transgenic Tobacco

    Directory of Open Access Journals (Sweden)

    Avinash Mishra

    2017-04-01

    Full Text Available An obligate halophyte, Salicornia brachiata grows in salt marshes and is considered to be a potential resource of salt- and drought-responsive genes. It is important to develop an understanding of the mechanisms behind enhanced salt tolerance. To increase this understanding, a novel SbSRP gene was cloned, characterized, over-expressed, and functionally validated in the model plant Nicotiana tabacum. The genome of the halophyte S. brachiata contains two homologs of an intronless SbSRP gene of 1,262 bp in length that encodes for a stress-related protein. An in vivo localization study confirmed that SbSRP is localized on the plasma membrane. Transgenic tobacco plants (T1 that constitutively over-express the SbSRP gene showed improved salinity and osmotic stress tolerance. In comparison to Wild Type (WT and Vector Control (VC plants, transgenic lines showed elevated relative water and chlorophyll content, lower malondialdehyde content, lower electrolyte leakage and higher accumulation of proline, free amino acids, sugars, polyphenols, and starch under abiotic stress treatments. Furthermore, a lower build-up of H2O2 content and superoxide-radicals was found in transgenic lines compared to WT and VC plants under stress conditions. Transcript expression of Nt-APX (ascorbate peroxidase, Nt-CAT (catalase, Nt-SOD (superoxide dismutase, Nt-DREB (dehydration responsive element binding factor, and Nt-AP2 (apetala2 genes was higher in transgenic lines under stress compared to WT and VC plants. The results suggested that overexpression of membrane-localized SbSRP mitigates salt and osmotic stress in the transgenic tobacco plant. It was hypothesized that SbSRP can be a transporter protein to transmit the environmental stimuli downward through the plasma membrane. However, a detailed study is required to ascertain its exact role in the abiotic stress tolerance mechanism. Overall, SbSRP is a potential candidate to be used for engineering salt and osmotic

  8. Constitutive expression of a salinity-induced wheat WRKY transcription factor enhances salinity and ionic stress tolerance in transgenic Arabidopsis thaliana

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Yuxiang, E-mail: yuxiangqin@126.com [Department of Biotechnology, University of Jinan, Jinan 250022 (China); Tian, Yanchen [The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, Jinan 250100 (China); Han, Lu; Yang, Xinchao [Department of Biotechnology, University of Jinan, Jinan 250022 (China)

    2013-11-15

    Highlights: •A class II WRKY transcription factor, TaWRKY79 was isolated and characterized. •TaWRKY79 was induced by NaCl or abscisic acid. •843 bp regulatory segment was sufficient to respond to ABA or NaCl treatment. •TaWRKY79 enhanced salinity and ionic tolerance while reduced sensitivity to ABA. •TaWRKY79 increased salinity and ionic tolerance in an ABA-dependent pathway. -- Abstract: The isolation and characterization of TaWRKY79, a wheat class II WRKY transcription factor, is described. Its 1297 bp coding region includes a 987 bp long open reading frame. TaWRKY79 was induced by stressing seedlings with either NaCl or abscisic acid (ABA). When a fusion between an 843 bp segment upstream of the TaWRKY79 coding sequence and GUS was introduced into Arabidopsis thaliana, GUS staining indicated that this upstream segment captured the sequence(s) required to respond to ABA or NaCl treatment. When TaWRKY79 was constitutively expressed as a transgene in A. thaliana, the transgenic plants showed an improved capacity to extend their primary root in the presence of either 100 mM NaCl, 10 mM LiCl or 2 μM ABA. The inference was that TaWRKY79 enhanced the level of tolerance to both salinity and ionic stress, while reducing the level of sensitivity to ABA. The ABA-related genes ABA1, ABA2 ABI1 and ABI5 were all up-regulated in the TaWRKY79 transgenic plants, suggesting that the transcription factor operates in an ABA-dependent pathway.

  9. Constitutive expression of a salinity-induced wheat WRKY transcription factor enhances salinity and ionic stress tolerance in transgenic Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Qin, Yuxiang; Tian, Yanchen; Han, Lu; Yang, Xinchao

    2013-01-01

    Highlights: •A class II WRKY transcription factor, TaWRKY79 was isolated and characterized. •TaWRKY79 was induced by NaCl or abscisic acid. •843 bp regulatory segment was sufficient to respond to ABA or NaCl treatment. •TaWRKY79 enhanced salinity and ionic tolerance while reduced sensitivity to ABA. •TaWRKY79 increased salinity and ionic tolerance in an ABA-dependent pathway. -- Abstract: The isolation and characterization of TaWRKY79, a wheat class II WRKY transcription factor, is described. Its 1297 bp coding region includes a 987 bp long open reading frame. TaWRKY79 was induced by stressing seedlings with either NaCl or abscisic acid (ABA). When a fusion between an 843 bp segment upstream of the TaWRKY79 coding sequence and GUS was introduced into Arabidopsis thaliana, GUS staining indicated that this upstream segment captured the sequence(s) required to respond to ABA or NaCl treatment. When TaWRKY79 was constitutively expressed as a transgene in A. thaliana, the transgenic plants showed an improved capacity to extend their primary root in the presence of either 100 mM NaCl, 10 mM LiCl or 2 μM ABA. The inference was that TaWRKY79 enhanced the level of tolerance to both salinity and ionic stress, while reducing the level of sensitivity to ABA. The ABA-related genes ABA1, ABA2 ABI1 and ABI5 were all up-regulated in the TaWRKY79 transgenic plants, suggesting that the transcription factor operates in an ABA-dependent pathway

  10. The Mitochondrion-Located Protein OsB12D1 Enhances Flooding Tolerance during Seed Germination and Early Seedling Growth in Rice

    Directory of Open Access Journals (Sweden)

    Dongli He

    2014-07-01

    Full Text Available B12D belongs to a function unknown subgroup of the Balem (Barley aleurone and embryo proteins. In our previous work on rice seed germination, we identified a B12D-like protein encoded by LOC_Os7g41350 (named OsB12D1. OsB12D1 pertains to an ancient protein family with an amino acid sequence highly conserved from moss to angiosperms. Among the six OsB12Ds, OsB12D1 is one of the major transcripts and is primarily expressed in germinating seed and root. Bioinformatics analyses indicated that OsB12D1 is an anoxic or submergence resistance-related gene. RT-PCR results showed OsB12D1 is induced remarkably in the coleoptiles or roots by flooding during seed germination and early seedling growth. The OsB12D1-overexpressed rice seeds could protrude radicles in 8 cm deep water, further exhibiting significant flooding tolerance compared to the wild type. Moreover, this tolerance was not affected by the gibberellin biosynthesis inhibitor paclobutrazol. OsB12D1 was identified in the mitochondrion by subcellular localization analysis and possibly enhances electron transport through mediating Fe and oxygen availability under flooded conditions. This work indicated that OsB12D1 is a promising gene that can help to enhance rice seedling establishment in farming practices, especially for direct seeding.

  11. Drought-tolerance of wheat improved by rhizosphere bacteria from harsh environments: enhanced biomass production and reduced emissions of stress volatiles.

    Directory of Open Access Journals (Sweden)

    Salme Timmusk

    Full Text Available Water is the key resource limiting world agricultural production. Although an impressive number of research reports have been published on plant drought tolerance enhancement via genetic modifications during the last few years, progress has been slower than expected. We suggest a feasible alternative strategy by application of rhizospheric bacteria coevolved with plant roots in harsh environments over millions of years, and harboring adaptive traits improving plant fitness under biotic and abiotic stresses. We show the effect of bacterial priming on wheat drought stress tolerance enhancement, resulting in up to 78% greater plant biomass and five-fold higher survivorship under severe drought. We monitored emissions of seven stress-related volatiles from bacterially-primed drought-stressed wheat seedlings, and demonstrated that three of these volatiles are likely promising candidates for a rapid non-invasive technique to assess crop drought stress and its mitigation in early phases of stress development. We conclude that gauging stress by elicited volatiles provides an effectual platform for rapid screening of potent bacterial strains and that priming with isolates of rhizospheric bacteria from harsh environments is a promising, novel way to improve plant water use efficiency. These new advancements importantly contribute towards solving food security issues in changing climates.

  12. Overexpression of an alfalfa GDP-mannose 3, 5-epimerase gene enhances acid, drought and salt tolerance in transgenic Arabidopsis by increasing ascorbate accumulation.

    Science.gov (United States)

    Ma, Lichao; Wang, Yanrong; Liu, Wenxian; Liu, Zhipeng

    2014-11-01

    GDP-mannose 3', 5'-epimerase (GME) catalyses the conversion of GDP-D-mannose to GDP-L-galactose, an important step in the ascorbic acid (ascorbic acid) biosynthetic pathway in higher plants. In this study, a novel cDNA fragment (MsGME) encoding a GME protein was isolated and characterised from alfalfa (Medicago sativa). An expression analysis confirmed that MsGME expression was induced by salinity, PEG and acidity stresses. MsGME overexpression in Arabidopsis enhanced tolerance of the transgenic plants to salt, drought and acid. Real-time PCR analysis revealed that the transcript levels of GDP-D-mannose pyrophosphorylase (GMP), L-galactose-phosphate 1-P phosphatase (GP) and GDP-L-galactose phosphorylase (GGP) were increased in transgenic Arabidopsis (T3 generation). Moreover, the ascorbate content was increased in transgenic Arabidopsis. Our results suggest that MsGME can effectively enhance tolerance of transgenic Arabidopsis to acid, drought and salt by increasing ascorbate accumulation.

  13. Core Flood study for enhanced oil recovery through ex-situ bioaugmentation with thermo- and halo-tolerant rhamnolipid produced by Pseudomonas aeruginosa NCIM 5514.

    Science.gov (United States)

    Varjani, Sunita J; Upasani, Vivek N

    2016-11-01

    The aim of this work was to study the Microbial Enhanced Oil Recovery (MEOR) employing core field model ex-situ bioaugmenting a thermo- and halo-tolerant rhamnolipid produced by Pseudomonas aeruginosa. Thin Layer Chromatography (TLC) revealed that the biosurfactant produced was rhamnolipid type. Nuclear Magnetic Resonance analysis showed that the purified rhamnolipids comprised two principal rhamnolipid homologues, i.e., Rha-Rha-C10-C14:1 and Rha-C8-C10. The rhamnolipid was stable under wide range of temperature (4°C, 30-100°C), pH (2.0-10.0) and NaCl concentration (0-18%, w/v). Core Flood model was designed for oil recovery operations using rhamnolipid. The oil recovery enhancement over Residual Oil Saturation was 8.82% through ex-situ bioaugmentation with rhamnolipid. The thermal stability of rhamnolipid shows promising scope for its application at conditions where high temperatures prevail in oil recovery processes, whereas its halo-tolerant nature increases its application in marine environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. A bell pepper cultivar tolerant to chilling enhanced nitrogen allocation and stress-related metabolite accumulation in the roots in response to low root-zone temperature.

    Science.gov (United States)

    Aidoo, Moses Kwame; Sherman, Tal; Lazarovitch, Naftali; Fait, Aaron; Rachmilevitch, Shimon

    2017-10-01

    Two bell pepper (Capsicum annuum) cultivars, differing in their response to chilling, were exposed to three levels of root-zone temperatures. Gas exchange, shoot and root phenology, and the pattern of change of the central metabolites and secondary metabolites caffeate and benzoate in the leaves and roots were profiled. Low root-zone temperature significantly inhibited gaseous exchange, with a greater effect on the sensitive commercial pepper hybrid (Canon) than on the new hybrid bred to enhance abiotic stress tolerance (S103). The latter was less affected by the treatment with respect to plant height, shoot dry mass, root maximum length, root projected area, number of root tips and root dry mass. More carbon was allocated to the leaves of S103 than nitrogen at 17°C, while in the roots at 17°C, more nitrogen was allocated and the ratio between C/N decreased. Metabolite profiling showed greater increase in the root than in the leaves. Leaf response between the two cultivars differed significantly. The roots accumulated stress-related metabolites including γ-aminobutyric acid (GABA), proline, galactinol and raffinose and at chilling (7°C) resulted in an increase of sugars in both cultivars. Our results suggest that the enhanced tolerance of S103 to root cold stress, reflected in the relative maintenance of shoot and root growth, is likely linked to a more effective regulation of photosynthesis facilitated by the induction of stress-related metabolism. © 2017 Scandinavian Plant Physiology Society.

  15. Heterologous expression of wheat VERNALIZATION 2 (TaVRN2 gene in Arabidopsis delays flowering and enhances freezing tolerance.

    Directory of Open Access Journals (Sweden)

    Amadou Diallo

    Full Text Available The vernalization gene 2 (VRN2, is a major flowering repressor in temperate cereals that is regulated by low temperature and photoperiod. Here we show that the gene from Triticum aestivum (TaVRN2 is also regulated by salt, heat shock, dehydration, wounding and abscissic acid. Promoter analysis indicates that TaVRN2 regulatory region possesses all the specific responsive elements to these stresses. This suggests pleiotropic effects of TaVRN2 in wheat development and adaptability to the environment. To test if TaVRN2 can act as a flowering repressor in species different from the temperate cereals, the gene was ectopically expressed in the model plant Arabidopsis. Transgenic plants showed no alteration in morphology, but their flowering time was significantly delayed compared to controls plants, indicating that TaVRN2, although having no ortholog in Brassicaceae, can act as a flowering repressor in these species. To identify the possible mechanism by which TaVRN2 gene delays flowering in Arabidopsis, the expression level of several genes involved in flowering time regulation was determined. The analysis indicates that the late flowering of the 35S::TaVRN2 plants was associated with a complex pattern of expression of the major flowering control genes, FCA, FLC, FT, FVE and SOC1. This suggests that heterologous expression of TaVRN2 in Arabidopsis can delay flowering by modulating several floral inductive pathways. Furthermore, transgenic plants showed higher freezing tolerance, likely due to the accumulation of CBF2, CBF3 and the COR genes. Overall, our data suggests that TaVRN2 gene could modulate a common regulator of the two interacting pathways that regulate flowering time and the induction of cold tolerance. The results also demonstrate that TaVRN2 could be used to manipulate flowering time and improve cold tolerance in other species.

  16. Silicon Priming Created an Enhanced Tolerance in Alfalfa (Medicago sativa L.) Seedlings in Response to High Alkaline Stress.

    Science.gov (United States)

    Liu, Duo; Liu, Miao; Liu, Xiao-Long; Cheng, Xian-Guo; Liang, Zheng-Wei

    2018-01-01

    Alkaline stress as a result of higher pH usually triggers more severe physiological damage to plants than that of saline stress with a neutral pH. In the present study, we demonstrated that silicon (Si) priming of alfalfa ( Medicago sativa L.) seedlings increased their tolerance to high alkaline stress situations. Gongnong No. 1 seedlings were subjected to alkaline stress simulated by 25 mM Na 2 CO 3 (pH 11.2). Alkaline stress greatly decreased the biomass and caused severe lodging or wilting of alfalfa seedlings. In contrast, the application of Si to alfalfa seedlings 36 h prior to the alkaline treatment significantly alleviated the damage symptoms and greatly increased the biomass and chlorophyll content. Because of being concomitant with increasing photosynthesis and water use efficiency, decreasing membrane injury and malondialdehyde content, and increasing peroxidase and catalase ascorbate activities in alfalfa leaves, thereby alleviating the triggered oxidative damage by alkaline stress to the plant. Furthermore, Si priming significantly decreased the accumulation of protein and proline content in alfalfa, thus reducing photosynthetic feedback repression. Si priming significantly accumulated more Na in the roots, but led to a decrease of Na accumulation and an increase of K accumulation in the leaves under alkaline stress. Meanwhile, Si priming decreased the accumulation of metal ions such as Mg, Fe, Mn, and Zn in the roots of alfalfa seedlings under alkaline stress. Collectively, these results suggested that Si is involved in the metabolic or physiological changes and has a potent priming effect on the alkaline tolerance of alfalfa seedlings. The present study indicated that Si priming is a new approach to improve the alkaline tolerance in alfalfa and provides increasing information for further exploration of the alkaline stress response at the molecular level in alfalfa.

  17. First-principles study for the enhanced sulfur tolerance of Ni(1 1 1) surface alloyed with Pb

    Science.gov (United States)

    Zhang, Yanxing; Yang, Zongxian

    2018-04-01

    The adsorption of H2S, HS, S, H and the dissociation of H2S on the Ni2Pb/Ni (1 1 1) are systematically studied using the first-principles method based on density functional theory. It is found that H2S dissociation barriers are greatly increased by alloying with Pb atoms in the Ni(1 1 1) surface, while the barrier for H2S formation is greatly reduced. In addition, the adsorption of sulfur atom is weakened a lot. The results indicate that alloying with Pb may be a good way to increase the sulfur tolerance of Ni based anode catalysts of solid oxide fuel cells.

  18. BoALMT1, an Al-Induced Malate Transporter in Cabbage, Enhances Aluminum Tolerance in Arabidopsis thaliana

    OpenAIRE

    Zhang, Lei; Wu, Xin-Xin; Wang, Jinfang; Qi, Chuandong; Wang, Xiaoyun; Wang, Gongle; Li, Mingyue; Li, Xingsheng; Guo, Yang-Dong

    2018-01-01

    Aluminum (Al) is present in approximately 50% of the arable land worldwide and is regarded as the main limiting factor of crop yield on acidic soil. Al-induced root malate efflux plays an important role in the Al tolerance of plants. Here, the aluminum induced malate transporter BoALMT1 (KF322104) was cloned from cabbage (Brassica oleracea). BoALMT1 showed higher expression in roots than in shoots. The expression of BoALMT1 was specifically induced by Al treatment, but not the trivalent catio...

  19. Nickel-tolerant ectomycorrhizal Pisolithus albus ultramafic ecotype isolated from nickel mines in New Caledonia strongly enhance growth of the host plant Eucalyptus globulus at toxic nickel concentrations.

    Science.gov (United States)

    Jourand, Philippe; Ducousso, Marc; Reid, Robert; Majorel, Clarisse; Richert, Clément; Riss, Jennifer; Lebrun, Michel

    2010-10-01

    Ectomycorrhizal (ECM) Pisolithus albus (Cooke & Massee), belonging to the ultramafic ecotype isolated in nickel-rich serpentine soils from New Caledonia (a tropical hotspot of biodiversity) and showing in vitro adaptive nickel tolerance, were inoculated to Eucalyptus globulus Labill used as a Myrtaceae plant-host model to study ectomycorrhizal symbiosis. Plants were then exposed to a nickel (Ni) dose-response experiment with increased Ni treatments up to 60 mg kg( - )(1) soil as extractable Ni content in serpentine soils. Results showed that plants inoculated with ultramafic ECM P. albus were able to tolerate high and toxic concentrations of Ni (up to 60 μg g( - )(1)) while uninoculated controls were not. At the highest Ni concentration tested, root growth was more than 20-fold higher and shoot growth more than 30-fold higher in ECM plants compared with control plants. The improved growth in ECM plants was associated with a 2.4-fold reduction in root Ni concentration but a massive 60-fold reduction in transfer of Ni from root to shoots. In vitro, P. albus strains could withstand high Ni concentrations but accumulated very little Ni in its tissue. The lower Ni uptake by mycorrhizal plants could not be explained by increased release of metal-complexing chelates since these were 5- to 12-fold lower in mycorrhizal plants at high Ni concentrations. It is proposed that the fungal sheath covering the plant roots acts as an effective barrier to limit transfer of Ni from soil into the root tissue. The degree of tolerance conferred by the ultramafic P. albus isolates to growth of the host tree species is considerably greater than previously reported for other ECM. The primary mechanisms underlying this improved growth were identified as reduced Ni uptake into the roots and markedly reduced transfer from root to shoot in mycorrhizal plants. The fact that these positive responses were observed at Ni concentrations commonly observed in serpentinic soils suggests that

  20. Constitutive Expression of a miR319 Gene Alters Plant Development and Enhances Salt and Drought Tolerance in Transgenic Creeping Bentgrass1[W][OA

    Science.gov (United States)

    Zhou, Man; Li, Dayong; Li, Zhigang; Hu, Qian; Yang, Chunhua; Zhu, Lihuang; Luo, Hong

    2013-01-01

    MicroRNA319 (miR319) is one of the first characterized and conserved microRNA families in plants and has been demonstrated to target TCP (for TEOSINTE BRANCHED/CYCLOIDEA/PROLIFERATING CELL FACTORS [PCF]) genes encoding plant-specific transcription factors. MiR319 expression is regulated by environmental stimuli, suggesting its involvement in plant stress response, although experimental evidence is lacking and the underlying mechanism remains elusive. This study investigates the role that miR319 plays in the plant response to abiotic stress using transgenic creeping bentgrass (Agrostis stolonifera) overexpressing a rice (Oryza sativa) miR319 gene, Osa-miR319a. We found that transgenic plants overexpressing Osa-miR319a displayed morphological changes and exhibited enhanced drought and salt tolerance associated with increased leaf wax content and water retention but reduced sodium uptake. Gene expression analysis indicated that at least four putative miR319 target genes, AsPCF5, AsPCF6, AsPCF8, and AsTCP14, and a homolog of the rice NAC domain gene AsNAC60 were down-regulated in transgenic plants. Our results demonstrate that miR319 controls plant responses to drought and salinity stress. The enhanced abiotic stress tolerance in transgenic plants is related to significant down-regulation of miR319 target genes, implying their potential for use in the development of novel molecular strategies to genetically engineer crop species for enhanced resistance to environmental stress. PMID:23292790

  1. Overexpression of Rice Auxilin-Like Protein, XB21, Induces Necrotic Lesions, up-Regulates Endocytosis-Related Genes, and Confers Enhanced Resistance to Xanthomonas oryzae pv. oryzae.

    Science.gov (United States)

    Park, Chang-Jin; Wei, Tong; Sharma, Rita; Ronald, Pamela C

    2017-12-01

    The rice immune receptor XA21 confers resistance to the bacterial pathogen, Xanthomonas oryzae pv. oryzae (Xoo). To elucidate the mechanism of XA21-mediated immunity, we previously performed a yeast two-hybrid screening for XA21 interactors and identified XA21 binding protein 21 (XB21). Here, we report that XB21 is an auxilin-like protein predicted to function in clathrin-mediated endocytosis. We demonstrate an XA21/XB21 in vivo interaction using co-immunoprecipitation in rice. Overexpression of XB21 in rice variety Kitaake and a Kitaake transgenic line expressing XA21 confers a necrotic lesion phenotype and enhances resistance to Xoo. RNA sequencing reveals that XB21 overexpression results in the differential expression of 8735 genes (4939 genes up- and 3846 genes down-regulated) (≥2-folds, FDR ≤0.01). The up-regulated genes include those predicted to be involved in 'cell death' and 'vesicle-mediated transport'. These results indicate that XB21 plays a role in the plant immune response and in regulation of cell death. The up-regulation of genes controlling 'vesicle-mediated transport' in XB21 overexpression lines is consistent with a functional role for XB21 as an auxilin.

  2. Evolutionary engineering strategies to enhance tolerance of xylose utilizing recombinant yeast to inhibitors derived from spruce biomass

    Directory of Open Access Journals (Sweden)

    Koppram Rakesh

    2012-05-01

    Full Text Available Abstract Background One of the crucial factors for a sustainable and economical production of lignocellulosic based bioethanol is the availability of a robust fermenting microorganism with high tolerance to inhibitors generated during the pretreatment of lignocellulosic raw materials, since these inhibitors are known to severely hinder growth and fermentation. Results A long-term adaptation in repetitive batch cultures in shake flasks using a cocktail of 12 different inhibitors and a long-term chemostat adaptation using spruce hydrolysate were used as evolutionary engineering strategies to improve the inhibitor tolerance in the metabolically engineered xylose utilizing Saccharomyces cerevisiae strain, TMB3400. The yeast was evolved for a period of 429 and 97 generations in repetitive batch cultures and chemostat cultivation, respectively. During the evolutionary engineering in repetitive batch cultures the maximum specific growth rate increased from 0.18 h-1 to 0.33 h-1 and the time of lag phase was decreased from 48 h to 24 h. In the chemostat adaptation, after 97 generations, the specific conversion rates of HMF and furfural were found to be 3.5 and 4 folds higher respectively, compared to rates after three generations. Two evolved strains (RK60-5, RKU90-3 and one evolved strain (KE1-17 were isolated from evolutionary engineering in repetitive batches and chemostat cultivation, respectively. The strains displayed significantly improved growth performance over TMB3400 when cultivated in spruce hydrolysate under anaerobic conditions, the evolved strains exhibited 25 to 38% increase in specific consumption rate of sugars and 32 to 50% increased specific ethanol productivity compared to TMB3400. The evolved strains RK60-5 and RKU90-3 were unable to consume xylose under anaerobic conditions, whereas, KE1-17 was found to consume xylose at similar rates as TMB3400. Conclusion Using evolutionary engineering strategies in batch and chemostat

  3. Evaluation of salmon calcitonin (sCT) enteric-coated capsule for enhanced absorption and GI tolerability in rats.

    Science.gov (United States)

    Wu, Lei; Zhang, Ge; Lu, Qin; Sun, Qian; Wang, Mulan; Li, Na; Gao, Zidong; Sun, Ya; Li, Tingting; Han, Deen; Yu, Xue; Wang, Lei; Sun, Wei; Zhao, Di; Wu, Yaning; Lu, Yang; Chen, Xijing

    2010-03-01

    Considering the chronic and repeated nature of salmon calcitonin (sCT) therapy, the oral route is a preferred route of administration. But, the oral bioavailability of sCT is very low due to enzymatic degradation and poor permeation across intestinal epithelial cells. It was the aim of this study to investigate the pharmacodynamic (PD), pharmacokinetic (PK), and mucosal injury characteristic of sCT oral delivery system. In this study, PD experiments were performed to find a suitable releasing region of sCT, an effect absorption enhancer, and an optimal mass ratio of sCT/enhancer. In addition, the PK experiments were designed to validate the absorption enhancement of this oral delivery system. Histopathological evaluations on the intestinal mucosa were carried out to assess any potential toxicity of the absorption enhancer. Through the PD research, we determined that oral sCT enteric-coated capsules containing sCT and citric acid (CA) with a ratio of 1:20 may be an adaptable delivery. PK study further proved that the oral absorption of sCT was enhanced from this delivery system. Finally, no damage on intestinal mucosa was observed when rats received the delivery system containing CA for up to 7 days. These results suggested that enteric-coated capsules with a certain amount of CA might give enhanced oral delivery of peptide drugs like sCT.

  4. GmSALT3, which Confers Improved Soybean Salt Tolerance in the Field, Increases Leaf Cl– Exclusion prior to Na+ Exclusion but does not Improve Early Vigour under Salinity

    Directory of Open Access Journals (Sweden)

    Ying Liu

    2016-09-01

    Full Text Available Soil salinity reduces soybean growth and yield. The recently identified GmSALT3 (Glycine max salt Tolerance-associated gene on chromosome 3 has the potential to improve soybean yields in salinized conditions. To evaluate the impact of GmSALT3 on soybean performance under saline or non-saline conditions, three sets of near isogenic lines (NILs, with genetic similarity 95.6-99.3% between each pair of NIL-T and NIL-S, were generated from a cross between two varieties, 85-140 (salt-sensitive, S and Tiefeng 8 (salt-tolerant, T by using marker-assisted selection. Each NIL; 782-T, 820-T and 860-T, contained a common ~1000 kb fragment on chromosome 3 where GmSALT3 was located. We show that GmSALT3 does not contribute to an improvement in seedling emergence rate or early vigour under salt stress. However, when 12-day-old seedlings were exposed to NaCl stress, the NIL-T lines accumulated significantly less leaf Na+ compared with their corresponding NIL-S, while no significant difference of K+ concentration was observed between NIL-T and NIL-S; the magnitude of Na+ accumulation within each NIL-T set was influenced by the different genetic backgrounds. In addition, NIL-T lines accumulated less Cl– in the leaf and more in the root prior to any difference in Na+; in the field they accumulated less pod wall Cl– than the corresponding NIL-S lines. Under non-saline field conditions, no significant differences were observed for yield related traits within each pair of NIL-T and NIL-S lines, indicating there was no yield penalty for having the GmSALT3 gene. In contrast, under saline field conditions the NIL-T lines had significantly greater plant seed weight and 100-seed weight than the corresponding NIL-S lines, meaning GmSALT3 conferred a yield advantage to soybean plants in salinized fields. Our results indicated that GmSALT3 mediated regulation of both Na+ and Cl– accumulation in soybean, and contributes to improved soybean yield through maintaining a

  5. Enhanced Tolerance of House Mosquito to Different Insecticides due to Agricultural and Household Pesticides in Sewage System of Tehran, Iran

    Directory of Open Access Journals (Sweden)

    H Vatandoost, L Ezeddinloo, A H Mahvi, M R Abai, EB Kia, I Mobedi

    2004-07-01

    Full Text Available Different insecticides are being used for household and agricultural pest control in the capital city of Iran, Tehran. An investigation was carried out in order to evaluate the susceptibility level of laboratory and field collected mosquito, Culex quinquefasciatusin to different insecticides. Field strain was collected from sewage system of the city. Adult females were subjected to the diagnostic dose of different insecticides as recommended by WHO. Results showed that laboratory strains only exhibit resistant to DDT 4%, and susceptible to other insecticides. By using WHO criteria, field strain is resistant to DDT 4%, bendiocarb 0.1%, and tolerant to malathion 5%, permethrin 0.75%, deltamethrin 0.05%, lambdacyhalothrin 0.05% and etofenprox 5%. The field strain is still susceptible to cyfluthrin 0.15%.This findings indicate that routine use of pesticides in household and agricultural pest control may cause resistant in the wastewater mosquito, Culex quinquefasciatus.

  6. An examination of the damage tolerance enhancement of carbon/epoxy using an outer lamina of spectra (R)

    Science.gov (United States)

    Lance, D. G.; Nettles, A. T.

    1991-01-01

    Low velocity instrumented impact testing was utilized to examine the effects of an outer lamina of ultra-high molecular weight polyethylene (Spectra) on the damage tolerance of carbon epoxy composites. Four types of 16-ply quasi-isotropic panels (0, +45, 90, -45) were tested. Some panels contained no Spectra, while others had a lamina of Spectra bonded to the top (impacted side), bottom, or both sides of the composite plates. The specimens were impacted with energies up to 8.5 J. Force time plots and maximum force versus impact energy graphs were generated for comparison purposes. Specimens were also subjected to cross-sectional analysis and compression after impact tests. The results show that while the Spectra improved the maximum load that the panels could withstand before fiber breakage, the Spectra seemingly reduced the residual strength of the composites.

  7. Isolation of baker's yeast mutants with proline accumulation that showed enhanced tolerance to baking-associated stresses.

    Science.gov (United States)

    Tsolmonbaatar, Ariunzaya; Hashida, Keisuke; Sugimoto, Yukiko; Watanabe, Daisuke; Furukawa, Shuhei; Takagi, Hiroshi

    2016-12-05

    During bread-making processes, yeast cells are exposed to baking-associated stresses such as freeze-thaw, air-drying, and high-sucrose concentrations. Previously, we reported that self-cloning diploid baker's yeast strains that accumulate proline retained higher-level fermentation abilities in both frozen and sweet doughs than the wild-type strain. Although self-cloning yeasts do not have to be treated as genetically modified yeasts, the conventional methods for breeding baker's yeasts are more acceptable to consumers than the use of self-cloning yeasts. In this study, we isolated mutants resistant to the proline analogue azetidine-2-carboxylate (AZC) derived from diploid baker's yeast of Saccharomyces cerevisiae. Some of the mutants accumulated a greater amount of intracellular proline, and among them, 5 mutants showed higher cell viability than that observed in the parent wild-type strain under freezing or high-sucrose stress conditions. Two of them carried novel mutations in the PRO1 gene encoding the Pro247Ser or Glu415Lys variant of γ-glutamyl kinase (GK), which is a key enzyme in proline biosynthesis in S. cerevisiae. Interestingly, we found that these mutations resulted in AZC resistance of yeast cells and desensitization to proline feedback inhibition of GK, leading to intracellular proline accumulation. Moreover, baker's yeast cells expressing the PRO1 P247S and PRO1 E415K gene were more tolerant to freezing stress than cells expressing the wild-type PRO1 gene. The approach described here could be a practical method for the breeding of proline-accumulating baker's yeasts with higher tolerance to baking-associated stresses. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Ectopic expression of TaOEP16-2-5B, a wheat plastid outer envelope protein gene, enhances heat and drought stress tolerance in transgenic Arabidopsis plants.

    Science.gov (United States)

    Zang, Xinshan; Geng, Xiaoli; Liu, Kelu; Wang, Fei; Liu, Zhenshan; Zhang, Liyuan; Zhao, Yue; Tian, Xuejun; Hu, Zhaorong; Yao, Yingyin; Ni, Zhongfu; Xin, Mingming; Sun, Qixin; Peng, Huiru

    2017-05-01

    Abiotic stresses, such as heat and drought, are major environmental factors restricting crop productivity and quality worldwide. A plastid outer envelope protein gene, TaOEP16-2, was identified from our previous transcriptome analysis [1,2]. In this study, the isolation and functional characterization of the TaOEP16-2 gene was reported. Three homoeologous sequences of TaOEP16-2 were isolated from hexaploid wheat, which were localized on the chromosomes 5A, 5B and 5D, respectively. These three homoeologues exhibited different expression patterns under heat stress conditions, TaOEP16-2-5B was the dominant one, and TaOEP16-2-5B was selected for further analysis. Compared with wild type (WT) plants, transgenic Arabidopsis plants overexpressing the TaOEP16-2-5B gene exhibited enhanced tolerance to heat stress, which was supported by improved survival rate, strengthened cell membrane stability and increased sucrose content. It was also found that TaOEP16-2 was induced by drought stress and involved in drought stress tolerance. TaOEP16-2-5B has the same function in ABA-controlled seed germination as AtOEP16-2. Our results suggest that TaOEP16-2-5B plays an important role in heat and drought stress tolerance, and could be utilized in transgenic breeding of wheat and other crop plants. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Contribution of arbuscular mycorrhizal fungi and/or bacteria to enhancing plant drought tolerance under natural soil conditions: effectiveness of autochthonous or allochthonous strains.

    Science.gov (United States)

    Ortiz, N; Armada, E; Duque, E; Roldán, A; Azcón, R

    2015-02-01

    Autochthonous microorganisms [a consortium of arbuscular-mycorrhizal (AM) fungi and Bacillus thuringiensis (Bt)] were assayed and compared to Rhizophagus intraradices (Ri), Bacillus megaterium (Bm) or Pseudomonas putida (Psp) and non-inoculation on Trifolium repens in a natural arid soil under drought conditions. The autochthonous bacteria Bt and the allochthonous bacteria Psp increased nutrients and the relative water content and decreased stomatal conductance, electrolyte leakage, proline and APX activity, indicating their abilities to alleviate the drought stress. Mycorrhizal inoculation significantly enhanced plant growth, nutrient uptake and the relative water content, particularly when associated with specific bacteria minimizing drought stress-imposed effects. Specific combinations of autochthonous or allochthonous inoculants also contributed to plant drought tolerance by changing proline and antioxidative activities. However, non-inoculated plants had low relative water and nutrients contents, shoot proline accumulation and glutathione reductase activity, but the highest superoxide dismutase activity, stomatal conductance and electrolyte leakage. Microbial activities irrespective of the microbial origin seem to be coordinately functioning in the plant as an adaptive response to modulated water stress tolerance and minimizing the stress damage. The autochthonous AM fungi with Bt or Psp and those allochthonous Ri with Bm or Psp inoculants increased water stress alleviation. The autochthonous Bt showed the greatest ability to survive under high osmotic stress compared to the allochthonous strains, but when single inoculated or associated with Ri or AM fungi were similarly efficient in terms of physiological and nutritional status and in increasing plant drought tolerance, attenuating and compensating for the detrimental effect of water limitation. Copyright © 2014 Elsevier GmbH. All rights reserved.

  10. Ferric Sulfate and Proline Enhance Heavy-Metal Tolerance of Halophilic/Halotolerant Soil Microorganisms and Their Bioremediation Potential for Spilled-Oil Under Multiple Stresses

    Science.gov (United States)

    Al-Mailem, Dina M.; Eliyas, Mohamed; Radwan, Samir S.

    2018-01-01

    The aim of this study was to explore the heavy-metal resistance and hydrocarbonoclastic potential of microorganisms in a hypersaline soil. For this, hydrocarbonoclastic microorganisms were counted on a mineral medium with oil vapor as a sole carbon source in the presence of increasing concentrations of ZnSO4, HgCl2, CdSO4, PbNO3, CuSO4, and Na2HAsO4. The colony-forming units counted decreased in number from about 150 g-1 on the heavy-metal-free medium to zero units on media with 40–100 mg l-1 of HgCl2, CdSO4, PbNO3, or Na2HAsO4. On media with CuSO4 or ZnSO4 on the other hand, numbers increased first reaching maxima on media with 50 mg l-1 CuSO4 and 90 mg l-1 ZnSO4. Higher concentrations reduced the numbers, which however, still remained considerable. Pure microbial isolates in cultures tolerated 200–1600 mg l-1 of HgCl2, CdSO4, PbNO3, CuSO4, and Na2HAsO4 in the absence of crude oil. In the presence of oil vapor, the isolates tolerated much lower concentrations of the heavy metals, only 10–80 mg l-1. The addition of 10 Fe2(SO4)3 and 200 mg l-1 proline (by up to two- to threefold) enhanced the tolerance of several isolates to heavy metals, and consequently their potential for oil biodegradation in their presence. The results are useful in designing bioremediation technologies for oil spilled in hypersaline areas. PMID:29563904

  11. Overexpression of the autophagy-related gene SiATG8a from foxtail millet (Setaria italica L.) confers tolerance to both nitrogen starvation and drought stress in Arabidopsis.

    Science.gov (United States)

    Li, Wei-wei; Chen, Ming; Zhong, Li; Liu, Jia-ming; Xu, Zhao-shi; Li, Lian-cheng; Zhou, Yong-Bin; Guo, Chang-Hong; Ma, You-Zhi

    2015-12-25

    Autophagy is an evolutionarily conserved biological process in all eukaryotes for the degradation of intracellular components for nutrient recycling. Autophagy is known to be involved in responses to low nitrogen stress in Arabidopsis. Foxtail millet has strong abiotic stress resistance to both low nutrient and drought stress. However, to date, there have only been a few genes reported to be related with abiotic stress resistance in foxtail millet. In this study, we identified an autophagy-related gene, SiATG8a, from foxtail millet. SiATG8a is mainly expressed in stems and its expression was dramatically induced by drought stress and nitrogen starvation treatments. SiATG8a was localized in the membrane and cytoplasm of foxtail millet. Overexpression of SiATG8a in Arabidopsis conferred tolerance to both nitrogen starvation and to drought stress. Under nitrogen starvation conditions, the SiATG8a transgenic plants had larger root and leaf areas and accumulated more total nitrogen than wild-type plants. The transgenic plants had lower total protein concentrations than did the WT plants. Under drought stress, the SiATG8a transgenic plants had higher survival rates, chlorophyll content, and proline content, but had lower MDA content than wild type plants. Taken together, our results represent the first identified case where overexpression of autophagy related gene can simultaneously improve plant resistance to low nitrogen and drought stresses. These findings implicate plant autophagy in plant stress responses to low nitrogen and drought and should be helpful in efforts to improve stresses resistance to nitrogen starvation and drought of crops by genetic transformation. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. A novel cold-regulated gene from Phlox subulata, PsCor413im1, enhances low temperature tolerance in Arabidopsis.

    Science.gov (United States)

    Zhou, Aimin; Sun, Hongwei; Feng, Shuang; Zhou, Mi; Gong, Shufang; Wang, Jingang; Zhang, Shuzhen

    2018-01-08

    Low temperature stress adversely affects plant growth, development, and crop productivity. Analysis of the function of genes in the response of plants to low temperature stress is essential for understanding the mechanism of chilling and freezing tolerance. In this study, PsCor413im1, a novel cold-regulated gene isolated from Phlox subulata, was transferred to Arabidopsis to investigate its function under low temperature stress. Real-time quantitative PCR analysis revealed that PsCor413im1 expression was induced by cold and abscisic acid. Subcellular localization revealed that PsCor413im1-GFP fusion protein was localized to the periphery of the chloroplast, consistent with the localization of chloroplast inner membrane protein AtCor413im1, indicating that PsCor413im1 is a chloroplast membrane protein. Furthermore, the N-terminal of PsCor413im1 was determined to be necessary for its localization. Compared to the wild-type plants, transgenic plants showed higher germination and survival rates under cold and freezing stress. Moreover, the expression of AtCor15 in transgenic plants was higher than that in the wild-type plants under cold stress. Taken together, our results suggest that the overexpression of PsCor413im1 enhances low temperature tolerance in Arabidopsis. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Co-transforming bar and CsLEA enhanced tolerance to drought and salt stress in transgenic alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Zhang, Jiyu; Duan, Zhen; Zhang, Daiyu; Zhang, Jianquan; Di, Hongyan; Wu, Fan; Wang, Yanrong

    2016-03-25

    Drought and high salinity are two major abiotic factors that restrict alfalfa productivity. A dehydrin protein, CsLEA, from the desert grass Cleistogenes songorica was transformed into alfalfa (Medicago sativa L.) via Agrobacterium-mediated transformation using the bar gene as a selectable marker, and the drought and salt stress tolerances of the transgenic plants were assessed. Thirty-nine of 119 transformants were positive, as screened by Basta, and further molecularly authenticated using PCR and RT-PCR. Phenotype observations revealed that the transgenic plants grew better than the wild-type (WT) plants after 15d of drought stress and 10d of salt stress: the leaves of WT alfalfa turned yellow, whereas the transgenic alfalfa leaves only wilted; after rewatering, the transgenic plants returned to a normal state, though the WT plants could not be restored. Evaluation of physiologic and biochemical indices during drought and salt stresses showed a relatively lower Na(+) content in the leaves of the transgenic plants, which would reduce toxic ion effects. In addition, the transgenic plants were able to maintain a higher relative water content (RWC), higher shoot biomass, fewer photosystem changes, decreased membrane injury, and a lower level of osmotic stress injury. These results demonstrate that overexpression of the CsLEA gene can enhance the drought and salt tolerance of transgenic alfalfa; in addition, carrying the bar gene in the genome may increase herbicide resistance. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Impact of conference attendance on librarians' leadership ...

    African Journals Online (AJOL)

    ... attendance to leadership developments hows approximately 0.370.m Conference attendance was highly recommended as a means of enhancing leadership development of academic librarians. Keywords: Experiential learning, self efficacy, attitude, Conference, Impact, Leadership, Teamwork, development, brainstorm, ...

  15. A novel cold-regulated gene from Camellia sinensis, CsCOR1, enhances salt- and dehydration-tolerance in tobacco

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xian-Wen, E-mail: xianwenli01@sina.com [College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); College of Life Science, Xinyang Normal University, Xinyang 464000 (China); Key Laboratory of Horticultural Plant Biology of the Ministry of Education, Huazhong Agricultural University, Wuhan 430070 (China); Feng, Zhi-Guo; Yang, Hui-Min; Zhu, Xiao-Pei [College of Life Science, Xinyang Normal University, Xinyang 464000 (China); Liu, Jun, E-mail: liujun@mail.hzau.edu.cn [College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Key Laboratory of Horticultural Plant Biology of the Ministry of Education, Huazhong Agricultural University, Wuhan 430070 (China); Yuan, Hong-Yu, E-mail: yhongyu92@163.com [College of Life Science, Xinyang Normal University, Xinyang 464000 (China)

    2010-04-02

    In present research, the full-length cDNA and the genomic sequence of a novel cold-regulated gene, CsCOR1, were isolated from Camellia sinensis L. The deduced protein CsCOR1 contains a hydrophobic N-terminus as a signal peptide and a hydrophilic C-terminal domain that is rich in glycine, arginine and proline. Two internal repetitive tridecapeptide fragments (HSVTAGRGGYNRG) exist in the middle of the C-terminal domain and the two nucleotide sequences encoding them are identical. CsCOR1 was localized in the cell walls of transgenic-tobaccos via CsCOR1::GFP fusion approach. The expression of CsCOR1 in tea leaves was enhanced dramatically by both cold- and dehydration-stress. And overexpression of CsCOR1 in transgenic-tobaccos improved obviously the tolerance to salinity and dehydration.

  16. Manipulating environmental stresses and stress tolerance of microalgae for enhanced production of lipids and value-added products-A review.

    Science.gov (United States)

    Chen, Bailing; Wan, Chun; Mehmood, Muhammad Aamer; Chang, Jo-Shu; Bai, Fengwu; Zhao, Xinqing

    2017-11-01

    Microalgae have promising potential to produce lipids and a variety of high-value chemicals. Suitable stress conditions such as nitrogen starvation and high salinity could stimulate synthesis and accumulation of lipids and high-value products by microalgae, therefore, various stress-modification strategies were developed to manipulate and optimize cultivation processes to enhance bioproduction efficiency. On the other hand, advancements in omics-based technologies have boosted the research to globally understand microalgal gene regulation under stress conditions, which enable further improvement of production efficiency via genetic engineering. Moreover, integration of multi-omics data, synthetic biology design, and genetic engineering manipulations exhibits a tremendous potential in the betterment of microalgal biorefinery. This review discusses the process manipulation strategies and omics studies on understanding the regulation of metabolite biosynthesis under various stressful conditions, and proposes genetic engineering of microalgae to improve bioproduction via manipulating stress tolerance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Root Fungal Endophytes Enhance Heavy-Metal Stress Tolerance of Clethra barbinervis Growing Naturally at Mining Sites via Growth Enhancement, Promotion of Nutrient Uptake and Decrease of Heavy-Metal Concentration.

    Directory of Open Access Journals (Sweden)

    Keiko Yamaji

    Full Text Available Clethra barbinervis Sieb. et Zucc. is a tree species that grows naturally at several mine sites and seems to be tolerant of high concentrations of heavy metals, such as Cu, Zn, and Pb. The purpose of this study is to clarify the mechanism(s underlying this species' ability to tolerate the sites' severe heavy-metal pollution by considering C. barbinervis interaction with root fungal endophytes. We measured the heavy metal concentrations of root-zone soil, leaves, branches, and fine roots collected from mature C. barbinervis at Hitachi mine. We isolated fungal endophytes from surface-sterilized root segments, and we examined the growth, and heavy metal and nutrient absorption of C. barbinervis seedlings growing in sterilized mine soil with or without root fungal endophytes. Field analyses showed that C. barbinervis contained considerably high amounts of Cu, Zn, and Pb in fine roots and Zn in leaves. The fungi, Phialocephala fortinii, Rhizodermea veluwensis, and Rhizoscyphus sp. were frequently isolated as dominant fungal endophyte species. Inoculation of these root fungal endophytes to C. barbinervis seedlings growing in sterilized mine soil indicated that these fungi significantly enhanced the growth of C. barbinervis seedlings, increased K uptake in shoots and reduced the concentrations of Cu, Ni, Zn, Cd, and Pb in roots. Without root fungal endophytes, C. barbinervis could hardly grow under the heavy-metal contaminated condition, showing chlorosis, a symptom of heavy-metal toxicity. Our results indicate that the tree C. barbinervis can tolerate high heavy-metal concentrations due to the support of root fungal endophytes including P. fortinii, R. veluwensis, and Rhizoscyphus sp. via growth enhancement, K uptake promotion and decrease of heavy metal concentrations.

  18. A new Em-like protein from Lactuca sativa, LsEm1, enhances drought and salt stress tolerance in Escherichia coli and rice.

    Science.gov (United States)

    Xiang, Dian-Jun; Man, Li-Li; Zhang, Chun-Lan; Peng-Liu; Li, Zhi-Gang; Zheng, Gen-Chang

    2018-02-07

    genes may be involved in the enhanced drought and salt tolerance of transgenic rice. Thus, this work paves the way for improvement in tolerance of crops by genetic engineering breeding.

  19. A Dehydration-Induced Eukaryotic Translation Initiation Factor iso4G Identified in a Slow Wilting Soybean Cultivar Enhances Abiotic Stress Tolerance in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Juan P. Gallino

    2018-03-01

    Full Text Available Water is usually the main limiting factor for soybean productivity worldwide and yet advances in genetic improvement for drought resistance in this crop are still limited. In the present study, we investigated the physiological and molecular responses to drought in two soybean contrasting genotypes, a slow wilting N7001 and a drought sensitive TJS2049 cultivars. Measurements of stomatal conductance, carbon isotope ratios and accumulated dry matter showed that N7001 responds to drought by employing mechanisms resulting in a more efficient water use than TJS2049. To provide an insight into the molecular mechanisms that these cultivars employ to deal with water stress, their early and late transcriptional responses to drought were analyzed by suppression subtractive hybridization. A number of differentially regulated genes from N7001 were identified and their expression pattern was compared between in this genotype and TJS2049. Overall, the data set indicated that N7001 responds to drought earlier than TJ2049 by up-regulating a larger number of genes, most of them encoding proteins with regulatory and signaling functions. The data supports the idea that at least some of the phenotypic differences between slow wilting and drought sensitive plants may rely on the regulation of the level and timing of expression of specific genes. One of the genes that exhibited a marked N7001-specific drought induction profile encoded a eukaryotic translation initiation factor iso4G (GmeIFiso4G-1a. GmeIFiso4G-1a is one of four members of this protein family in soybean, all of them sharing high sequence identity with each other. In silico analysis of GmeIFiso4G-1 promoter sequences suggested a possible functional specialization between distinct family members, which can attain differences at the transcriptional level. Conditional overexpression of GmeIFiso4G-1a in Arabidopsis conferred the transgenic plants increased tolerance to osmotic, salt, drought and low

  20. Enhancement of radiation tolerance in GaAs/AlGaAs core–shell and InP nanowires

    Science.gov (United States)

    Li, Fajun; Xie, Xiaolong; Gao, Qian; Tan, Liying; Zhou, Yanping; Yang, Qingbo; Ma, Jing; Fu, Lan; Tan, Hark Hoe; Jagadish, Chennupati

    2018-06-01

    Radiation effects on semiconductor nanowires (NWs) have attracted the attention of the research community due to their potential applications in space and atomic fields. The effective implementation of NW devices in a radiation environment is a matter of concern. Here, the photoluminescence (PL) and time-resolved PL (TRPL) measurements were performed on both GaAs and InP NWs at room temperature before and after 1 MeV H+ irradiation with fluences ranging from 1 × 1011 to 5 × 1013 p cm‑2. It is found that the degradation of lifetime is size-dependent, and typically the minority carrier lifetime damage coefficient is closely correlated with the material and NW diameter. Compared to GaAs and InP bulk material counterparts, the lifetime damage coefficient of NWs decreases by a factor of about one order of magnitude. After irradiation, GaAs NWs with a smaller diameter show a much lower lifetime damage coefficient while InP NWs show an increase in carrier radiative lifetime. The increased size-dependent radiation hardness is mainly attributed to the defect sink effect and/or the improvement of a room temperature dynamic annealing mechanism of the NWs. The InP NWs also showed higher radiation tolerance than GaAs NWs.

  1. 24-Epibrassinoslide enhances plant tolerance to stress from low temperatures and poor light intensities in tomato (Lycopersicon esculentum Mill.).

    Science.gov (United States)

    Cui, Lirong; Zou, Zhirong; Zhang, Jing; Zhao, Yanyan; Yan, Fei

    2016-01-01

    Brassinosteroids (Brs) are a newly recognized group of active steroidal hormones that occur at low concentrations in all plant parts and one of the active and stable forms is 24-epibrassinolide (EBR). We investigated the effect of EBR on tomato (Lycopersicon esculentum Mill.) and its mechanism when seedlings were exposed to low temperature and poor light stress conditions. Leaves of stress-tolerant 'Zhongza9' and stress-sensitive 'Zhongshu4' cultivars were pre-treated with spray solutions containing either 0.1 μM EBR or no EBR (control). The plants were then transferred to chambers where they were exposed to low temperatures of 12 °C/6 °C (day/night) under a low light (LL) level of 80 μmol · m(-2) · s(-1). Exogenous application of EBR significantly increased the antioxidant activity of superoxide dismutase, catalase and peroxidase, and decreased the rate of O2 · (-) formation and H2O2 and malondialdehyde contents. Additionally, the ATP synthase β subunit content was increased by exogenous hormone application. Based on these results, we conclude that exogenous EBR can elicit synergism between the antioxidant enzyme systems and the ATP synthase β subunit so that scavenging of reactive oxygen species becomes more efficient. These activities enable plants to cope better under combined low temperature and poor light stresses.

  2. Enhancement of radiation tolerance in GaAs/AlGaAs core-shell and InP nanowires.

    Science.gov (United States)

    Li, Fajun; Xie, Xiaolong; Gao, Qian; Tan, Liying; Zhou, Yanping; Yang, Qingbo; Ma, Jing; Fu, Lan; Tan, Hark Hoe; Jagadish, Chennupati

    2018-06-01

    Radiation effects on semiconductor nanowires (NWs) have attracted the attention of the research community due to their potential applications in space and atomic fields. The effective implementation of NW devices in a radiation environment is a matter of concern. Here, the photoluminescence (PL) and time-resolved PL (TRPL) measurements were performed on both GaAs and InP NWs at room temperature before and after 1 MeV H + irradiation with fluences ranging from 1 × 10 11 to 5 × 10 13 p cm -2 . It is found that the degradation of lifetime is size-dependent, and typically the minority carrier lifetime damage coefficient is closely correlated with the material and NW diameter. Compared to GaAs and InP bulk material counterparts, the lifetime damage coefficient of NWs decreases by a factor of about one order of magnitude. After irradiation, GaAs NWs with a smaller diameter show a much lower lifetime damage coefficient while InP NWs show an increase in carrier radiative lifetime. The increased size-dependent radiation hardness is mainly attributed to the defect sink effect and/or the improvement of a room temperature dynamic annealing mechanism of the NWs. The InP NWs also showed higher radiation tolerance than GaAs NWs.

  3. Regulation of galactolipid biosynthesis by overexpression of the rice MGD gene contributes to enhanced aluminum tolerance in tobacco

    Directory of Open Access Journals (Sweden)

    Meijuan eZhang

    2016-03-01

    Full Text Available Membrane lipid alterations affect Al tolerance in plants, but little is known about the regulation of membrane lipid metabolism in response to Al stress. Transgenic tobacco (Nicotiana tabacum overexpressing rice monogalactosyldiacylglycerol (MGDG synthase (OsMGD gene and wild-type tobacco plants were exposed to AlCl3, and the impact of Al toxicity on root growth, Al accumulation, plasma membrane integrity, lipid peroxidation and membrane lipid composition were investigated. Compared with the wild type, the transgenic plants exhibited rapid regrowth of roots after removal of Al and less damage to membrane integrity and lipid peroxidation under Al stress, meanwhile, the Al accumulation showed no difference between wild-type and transgenic plants. Lipid analysis showed that Al treatment dramatically decreased the content of MGDG and the ratio of MGDG to digalactosyldiacylglycerol (DGDG in wild-type plants, while it was unchanged in transgenic plants. The stable of MGDG level and the ratio of MGDG/DGDG contribute to maintain the membrane stability and permeability. Moreover, Al caused a significant increase in phospholipids in wild-type plants, resulting in a high proportion of phospholipids and low proportion of galactolipids, but these proportions were unaffected in transgenic plants. The high proportion of phospholipids could contribute to a higher rate of Al3+ binding in the membrane and thereby leads to more membrane perturbation and damage. These results show that the regulation of galactolipid biosynthesis could play an important role in maintaining membrane structure and function under Al stress.

  4. The evolution of prestige: freely conferred deference as a mechanism for enhancing the benefits of cultural transmission.

    Science.gov (United States)

    Henrich, J; Gil-White, F J.

    2001-05-01

    This paper advances an "information goods" theory that explains prestige processes as an emergent product of psychological adaptations that evolved to improve the quality of information acquired via cultural transmission. Natural selection favored social learners who could evaluate potential models and copy the most successful among them. In order to improve the fidelity and comprehensiveness of such ranked-biased copying, social learners further evolved dispositions to sycophantically ingratiate themselves with their chosen models, so as to gain close proximity to, and prolonged interaction with, these models. Once common, these dispositions created, at the group level, distributions of deference that new entrants may adaptively exploit to decide who to begin copying. This generated a preference for models who seem generally "popular." Building on social exchange theories, we argue that a wider range of phenomena associated with prestige processes can more plausibly be explained by this simple theory than by others, and we test its predictions with data from throughout the social sciences. In addition, we distinguish carefully between dominance (force or force threat) and prestige (freely conferred deference).

  5. Enhanced tolerance against early and late apoptotic oxidative stress in mammalian neurons through nicotinamidase and sirtuin mediated pathways.

    Science.gov (United States)

    Chong, Zhao Zhong; Maiese, Kenneth

    2008-08-01

    Focus upon therapeutic strategies that intersect between pathways that govern cellular metabolism and cellular survival may offer the greatest impact for the treatment of a number of neurodegenerative and metabolic disorders, such as diabetes mellitus. In this regard, we investigated the role of a Drosophila nicotinamidase (DN) in mammalian SH-SY5Y neuronal cells during oxidative stress. We demonstrate that during free radical exposure to nitric oxide generators DN neuronal expression significantly increased cell survival and blocked cellular membrane injury. Furthermore, DN neuronal expression prevented both apoptotic late DNA degradation and early phosphatidylserine exposure that may serve to modulate inflammatory cell activation in vivo. Nicotinamidase activity that limited nicotinamide cellular concentrations appeared to be necessary for DN neuroprotection, since application of progressive nicotinamide concentrations could abrogate the benefits of DN expression during oxidative stress. Pathways that involved sirtuin activation and SIRT1 were suggested to be vital, at least in part, for DN to confer protection through a series of studies. First, application of resveratrol increased cell survival during oxidative stress either alone or in conjunction with the expression of DN to a similar degree, suggesting that DN may rely upon SIRT1 activation to foster neuronal protection. Second, the overexpression of either SIRT1 or DN in neurons prevented apoptotic injury specifically in neurons expressing these proteins during oxidative stress, advancing the premise that DN and SIRT1 may employ similar pathways for neuronal protection. Third, inhibition of sirtuin activity with sirtinol was detrimental to neuronal survival during oxidative stress and prevented neuronal protection during overexpression of DN or SIRT1, further supporting that SIRT1 activity may be necessary for DN neuroprotection during oxidative stress. Implementation of further work to elucidate the

  6. Overexpression of ERF1-V from Haynaldia villosa Can Enhance the Resistance of Wheat to Powdery Mildew and Increase the Tolerance to Salt and Drought Stresses

    Directory of Open Access Journals (Sweden)

    Liping Xing

    2017-11-01

    Full Text Available The APETALA 2/Ethylene-responsive element binding factor (AP2/ERF transcription factor gene family is widely involved in the biotic and abiotic stress regulation. Haynaldia villosa (VV, 2n = 14, a wild species of wheat, is a potential gene pool for wheat improvement. H. villosa confers high resistance to several wheat diseases and high tolerance to some abiotic stress. In this study, ERF1-V, an ethylene-responsive element-binding factor gene of the AP2/ERF transcription factor gene family from wild H. villosa, was cloned and characterized. Sequence and phylogenetic analysis showed that ERF1-V is a deduced B2 type ERF gene. ERF1-V was first identified as a Blumeria graminis f. sp. tritici (Bgt up-regulated gene, and later found to be induced by drought, salt and cold stresses. In responses to hormones, ERF1-V was up-regulated by ethylene and abscisic acid, but down-regulated by salicylic acid and jasmonic acid. Over expression of ERF1-V in wheat could improve resistance to powdery mildew, salt and drought stress. Chlorophyll content, malondialdehyde content, superoxide dismutase and peroxidase activity were significantly differences between the recipient Yangmai158 and the transgenic plants following salt treatment. Furthermore, the expression levels of some stress responsive genes were differences after drought or salt treatments. Although ERF1-V was activated by the constitutive promoter, the agronomic traits, including flowering time, plant height, effective tiller number, spikelet number per spike and grain size, did not changed significantly. ERF1-V is a valuable gene for wheat improvement by genetic engineering.

  7. The Expression of Millettia pinnata Chalcone Isomerase in Saccharomyces cerevisiae Salt-Sensitive Mutants Enhances Salt-Tolerance

    OpenAIRE

    Wang, Hui; Hu, Tangjin; Huang, Jianzi; Lu, Xiang; Huang, Baiqu; Zheng, Yizhi

    2013-01-01

    The present study demonstrates a new Millettia pinnata chalcone isomerase (MpCHI) whose transcription level in leaf was confirmed to be enhanced after being treated by seawater or NaCl (500 mM) via transcriptome sequencing and Real-Time Quantitative Reverse Transcription PCR (QRT-PCR) analyses. Its full length cDNA (666 bp) was obtained by 3'-end and 5'-end Rapid Amplification of cDNA Ends (RACE). The analysis via NCBI BLAST indicates that both aminoacid sequence and nucleotide sequ...

  8. Exogenous spermidine is enhancing tomato tolerance to salinity-alkalinity stress by regulating chloroplast antioxidant system and chlorophyll metabolism.

    Science.gov (United States)

    Li, Jianming; Hu, Lipan; Zhang, Li; Pan, Xiongbo; Hu, Xiaohui

    2015-12-29

    Salinity-alkalinity stress is known to adversely affect a variety of processes in plants, thus inhibiting growth and decreasing crop yield. Polyamines protect plants against a variety of environmental stresses. However, whether exogenous spermidine increases the tolerance of tomato seedlings via effects on chloroplast antioxidant enzymes and chlorophyll metabolism is unknown. In this study, we examined the effect of exogenous spermidine on chlorophyll synthesis and degradation pathway intermediates and related enzyme activities, as well as chloroplast ultrastructure, gene expression, and antioxidants in salinity-alkalinity-stressed tomato seedlings. Salinity-alkalinity stress disrupted chlorophyll metabolism and hindered uroorphyrinogen III conversion to protoporphyrin IX. These effects were more pronounced in seedlings of cultivar Zhongza No. 9 than cultivar Jinpengchaoguan. Under salinity-alkalinity stress, exogenous spermidine alleviated decreases in the contents of total chlorophyll and chlorophyll a and b in seedlings of both cultivars following 4 days of stress. With extended stress, exogenous spermidine reduced the accumulation of δ-aminolevulinic acid, porphobilinogen, and uroorphyrinogen III and increased the levels of protoporphyrin IX, Mg-protoporphyrin IX, and protochlorophyllide, suggesting that spermidine promotes the conversion of uroorphyrinogen III to protoporphyrin IX. The effect occurred earlier in cultivar Jinpengchaoguan than in cultivar Zhongza No. 9. Exogenous spermidine also alleviated the stress-induced increases in malondialdehyde content, superoxide radical generation rate, chlorophyllase activity, and expression of the chlorophyllase gene and the stress-induced decreases in the activities of antioxidant enzymes, antioxidants, and expression of the porphobilinogen deaminase gene. In addition, exogenous spermidine stabilized the chloroplast ultrastructure in stressed tomato seedlings. The tomato cultivars examined exhibited different

  9. Conference summaries

    International Nuclear Information System (INIS)

    1991-01-01

    This volume contains conference summaries for the 31. annual conference of the Canadian Nuclear Association and the 12. annual conference of the Canadian Nuclear Society. Topics of discussion include: reactor physics; thermalhydraulics; industrial irradiation; computer applications; fuel channel analysis; small reactors; severe accidents; fuel behaviour under accident conditions; reactor components, safety related computer software; nuclear fuel management; fuel behaviour and performance; reactor safety; reactor engineering; nuclear waste management; and, uranium mining and processing

  10. INTERCARTO CONFERENCES

    OpenAIRE

    Vladimir Tikunov

    2010-01-01

    The InterCarto conferences are thematically organized to target one of the most pressing problems of modern geography—creation and use of geographical information systems (GISs) as effective tools for achieving sustainable development of territories. Over the years, from 1994 to 2009, 1872 participants from 51 countries and 156 cities, who made 1494 reports, attended the conferences. There were 1508 participants from 49 regions of Russia making 1340 presentations. The conferences hosted 31 di...

  11. A New Player in the Biorefineries Field: Phasin PhaP Enhances Tolerance to Solvents and Boosts Ethanol and 1,3-Propanediol Synthesis in Escherichia coli.

    Science.gov (United States)

    Mezzina, Mariela P; Álvarez, Daniela S; Egoburo, Diego E; Díaz Peña, Rocío; Nikel, Pablo I; Pettinari, M Julia

    2017-07-15

    The microbial production of biofuels and other added-value chemicals is often limited by the intrinsic toxicity of these compounds. The phasin PhaP from the soil bacterium Azotobacter sp. strain FA8 is a polyhydroxyalkanoate granule-associated protein that protects recombinant Escherichia coli against several kinds of stress. PhaP enhances growth and poly(3-hydroxybutyrate) synthesis in polymer-producing recombinant strains and reduces the formation of inclusion bodies during overproduction of heterologous proteins. In this work, the heterologous expression of this phasin in E. coli was used as a strategy to increase tolerance to several biotechnologically relevant chemicals. PhaP was observed to enhance bacterial fitness in the presence of biofuels, such as ethanol and butanol, and other chemicals, such as 1,3-propanediol. The effect of PhaP was also studied in a groELS mutant strain, in which both GroELS and PhaP were observed to exert a beneficial effect that varied depending on the chemical tested. Lastly, the potential of PhaP and GroEL to enhance the accumulation of ethanol or 1,3-propanediol was analyzed in recombinant E. coli Strains that overexpressed either groEL or phaP had increased growth, reflected in a higher final biomass and product titer than the control strain. Taken together, these results add a novel application to the already multifaceted phasin protein group, suggesting that expression of these proteins or other chaperones can be used to improve the production of biofuels and other chemicals. IMPORTANCE This work has both basic and applied aspects. Our results demonstrate that a phasin with chaperone-like properties can increase bacterial tolerance to several biochemicals, providing further evidence of the diverse properties of these proteins. Additionally, both the PhaP phasin and the well-known chaperone GroEL were used to increase the biosynthesis of the biotechnologically relevant compounds ethanol and 1,3-propanediol in recombinant E

  12. Enhancing Sulfur Tolerance of Ni-Based Cermet Anodes of Solid Oxide Fuel Cells by Ytterbium-Doped Barium Cerate Infiltration.

    Science.gov (United States)

    Li, Meng; Hua, Bin; Luo, Jing-Li; Jiang, San Ping; Pu, Jian; Chi, Bo; Li, Jian

    2016-04-27

    Conventional anode materials for solid oxide fuel cells (SOFCs) are Ni-based cermets, which are highly susceptible to deactivation by contaminants in hydrocarbon fuels. Hydrogen sulfide is one of the commonly existed contaminants in readily available natural gas and gasification product gases of pyrolysis of biomasses. Development of sulfur tolerant anode materials is thus one of the critical challenges for commercial viability and practical application of SOFC technologies. Here we report a viable approach to enhance substantially the sulfur poisoning resistance of a Ni-gadolinia-doped ceria (Ni-GDC) anode through impregnation of proton conducting perovskite BaCe0.9Yb0.1O3-δ (BCYb). The impregnation of BCYb nanoparticles improves the electrochemical performance of the Ni-GDC anode in both H2 and H2S containing fuels. Moreover, more importantly, the enhanced stability is observed in 500 ppm of H2S/H2. The SEM and XPS analysis indicate that the infiltrated BCYb fine particles inhibit the adsorption of sulfur and facilitate sulfur removal from active sites, thus preventing the detrimental interaction between sulfur and Ni-GDC and the formation of cerium sulfide. The preliminary results of the cell with the BCYb+Ni-GDC anode in methane fuel containing 5000 ppm of H2S show the promising potential of the BCYb infiltration approach in the development of highly active and stable Ni-GDC-based anodes fed with hydrocarbon fuels containing a high concentration of sulfur compounds.

  13. Overexpression of SoCYP85A1, a Spinach Cytochrome p450 Gene in Transgenic Tobacco Enhances Root Development and Drought Stress Tolerance

    Directory of Open Access Journals (Sweden)

    Fangmeng Duan

    2017-11-01

    Full Text Available Brassinosteroids (BRs play an essential role in plant growth, development, and responses to diverse abiotic stresses. However, previous studies mainly analyzed how exogenous BRs influenced plant physiological reactions to drought stress, therefore, genetic evidences for the endogenous BRs-mediated regulation of plant responses still remain elusive. In this study, a key BRs biosynthetic gene, SoCYP85A1 was cloned from Spinacia oleracea, which has a complete open reading frame of 1,392 bp encoding a 464 amino acid peptide and shares high sequence similarities with CYP85A1 from other plants. The expression of SoCYP85A1 which was higher in leaf compared with root and stem, was induced by treatments of PEG6000, abscisic acid (ABA, low temperature and high salt. Increases in both SoCYP85A1 transcripts and endogenous BRs in transgenic tobacco which resulted in longer primary root and more lateral roots enhanced drought tolerance compared with wild types. The transgenic tobacco accumulated much lower levels of reactive oxygen species and malondialdehyde (MDA than wild types did, accompanied by significantly higher content of proline and notably enhanced activities of antioxidant enzymes. Besides, transcriptional expressions of six stress-responsive genes were regulated to higher levels in transgenic lines under drought stress. Taken together, our results demonstrated that SoCYP85A1 involves in response to drought stress by promoting root development, scavenging ROS, and regulating expressions of stress-responsive genes.

  14. Constitutive over-expression of rice chymotrypsin protease inhibitor gene OCPI2 results in enhanced growth, salinity and osmotic stress tolerance of the transgenic Arabidopsis plants.

    Science.gov (United States)

    Tiwari, Lalit Dev; Mittal, Dheeraj; Chandra Mishra, Ratnesh; Grover, Anil

    2015-07-01

    Protease inhibitors are involved primarily in defense against pathogens. In recent years, these proteins have also been widely implicated in response of plants to diverse abiotic stresses. Rice chymotrypsin protease inhibitor gene OCPI2 is highly induced under salt and osmotic stresses. The construct containing the complete coding sequence of OCPI2 cloned downstream to CaMV35S promoter was transformed in Arabidopsis and single copy, homozygous transgenic lines were produced. The transgenic plants exhibited significantly enhanced tolerance to NaCl, PEG and mannitol stress as compared to wild type plants. Importantly, the vegetative and reproductive growth of transgenic plants under unstressed, control conditions was also enhanced: transgenic plants were more vigorous than wild type, resulting into higher yield in terms of silique number. The RWC values and membrane stability index of transgenic in comparison to wild type plants was higher. Higher proline content was observed in the AtOCPI2 lines, which was associated with higher transcript expression of pyrroline-5-carboxylate synthase and lowered levels of proline dehydrogenase genes. The chymotrypsin protease activities were lower in the transgenic as against wild type plants, under both unstressed, control as well as stressed conditions. It thus appears that rice chymotrypsin protease inhibitor gene OCPI2 is a useful candidate gene for genetic improvement of plants against salt and osmotic stress. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  15. SlMAPK3 enhances tolerance to tomato yellow leaf curl virus (TYLCV) by regulating salicylic acid and jasmonic acid signaling in tomato (Solanum lycopersicum).

    Science.gov (United States)

    Li, Yunzhou; Qin, Lei; Zhao, Jingjing; Muhammad, Tayeb; Cao, Hehe; Li, Hailiang; Zhang, Yan; Liang, Yan

    2017-01-01

    Several recent studies have reported on the role of mitogen-activated protein kinase (MAPK3) in plant immune responses. However, little is known about how MAPK3 functions in tomato (Solanum lycopersicum L.) infected with tomato yellow leaf curl virus (TYLCV). There is also uncertainty about the connection between plant MAPK3 and the salicylic acid (SA) and jasmonic acid (JA) defense-signaling pathways. The results of this study indicated that SlMAPK3 participates in the antiviral response against TYLCV. Tomato seedlings were inoculated with TYLCV to investigate the possible roles of SlMAPK1, SlMAPK2, and SlMAPK3 against this virus. Inoculation with TYLCV strongly induced the expression and the activity of all three genes. Silencing of SlMAPK1, SlMAPK2, and SlMAPK3 reduced tolerance to TYLCV, increased leaf H2O2 concentrations, and attenuated expression of defense-related genes after TYLCV infection, especially in SlMAPK3-silenced plants. Exogenous SA and methyl jasmonic acid (MeJA) both significantly induced SlMAPK3 expression in tomato leaves. Over-expression of SlMAPK3 increased the transcript levels of SA/JA-mediated defense-related genes (PR1, PR1b/SlLapA, SlPI-I, and SlPI-II) and enhanced tolerance to TYLCV. After TYLCV inoculation, the leaves of SlMAPK3 over-expressed plants compared with wild type plants showed less H2O2 accumulation and greater superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) activity. Overall, the results suggested that SlMAPK3 participates in the antiviral response of tomato to TYLCV, and that this process may be through either the SA or JA defense-signaling pathways.

  16. SlMAPK3 enhances tolerance to tomato yellow leaf curl virus (TYLCV by regulating salicylic acid and jasmonic acid signaling in tomato (Solanum lycopersicum.

    Directory of Open Access Journals (Sweden)

    Yunzhou Li

    Full Text Available Several recent studies have reported on the role of mitogen-activated protein kinase (MAPK3 in plant immune responses. However, little is known about how MAPK3 functions in tomato (Solanum lycopersicum L. infected with tomato yellow leaf curl virus (TYLCV. There is also uncertainty about the connection between plant MAPK3 and the salicylic acid (SA and jasmonic acid (JA defense-signaling pathways. The results of this study indicated that SlMAPK3 participates in the antiviral response against TYLCV. Tomato seedlings were inoculated with TYLCV to investigate the possible roles of SlMAPK1, SlMAPK2, and SlMAPK3 against this virus. Inoculation with TYLCV strongly induced the expression and the activity of all three genes. Silencing of SlMAPK1, SlMAPK2, and SlMAPK3 reduced tolerance to TYLCV, increased leaf H2O2 concentrations, and attenuated expression of defense-related genes after TYLCV infection, especially in SlMAPK3-silenced plants. Exogenous SA and methyl jasmonic acid (MeJA both significantly induced SlMAPK3 expression in tomato leaves. Over-expression of SlMAPK3 increased the transcript levels of SA/JA-mediated defense-related genes (PR1, PR1b/SlLapA, SlPI-I, and SlPI-II and enhanced tolerance to TYLCV. After TYLCV inoculation, the leaves of SlMAPK3 over-expressed plants compared with wild type plants showed less H2O2 accumulation and greater superoxide dismutase (SOD, peroxidase (POD, catalase (CAT, and ascorbate peroxidase (APX activity. Overall, the results suggested that SlMAPK3 participates in the antiviral response of tomato to TYLCV, and that this process may be through either the SA or JA defense-signaling pathways.

  17. Epidermal transmittance and phenolic composition in leaves of atrazine-tolerant and atrazine-sensitive cultivars of Brassica napus grown under enhanced UV-B radiation

    International Nuclear Information System (INIS)

    Olsson, L.C.; Veit, M.; Bornman, J.F.

    1999-01-01

    Experiments were conducted on the atrazine-tolerant mutant Stallion and the atrazine-sensitive cv. Paroll of Brassica napus L., which were grown under either visible light or with the addition of UV-B radiation (280–320 nm) for 15 days. The mutant has been shown to be sensitive to high levels of visible light as compared to the atrazine-sensitive cultivar and therefore we wished to determine plant response to UV-B radiation with respect to potential pigment changes, certain anatomical features, radiation penetration and partial photosynthesis. With regard to pigment changes, we were particularly interested in whether the compositional shift in flavonol pigments under enhanced UV-B radiation, previously suggested to favour increased antioxidant activity, is confined to the adaxial epidermis, which generally receives most UV-B radiation or whether the pigment shift is also inducible in the abaxial epidermis.As was to be expected, the penetration of UV-B radiation (310 nm) was lower in the UV-B-exposed plants, which was correlated with an increased amount of UV-screening pigments in the adaxial and abaxial epidermal layers. The main flavonoid glycosides showed the largest shift from kaempferol to quercetin as aglycone moiety in the adaxial epidermal layer. However, in the abaxial epidermal layer the hydroxycinnamic acid (HCA) derivatives and kaempferol glycosides were predominant. Penetration of 430 nm light was higher after UV-B exposure, and probably contributed to the fact that photosynthetic efficiency of photosystem II was unchanged or higher after UV-B exposure. UV-B radiation decreased leaf area in the atrazine-tolerant mutant only. Both cultivars showed an increased leaf thickness after UV-B exposure due to cell elongation mainly of the palisade tissue. This was especially evident in the mutant

  18. Gm1-MMP is involved in growth and development of leaf and seed, and enhances tolerance to high temperature and humidity stress in transgenic Arabidopsis.

    Science.gov (United States)

    Liu, Sushuang; Liu, Yanmin; Jia, Yanhong; Wei, Jiaping; Wang, Shuang; Liu, Xiaolin; Zhou, Yali; Zhu, Yajing; Gu, Weihong; Ma, Hao

    2017-06-01

    Matrix metalloproteinases (MMPs) are a family of zinc- and calcium-dependent endopeptidases. Gm1-MMP was found to play an important role in soybean tissue remodeling during leaf expansion. In this study, Gm1-MMP was isolated and characterized. Its encoding protein had a relatively low phylogenetic relationship with the MMPs in other plant species. Subcellular localization indicated that Gm1-MMP was a plasma membrane protein. Gm1-MMP showed higher expression levels in mature leaves, old leaves, pods, and mature seeds, as well as was involved in the development of soybean seed. Additionally, it was involved in response to high temperature and humidity (HTH) stress in R7 leaves and seeds in soybean. The analysis of promoter of Gm1-MMP suggested that the fragment from -399 to -299 was essential for its promoter activity in response to HTH stress. The overexpression of Gm1-MMP in Arabidopsis affected the growth and development of leaves, enhanced leaf and developing seed tolerance to HTH stress and improved seed vitality. The levels of hydrogen peroxide (H 2 O 2 ) and ROS in transgenic Arabidopsis seeds were lower than those in wild type seeds under HTH stress. Gm1-MMP could interact with soybean metallothionein-II (GmMT-II), which was confirmed by analysis of yeast two-hybrid assay and BiFC assays. All the results indicated that Gm1-MMP plays an important role in the growth and development of leaves and seeds as well as in tolerance to HTH stress. It will be helpful for us understanding the functions of Gm1-MMP in plant growth and development, and in response to abiotic stresses. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Enhanced Glucose Tolerance and Pancreatic Beta Cell Function by Low Dose Aspirin in Hyperglycemic Insulin-Resistant Type 2 Diabetic Goto-Kakizaki (GK Rats

    Directory of Open Access Journals (Sweden)

    Layla Amiri

    2015-07-01

    . Conclusion: The improved glucose tolerance in ASA-treated GK rats may be associated with increased insulin responses due to the anti-inflammatory properties of ASA and enhanced nitric oxide (NO level which facilitated insulin signaling and energy utilization in target tissues. These results may have implications in determining the therapeutic use of ASA in insulin-resistant type 2 diabetes.

  20. Enhancement of pump absorption efficiency by bending and twisting of double clad rare earth doped fibers (Conference Presentation)

    Science.gov (United States)

    Koška, Pavel; Peterka, Pavel; Doya, Valérie; Aubrecht, Jan; Kasik, Ivan; Podrazký, Ondřej

    2017-05-01

    High-power operation of fiber lasers was enabled by the invention of cladding-pumping in a double-clad fiber structure. Because of existence of so called skew rays in the inner clad of the fiber, pump absorption saturates along the fiber and pumping becomes inefficient. First studies of pump absorption efficiency enhancement were focused on fibers with broken circular symmetry of inner cladding eliminating skew rays [1,2]. Later, techniques of unconventional fiber coiling were proposed [3]. However, theoretical studies were limited to the assumption of a straight fiber. Even recently, the rigorous model accounting for fiber bending and twisting was described [4-6]. It was found that bending of the fiber influences modal spectra of the pump radiation and twisting provides quite efficient mode-scrambling. These effects in a synergic manner significantly enhances pump absorption rate in double clad fibers and improves laser system efficiency. In our contribution we review results of numerical modelling of pump absorption in various types of double-clad fibers, e.g., with cross section shape of hexagon, stadium, and circle; two-fiber bundle (so-called GTWave fiber structure) a panda fibers are also analyzed. We investigate pump field modal spectra evolution in hexagonally shaped fiber in straight, bended, and simultaneously bended and twisted fiber which brings new quality to understanding of the mode-scrambling and pump absorption enhancement. Finally, we evaluate the impact of enhanced pump absorption on signal gain in the fiber. These results can have practical impact in construction of fiber lasers: with pump absorption efficiency optimized by our new model (the other models did not take into account fiber twist), the double-clad fiber of shorter length can be used in the fiber lasers and amplifiers. In such a way the harmful influence of background losses and nonlinear effects can be minimized. [1] Doya, V., Legrand, O., Mortessagne, F., "Optimized absorption in a

  1. 2nd CEAS Specialist Conference on Guidance, Navigation and Control

    CERN Document Server

    Mulder, Bob; Choukroun, Daniel; Kampen, Erik-Jan; Visser, Coen; Looye, Gertjan

    2013-01-01

    Following the successful 1st CEAS (Council of European Aerospace Societies) Specialist Conference on Guidance, Navigation and Control (CEAS EuroGNC) held in Munich, Germany in 2011, Delft University of Technology happily accepted the invitation of organizing the 2nd  CEAS EuroGNC in Delft, The Netherlands in 2013. The goal of the conference is to promote new advances in aerospace GNC theory and technologies for enhancing safety, survivability, efficiency, performance, autonomy and intelligence of aerospace systems using on-board sensing, computing and systems. A great push for new developments in GNC are the ever higher safety and sustainability requirements in aviation. Impressive progress was made in new research fields such as sensor and actuator fault detection and diagnosis, reconfigurable and fault tolerant flight control, online safe flight envelop prediction and protection, online global aerodynamic model identification, online global optimization and flight upset recovery. All of these challenges de...

  2. Enhancing Scientific Collaboration, Transparency, and Public Access: Utilizing the Second Life Platform to Convene a Scientific Conference in 3-D Virtual Space

    Science.gov (United States)

    McGee, B. W.

    2006-12-01

    Recent studies reveal a general mistrust of science as well as a distorted perception of the scientific method by the public at-large. Concurrently, the number of science undergraduate and graduate students is in decline. By taking advantage of emergent technologies not only for direct public outreach but also to enhance public accessibility to the science process, it may be possible to both begin a reversal of popular scientific misconceptions and to engage a new generation of scientists. The Second Life platform is a 3-D virtual world produced and operated by Linden Research, Inc., a privately owned company instituted to develop new forms of immersive entertainment. Free and downloadable to the public, Second Life offers an imbedded physics engine, streaming audio and video capability, and unlike other "multiplayer" software, the objects and inhabitants of Second Life are entirely designed and created by its users, providing an open-ended experience without the structure of a traditional video game. Already, educational institutions, virtual museums, and real-world businesses are utilizing Second Life for teleconferencing, pre-visualization, and distance education, as well as to conduct traditional business. However, the untapped potential of Second Life lies in its versatility, where the limitations of traditional scientific meeting venues do not exist, and attendees need not be restricted by prohibitive travel costs. It will be shown that the Second Life system enables scientific authors and presenters at a "virtual conference" to display figures and images at full resolution, employ audio-visual content typically not available to conference organizers, and to perform demonstrations or premier three-dimensional renderings of objects, processes, or information. An enhanced presentation like those possible with Second Life would be more engaging to non- scientists, and such an event would be accessible to the general users of Second Life, who could have an

  3. Enhanced salt stress tolerance of rice plants expressing a vacuolar H+-ATPase subunit c1 (SaVHAc1) gene from the halophyte grass Spartina alterniflora Löisel

    Science.gov (United States)

    The physiological role of a vacuolar ATPase subunit c1 (SaVHAc1) from a halophyte grass Spartina alterniflora was studied through its expression in rice. The SaVHAc1– expressing plants showed enhanced tolerance to salt stress than the wild-type plants, mainly through adjustments in early stage and p...

  4. Osmotic stress confers enhanced cell integrity to hydrostatic pressure but impairs growth in Alcanivorax borkumensis SK2

    Directory of Open Acces