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Sample records for salt stress tolerance

  1. Halophytes: Potential Resources for Salt Stress Tolerance Genes and Promoters

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    Avinash Mishra

    2017-05-01

    Full Text Available Halophytes have demonstrated their capability to thrive under extremely saline conditions and thus considered as one of the best germplasm for saline agriculture. Salinity is a worldwide problem, and the salt-affected areas are increasing day-by-day because of scanty rainfall, poor irrigation system, salt ingression, water contamination, and other environmental factors. The salinity stress tolerance mechanism is a very complex phenomenon, and some pathways are coordinately linked for imparting salinity tolerance. Though a number of salt responsive genes have been reported from the halophytes, there is always a quest for promising stress-responsive genes that can modulate plant physiology according to the salt stress. Halophytes such as Aeluropus, Mesembryanthemum, Suaeda, Atriplex, Thellungiella, Cakile, and Salicornia serve as a potential candidate for the salt-responsive genes and promoters. Several known genes like antiporters (NHX, SOS, HKT, VTPase, ion channels (Cl−, Ca2+, aquaporins, antioxidant encoding genes (APX, CAT, GST, BADH, SOD and some novel genes such as USP, SDR1, SRP etc. were isolated from halophytes and explored for developing stress tolerance in the crop plants (glycophytes. It is evidenced that stress triggers salt sensors that lead to the activation of stress tolerance mechanisms which involve multiple signaling proteins, up- or down-regulation of several genes, and finally the distinctive or collective effects of stress-responsive genes. In this review, halophytes are discussed as an excellent platform for salt responsive genes which can be utilized for developing salinity tolerance in crop plants through genetic engineering.

  2. Invasive Knotweeds are Highly Tolerant to Salt Stress

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    Rouifed, Soraya; Byczek, Coline; Laffray, Daniel; Piola, Florence

    2012-12-01

    Japanese knotweed s.l. are some of the most invasive plants in the world. Some genotypes are known to be tolerant to the saline concentrations found in salt marshes. Here we focus on tolerance to higher concentrations in order to assess whether the species are able to colonize and establish in highly stressful environments, or whether salt is an efficient management tool. In a first experiment, adult plants of Fallopia japonica, Fallopia × bohemica and Fallopia sachalinensis were grown under salt stress conditions by watering with saline concentrations of 6, 30, 120, or 300 g L-1 for three weeks to assess the response of the plants to a spill of salt. At the two highest concentrations, their leaves withered and fell. There were no effects on the aboveground parts at the lowest concentrations. Belowground dry weight and number of buds were reduced from 30 and 120 g L-1 of salt, respectively. In a second experiment, a single spraying of 120 g L-1 of salt was applied to individuals of F. × bohemica and their stems were clipped to assess the response to a potential control method. 60 % of the plants regenerated. Regeneration was delayed by the salt treatment and shoot growth slowed down. This study establishes the tolerance of three Fallopia taxa to strong salt stress, with no obvious differences between taxa. Their salt tolerance could be an advantage in their ability to colonize polluted environments and to survive to spills of salt.

  3. Salt Tolerant and Sensitive Rice Varieties Display Differential Methylome Flexibility under Salt Stress

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    Ferreira, Liliana J.; Azevedo, Vanessa; Maroco, João; Oliveira, M. Margarida; Santos, Ana Paula

    2015-01-01

    DNA methylation has been referred as an important player in plant genomic responses to environmental stresses but correlations between the methylome plasticity and specific traits of interest are still far from being understood. In this study, we inspected global DNA methylation levels in salt tolerant and sensitive rice varieties upon salt stress imposition. Global DNA methylation was quantified using the 5-methylcytosine (5mC) antibody and an ELISA-based technique, which is an affordable and quite pioneer assay in plants, and in situ imaging of methylation sites in interphase nuclei of tissue sections. Variations of global DNA methylation levels in response to salt stress were tissue- and genotype-dependent. We show a connection between a higher ability of DNA methylation adjustment levels and salt stress tolerance. The salt-tolerant rice variety Pokkali was remarkable in its ability to quickly relax DNA methylation in response to salt stress. In spite of the same tendency for reduction of global methylation under salinity, in the salt-sensitive rice variety IR29 such reduction was not statistically supported. In ‘Pokkali’, the salt stress-induced demethylation may be linked to active demethylation due to increased expression of DNA demethylases under salt stress. In ‘IR29’, the induction of both DNA demethylases and methyltransferases may explain the lower plasticity of DNA methylation. We further show that mutations for epigenetic regulators affected specific phenotypic parameters related to salinity tolerance, such as the root length and biomass. This work emphasizes the role of differential methylome flexibility between salt tolerant and salt sensitive rice varieties as an important player in salt stress tolerance, reinforcing the need to better understand the connection between epigenetic networks and plant responses to environmental stresses. PMID:25932633

  4. Salt Tolerant and Sensitive Rice Varieties Display Differential Methylome Flexibility under Salt Stress.

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    Liliana J Ferreira

    Full Text Available DNA methylation has been referred as an important player in plant genomic responses to environmental stresses but correlations between the methylome plasticity and specific traits of interest are still far from being understood. In this study, we inspected global DNA methylation levels in salt tolerant and sensitive rice varieties upon salt stress imposition. Global DNA methylation was quantified using the 5-methylcytosine (5mC antibody and an ELISA-based technique, which is an affordable and quite pioneer assay in plants, and in situ imaging of methylation sites in interphase nuclei of tissue sections. Variations of global DNA methylation levels in response to salt stress were tissue- and genotype-dependent. We show a connection between a higher ability of DNA methylation adjustment levels and salt stress tolerance. The salt-tolerant rice variety Pokkali was remarkable in its ability to quickly relax DNA methylation in response to salt stress. In spite of the same tendency for reduction of global methylation under salinity, in the salt-sensitive rice variety IR29 such reduction was not statistically supported. In 'Pokkali', the salt stress-induced demethylation may be linked to active demethylation due to increased expression of DNA demethylases under salt stress. In 'IR29', the induction of both DNA demethylases and methyltransferases may explain the lower plasticity of DNA methylation. We further show that mutations for epigenetic regulators affected specific phenotypic parameters related to salinity tolerance, such as the root length and biomass. This work emphasizes the role of differential methylome flexibility between salt tolerant and salt sensitive rice varieties as an important player in salt stress tolerance, reinforcing the need to better understand the connection between epigenetic networks and plant responses to environmental stresses.

  5. Male Gametophytic Screening of Citrus Genotypes for Salt Stress Tolerance

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    A. Barandan

    2016-07-01

    Full Text Available Citrus species are classified as a sensitive group of trees to salt stress, but the levels of their sensitivity or tolerance to salt are different among cultivars. In order to evaluate the effects of salinity stress on pollen germination of some citrus cultivars, an experiment was performed in factorial, based on completely randomized design in three replications with Cleopatra mandarin (Citrus reshni and Poncirus trifoliata as tolerant and sensitive controls along with 13 genotypes. Pollen grains of these genotypes were cultured in media containing different levels of sodium chloride (0, 0.87, 1.6, 2.4, 3.1 dS/m along with 15% sucrose, 0.7% agar and 100 mg/L boric acid. In order to understand the biochemical responses of pollen grains to salt stress, they were cultured in liquid media with three levels of salinity (i.e. 0, 0.87 and 1.6 dS/m and then the amounts of total protein and enzyme activities of superoxide dismutase (SOD and ascorbate peroxidase (APX were evaluated. Significant differences of pollen germination (P ≤ 0.01 were observed in different salinity levels, but there were no significant differences in pollen tube growth. Pollen germination in Cleopatra was greater in comparison to Poncirus trifoliate, indicating that Cleopatra is a tolerant cultivar. The amounts of total protein and enzyme activities of SOD and APX were influenced by genotypes, salinity levels and their interactions (P ≤ 0.01. Considering the fastness and accuracy of this type of experiment, the evaluation of citrus pollen responses may, potentially, be hired as an initial screening criteria for detecting salt-sensitive varieties from the tolerant citrus ones.

  6. Stress Tolerance Profiling of a Collection of Extant Salt-Tolerant Rice Varieties and Transgenic Plants Overexpressing Abiotic Stress Tolerance Genes

    National Research Council Canada - National Science Library

    Kurotani, Ken-ichi; Yamanaka, Kazumasa; Toda, Yosuke; Ogawa, Daisuke; Tanaka, Maiko; Kozawa, Hirotsugu; Nakamura, Hidemitsu; Hakata, Makoto; Ichikawa, Hiroaki; Hattori, Tsukaho; Takeda, Shin

    2015-01-01

    .... In this study, we investigated the profiles of stress tolerance of nine salt-tolerant rice varieties and transgenic rice lines carrying constitutively expressed genes that are potentially involved...

  7. Effects, tolerance mechanisms and management of salt stress in grain legumes.

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    Farooq, Muhammad; Gogoi, Nirmali; Hussain, Mubshar; Barthakur, Sharmistha; Paul, Sreyashi; Bharadwaj, Nandita; Migdadi, Hussein M; Alghamdi, Salem S; Siddique, Kadambot H M

    2017-09-01

    Salt stress is an ever-present threat to crop yields, especially in countries with irrigated agriculture. Efforts to improve salt tolerance in crop plants are vital for sustainable crop production on marginal lands to ensure future food supplies. Grain legumes are a fascinating group of plants due to their high grain protein contents and ability to fix biological nitrogen. However, the accumulation of excessive salts in soil and the use of saline groundwater are threatening legume production worldwide. Salt stress disturbs photosynthesis and hormonal regulation and causes nutritional imbalance, specific ion toxicity and osmotic effects in legumes to reduce grain yield and quality. Understanding the responses of grain legumes to salt stress and the associated tolerance mechanisms, as well as assessing management options, may help in the development of strategies to improve the performance of grain legumes under salt stress. In this manuscript, we discuss the effects, tolerance mechanisms and management of salt stress in grain legumes. The principal inferences of the review are: (i) salt stress reduces seed germination (by up to more than 50%) either by inhibiting water uptake and/or the toxic effect of ions in the embryo, (ii) salt stress reduces growth (by more than 70%), mineral uptake, and yield (by 12-100%) due to ion toxicity and reduced photosynthesis, (iii) apoplastic acidification is a good indicator of salt stress tolerance, (iv) tolerance to salt stress in grain legumes may develop through excretion and/or compartmentalization of toxic ions, increased antioxidant capacity, accumulation of compatible osmolytes, and/or hormonal regulation, (v) seed priming and nutrient management may improve salt tolerance in grain legumes, (vi) plant growth promoting rhizobacteria and arbuscular mycorrhizal fungi may help to improve salt tolerance due to better plant nutrient availability, and (vii) the integration of screening, innovative breeding, and the development of

  8. [Study on salt stress tolerance of Chrysanthemum morifolium 'Hangbaiju' and 'Huangju' and F1 seedlings].

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    Wang, Kangcai; Huang, Ying; Tang, Xingli; Li, Danxia

    2011-09-01

    To study the salt stress tolerance of Hongxinju, Huangju and F1 seedlings from orthogonal and reciprocal cross under different salt treatments. Grope for transmissibility of salt tolerance between parents and F1 seedlings, and relativity between flavone, chlorogenic acid contents and salt tolerance. The materials were put in 5 different concentrations of Hoagland nutrient solution (0, 40, 80, 120, 160 mmol x L(-1)) containing NaCl, keeping grads while raising the consistency of NaCl day by day. The injured leaf area per plant, proline, betaine, MDA, flavones and chlorogenic acid contents were measured and analyzed after treatment. As NaCl concentration was below 120 mmol x L(-1), the salt tolerance of Hongxinju was higher than that of Huangju, the salt tolerance of Hongxinju x Huangju higher than that of parents, the salt tolerance of Huangju x Hongxinju was at the level of parents. As NaCl concentration between 120 to 160 mmol x L(-1), the salt tolerance of Huangju was higher than that of Hongxinju, the salt tolerance of Huangju x Hongxinju higher than that of parents and the salt tolerance of Hongxinju x Huangju was at the level of parents. Salt tolerance of F1 is more influenced by female parent, relativity showed between flavonoids, chlorogenic acid contents and salt tolerance.

  9. Acclimation improves salt stress tolerance in Zea mays plants.

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    Pandolfi, Camilla; Azzarello, Elisa; Mancuso, Stefano; Shabala, Sergey

    2016-08-20

    Plants exposure to low level salinity activates an array of processes leading to an improvement of plant stress tolerance. Although the beneficial effect of acclimation was demonstrated in many herbaceous species, underlying mechanisms behind this phenomenon remain poorly understood. In the present study we have addressed this issue by investigating ionic mechanisms underlying the process of plant acclimation to salinity stress in Zea mays. Effect of acclimation were examined in two parallel sets of experiments: a growth experiment for agronomic assessments, sap analysis, stomatal conductance, chlorophyll content, and confocal laser scanning imaging; and a lab experiment for in vivo ion flux measurements from root tissues. Being exposed to salinity, acclimated plants (1) retain more K(+) but accumulate less Na(+) in roots; (2) have better vacuolar Na(+) sequestration ability in leaves and thus are capable of accumulating larger amounts of Na(+) in the shoot without having any detrimental effect on leaf photochemistry; and (3) rely more on Na(+) for osmotic adjustment in the shoot. At the same time, acclimation affect was not related in increased root Na(+) exclusion ability. It appears that even in a such salt-sensitive species as maize, Na(+) exclusion from uptake is of a much less importance compared with the efficient vacuolar Na(+) sequestration in the shoot. Copyright © 2016 Elsevier GmbH. All rights reserved.

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

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    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.

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

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    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.

  12. Salt Stess On Soybean Glycine Max L Merr Improving Salt Stress Tolerance Through Seed Priming

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    Maman Suryaman

    2017-08-01

    Full Text Available Soybean seeds rapidly deteriorate or loss of viability and vigor especially in stress conditions including by saline. This study was aimed to obtain the best seed viability and vigor of soybean treated by seed priming under salt stress. This study used a randomized completely block design with factorial pattern. First factor was the saline stress of NaCl concentration C which consisted of three levels c0 0 0.5 c1 c2 1.Second factor was the treatment of seed priming P that consisted of 4 levels p0 hydropriming p1 osmopriming p2 matripriming p3 vitamin priming. The experiment was repeated three times. Data collected consisted of germination capacity germination rate hypocotyl and epicotyl length the weight of seedling and the electrical conductivity. Data were analyzed by analysis of variance followed by Duncans multiple range test at 5 percent. The results showed that osmopriming matripriming and vitamin priming improved total germination and germination rate of soybean seeds under salinity stress while seed priming with hydropriming caused significantly the reduction of germination total and germination rate in salinity stress of 1 percent. Increased salinity stress from 0 to 1 percent caused a reduction in hypocotyl and epicotyl length different with osmopriming matripriming and vitamin priming that produced hypocotyl and epicotyl longer than hydropriming. In all seed primings increased salinity stress from 0 to 1 percent lowered the weight of seedlings and most drastic reduction of seedling weight occurred in seeds treated with hydropriming. Among seed priming treatments osmopriming matripriming and vitamin priming were more able to reduce membrane leakage compared to hydropriming as indicated by lower electrical conductivity rates contributing the increase in tolerance to salt stress and high in seed viability and vigor.

  13. Salt stress-induced changes in antioxidative defense system and proteome profiles of salt-tolerant and sensitive Frankia strains.

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    Srivastava, Amrita; Singh, Anumeha; Singh, Satya S; Mishra, Arun K

    2017-04-16

    An appreciation of comparative microbial survival is most easily done while evaluating their adaptive strategies during stress. In the present experiment, antioxidative and whole cell proteome variations based on spectrophotometric analysis and SDS-PAGE and 2-dimensional gel electrophoresis have been analysed among salt-tolerant and salt-sensitive Frankia strains. This is the first report of proteomic basis underlying salt tolerance in these newly isolated Frankia strains from Hippophae salicifolia D. Don. Salt-tolerant strain HsIi10 shows higher increment in the contents of superoxide dismutase, catalase and ascorbate peroxidase as compared to salt-sensitive strain HsIi8. Differential 2-DGE profile has revealed differential profiles for salt-tolerant and salt-sensitive strains. Proteomic confirmation of salt tolerance in the strains with inbuilt efficiency of thriving in nitrogen-deficient locales is a definite advantage for these microbes. This would be equally beneficial for improvement of soil nitrogen status. Efficient protein regulation in HsIi10 suggests further exploration for its potential use as biofertilizer in saline soils.

  14. Comparative study of wild and transformed salt tolerant bacterial strains on Triticum aestivum growth under salt stress

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    Shazia Afrasayab

    2010-12-01

    Full Text Available Eleven salt tolerant bacteria isolated from different sources (soil, plants and their transformed strains were used to study their influence on Triticum aestivum var. Inqlab-91 growth under salt (100 mM NaCl stress. Salt stress caused reduction in germination (19.4%, seedling growth (46% and fresh weight (39% in non-inoculated plants. In general, both wild and transformed strains stimulated germination, seedling growth and fresh weight in salt free and salt stressed conditions. At 100 mM NaCl, Staphylococcus xylosus ST-1 caused 25% increments in seedling length over respective control. Soluble protein content significantly enhanced (49% under salt stress as compared to salt free control. At 100 mM NaCl parental strain PT-5 resulted about 32% enhancement in protein content over respective control treatment. Salt stress induced the promotion of auxin content in seedlings. Overall, Bacillus subtilis HAa2 and transformed E. coli-SP-7-T, caused 33% and 30% increases in auxin content, respectively, were recorded under salt stress in comparison to control.

  15. Differential contribution of individual dehydrin genes from Physcomitrella patens to salt and osmotic stress tolerance.

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    Ruibal, Cecilia; Salamó, Imma Pérez; Carballo, Valentina; Castro, Alexandra; Bentancor, Marcel; Borsani, Omar; Szabados, László; Vidal, Sabina

    2012-07-01

    The moss Physcomitrella patens can withstand extreme environmental conditions including drought and salt stress. Tolerance to dehydration in mosses is thought to rely on efficient limitation of stress-induced cell damage and repair of cell injury upon stress relief. Dehydrin proteins (DHNs) are part of a conserved cell protecting mechanism in plants although their role in stress tolerance is not well understood. Four DHNs and two DHN-like proteins were identified in the predicted proteome of P. patens. Expression of PpDHNA and PpDHNB was induced by salt and osmotic stress and controlled by abscisic acid. Subcellular localization of the encoded proteins suggested that these dehydrins are localized in cytosol and accumulate near membranes during stress. Comparative analysis of dhnA and dhnB targeted knockout mutants of P. patens revealed that both genes play a role in cellular protection during salt and osmotic stress, although PpDHNA has a higher contribution to stress tolerance. Overexpression of PpDHNA and PpDHNB genes in transgenic Arabidopsis improved rosette and root growth in stress conditions, although PpDHNA was more efficient in this role. These results suggest that specific DHNs contribute considerably to the high stress tolerance of mosses and offer novel tools for genetic engineering stress tolerance of higher plants. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  16. A bi-functional xyloglucan galactosyltransferase is an indispensable salt stress tolerance determinant in arabidop

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    Li, Wenbo

    2013-07-01

    Salinity is an abiotic stress that substantially limits crop production worldwide. To identify salt stress tolerance determinants, we screened for Arabidopsis mutants that are hypersensitive to salt stress and designated these mutants as short root in salt medium (rsa). One of these mutants, rsa3-1, is hypersensitive to NaCl and LiCl but not to CsCl or to general osmotic stress. Reactive oxygen species (ROS) over-accumulate in rsa3-1 plants under salt stress. Gene expression profiling with Affymetrix microarray analysis revealed that RSA3 controls expression of many genes including genes encoding proteins for ROS detoxification under salt stress. Map-based cloning showed that RSA3 encodes a xyloglucan galactosyltransferase, which is allelic to a gene previously named MUR3/KAM1. The RSA3/ MUR3/KAM1-encoded xylogluscan galactosyltransferase regulates actin microfilament organization (and thereby contributes to endomembrane distribution) and is also involved in cell wall biosynthesis. In rsa3-1, actin cannot assemble and form bundles as it does in the wild-type but instead aggregates in the cytoplasm. Furthermore, addition of phalloidin, which prevents actin depolymerization, can rescue salt hypersensitivity of rsa3-1. Together, these results suggest that RSA3/MUR3/KAM1 along with other cell wall-associated proteins plays a critical role in salt stress tolerance by maintaining the proper organization of actin microfilaments in order to minimize damage caused by excessive ROS. © 2013 The Author.

  17. Comparative proteomics of contrasting maize genotypes provides insights into salt-stress tolerance mechanisms.

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    Luo, Meijie; Zhao, Yanxin; Wang, Yuandong; Shi, Zi; Zhang, Panpan; Zhang, Yunxia; Song, Wei; Zhao, Jiuran

    2017-12-01

    Salt stress is a major abiotic factor limiting maize yield. To characterize the mechanism underlying maize salt tolerance, we compared the seedling root proteomes of salt-tolerant Jing724 and salt-sensitive D9H. The germination rate and growth parameter values (weight and length) were higher for Jing724 than for D9H under saline conditions. Using an iTRAQ-based method, we identified 513 differentially regulated proteins (DRPs), with 83 and 386 DRPs specific to Jing724 and D9H, respectively. In salt-stressed Jing724, the DRPs were primarily associated with the pentose phosphate pathway, glutathione metabolism, and nitrogen metabolism. Key DRPs, such as glucose-6-phosphate 1-dehydrogenase, NADPH-producing dehydrogenase, glutamate synthase, and glutamine synthetase, were identified based on pathway enrichment and protein-protein interaction analyses. Moreover, salt-responsive proteins in Jing724 seedlings were implicated in energy management, maintenance of redox homeostasis, detoxification of ammonia, regulation of osmotic homeostasis, stress defense and adaptation, biotic cross-tolerance, and regulation of gene expression. Quantitative analyses of superoxide dismutase activity, malondialdehyde content, relative electrolyte leakage, and proline content were consistent with the predicted changes based on DRP functions. Furthermore, changes in the abundance of eight representative DRPs were correlated with the corresponding mRNA levels. Our results may be useful for elucidating the molecular networks mediating salt tolerance.

  18. Transcriptome analysis reveals that distinct metabolic pathways operate in salt-tolerant and salt-sensitive upland cotton varieties subjected to salinity stress.

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    Guo, Jinyan; Shi, Gongyao; Guo, Xiaoyan; Zhang, Liwei; Xu, Wenying; Wang, Yumei; Su, Zhen; Hua, Jinping

    2015-09-01

    Salinity stress is one of the most devastating abiotic stresses in crop plants. As a moderately salt-tolerant crop, upland cotton (Gossypium hirsutum L.) is a major cash crop in saline areas and a suitable model for salt stress tolerance research. In this study, we compared the transcriptome changes between the salt-tolerant upland cotton cultivar Zhong 07 and salt-sensitive cultivar Zhong G5 in response to NaCl treatments. Transcriptional regulation, signal transduction and secondary metabolism in two varieties showed significant differences, all of which might be related to mechanisms underlying salt stress tolerance. The transcriptional profiles presented here provide a foundation for deciphering the mechanism underlying salt tolerance. Based on our findings, we proposed several candidate genes that might be used to improve salt tolerance in upland cotton. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. Comparative metabolite profiling of two rice genotypes with contrasting salt stress tolerance at the seedling stage.

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    Xiuqin Zhao

    Full Text Available BACKGROUND: Rice is sensitive to salt stress, especially at the seedling stage, with rice varieties differing remarkably in salt tolerance (ST. To understand the physiological mechanisms of ST, we investigated salt stress responses at the metabolite level. METHODS: Gas chromatography-mass spectrometry was used to profile metabolite changes in the salt-tolerant line FL478 and the sensitive variety IR64 under a salt-stress time series. Additionally, several physiological traits related to ST were investigated. RESULTS: We characterized 92 primary metabolites in the leaves and roots of the two genotypes under stress and control conditions. The metabolites were temporally, tissue-specifically and genotype-dependently regulated under salt stress. Sugars and amino acids (AAs increased significantly in the leaves and roots of both genotypes, while organic acids (OAs increased in roots and decreased in leaves. Compared with IR64, FL478 experienced greater increases in sugars and AAs and more pronounced decreases in OAs in both tissues; additionally, the maximum change in sugars and AAs occurred later, while OAs changed earlier. Moreover, less Na+ and higher relative water content were observed in FL478. Eleven metabolites, including AAs and sugars, were specifically increased in FL478 over the course of the treatment. CONCLUSIONS: Metabolic responses of rice to salt stress are dynamic and involve many metabolites. The greater ST of FL478 is due to different adaptive reactions at different stress times. At early salt-stress stages, FL478 adapts to stress by decreasing OA levels or by quickly depressing growth; during later stages, more metabolites are accumulated, thereby serving as compatible solutes against osmotic challenge induced by salt stress.

  20. Comparative Metabolite Profiling of Two Rice Genotypes with Contrasting Salt Stress Tolerance at the Seedling Stage

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    Zhang, Fan; Deng, Jianli; Li, Zhikang; Fu, Binying

    2014-01-01

    Background Rice is sensitive to salt stress, especially at the seedling stage, with rice varieties differing remarkably in salt tolerance (ST). To understand the physiological mechanisms of ST, we investigated salt stress responses at the metabolite level. Methods Gas chromatography-mass spectrometry was used to profile metabolite changes in the salt-tolerant line FL478 and the sensitive variety IR64 under a salt-stress time series. Additionally, several physiological traits related to ST were investigated. Results We characterized 92 primary metabolites in the leaves and roots of the two genotypes under stress and control conditions. The metabolites were temporally, tissue-specifically and genotype-dependently regulated under salt stress. Sugars and amino acids (AAs) increased significantly in the leaves and roots of both genotypes, while organic acids (OAs) increased in roots and decreased in leaves. Compared with IR64, FL478 experienced greater increases in sugars and AAs and more pronounced decreases in OAs in both tissues; additionally, the maximum change in sugars and AAs occurred later, while OAs changed earlier. Moreover, less Na+ and higher relative water content were observed in FL478. Eleven metabolites, including AAs and sugars, were specifically increased in FL478 over the course of the treatment. Conclusions Metabolic responses of rice to salt stress are dynamic and involve many metabolites. The greater ST of FL478 is due to different adaptive reactions at different stress times. At early salt-stress stages, FL478 adapts to stress by decreasing OA levels or by quickly depressing growth; during later stages, more metabolites are accumulated, thereby serving as compatible solutes against osmotic challenge induced by salt stress. PMID:25265195

  1. Seed priming and transgenerational drought memory improves tolerance against salt stress in bread wheat.

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    Tabassum, Tahira; Farooq, Muhammad; Ahmad, Riaz; Zohaib, Ali; Wahid, Abdul

    2017-09-01

    This study was conducted to evaluate the potential of seed priming following terminal drought on tolerance against salt stress in bread wheat. Drought was imposed in field sown wheat at reproductive stage (BBCH growth stage 49) and was maintained till physiological maturity (BBCH growth stage 83). Seeds of bread wheat, collected from crop raised under terminal drought and/or well-watered conditions, were subjected to hydropriming and osmopriming (with 1.5% CaCl2) and were sown in soil-filled pots. After stand establishment, salt stress treatments viz. 10 mM NaCl (control) and 100 mM NaCl were imposed. Seed from terminal drought stressed source had less fat (5%), and more fibers (11%), proteins (22%) and total soluble phenolics (514%) than well-watered seed source. Salt stress reduced the plant growth, perturbed water relations and decreased yield. However, an increase in osmolytes accumulation (4-18%), malondialdehyde (MDA) (27-35%) and tissue Na+ contents (149-332%) was observed under salt stress. The seeds collected from drought stressed crop had better tolerance against salt stress as indicated by better yield (28%), improved water relations (3-18%), osmolytes accumulation (21-33%), and less MDA (8%) and Na contents (35%) than progeny of well-watered crop. Seed priming, osmopriming in particular, further improved the tolerance against salt stress through improvement in leaf area, water relations, leaf proline, glycine betaine and grain yield while lowering MDA and Na+ contents. In conclusion, changed seed composition during terminal drought and seed priming improved the salt tolerance in wheat by modulating the water relations, osmolytes accumulation and lipid peroxidation. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

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

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    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.

  3. The Populus trichocarpa PtHSP17.8 involved in heat and salt stress tolerances.

    Science.gov (United States)

    Li, Jianbo; Zhang, Jin; Jia, Huixia; Li, Yu; Xu, Xiangdong; Wang, Lijuan; Lu, Mengzhu

    2016-08-01

    PtHSP17.8 was regulated by various abiotic stresses. Overexpression of PtHSP17.8 enhanced the tolerance to heat and salt stresses through maintain ROS homeostasis and cooperate with stress-related genes in Arabidopsis. Small heat shock proteins (sHSPs) play important roles in response to diverse biotic and abiotic stresses, especially in heat tolerance. However, limited information is available on the stress tolerance roles of sHSPs in woody species. To explore the function of sHSPs in poplar, we isolated and characterized PtHSP17.8 from Populus trichocarpa. Phylogenetic analysis and subcellular localization revealed that PtHSP17.8 was a cytosolic class I sHSP. The gene expression profile of PtHSP17.8 in various tissues showed that it was significantly accumulated in stem and root, which was consistent with the GUS expression pattern driven by promoter of PtHSP17.8. The expression of PtHSP17.8 could be induced by various abiotic stresses and significantly activated by heat stress. Overexpression of PtHSP17.8 enhanced the tolerance to heat and salt stresses in Arabidopsis. The seedling survival rate, root length, relative water content, antioxidative enzyme activities, proline, and soluble sugar content were increased in transgenic Arabidopsis under heat and salt stresses, but not in normal condition. The co-expression network of PtHSP17.8 were constructed and demonstrated many stress responsive genes included. The stress-related genes in the co-expression network were up-regulated in the PtHSP17.8 overexpression seedlings. These results suggest that PtHSP17.8 confers heat and salt tolerances in plants.

  4. Potassium Retention under Salt Stress Is Associated with Natural Variation in Salinity Tolerance among Arabidopsis Accessions.

    Directory of Open Access Journals (Sweden)

    Yanling Sun

    Full Text Available Plants are exposed to various environmental stresses during their life cycle such as salt, drought and cold. Natural variation mediated plant growth adaptation has been employed as an effective approach in response to the diverse environmental cues such as salt stress. However, the molecular mechanism underlying this process is not well understood. In the present study, a collection of 82 Arabidopsis thaliana accessions (ecotypes was screened with a view to identify variation for salinity tolerance. Seven accessions showed a higher level of tolerance than Col-0. The young seedlings of the tolerant accessions demonstrated a higher K(+ content and a lower Na(+/K(+ ratio when exposed to salinity stress, but its Na(+ content was the same as that of Col-0. The K(+ transporter genes AtHAK5, AtCHX17 and AtKUP1 were up-regulated significantly in almost all the tolerant accessions, even in the absence of salinity stress. There was little genetic variation or positive transcriptional variation between the selections and Col-0 with respect to Na+-related transporter genes, as AtSOS genes, AtNHX1 and AtHKT1;1. In addition, under salinity stress, these selections accumulated higher compatible solutes and lower reactive oxygen species than did Col-0. Taken together, our results showed that natural variation in salinity tolerance of Arabidopsis seems to have been achieved by the strong capacity of K(+ retention.

  5. Overexpression of SDH confers tolerance to salt and osmotic stress, but decreases ABA sensitivity in Arabidopsis.

    Science.gov (United States)

    Shi, Xiao-Pu; Ren, Jing-Jing; Yu, Qin; Zhou, Shu-Mei; Ren, Qiu-Ping; Kong, Lan-Jing; Wang, Xiu-Ling

    2017-11-10

    Sorbitol dehydrogenase (SDH) catalyzes the reversible oxidation of sorbitol, xylitol and ribitol to their corresponding ketoses. In this study, we investigated the expression and role of Arabidopsis SDH in salt and osmotic stress tolerance, and abscisic acid (ABA) response. The expression patterns of SDH were investigated using transgenic Arabidopsis plants expressing beta-glucuronidase (GUS) under the control of promoter with the first intron of SDH. qRT-PCR and histochemical assay of GUS activity were used to study SDH expression regulation by ABA, salt and osmotic stress. The SDH-overexpression lines of Arabidopsis were used to investigate the role of SDH involved in salt and osmotic stress, and ABA response. Arabidopsis SDH was predominantly expressed in source organs such as green cotyledons, fully expanded leaves and sepals, especially in the vascular tissues of theses organs. The SDH expression was inhibited by NaCl and mannitol treatments. Seed germination and post-germination growth of SDH-overexpressing lines exhibited decreased sensitivity toward salt and osmotic stress compared to wild-type plants. The transcript of SDH was induced by ABA. Overexpression of SDH decreased sensitivity to ABA during seed germination and post-germination growth. Expression of AAO3 was increased but ABI5 and MYB2 was decreased in SDH-overexpressing lines after ABA treatment. This study demonstrated that the expression of SDH is regulated by ABA, salt and osmotic stress. SDH functions in plant tolerance to salt and osmotic stress, and ABA response via specific regulating gene expression of ABA synthesis and signaling in Arabidopsis. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  6. The Arabidopsis RNA-Binding Protein AtRGGA Regulates Tolerance to Salt and Drought Stress

    KAUST Repository

    Ambrosone, Alfredo

    2015-03-17

    Salt and drought stress severely reduce plant growth and crop productivity worldwide. The identification of genes underlying stress response and tolerance is the subject of intense research in plant biology. Through microarray analyses, we previously identified in potato (Solanum tuberosum) StRGGA, coding for an Arginine Glycine Glycine (RGG) box-containing RNA-binding protein, whose expression was specifically induced in potato cell cultures gradually exposed to osmotic stress. Here, we show that the Arabidopsis (Arabidopsis thaliana) ortholog, AtRGGA, is a functional RNA-binding protein required for a proper response to osmotic stress. AtRGGA gene expression was up-regulated in seedlings after long-term exposure to abscisic acid (ABA) and polyethylene glycol, while treatments with NaCl resulted in AtRGGA down-regulation. AtRGGA promoter analysis showed activity in several tissues, including stomata, the organs controlling transpiration. Fusion of AtRGGA with yellow fluorescent protein indicated that AtRGGA is localized in the cytoplasm and the cytoplasmic perinuclear region. In addition, the rgga knockout mutant was hypersensitive to ABA in root growth and survival tests and to salt stress during germination and at the vegetative stage. AtRGGA-overexpressing plants showed higher tolerance to ABA and salt stress on plates and in soil, accumulating lower levels of proline when exposed to drought stress. Finally, a global analysis of gene expression revealed extensive alterations in the transcriptome under salt stress, including several genes such as ASCORBATE PEROXIDASE2, GLUTATHIONE S-TRANSFERASE TAU9, and several SMALL AUXIN UPREGULATED RNA-like genes showing opposite expression behavior in transgenic and knockout plants. Taken together, our results reveal an important role of AtRGGA in the mechanisms of plant response and adaptation to stress.

  7. Isolation and characterization of maize PMP3 genes involved in salt stress tolerance.

    Directory of Open Access Journals (Sweden)

    Jing Fu

    Full Text Available Plasma membrane protein 3 (PMP3, a class of small hydrophobic polypeptides with high sequence similarity, is responsible for salt, drought, cold, and abscisic acid. These small hydrophobic ploypeptides play important roles in maintenance of ion homeostasis. In this study, eight ZmPMP3 genes were cloned from maize and responsive to salt, drought, cold and abscisic acid. The eight ZmPMP3s were membrane proteins and their sequences in trans-membrane regions were highly conserved. Phylogenetic analysis showed that they were categorized into three groups. All members of group II were responsive to ABA. Functional complementation showed that with the exception of ZmPMP3-6, all were capable of maintaining membrane potential, which in turn allows for regulation of intracellular ion homeostasis. This process was independent of the presence of Ca(2+. Lastly, over-expression of ZmPMP3-1 enhanced growth of transgenic Arabidopsis under salt condition. Through expression analysis of deduced downstream genes in transgenic plants, expression levels of three ion transporter genes and four important antioxidant genes in ROS scavenging system were increased significantly in transgenic plants during salt stress. This tolerance was likely achieved through diminishing oxidative stress due to the possibility of ZmPMP3-1's involvement in regulation of ion homeostasis, and suggests that the modulation of these conserved small hydrophobic polypeptides could be an effective way to improve salt tolerance in plants.

  8. 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.

  9. Exogenous jasmonic acid can enhance tolerance of wheat seedlings to salt stress.

    Science.gov (United States)

    Qiu, ZongBo; Guo, JunLi; Zhu, AiJing; Zhang, Liang; Zhang, ManMan

    2014-06-01

    Jasmonic acid (JA) is regarded as endogenous regulator that plays an important role in regulating stress responses, plant growth and development. To investigate the physiological mechanisms of salt stress mitigated by exogenous JA, foliar application of 2mM JA was done to wheat seedlings for 3days and then they were subjected to 150mM NaCl. Our results showed that 150mM NaCl treatment significantly decreased plant height, root length, shoot dry weight, root dry weight, the concentration of glutathione (GSH), chlorophyll b (Chl b) and carotenoid (Car), the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), enhanced the concentration of malondialdehyde (MDA), hydrogen peroxide (H2O2) and the rate of superoxide radical (O2•-) generation in the wheat seedlings when compared with the control. However, treatments with exogenous JA for 3 days significantly enhanced salt stress tolerance in wheat seedlings by decreasing the concentration of MDA and H2O2, the production rate of O2•- and increasing the transcript levels and activities of SOD, POD, CAT and APX and the contents of GSH, Chl b and Car, which, in turn, enhanced the growth of salt stressed seedlings. These results suggested that JA could effectively protect wheat seedlings from salt stress damage by enhancing activities of antioxidant enzymes and the concentration of antioxidative compounds to quench the excessive reactive oxygen species caused by salt stress and presented a practical implication for wheat cultivation in salt-affected soils. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. An Arabidopsis mitochondrial uncoupling protein confers tolerance to drought and salt stress in transgenic tobacco plants.

    Directory of Open Access Journals (Sweden)

    Kevin Begcy

    Full Text Available BACKGROUND: Plants are challenged by a large number of environmental stresses that reduce productivity and even cause death. Both chloroplasts and mitochondria produce reactive oxygen species under normal conditions; however, stress causes an imbalance in these species that leads to deviations from normal cellular conditions and a variety of toxic effects. Mitochondria have uncoupling proteins (UCPs that uncouple electron transport from ATP synthesis. There is evidence that UCPs play a role in alleviating stress caused by reactive oxygen species overproduction. However, direct evidence that UCPs protect plants from abiotic stress is lacking. METHODOLOGY/PRINCIPAL FINDINGS: Tolerances to salt and water deficit were analyzed in transgenic tobacco plants that overexpress a UCP (AtUCP1 from Arabidopsis thaliana. Seeds of AtUCP1 transgenic lines germinated faster, and adult plants showed better responses to drought and salt stress than wild-type (WT plants. These phenotypes correlated with increased water retention and higher gas exchange parameters in transgenic plants that overexpress AtUCP1. WT plants exhibited increased respiration under stress, while transgenic plants were only slightly affected. Furthermore, the transgenic plants showed reduced accumulation of hydrogen peroxide in stressed leaves compared with WT plants. CONCLUSIONS/SIGNIFICANCE: Higher levels of AtUCP1 improved tolerance to multiple abiotic stresses, and this protection was correlated with lower oxidative stress. Our data support previous assumptions that UCPs reduce the imbalance of reactive oxygen species. Our data also suggest that UCPs may play a role in stomatal closure, which agrees with other evidence of a direct relationship between these proteins and photosynthesis. Manipulation of the UCP protein expression in mitochondria is a new avenue for crop improvement and may lead to crops with greater tolerance for challenging environmental conditions.

  11. An Arabidopsis Mitochondrial Uncoupling Protein Confers Tolerance to Drought and Salt Stress in Transgenic Tobacco Plants

    Science.gov (United States)

    Begcy, Kevin; Mariano, Eduardo D.; Mattiello, Lucia; Nunes, Alessandra V.; Mazzafera, Paulo; Maia, Ivan G.; Menossi, Marcelo

    2011-01-01

    Background Plants are challenged by a large number of environmental stresses that reduce productivity and even cause death. Both chloroplasts and mitochondria produce reactive oxygen species under normal conditions; however, stress causes an imbalance in these species that leads to deviations from normal cellular conditions and a variety of toxic effects. Mitochondria have uncoupling proteins (UCPs) that uncouple electron transport from ATP synthesis. There is evidence that UCPs play a role in alleviating stress caused by reactive oxygen species overproduction. However, direct evidence that UCPs protect plants from abiotic stress is lacking. Methodology/Principal Findings Tolerances to salt and water deficit were analyzed in transgenic tobacco plants that overexpress a UCP (AtUCP1) from Arabidopsis thaliana. Seeds of AtUCP1 transgenic lines germinated faster, and adult plants showed better responses to drought and salt stress than wild-type (WT) plants. These phenotypes correlated with increased water retention and higher gas exchange parameters in transgenic plants that overexpress AtUCP1. WT plants exhibited increased respiration under stress, while transgenic plants were only slightly affected. Furthermore, the transgenic plants showed reduced accumulation of hydrogen peroxide in stressed leaves compared with WT plants. Conclusions/Significance Higher levels of AtUCP1 improved tolerance to multiple abiotic stresses, and this protection was correlated with lower oxidative stress. Our data support previous assumptions that UCPs reduce the imbalance of reactive oxygen species. Our data also suggest that UCPs may play a role in stomatal closure, which agrees with other evidence of a direct relationship between these proteins and photosynthesis. Manipulation of the UCP protein expression in mitochondria is a new avenue for crop improvement and may lead to crops with greater tolerance for challenging environmental conditions. PMID:21912606

  12. A Benzimidazole Proton Pump Inhibitor Increases Growth and Tolerance to Salt Stress in Tomato

    Directory of Open Access Journals (Sweden)

    Michael J. Van Oosten

    2017-07-01

    Full Text Available Pre-treatment of tomato plants with micromolar concentrations of omeprazole (OP, a benzimidazole proton pump inhibitor in mammalian systems, improves plant growth in terms of fresh weight of shoot and roots by 49 and 55% and dry weight by 54 and 105% under salt stress conditions (200 mM NaCl, respectively. Assessment of gas exchange, ion distribution, and gene expression profile in different organs strongly indicates that OP interferes with key components of the stress adaptation machinery, including hormonal control of root development (improving length and branching, protection of the photosynthetic system (improving quantum yield of photosystem II and regulation of ion homeostasis (improving the K+:Na+ ratio in leaves and roots. To our knowledge OP is one of the few known molecules that at micromolar concentrations manifests a dual function as growth enhancer and salt stress protectant. Therefore, OP can be used as new inducer of stress tolerance to better understand molecular and physiological stress adaptation paths in plants and to design new products to improve crop performance under suboptimal growth conditions.Highlight: Omeprazole enhances growth of tomato and increases tolerance to salinity stress through alterations of gene expression and ion uptake and transport.

  13. Soil bacteria conferred a positive relationship and improved salt stress tolerance in transgenic pea (Pisum sativum L.) harboring Na+/H+ antiporter

    OpenAIRE

    ALI, ZAHID; ULLAH, NASR; NASEEM, SAADIA; HAQ, MUHAMMAD INAM UL; JACOBSEN, HANS JOERG

    2015-01-01

    Among grain legumes, peas (Pisum sativum L.) are highly sensitive to salt stress. Acclimatization of plants to such conditions is mandatory. We provide improved salt stress tolerance response of transgenic pea plants overexpressing the Na+/H+ gene from Arabidopsis thaliana and a positive association with salt-tolerant plant growth-promoting rhizobacteria (PGPR). In addition to salt stress tolerance and phosphate solubilization, the selected rhizobacterial isolates were identified for indole a...

  14. 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.

  15. Interactive role of nitric oxide and calcium chloride in enhancing tolerance to salt stress.

    Science.gov (United States)

    Khan, M Nasir; Siddiqui, Manzer H; Mohammad, Firoz; Naeem, M

    2012-12-01

    Nitric oxide (NO), a small diffusible, ubiquitous bioactive molecule, acts as prooxidant as well as antioxidant, and also regulates remarkable spectrum of plant cellular mechanisms. The present work was undertaken to investigate the role of nitric oxide donor sodium nitroprusside (SNP) and/or calcium chloride (CaCl(2)) in the tolerance of excised mustard leaves to salt stress. After 24h, salt stressed leaves treated with SNP and/or CaCl(2), showed an improvement in the activities of carbonic anhydrase (CA) and nitrate reductase (NR), and leaf chlorophyll (Chl) content, leaf relative water content (LRWC) and leaf ion concentration as compared with the leaves treated with NaCl only. Salinity stress caused a significant increase in H(2)O(2) content and membrane damage which is witnessed by enhanced levels of thiobarbituric acid reactive substances (TBARS) and electrolyte leakage. By contrast, such increases were blocked by the application of 0.2mM SNP and 10mM CaCl(2) to salt stressed leaves. Application of SNP and/or CaCl(2) alleviated NaCl stress by enhancing the activities of antioxidative enzymes viz. superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), ascorbate peroxidase (APX) and glutathione reductase (GR) and by enhancing proline (Pro) and glycinebetaine (GB) accumulation with a concomitant decrease in H(2)O(2) content, TBARS and electrolyte leakage, which is manifested in the tolerance of plants to salinity stress. Moreover, application of SNP with CaCl(2) was more effective to reduce the detrimental effects of NaCl stress on excised mustard leaves. In addition to this, ameliorating effect of SNP was not effective in presence of NO scavenger cPTIO [2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide]. To put all these in a nut shell, the results advocate that SNP in association with CaCl(2) plays a role in enhancing the tolerance of plants to salt stress by improving antioxidative defence system, osmolyte accumulation and ionic

  16. Spliceosomal protein U1A is involved in alternative splicing and salt stress tolerance in Arabidopsis thaliana

    KAUST Repository

    Gu, Jinbao

    2017-12-01

    Soil salinity is a significant threat to sustainable agricultural production worldwide. Plants must adjust their developmental and physiological processes to cope with salt stress. Although the capacity for adaptation ultimately depends on the genome, the exceptional versatility in gene regulation provided by the spliceosome-mediated alternative splicing (AS) is essential in these adaptive processes. However, the functions of the spliceosome in plant stress responses are poorly understood. Here, we report the in-depth characterization of a U1 spliceosomal protein, AtU1A, in controlling AS of pre-mRNAs under salt stress and salt stress tolerance in Arabidopsis thaliana. The atu1a mutant was hypersensitive to salt stress and accumulated more reactive oxygen species (ROS) than the wild-type under salt stress. RNA-seq analysis revealed that AtU1A regulates AS of many genes, presumably through modulating recognition of 5′ splice sites. We showed that AtU1A is associated with the pre-mRNA of the ROS detoxification-related gene ACO1 and is necessary for the regulation of ACO1 AS. ACO1 is important for salt tolerance because ectopic expression of ACO1 in the atu1a mutant can partially rescue its salt hypersensitive phenotype. Our findings highlight the critical role of AtU1A as a regulator of pre-mRNA processing and salt tolerance in plants.

  17. Screening for Abiotic Stress Tolerance in Rice: Salt, Cold, and Drought.

    Science.gov (United States)

    Almeida, Diego M; Almadanim, M Cecília; Lourenço, Tiago; Abreu, Isabel A; Saibo, Nelson J M; Oliveira, M Margarida

    2016-01-01

    Rice (Oryza sativa) is the primary source of food for more than half of the world population. Most rice varieties are severely injured by abiotic stresses, with strong social and economic impact. Understanding rice responses to stress may help breeding for more tolerant varieties. However, papers dealing with stress experiments often describe very different experimental designs, thus making comparisons difficult. The use of identical setups is the only way to generate comparable data. This chapter is organized into three sections, describing the experimental conditions established at the Genomics of Plant Stress (GPlantS) unit of ITQB to assess the response of rice plants to three different abiotic stresses--high salinity, cold stress, and drought. All sections include a detailed description of the materials and methodology, as well as useful notes gathered from the GPlantS team's experience. We use rice seedlings as plants at this stage show high sensitivity to abiotic stresses. For the salt and cold stress assays we use hydroponic cultures, while for the drought assay plants are grown in soil and subjected to water withholding. All setups enable visual score determination and are suitable for sample collection along the imposition of stress. The proposed methodologies are simple and affordable to implement in most labs, allowing the discrimination of several rice genotypes at the molecular and phenotypic level.

  18. Genetic engineering of the biosynthesis of glycinebetaine leads to increased tolerance of photosynthesis to salt stress in transgenic tobacco plants.

    Science.gov (United States)

    Yang, Xinghong; Liang, Zheng; Wen, Xiaogang; Lu, Congming

    2008-01-01

    Genetically engineered tobacco (Nicotiana tabacum L.) with the ability to synthesis glycinebetaine (GB) in chloroplasts was established by introducing the BADH gene for betaine aldehyde dehydrogenase from spinach (Spinacia oleracea L.). The genetic engineering resulted in enhanced tolerance of growth of young seedlings to salt stress. This increased tolerance was not due to improved water status, since there were no significant differences in accumulation of sodium and chloride, leaf water potential, and relative water content between wild type and transgenic plants under salt stress. Salt stress resulted in a decrease in CO2 assimilation and such a decrease was much greater in wild type plants than in transgenic plants. Though salt stress showed no damage to PSII, there were a decrease in the maximal PSII electron transport rate in vivo and an increase in non-photochemical quenching (NPQ) and these changes were greater in wild type plants than in transgenic plants. In addition, salt stress inhibited the activities of ribulose 1,5-bisphosphate carboxylase/oxygenase, chloroplastic fructose-1,6-bisphosphatase, fructose-1,6-bisphosphate aldolase, and phosphoribulokinase and such a decrease was also greater in wild type plants than in transgenic plants, suggesting that GB protects these enzymes against salt stress. However, there were no significant changes in the activities of phosphoglycerate kinase, triose phosphate isomerase, ribulose-5-phosphate isomerase, transketolase, and sedoheptulose-1,7-bisphosphatase in both wild type and transgenic plants. The results in this study suggest that enhanced tolerance of CO2 assimilation to salt stress may be one of physiological bases for increased tolerance of growth of transgenic plants to salt stress.

  19. 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.

  20. Physiological Basis for the Tolerance of Yeast Zygosaccharomyces bisporus to Salt Stress

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    Akshya Sharma

    2017-10-01

    Full Text Available Zygosaccharomyces bisporus is a moderately halotolerant yeast isolated from highly sugary and salty foods. We performed various evident biochemical and in vivo experiments as first of its kind to sketch out the possible overlay of salt tolerance mechanism in this model organism. The growth and survival curve analysis revealed that 1.0 M NaCl concentration (sublethal enacts growth inhibitory effects with prompting immediate delay in cell division cycle; however, yeast cells adopted modified stress physiologically with further stretched stress spans which was accompanied by an upsurge in the level of cellular metabolites such as trehalose (reserve carbohydrate and chiefly glycerol (polyols as major compatible osmolytes, suggesting their role in defense mechanism against osmotic stress. To further elucidate the relation of osmotic stress cell physiology to salinity, thiobarbituric acid reactive substances, protein carbonyl, and reduced glutathione content were measured in salt-stressed cells demonstrating positive correlation of reactive oxygen species generation in Z. bisporus with an elevated concentration of lipid and protein oxidation, thereby damaging cell membrane and eventually causing cell death. We assessed NaCl exposure sourcing increased intracellular reactive oxygen species concentration, by an electron transfer-based colorimetric cupric-reducing antioxidant capacity assay justifying that cellular total antioxidant capacity which uses all the combined antioxidant activities present within vitamins, proteins, lipids, and glutathione reverses these deleterious stress effects. Henceforth, performance of Z. bisporus MTCC 4801 mounted because of stress regime seems to be multifactorial.

  1. 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

    -related stress tolerance phenotypes. To accomplish this, 166 L. monocytogenes isolates were sequenced and evaluated for their ability to grow in cold (4°C), salt (6% NaCl, 25°C), and acid (pH 5, 25°C) stress conditions as well as survive desiccation (33% RH, 20°C). The results revealed that the stress tolerance...... 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...... of L. monocytogenes is associated with serotype, clonal complex (CC), full length inlA profiles, and the presence of a plasmid which was identified in 55% of isolates. Isolates with full length inlA exhibited significantly (p tolerance relative to those harboring a premature stop...

  2. Overexpression of Small Heat Shock Protein Enhances Heat- and Salt-Stress Tolerance of Bifidobacterium longum NCC2705.

    Science.gov (United States)

    Khaskheli, Gul Bahar; Zuo, FangLei; Yu, Rui; Chen, ShangWu

    2015-07-01

    Bifidobacteria are probiotics that are incorporated live into various dairy products. They confer health-promotive effects via gastrointestinal tract colonization. However, to provide their health-beneficial properties, they must battle the various abiotic stresses in that environment, such as bile salts, acids, oxygen, and heat. In this study, Bifidobacterium longum salt- and heat-stress tolerance was enhanced by homologous overexpression of a small heat shock protein (sHsp). A positive contribution of overproduced sHsp to abiotic stress tolerance was observed when the bacterium was exposed to heat and salt stresses. Significantly higher survival of B. l ongum NCC2705 overexpressing sHsp was observed at 30 and 60 min into heat (55 °C) and salt (5 M NaCl) treatment, respectively. Thermotolerance analysis at 47 °C with sampling every 2 h also revealed the great potential tolerance of the engineered strain. Cell density and acid production rate increased for the sHsp-overexpressing strain after 8 and 10 h of both heat and salt stresses. In addition, tolerance to bile salts, low pH (3.5) and low temperature (4 °C) was also increased by homologous overexpression of the sHsp hsp20 in B. l ongum. Results revealed that hsp20 overexpression in B longum NCC2705 plays a positive cross-protective role in upregulating abiotic responses, ensuring the organism's tolerance to various stress conditions; therefore, sHsp-overexpressing B. l ongum is advised for fermented dairy foods and other probiotic product applications.

  3. Salt stress tolerance of methylotrophic bacteria Methylophilus sp. and Methylobacterium sp. isolated from coal mine spoils.

    Science.gov (United States)

    Giri, Deen Dayal; Kumar, Ajay; Shukla, Prabhu Nath; Singh, Ritu; Singh, P K; Pandey, Kapil Deo

    2013-01-01

    Two methylotrophic strains of Bina coalmine spoil BNV7b and BRV25 were identified based on physiological traits and 16S rDNA sequence as Methylophilus and Methylobacterium species.' The strains exhibited similar carbon utilization but differed in N utilization and their response to the metabolic inhibitors. Methylophilus sp. was less tolerant to salt stress and it viability declined to one tenth within 4 h of incubation in 2M NaCI due to membrane damage and leakage of the intracellular electrolytes as evident from malondiaaldehyde (MDA) assay. In 200 mM NaCI, they exhibited increased superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) activity while in 500 mM NaCI, enzyme activities declined in Methylophilus sp. and increased in Methylobacterium sp. Among exogenously applied osmoprotectants proline was most efficient; however, polyols (mannitol, sorbitol and glycerol) also supported growth under lethal NaCI concentration.

  4. CarNAC4, a NAC-type chickpea transcription factor conferring enhanced drought and salt stress tolerances in Arabidopsis.

    Science.gov (United States)

    Yu, Xingwang; Liu, Yanmin; Wang, Shuang; Tao, Yuan; Wang, Zhankui; Shu, Yingjie; Peng, Hui; Mijiti, Abudoukeyumu; Wang, Ze; Zhang, Hua; Ma, Hao

    2016-03-01

    CarNAC4 is a typical stress-responsive NAC transcription factor and enhances drought and salt stress tolerances in transgenic Arabidopsis. Chickpea (Cicer arietinum L.) is relatively vulnerable to abiotic stress conditions, but the tolerance mechanisms for such stresses in chickpea are largely unknown. To identify stress-related factors in chickpea, we previously constructed a cDNA library of chickpea leaves exposed to drought stress conditions. A cDNA encoding a putative NAC transcription factor (CarNAC4) was identified as a putative stress-responsive gene. Our study indicated that the transcript levels of CarNAC4 were enhanced in response to several abiotic stresses and phytohormones. Promoter analysis demonstrated that multiple stress-related cis-acting elements exist in promoter region of CarNAC4. CarNAC4 is localized in the nucleus and binds to the DNA sequence containing CGT[G/A], while the C-terminal region of CarNAC4 contains a transcriptional activation domain. Over-expression of CarNAC4 in Arabidopsis plants improved tolerance to drought and salt stresses. Transgenic plants exhibited greater reduced rates of water loss and more proline accumulation than Col-0 plants under drought stress and less MDA contents than Col-0 plants under salt stress. In addition, over-expression of CarNAC4 enhanced the expression of stress-responsive genes such as RD29A, ERD10, COR15A, COR47, KIN1 and DREB2A. These results indicated that CarNAC4 functions as a transcription factor involved in the regulation of drought and salt stress response.

  5. Ectopic expression of Mesembryanthemum crystallinum sodium transporter McHKT2 provides salt stress tolerance in Arabidopsis thaliana.

    Science.gov (United States)

    Nishijima, Taiga; Furuhashi, Megumi; Sakaoka, Satomi; Morikami, Atsushi; Tsukagoshi, Hironaka

    2017-11-01

    Most plants do not tolerate highly saline environments; the development of salt stress tolerance is crucial for improving crop yield. An efficient way of finding genes involved in salt tolerance is to study and use data from halophytes. In this study, we used the Mesembryanthemum crystallinum (ice plant) expression data-set and selected for further study the gene McHKT2, which encodes for the Arabidopsis sodium transporter ortholog AtHKT1. In comparison with the HKT1 amino acid sequences from other plants, McHKT2 has several unique features. It seems to be localized to the plasma membrane, and its overexpression confers strong salt tolerance in Arabidopsis thaliana. Our results indicate that McHKT2 is a suitable candidate protein that can induce salt tolerance in non-halophytes. Like McHKT2, using transcriptome data-sets from halophytes such as ice plant give us an efficiency way to obtain new gene resources that might involve in plant salt tolerance.

  6. Over-expression of a novel JAZ family gene from Glycine soja, increases salt and alkali stress tolerance.

    Science.gov (United States)

    Zhu, Dan; Cai, Hua; Luo, Xiao; Bai, Xi; Deyholos, Michael K; Chen, Qin; Chen, Chao; Ji, Wei; Zhu, Yanming

    2012-09-21

    Salt and alkali stress are two of the main environmental factors limiting crop production. Recent discoveries show that the JAZ family encodes plant-specific genes involved in jasmonate signaling. However, there is only limited information about this gene family in abiotic stress response, and in wild soybean (Glycine soja), which is a species noted for its tolerance to alkali and salinity. Here, we isolated and characterized a novel JAZ family gene, GsJAZ2, from G. soja. Transcript abundance of GsJAZ2 increased following exposure to salt, alkali, cold and drought. Over-expression of GsJAZ2 in Arabidopsis resulted in enhanced plant tolerance to salt and alkali stress. The expression levels of some alkali stress response and stress-inducible marker genes were significantly higher in the GsJAZ2 overexpression lines as compared to wild-type plants. Subcellular localization studies using a GFP fusion protein showed that GsJAZ2 was localized to the nucleus. These results suggest that the newly isolated wild soybean GsJAZ2 is a positive regulator of plant salt and alkali stress tolerance. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

  7. Over-expression of a novel JAZ family gene from Glycine soja, increases salt and alkali stress tolerance

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Dan; Cai, Hua; Luo, Xiao; Bai, Xi [Plant Bioengineering Laboratory, Northeast Agricultural University, Harbin 150030 (China); Deyholos, Michael K. [Department of Biological Sciences, University of Alberta, Edmonton, Canada T6G 2E9 (Canada); Chen, Qin [Lethbridge Research Centre, Agriculture and Agri-Food Canada, 5403-1 Ave., South P.O. Box 3000, Lethbridge, AB, Canada T1J 4B1 (Canada); Chen, Chao; Ji, Wei [Plant Bioengineering Laboratory, Northeast Agricultural University, Harbin 150030 (China); Zhu, Yanming, E-mail: ymzhu@neau.edu.cn [Plant Bioengineering Laboratory, Northeast Agricultural University, Harbin 150030 (China)

    2012-09-21

    Highlights: Black-Right-Pointing-Pointer We isolated and characterized a novel JAZ family gene, GsJAZ2, from Glycine soja. Black-Right-Pointing-Pointer Overexpression of GsJAZ2 enhanced plant tolerance to salt and alkali stress. Black-Right-Pointing-Pointer The transcriptions of stress marker genes were higher in GsJAZ2 overexpression lines. Black-Right-Pointing-Pointer GsJAZ2 was localized to nucleus. -- Abstract: Salt and alkali stress are two of the main environmental factors limiting crop production. Recent discoveries show that the JAZ family encodes plant-specific genes involved in jasmonate signaling. However, there is only limited information about this gene family in abiotic stress response, and in wild soybean (Glycine soja), which is a species noted for its tolerance to alkali and salinity. Here, we isolated and characterized a novel JAZ family gene, GsJAZ2, from G. soja. Transcript abundance of GsJAZ2 increased following exposure to salt, alkali, cold and drought. Over-expression of GsJAZ2 in Arabidopsis resulted in enhanced plant tolerance to salt and alkali stress. The expression levels of some alkali stress response and stress-inducible marker genes were significantly higher in the GsJAZ2 overexpression lines as compared to wild-type plants. Subcellular localization studies using a GFP fusion protein showed that GsJAZ2 was localized to the nucleus. These results suggest that the newly isolated wild soybean GsJAZ2 is a positive regulator of plant salt and alkali stress tolerance.

  8. OsPEX11, a peroxisomal biogenesis factor 11, contributes to salt stress tolerance in Oryza sativa

    Directory of Open Access Journals (Sweden)

    Cui Peng

    2016-09-01

    Full Text Available Peroxisomes are single membrane-bound organelles, whose basic enzymatic constituents are catalase and H2O2-producing flavin oxidases. Previous reports showed that peroxisome is involved in numerous processes including primary and secondary metabolism, plant development and abiotic stress responses. However, knowledge on the function of different peroxisome genes from rice and its regulatory roles in salt and other abiotic stresses is limited. Here, a novel prey protein, OsPEX11 (Os03g0302000, was screened and identified by yeast two-hybrid and GST pull down assays. Phenotypic analysis of OsPEX11 overexpression seedlings demonstrated that they had better tolerance to salt stress than wild type and OsPEX11-RNAi seedlings. Compared with wild type and OsPEX11-RNAi seedlings, overexpression of OsPEX11 had lower level of lipid peroxidation, Na+/K+ ratio, higher activities of antioxidant enzymes (SOD, POD and CAT and proline accumulation. Furthermore, qPCR data suggested that OsPEX11 acted as a positive regulator of salt tolerance by reinforcing the expression of several well-known rice transporters (OsHKT2;1, OsHKT1;5, OsLti6a, OsLti6b, OsSOS1, OsNHX1 and OsAKT1 involved in Na+/K+ homeostasis in transgenic plants under salinity. Ultrastructural observations of OsPEX11-RNAi seedlings showed that they were less sensitive to salt stress than wild type and overexpression lines. These results provide experimental evidence that OsPEX11 is an important gene implicated in Na+ and K+ regulation, and plays a critical role in salt stress tolerance by modulating the expression of cation transporters and antioxidant defense. Thus, OsPEX11 could be considered in transgenic breeding for improvement of salt stress tolerance in rice crop.

  9. High tolerance to salinity and herbivory stresses may explain the expansion of Ipomoea cairica to salt marshes.

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    Gang Liu

    Full Text Available BACKGROUND: Invasive plants are often confronted with heterogeneous environments and various stress factors during their secondary phase of invasion into more stressful habitats. A high tolerance to stress factors may allow exotics to successfully invade stressful environments. Ipomoea cairica, a vigorous invader in South China, has recently been expanding into salt marshes. METHODOLOGY/PRINCIPAL FINDINGS: To examine why this liana species is able to invade a stressful saline environment, we utilized I. cairica and 3 non-invasive species for a greenhouse experiment. The plants were subjected to three levels of salinity (i.e., watered with 0, 4 and 8 g L(-1 NaCl solutions and simulated herbivory (0, 25 and 50% of the leaf area excised treatments. The relative growth rate (RGR of I. cairica was significantly higher than the RGR of non-invasive species under both stress treatments. The growth performance of I. cairica was not significantly affected by either stress factor, while that of the non-invasive species was significantly inhibited. The leaf condensed tannin content was generally lower in I. cairica than in the non-invasive I. triloba and Paederia foetida. Ipomoea cairica exhibited a relatively low resistance to herbivory, however, its tolerance to stress factors was significantly higher than either of the non-invasive species. CONCLUSIONS/SIGNIFICANCE: This is the first study examining the expansion of I. cairica to salt marshes in its introduced range. Our results suggest that the high tolerance of I. cairica to key stress factors (e.g., salinity and herbivory contributes to its invasion into salt marshes. For I. cairica, a trade-off in resource reallocation may allow increased resources to be allocated to tolerance and growth. This may contribute to a secondary invasion into stressful habitats. Finally, we suggest that I. cairica could spread further and successfully occupy salt marshes, and countermeasures based on herbivory could be

  10. Antarctic Moss Multiprotein Bridging Factor 1c Overexpression in Arabidopsis Resulted in Enhanced Tolerance to Salt Stress

    Directory of Open Access Journals (Sweden)

    Hemasundar Alavilli

    2017-07-01

    Full Text Available Polytrichastrum alpinum is one of the moss species that survives extreme conditions in the Antarctic. In order to explore the functional benefits of moss genetic resources, P. alpinum multiprotein-bridging factor 1c gene (PaMBF1c was isolated and characterized. The deduced amino acid sequence of PaMBF1c comprises of a multiprotein-bridging factor (MBF1 domain and a helix-turn-helix (HTH domain. PaMBF1c expression was induced by different abiotic stresses in P. alpinum, implying its roles in stress responses. We overexpressed PaMBF1c in Arabidopsis and analyzed the resulting phenotypes in comparison with wild type and/or Arabidopsis MBF1c (AtMBF1c overexpressors. Overexpression of PaMBF1c in Arabidopsis resulted in enhanced tolerance to salt and osmotic stress, as well as to cold and heat stress. More specifically, enhanced salt tolerance was observed in PaMBF1c overexpressors in comparison to wild type but not clearly observable in AtMBF1c overexpressing lines. Thus, these results implicate the evolution of PaMBF1c under salt-enriched Antarctic soil. RNA-Seq profiling of NaCl-treated plants revealed that 10 salt-stress inducible genes were already up-regulated in PaMBF1c overexpressing plants even before NaCl treatment. Gene ontology enrichment analysis with salt up-regulated genes in each line uncovered that the terms lipid metabolic process, ion transport, and cellular amino acid biosynthetic process were significantly enriched in PaMBF1c overexpressors. Additionally, gene enrichment analysis with salt down-regulated genes in each line revealed that the enriched categories in wild type were not significantly overrepresented in PaMBF1c overexpressing lines. The up-regulation of several genes only in PaMBF1c overexpressing lines suggest that enhanced salt tolerance in PaMBF1c-OE might involve reactive oxygen species detoxification, maintenance of ATP homeostasis, and facilitation of Ca2+ signaling. Interestingly, many salt down

  11. Hydrogen sulfide regulates salt tolerance in rice by maintaining Na+/K+ balance, mineral homeostasis and oxidative metabolism under excessive salt stress

    Directory of Open Access Journals (Sweden)

    Mohammad Golam Mostofa

    2015-12-01

    Full Text Available Being a salt sensitive crop, rice growth and development are frequently affected by soil salinity. Hydrogen sulfide (H2S has been recently explored as an important priming agent regulating diverse physiological processes of plant growth and development. Despite its enormous prospects in plant systems, the role of H2S in plant stress tolerance is still elusive. Here, a combined pharmacological, physiological and biochemical approach was executed aiming to examine the possible mechanism of H2S in enhancement of salt stress tolerance in rice. We show that pretreating rice plants with H2S donor sodium bisulfide (NaHS clearly improved, but application of H2S scavenger hypotaurine with NaHS decreased growth and biomass-related parameters under salt stress. NaHS-pretreated salt-stressed plants exhibited increased chlorophyll, carotenoid and soluble protein contents, as well as suppressed accumulation of reactive oxygen species (ROS, contributing to oxidative damage protection. The protective mechanism of H2S against oxidative stress was correlated with the elevated levels of ascorbic acid, glutathione, redox states, and the enhanced activities of ROS- and methylglyoxal-detoxifying enzymes. Notably, decreased uptake of Na+, decreased Na+/K+ ratio and balanced mineral contents indicated a role of H2S in ion homeostasis under salt stress. Altogether, our results highlight that modulation of the level of endogenous H2S genetically or exogenously could be employed to attain better growth and development of rice, and perhaps other crops, under salt stress. Furthermore, our study reveals the importance of the implication of gasotransmitter like H2S for the management of salt stress, thus assisting rice plants to adapt to adverse environmental changes.

  12. Native-Invasive Plants vs. Halophytes in Mediterranean Salt Marshes: Stress Tolerance Mechanisms in Two Related Species.

    Science.gov (United States)

    Al Hassan, Mohamad; Chaura, Juliana; López-Gresa, María P; Borsai, Orsolya; Daniso, Enrico; Donat-Torres, María P; Mayoral, Olga; Vicente, Oscar; Boscaiu, Monica

    2016-01-01

    Dittrichia viscosa is a Mediterranean ruderal species that over the last decades has expanded into new habitats, including coastal salt marshes, ecosystems that are per se fragile and threatened by human activities. To assess the potential risk that this native-invasive species represents for the genuine salt marsh vegetation, we compared its distribution with that of Inula crithmoides, a taxonomically related halophyte, in three salt marshes located in "La Albufera" Natural Park, near the city of Valencia (East Spain). The presence of D. viscosa was restricted to areas of low and moderate salinity, while I. crithmoides was also present in the most saline zones of the salt marshes. Analyses of the responses of the two species to salt and water stress treatments in controlled experiments revealed that both activate the same physiological stress tolerance mechanisms, based essentially on the transport of toxic ions to the leaves-where they are presumably compartmentalized in vacuoles-and the accumulation of specific osmolytes for osmotic adjustment. The two species differ in the efficiency of those mechanisms: salt-induced increases in Na(+) and Cl(-) contents were higher in I. crithmoides than in D. viscosa, and the osmolytes (especially glycine betaine, but also arabinose, fructose and glucose) accumulated at higher levels in the former species. This explains the (slightly) higher stress tolerance of I. crithmoides, as compared to D. viscosa, established from growth inhibition measurements and their distribution in nature. The possible activation of K(+) transport to the leaves under high salinity conditions may also contribute to salt tolerance in I. crithmoides. Oxidative stress level-estimated from malondialdehyde accumulation-was higher in the less tolerant D. viscosa, which consequently activated antioxidant responses as a defense mechanism against stress; these responses were weaker or absent in the more tolerant I. crithmoides. Based on these results, we

  13. Native-invasive plants vs. halophytes in Mediterranean salt marshes: Stress tolerance mechanisms in two related species

    Directory of Open Access Journals (Sweden)

    Mohamad eAl Hassan

    2016-04-01

    Full Text Available Dittrichia viscosa is a Mediterranean ruderal species that over the last decades has expanded into new habitats, including coastal salt marshes, ecosystems that are per se fragile and threatened by human activities. To assess the potential risk that this native-invasive species represents for the genuine salt marsh vegetation, we compared its distribution with that of Inula crithmoides, a taxonomically related halophyte, in three salt marshes located in ‘La Albufera’ Natural Park, near the city of Valencia (East Spain. The presence of D. viscosa was restricted to areas of low and moderate salinity, while I. crithmoides was also present in the most saline zones of the salt marshes. Analyses of the responses of the two species to salt and water stress treatments in controlled experiments revealed that both activate the same physiological stress tolerance mechanisms, based essentially on the transport of toxic ions to the leaves – where they are presumably compartmentalized in vacuoles – and the accumulation of specific osmolytes for osmotic adjustment. The two species differ in the efficiency of those mechanisms: salt-induced increases in Na+ and Cl- contents were higher in I. crithmoides than in D. viscosa, and the osmolytes (especially glycine betaine, but also arabinose, fructose and glucose accumulated at higher levels in the former species. This explains the (slightly higher stress tolerance of I. crithmoides, as compared to D. viscosa, established from growth inhibition measurements and their distribution in nature. The possible activation of K+ transport to the leaves under high salinity conditions may also contribute to salt tolerance in I. crithmoides. Oxidative stress level – estimated from malondialdehyde accumulation – was higher in the less tolerant D. viscosa, which consequently activated antioxidant responses as a defense mechanism against stress; these responses were weaker or absent in the more tolerant I. crithmoides

  14. A banana aquaporin gene, MaPIP1;1, is involved in tolerance to drought and salt stresses.

    Science.gov (United States)

    Xu, Yi; Hu, Wei; Liu, Juhua; Zhang, Jianbin; Jia, Caihong; Miao, Hongxia; Xu, Biyu; Jin, Zhiqiang

    2014-03-08

    Aquaporin (AQP) proteins function in transporting water and other small molecules through the biological membranes, which is crucial for plants to survive in drought or salt stress conditions. However, the precise role of AQPs in drought and salt stresses is not completely understood in plants. In this study, we have identified a PIP1 subfamily AQP (MaPIP1;1) gene from banana and characterized it by overexpression in transgenic Arabidopsis plants. Transient expression of MaPIP1;1-GFP fusion protein indicated its localization at plasma membrane. The expression of MaPIP1;1 was induced by NaCl and water deficient treatment. Overexpression of MaPIP1;1 in Arabidopsis resulted in an increased primary root elongation, root hair numbers and survival rates compared to WT under salt or drought conditions. Physiological indices demonstrated that the increased salt tolerance conferred by MaPIP1;1 is related to reduced membrane injury and high cytosolic K+/Na+ ratio. Additionally, the improved drought tolerance conferred by MaPIP1;1 is associated with decreased membrane injury and improved osmotic adjustment. Finally, reduced expression of ABA-responsive genes in MaPIP1;1-overexpressing plants reflects their improved physiological status. Our results demonstrated that heterologous expression of banana MaPIP1;1 in Arabidopsis confers salt and drought stress tolerances by reducing membrane injury, improving ion distribution and maintaining osmotic balance.

  15. Influence of the24-epibrassinolide on tolerance to salt stress in rice seedlings

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    Cristina Ferreira Larré

    2014-02-01

    Full Text Available Salinity can be considered a limiting factor to the growth and development of plants to affect various physiological processes. The aim of this study was to determine the effect of 24 – epibrassinolide in emergence, seedling growth, leaf area and chlorophyll concentration in two cultivars of rice in salt stress condition. The study was conducted at the research laboratory of seeds and greenhouse of the Department of Botany UFPel. Rice seeds of cvs. BRS Bojurú tolerant to salinity and BRS Querência not tolerant, were soaked for two hours in water, 100 mMNaCl and 100 mMNaCl solutions supplemented with 24 – epibrassinolide at concentrations of 0.01, 0,1 and 1.0 mM and sown in expanded polypropylene tray. The experimental design was completely randomized with five treatments, two cultivars and four replications. Means were compared by Tukey test (p < 5 %, within each cultivar. In cv. BRS Querência the application of 24 – epibrassinolide increased chlorophyll concentration, leaf area, seedling length and dry mass of shoots, reducing the effects caused by salinity. However, cv. BRS Bojurú, tolerant to salinity, the application of the 24 – epibrassinolide 0.01 mM did not affect the growth characteristics, but the concentrations of 0.1 and 1.0 mM reduced the same, no affecting the concentration of chlorophyll. The 24 – epibrassinolide in cv. BRS Querencia, induces an increase in all growth characteristics, minimizing the deleterious effects of salinity on the sensitive cultivar. In cv. BRS Bojurú, higher concentrations reduce the growth characteristics, not by changing the concentration of chlorophyll.

  16. [Natural nucleotide polymorphism of the Srlk gene that determines salt stress tolerance in alfalfa (Medicago sativa L)].

    Science.gov (United States)

    Vishnevskaia, M S; Pavlov, A V; Dziubenko, E A; Dziubenko, N I; Potokina, E K

    2014-04-01

    Based on legume genome syntheny, the nucleotide sequence of Srlk gene, key role of which in response to salt stress was demonstrated for the model species Medicago truncatula, was identified in the major forage and siderate crop alfalfa (Medicago sativa). In twelve alfalfa samples originating from regions with contrasting growing conditions, 19 SNPs were revealed in the Srlk gene. For two nonsynonymous SNPs, molecular markers were designed that could be further used to analyze the association between Srlk gene nucleotide polymorphism and the variability in salt stress tolerance among alfalfa cultivars.

  17. Approaches in modulating proline metabolism in plants for salt and drought stress tolerance: Phytohormones, mineral nutrients and transgenics.

    Science.gov (United States)

    Per, Tasir S; Khan, Nafees A; Reddy, Palakolanu Sudhakar; Masood, Asim; Hasanuzzaman, Mirza; Khan, M Iqbal R; Anjum, Naser A

    2017-06-01

    Major abiotic stress factors such as salt and drought adversely affect important physiological processes and biochemical mechanisms and cause severe loss in crop productivity worldwide. Plants develop various strategies to stand healthy against these stress factors. The accumulation of proline (Pro) is one of the striking metabolic responses of plants to salt and drought stress. Pro biosynthesis and signalling contribute to the redox balance of cell under normal and stressful conditions. However, literature is meager on the sustainable strategies potentially fit for modulating Pro biosynthesis and production in stressed plants. Considering the recent literature, this paper in its first part overviews Pro biosynthesis and transport in plants and also briefly highlights the significance of Pro in plant responses to salt and drought stress. Secondly, this paper discusses mechanisms underlying the regulation of Pro metabolism in salt and drought-exposed plant via phytohormones, mineral nutrients and transgenic approaches. The outcome of the studies may give new opportunities in modulating Pro metabolism for improving plant tolerance to salt and drought stress and benefit sustainable agriculture. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  18. Macroevolutionary patterns of salt tolerance in angiosperms

    Science.gov (United States)

    Bromham, Lindell

    2015-01-01

    Background Halophytes are rare, with only 0·25 % of angiosperm species able to complete their life cycle in saline conditions. This could be interpreted as evidence that salt tolerance is difficult to evolve. However, consideration of the phylogenetic distribution of halophytes paints a different picture: salt tolerance has evolved independently in many different lineages, and halophytes are widely distributed across angiosperm families. In this Viewpoint, I will consider what phylogenetic analysis of halophytes can tell us about the macroevolution of salt tolerance. Hypothesis Phylogenetic analyses of salt tolerance have shown contrasting patterns in different families. In some families, such as chenopods, salt tolerance evolved early in the lineage and has been retained in many lineages. But in other families, including grasses, there have been a surprisingly large number of independent origins of salt tolerance, most of which are relatively recent and result in only one or a few salt-tolerant species. This pattern of many recent origins implies either a high transition rate (salt tolerance is gained and lost often) or a high extinction rate (salt-tolerant lineages do not tend to persist over macroevolutionary timescales). While salt tolerance can evolve in a wide range of genetic backgrounds, some lineages are more likely to produce halophytes than others. This may be due to enabling traits that act as stepping stones to developing salt tolerance. The ability to tolerate environmental salt may increase tolerance of other stresses or vice versa. Conclusions Phylogenetic analyses suggest that enabling traits and cross-tolerances may make some lineages more likely to adapt to increasing salinization, a finding that may prove useful in assessing the probable impact of rapid environmental change on vegetation communities, and in selecting taxa to develop for use in landscape rehabilitation and agriculture. PMID:25452251

  19. A synergistic interaction between salt-tolerant Pseudomonas and Mesorhizobium strains improves growth and symbiotic performance of liquorice (Glycyrrhiza uralensis Fish.) under salt stress.

    Science.gov (United States)

    Egamberdieva, Dilfuza; Li, Li; Lindström, Kristina; Räsänen, Leena A

    2016-03-01

    Chinese liquorice (Glycyrrhiza uralensis Fish.) is a salt-tolerant medicinal legume that could be utilized for bioremediation of salt-affected soils. We studied whether co-inoculation of the symbiotic Mesorhizobium sp. strain NWXJ19 or NWXJ31 with the plant growth-promoting Pseudomonas extremorientalis TSAU20 could restore growth, nodulation, and shoot/root nitrogen contents of salt-stressed G. uralensis, which was grown in potting soil and irrigated with 0, 50, and 75 mM NaCl solutions under greenhouse conditions. Irrigation with NaCl solutions clearly retarded the growth of uninoculated liquorice, and the higher the NaCl concentration (75 and 100 mM NaCl), the more adverse is the effect. The two Mesorhizobium strains, added either alone or in combination with P. extremorientalis TSAU20, responded differently to the salt levels used. The strain NWXJ19 was a good symbiont for plants irrigated with 50 mM NaCl, whereas the strain NWXJ31 was more efficient for plants irrigated with water or 75 mM NaCl solution. P. extremorientalis TSAU20 combined with single Mesorhizobium strains alleviated the salt stress of liquorice plants and improved yield and nodule numbers significantly in comparison with single-strain-inoculated liquorice. Both salt stress and inoculation raised the nitrogen content of shoots and roots. The nitrogen contents were at their highest, i.e., 30 and 35 % greater compared to non-stressed uninoculated plants, when plants were inoculated with P. extremorientalis TSAU20 and Mesorhizobium sp. NWXJ31 as well as irrigated with 75 mM NaCl solution. From this study, we conclude that dual inoculation with plant growth-promoting rhizobacteria could be a new approach to improve the tolerance of G. uralensis to salt stress, thereby improving its suitability for the remediation of saline lands.

  20. 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.

  1. The maize WRKY transcription factor ZmWRKY17 negatively regulates salt stress tolerance in transgenic Arabidopsis plants.

    Science.gov (United States)

    Cai, Ronghao; Dai, Wei; Zhang, Congsheng; Wang, Yan; Wu, Min; Zhao, Yang; Ma, Qing; Xiang, Yan; Cheng, Beijiu

    2017-12-01

    We cloned and characterized the ZmWRKY17 gene from maize. Overexpression of ZmWRKY17 in Arabidopsis led to increased sensitivity to salt stress and decreased ABA sensitivity through regulating the expression of some ABA- and stress-responsive genes. The WRKY transcription factors have been reported to function as positive or negative regulators in many different biological processes including plant development, defense regulation and stress response. This study isolated a maize WRKY gene, ZmWRKY17, and characterized its role in tolerance to salt stress by generating transgenic Arabidopsis plants. Expression of the ZmWRKY17 was up-regulated by drought, salt and abscisic acid (ABA) treatments. ZmWRKY17 was localized in the nucleus with no transcriptional activation in yeast. Yeast one-hybrid assay showed that ZmWRKY17 can specifically bind to W-box, and it can activate W-box-dependent transcription in planta. Heterologous overexpression of ZmWRKY17 in Arabidopsis remarkably reduced plant tolerance to salt stress, as determined through physiological analyses of the cotyledons greening rate, root growth, relative electrical leakage and malondialdehyde content. Additionally, ZmWRKY17 transgenic plants showed decreased sensitivity to ABA during seed germination and early seedling growth. Transgenic plants accumulated higher content of ABA than wild-type (WT) plants under NaCl condition. Transcriptome and quantitative real-time PCR analyses revealed that some stress-related genes in transgenic seedlings showed lower expression level than that in the WT when treated with NaCl. Taken together, these results suggest that ZmWRKY17 may act as a negative regulator involved in the salt stress responses through ABA signalling.

  2. The Opuntia streptacantha OpsHSP18 Gene Confers Salt and Osmotic Stress Tolerance in Arabidopsis thaliana

    Science.gov (United States)

    Salas-Muñoz, Silvia; Gómez-Anduro, Gracia; Delgado-Sánchez, Pablo; Rodríguez-Kessler, Margarita; Jiménez-Bremont, Juan Francisco

    2012-01-01

    Abiotic stress limits seed germination, plant growth, flowering and fruit quality, causing economic decrease. Small Heat Shock Proteins (sHSPs) are chaperons with roles in stress tolerance. Herein, we report the functional characterization of a cytosolic class CI sHSP (OpsHSP18) from Opuntia streptacantha during seed germination in Arabidopsis thaliana transgenic lines subjected to different stress and hormone treatments. The over-expression of the OpsHSP18 gene in A. thaliana increased the seed germination rate under salt (NaCl) and osmotic (glucose and mannitol) stress, and in ABA treatments, compared with WT. On the other hand, the over-expression of the OpsHSP18 gene enhanced tolerance to salt (150 mM NaCl) and osmotic (274 mM mannitol) stress in Arabidopsis seedlings treated during 14 and 21 days, respectively. These plants showed increased survival rates (52.00 and 73.33%, respectively) with respect to the WT (18.75 and 53.75%, respectively). Thus, our results show that OpsHSP18 gene might have an important role in abiotic stress tolerance, in particular in seed germination and survival rate of Arabidopsis plants under unfavorable conditions. PMID:22949853

  3. Alternative oxidase pathway is involved in the exogenous SNP-elevated tolerance of Medicago truncatula to salt stress.

    Science.gov (United States)

    Jian, Wei; Zhang, Da-wei; Zhu, Feng; Wang, Shuo-xun; Pu, Xiao-jun; Deng, Xing-guang; Luo, Shi-shuai; Lin, Hong-hui

    2016-04-01

    Exogenous application of sodium nitroprusside (SNP) would enhance the tolerance of plants to stress conditions. Some evidences suggested that nitric oxide (NO) could induce the expression of alternative oxidase (AOX). In this study, Medicago truncatula (Medicago) was chosen to study the role of AOX in the SNP-elevated resistance to salt stress. Our results showed that the expression of AOX genes (especially AOX1 and AOX2b1) and cyanide-resistant respiration rate (Valt) could be significantly induced by salt stress. Exogenous application of SNP could further enhance the expression of AOX genes and Valt. Exogenous application of SNP could alleviate the oxidative damage and photosynthetic damage caused by salt stress. However, the stress resistance was significantly decreased in the plants which were pretreated with n-propyl gallate (nPG). More importantly, the damage in nPG-pretreated plants could not be alleviated by application of SNP. Further study showed that effects of nPG on the activities of antioxidant enzymes were minor. These results showed that AOX pathway played an important role in the SNP-elevated resistance of Medicago to salt stress. AOX could contribute to regulating the accumulation of reactive oxygen (ROS) and protect of photosystem, and we proposed that all these were depend on the ability of maintaining the homeostasis of redox state. Copyright © 2016 Elsevier GmbH. All rights reserved.

  4. Elevated compartmentalization of Na+ into vacuoles improves salt and cold stress tolerance in sweet potato (Ipomoea batatas).

    Science.gov (United States)

    Fan, Weijuan; Deng, Gaifang; Wang, Hongxia; Zhang, Hongxia; Zhang, Peng

    2015-08-01

    Salinity and low temperature are the main limiting factors for sweet potato (Ipomoea batatas) growth and agricultural productivity. Various studies have shown that plant NHX-type antiporter plays a crucial role in regulating plant tolerance to salt stress by intracellular Na(+) compartmentalization. The Arabidopsis thaliana AtNHX1 gene that encodes a vacuolar Na(+) /H(+) antiporter was introduced into the sweet potato cultivar Xushu-22 by Agrobacterium-mediated transformation to confer abiotic stress tolerance. Stable insertion of AtNHX1 into the sweet potato genome and its expression was confirmed by Southern blot and reverse transcription-polymerase chain reaction (RT-PCR). A remarkably higher Na(+) /H(+) exchange activity of tonoplast membrane from transgenic sweet potato lines (NOE) in comparison with wild-type (WT) plants confirmed the vacuolar antiporter function in mediating Na(+) /H(+) exchange. Under salt stress, NOE plants accumulated higher Na(+) and K(+) levels in their tissues compared with WT plants, maintaining high K(+) /Na(+) ratios. Consequently, NOE plants showed enhanced protection against cell damage due to the increased proline accumulation, preserved cell membrane integrity, enhanced reactive oxygen species (ROS) scavenging (e.g. increased superoxide dismutase activity), and reduced H2 O2 and malondialdehyde (MDA) production. Moreover, the transgenic plants showed improved cold tolerance through multiple mechanisms of action, revealing the first molecular evidence for NHX1 function in cold response. The transgenic plants showed better biomass production and root yield under stressful conditions. These findings demonstrate that overexpressing AtNHX1 in sweet potato renders the crop tolerant to both salt and cold stresses, providing a greater capacity for the use of AtNHX1 in improving crop performance under combined abiotic stress conditions. © 2014 Scandinavian Plant Physiology Society.

  5. Chrysanthemum WRKY gene DgWRKY5 enhances tolerance to salt stress in transgenic chrysanthemum.

    Science.gov (United States)

    Liang, Qian-Yu; Wu, Yin-Huan; Wang, Ke; Bai, Zhen-Yu; Liu, Qing-Lin; Pan, Yuan-Zhi; Zhang, Lei; Jiang, Bei-Bei

    2017-07-06

    WRKY transcription factors play important roles in plant growth development, resistance and substance metabolism regulation. However, the exact function of the response to salt stress in plants with specific WRKY transcription factors remains unclear. In this research, we isolated a new WRKY transcription factor DgWRKY5 from chrysanthemum. DgWRKY5 contains two WRKY domains of WKKYGQK and two C2H2 zinc fingers. The expression of DgWRKY5 in chrysanthemum was up-regulated under various treatments. Meanwhile, we observed higher expression levels in the leaves contrasted with other tissues. Under salt stress, the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) enzymes in transgenic chrysanthemum were significantly higher than those in WT, whereas the accumulation of H2O2, O2(-) and malondialdehyde (MDA) was reduced in transgenic chrysanthemum. Several parameters including root length, root length, fresh weight, chlorophyll content and leaf gas exchange parameters in transgenic chrysanthemum were much better compared with WT under salt stress. Moreover, the expression of stress-related genes DgAPX, DgCAT, DgNCED3A, DgNCED3B, DgCuZnSOD, DgP5CS, DgCSD1 and DgCSD2 was up-regulated in DgWRKY5 transgenic chrysanthemum compared with that in WT. These results suggested that DgWRKY5 could function as a positive regulator of salt stress in chrysanthemum.

  6. Selection of efficient salt-tolerant bacteria containing ACC deaminase for promotion of tomato growth under salinity stress

    Directory of Open Access Journals (Sweden)

    Kannika Chookietwattana* and Kedsukon Maneewan

    2012-05-01

    Full Text Available For successful application of plant growth promoting bacteria (PGPB in salt-affected soil, bioinoculant with salt-tolerant property is required in order to provide better survival and perform well in the field. The present study aimed to select the most efficient salt-tolerant bacterium containing 1-aminocyclopropane-1-carboxylic acid (ACC deaminase from eighty four bacterial strains and to investigate the effects of the selected bacterium on the germination and growth of tomato (Licopersicon esculentum Mill. cv. Seeda under saline conditions. The Bacillus licheniformis B2r was selected for its ability to utilize ACC as a sole nitrogen source under salinity stress. It also showed a high ACC deaminase activity at 0.6 M NaCl salinity. Tomato plants inoculated with the selected bacterium under various saline conditions (0, 30, 60, 90 and 120 mM NaCl revealed a significant increase in the germination percentage, germination index, root length, and seedling dry weight especially at salinity levels ranging from 30-90 mM NaCl. The work described in this report is an important step in developing an efficient salt-tolerant bioinoculant to facilitate plant growth in saline soil.

  7. The Fungus Aspergillus aculeatus Enhances Salt-Stress Tolerance, Metabolite Accumulation, and Improves Forage Quality in Perennial Ryegrass.

    Science.gov (United States)

    Li, Xiaoning; Han, Shijuan; Wang, Guangyang; Liu, Xiaoying; Amombo, Erick; Xie, Yan; Fu, Jinmin

    2017-01-01

    Perennial ryegrass (Lolium perenne) is an important forage grass with high yield and superior quality in temperate regions which is widely used in parks, sport field, and other places. However, perennial ryegrass is moderately tolerant to salinity stress compared to other commercial cultivars and salt stress reduces their growth and productivity. Aspergillus aculeatus has been documented to participate in alleviating damage induced by salinity. Therefore, the objective of this study was to investigate the mechanisms underlying A. aculeatus-mediated salt tolerance, and forage quality of perennial ryegrass exposed to 0, 200, and 400 mM NaCl concentrations. Physiological markers and forage quality of perennial ryegrass to salt stress were evaluated based on the growth rate, photosynthesis, antioxidant enzymes activity, lipid peroxidation, ionic homeostasis, the nutritional value of forage, and metabolites. Plants inoculated with A. aculeatus exhibited higher relative growth rate (RGR), turf and forage quality under salt stress than un-inoculated plants. Moreover, in inoculated plants, the fungus remarkably improved plant photosynthetic efficiency, reduced the antioxidant enzymes activity (POD and CAT), and attenuated lipid peroxidation (decreased H2O2 and MDA accumulation) induced by salinity, compared to un-inoculated plants. Furthermore, the fungus also acts as an important role in maintaining the lower Na/K ratio and metabolites and lower the amino acids (Alanine, Proline, GABA, and Asparagine), and soluble sugars (Glucose and Fructose) for inoculated plants than un-inoculated ones. Our results suggest that A. aculeatus may be involved in modulating perennial ryegrass tolerance to salinity in various ways.

  8. Transcriptome analyses of a salt-tolerant cytokinin-deficient mutant reveal differential regulation of salt stress response by cytokinin deficiency.

    Directory of Open Access Journals (Sweden)

    Rie Nishiyama

    Full Text Available Soil destruction by abiotic environmental conditions, such as high salinity, has resulted in dramatic losses of arable land, giving rise to the need of studying mechanisms of plant adaptation to salt stress aimed at creating salt-tolerant plants. Recently, it has been reported that cytokinins (CKs regulate plant environmental stress responses through two-component systems. A decrease in endogenous CK levels could enhance salt and drought stress tolerance. Here, we have investigated the global transcriptional change caused by a reduction in endogenous CK content under both normal and salt stress conditions. Ten-day-old Arabidopsis thaliana wild-type (WT and CK-deficient ipt1,3,5,7 plants were transferred to agar plates containing either 0 mM (control or 200 mM NaCl and maintained at normal growth conditions for 24 h. Our experimental design allowed us to compare transcriptome changes under four conditions: WT-200 mM vs. WT-0 mM, ipt1,3,5,7-0 mM vs. WT-0 mM, ipt1,3,5,7-200 mM vs. ipt1,3,5,7-0 mM and ipt1,3,5,7-200 mM vs. WT-200 mM NaCl. Our results indicated that the expression of more than 10% of all of the annotated Arabidopsis genes was altered by CK deficiency under either normal or salt stress conditions when compared to WT. We found that upregulated expression of many genes encoding either regulatory proteins, such as NAC, DREB and ZFHD transcription factors and the calcium sensor SOS3, or functional proteins, such as late embryogenesis-abundant proteins, xyloglucan endo-transglycosylases, glycosyltransferases, glycoside hydrolases, defensins and glyoxalase I family proteins, may contribute to improved salt tolerance of CK-deficient plants. We also demonstrated that the downregulation of photosynthesis-related genes and the upregulation of several NAC genes may cause the altered morphological phenotype of CK-deficient plants. This study highlights the impact of CK regulation on the well-known stress-responsive signaling pathways, which

  9. MusaDHN-1, a novel multiple stress-inducible SK(3)-type dehydrin gene, contributes affirmatively to drought- and salt-stress tolerance in banana.

    Science.gov (United States)

    Shekhawat, Upendra K Singh; Srinivas, Lingam; Ganapathi, Thumballi R

    2011-11-01

    Dehydrins are highly hydrophilic proteins involved in playing key adaptive roles in response to abiotic stress conditions having dehydration as a common component. In the present study, a novel banana SK(3)-type dehydrin, MusaDHN-1, was identified and later characterized using transgenic banana plants to investigate its functions in abiotic stress tolerance. Expression profiling in native banana plants demonstrated that MusaDHN-1 was induced in leaves by drought, salinity, cold, oxidative and heavy metal stress as well as by treatment with signalling molecules like abscisic acid, ethylene and methyl jasmonate. Promoter analysis carried out by making a MusaDHN-1 promoter: β-glucuronidase fusion construct reconfirmed the abiotic stress inducibility of MusaDHN-1. Transgenic banana plants constitutively overexpressing MusaDHN-1 were phenotypically normal and displayed improved tolerance to drought and salt-stress treatments in both in vitro and ex vitro assays. Enhanced accumulation of proline and reduced malondialdehyde levels in drought and salt-stressed MusaDHN-1 overexpressing plants further established their superior performance in stressed conditions. This study is the first to report generation of transgenic banana plants engineered for improved drought and salt-stress tolerance.

  10. Genetic Diversity of Salt Tolerance in Miscanthus

    Science.gov (United States)

    Chen, Chang-Lin; van der Schoot, Hanneke; Dehghan, Shiva; Alvim Kamei, Claire L.; Schwarz, Kai-Uwe; Meyer, Heike; Visser, Richard G. F.; van der Linden, C. Gerard

    2017-01-01

    Miscanthus is a woody rhizomatous C4 grass that can be used as a CO2 neutral biofuel resource. It has potential to grow in marginal areas such as saline soils, avoiding competition for arable lands with food crops. This study explored genetic diversity for salt tolerance in Miscanthus and discovered mechanisms and traits that can be used to improve the yield under salt stress. Seventy genotypes of Miscanthus (including 57 M. sinensis, 5 M. sacchariflorus, and 8 hybrids) were evaluated for salt tolerance under saline (150 mM NaCl) and normal growing conditions using a hydroponic system. Analyses of shoot growth traits and ion concentrations revealed the existence of large variation for salt tolerance in the genotypes. We identified genotypes with potential for high biomass production both under control and saline conditions that may be utilized for growth under marginal, saline conditions. Several relatively salt tolerant genotypes had clearly lower Na+ concentrations and showed relatively high K+/Na+ ratios in the shoots under salt stress, indicating that a Na+ exclusion mechanism was utilized to prevent Na+ accumulation in the leaves. Other genotypes showed limited reduction in leaf expansion and growth rate under saline conditions, which may be indicative of osmotic stress tolerance. The genotypes demonstrating potentially different salt tolerance mechanisms can serve as starting material for breeding programs aimed at improving salinity tolerance of Miscanthus. PMID:28261243

  11. Tolerance to drought and salt stress in plants: Unraveling the signaling networks

    Directory of Open Access Journals (Sweden)

    Dortje eGolldack

    2014-04-01

    Full Text Available Tolerance of plants to abiotic stressors such as drought and salinity is triggered by complex multicomponent signaling pathways to restore cellular homeostasis and promote survival. Major plant transcription factor families such as bZIP, NAC, AP2/ERF and MYB orchestrate regulatory networks underlying abiotic stress tolerance. Sucrose nonfermenting 1-related protein kinase 2 (SnRK2 and MAPK pathways contribute to initiation of stress adaptive downstream responses and promote plant growth and development. As a convergent point of multiple abiotic cues, cellular effects of environmental stresses are not only imbalances of ionic and osmotic homeostasis but also impaired photosynthesis, cellular energy depletion, and redox imbalances. Recent evidence of regulatory systems that link sensing and signaling of environmental conditions and the intracellular redox status have shed light on interfaces of stress and energy signaling. ROS (reactive oxygen species cause severe cellular damage by peroxidation and de-esterification of membrane lipids, however, current models also define a pivotal signaling function of ROS in triggering tolerance against stress. Recent research advances suggest and support a regulatory role of ROS in the cross talks of stress triggered hormonal signaling such as the abscisic acid (ABA pathway and endogenously induced redox and metabolite signals. Here, we discuss and review the versatile molecular convergence in the abiotic stress responsive signaling networks in the context of ROS and lipid derived signals and the specific role of stomatal signaling.

  12. Cold stress increases salt tolerance of the extremophytes Eutrema salsugineum (Thellungiella salsuginea) and Eutrema (Thellungiella) botschantzevii.

    Science.gov (United States)

    Shamustakimova, A O; Leonova, Т G; Taranov, V V; de Boer, A H; Babakov, A V

    2017-01-01

    A comparative study was performed to analyze the effect of cold acclimation on improving the resistance of Arabidopsis thaliana, Eutrema salsugineum and Eutrema botschantzevii plants to salt stress. Shoot FW, sodium and potassium accumulation, metabolite content, expression of proton pump genes VAB1, VAB2,VAB3, VP2, HA3 and genes encoding ion transporters SOS1, HKT1, NHX1, NHX2, NHX5 located in the plasma membrane or tonoplast were determined just after the cold treatment and the onset of the salt stress. In the same cold-acclimated E. botschantzevii plants, the Na(+) concentration after salt treatment was around 80% lower than in non-acclimated plants, whereas the K(+) concentration was higher. As a result of cold acclimation, the expression of, VAB3, NHX2, NHX5 genes and of SOS1, VP2, HA3 genes was strongly enhanced in E. botschantzevii and in E. salsugineum plants correspondently. None of the 10 genes analyzed showed any expression change in A. thaliana plants after cold acclimation. Altogether, the results indicate that cold-induced adaptation to subsequent salt stress exists in the extremophytes E. botschantzevii and to a lesser extend in E. salsugineum and is absent in Arabidopsis. This phenomenon may be attributed to the increased expression of ion transporter genes during cold acclimation in the Eutrema species. Copyright © 2016 Elsevier GmbH. All rights reserved.

  13. Contrasting responses of salinity-stressed salt-tolerant and intolerant winter wheat (Triticum aestivum L.) cultivars to ozone pollution.

    Science.gov (United States)

    Zheng, Y H; Li, X; Li, Y G; Miao, B H; Xu, H; Simmons, M; Yang, X H

    2012-03-01

    Contrasting winter wheat cultivars, salt-tolerant DK961 and intolerant JN17, which sown in no salinity (-S) and salinity (+S) boxes were exposed to charcoal filtered air (CF) and elevated O(3) (+O(3)) in open top chambers (OTCs) for 30 days. In -S DK961 and JN17 plants, +O(3) DK961 and JN17 plants had significantly lower light-saturated net photosynthetic rates (A(sat), 26% and 24%), stomatal conductance (g(s), 20% and 32%) and chlorophyll contents (10% and 21%), while O(3) considerably increased foliar electrolyte leakage (13% and 39%), malondialdehyde content (9% and 23%), POD activity and ABA content. However, responses of these parameters to O(3) were significant in DK961 but not in JN17 in +S treatment. Correlation coefficient of DK961 reached significance level of 0.01, but it was not significant in JN17 under interaction of O(3) and salinity. O(3)-induced reductions were larger in shoot than in root in both cultivars. Results indicate that the salt-tolerant cultivar sustained less damage from salinity than did the intolerant cultivar but was severely injured by O(3) under +S condition. Therefore, selecting for greater salt tolerance may not lead to the expected gains in yield in areas of moderate (100 mM) salinity when O(3) is present in high concentrations. In contrast, salinity-induced stomatal closure effectively reduced sensitivity to O(3) in the salt-intolerant cultivar. Hence we suggest salt-tolerant winter wheat cultivars might be well adapted to areas of high (>100 mM) salinity and O(3) stress, while intolerant cultivars might be adaptable to areas of mild/moderate salinity but high O(3) pollution. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  14. 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

    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-related stress tolerance phenotypes. To accomplish this, 166 L. monocytogenes isolates were sequenced and evaluated for their ability to grow in cold (4°C), salt (6% NaCl, 25°C), and acid (pH 5, 25°C) stress conditions as well as survive desiccation (33% RH, 20°C). The results revealed that the stress tolerance of L. monocytogenes is associated with serotype, clonal complex (CC), full length inlA profiles, and the presence of a plasmid which was identified in 55% of isolates. Isolates with full length inlA exhibited significantly (p stress tolerance of L. monocytogenes. Specifically, a number of cold and desiccation sensitive isolates contained PMSCs in σB regulator genes (rsbS, rsbU, rsbV). Collectively, the results suggest that knowing the sequence type of an isolate in addition to screening for the presence of full-length inlA and a plasmid, could help food processors and food agency investigators determine why certain isolates might be persisting in a food processing environment. Additionally, increased 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

  15. A Bowman-Birk type protease inhibitor is involved in the tolerance to salt stress in wheat.

    Science.gov (United States)

    Shan, Lei; Li, Cuiling; Chen, Fang; Zhao, Shuangyi; Xia, Guangmin

    2008-08-01

    A salt-responsive gene WRSI5 was characterized from salt-tolerant cultivar Shanrong No. 3 (SR3), an introgression line via asymmetric somatic hybrid between Triticum aestivum L. cv. Jinan177 (JN177) and Thinopyrum ponticum Podp. The peptide encoded by WRSI5 contains a Bowman-Birk domain sharing a high level of sequence identity to monocotyledonous protease inhibitors. When expressed in vitro, the WRSI5 gene product exhibited trypsin, but not chymotrypsin inhibition. The expression level of WRSI5 was increased in SR3 roots exposed to salt, drought or oxidative stress. In situ hybridization showed that it is induced in the endodermal cells of the mature region of the SR3 root tip, with no signal detectable in the corresponding region of the salt-susceptible cultivar JN177. SR3 has a higher selectivity for K(+) over Na(+), and therefore limits the transport of Na(+) from the root to the shoot. When overexpressed in Arabidopsis thaliana, WRSI5 improves the ability of seedlings to grow on a medium containing 150 mM NaCl. We suggest that WRSI5 plays an important role in regulating the plant growth rate or long-distance Na(+) transport in SR3 plants exposed to salt stress.

  16. Salt-tolerant and -sensitive alfalfa (Medicago sativa) cultivars have large variations in defense responses to the lepidopteran insect Spodoptera litura under normal and salt stress condition.

    Science.gov (United States)

    Lei, Yunting; Liu, Qing; Hettenhausen, Christian; Cao, Guoyan; Tan, Qing; Zhao, Weiye; Lin, Honghui; Wu, Jianqiang

    2017-01-01

    In nature, plants are often exposed to multiple stress factors at the same time. Yet, little is known about how plants modulate their physiology to counteract simultaneous abiotic and biotic stresses, such as soil salinity and insect herbivory. In this study, insect performance bioassays, phytohormone measurements, quantification of transcripts, and protein determination were employed to study the phenotypic variations of two alfalfa (Medicago sativa) cultivars in response to insect Spodoptera litura feeding under normal and salt stress condition. When being cultivated in normal soil, the salt-tolerant alfalfa cultivar Zhongmu-1 exhibited lower insect resistance than did the salt-sensitive cultivar Xinjiang Daye. Under salinity stress, the defense responses of Xinjiang Daye were repressed, whereas Zhongmu-1 did not show changes in resistance levels. It is likely that salinity influenced the resistance of Xinjiang Daye through suppressing the accumulation of jasmonic acid-isoleucine (JA-Ile), which is the bioactive hormone inducing herbivore defense responses, leading to attenuated trypsin proteinase inhibitor (TPI) activity. Furthermore, exogenous ABA supplementation suppressed the insect herbivory-induced JA/JA-Ile accumulation and levels of JAR1 (jasmonate resistant 1) and TPI, and further decreased the resistance of Xinjiang Daye, whereas Zhongmu-1 showed very little response to the increased ABA level. We propose a mechanism, in which high levels of abscisic acid induced by salt treatment may affect the expression levels of JAR1 and consequently decrease JA-Ile accumulation and thus partly suppress the defense of Xinjiang Daye against insects under salt stress. This study provides new insight into the mechanism by which alfalfa responds to concurrent abiotic and biotic stresses.

  17. Screening maize ( Zea mays L.) hybrids for salt stress tolerance at ...

    African Journals Online (AJOL)

    Plant breeding may provide a relatively cost effective short-term solution to the salinity problem by producing cultivars that are able to remain productive at low to moderate levels of salinity. To determine the most tolerant hybrid to salinity stress, an experiment was performed as factorial form under completely randomized ...

  18. 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

    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-related stress tolerance phenotypes. To accomplish this, 166 L. monocytogenes isolates were sequenced and evaluated for their ability to grow in cold (4°C), salt (6% NaCl, 25°C), and acid (pH 5, 25°C) stress conditions as well as survive desiccation (33% RH, 20°C). The results revealed that the stress tolerance of L. monocytogenes is associated with serotype, clonal complex (CC), full length inlA profiles, and the presence of a plasmid which was identified in 55% of isolates. Isolates with full length inlA exhibited significantly (p < 0.001) enhanced cold tolerance relative to those harboring a premature stop codon (PMSC) in this gene. Similarly, isolates possessing a plasmid demonstrated significantly (p = 0.013) enhanced acid tolerance. We also identified nine new L. monocytogenes sequence types, a new inlA PMSC, and several connections between CCs and the presence/absence or variations of specific genetic 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 and desiccation sensitive isolates contained PMSCs in σB regulator genes (rsbS, rsbU, rsbV). Collectively, the results suggest that knowing the sequence type of an isolate in

  19. Cerium oxide nanoparticles alter the salt stress tolerance of Brassica napus L. by modifying the formation of root apoplastic barriers.

    Science.gov (United States)

    Rossi, Lorenzo; Zhang, Weilan; Ma, Xingmao

    2017-10-01

    Rapidly growing global population adds significant strains on the fresh water resources. Consequently, saline water is increasingly tapped for crop irrigation. Meanwhile, rapid advancement of nanotechnology is introducing more and more engineered nanoparticles into the environment and in agricultural soils. While some negative effects of ENPs on plant health at very high concentrations have been reported, more beneficial effects of ENPs at relatively low concentrations are increasingly noticed, opening doors for potential applications of nanotechnology in agriculture. In particular, we found that cerium oxide nanoparticles (CeO2NPs) improved plant photosynthesis in salt stressed plants. Due to the close connections between salt stress tolerance and the root anatomical structures, we postulated that CeO2NPs could modify plant root anatomy and improve plant salt stress tolerance. This study aimed at testing the hypothesis with Brassica napus in the presence of CeO2NPs (0, 500 mg kg-1 dry sand) and/or NaCl (0, 50 mM) in a growth chamber. Free hand sections of fresh roots were taken every seven days for three weeks and the suberin lamellae development was examined under a fluorescence microscope. The results confirmed the hypothesis that CeO2NPs modified the formation of the apoplastic barriers in Brassica roots. In salt stressed plants, CeO2NPs shortened the root apoplastic barriers which allowed more Na+ transport to shoots and less accumulation of Na+ in plant roots. The altered Na+ fluxes and transport led to better physiological performance of Brassica and may lead to new applications of nanotechnology in agriculture. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. A salt-stress-regulator from the Poplar R2R3 MYB family integrates the regulation of lateral root emergence and ABA signaling to mediate salt stress tolerance in Arabidopsis.

    Science.gov (United States)

    Fang, Qing; Jiang, Tianzhi; Xu, Liangxiang; Liu, Hai; Mao, Hui; Wang, Xianqiang; Jiao, Bo; Duan, Yanjiao; Wang, Qiong; Dong, Qiannan; Yang, Li; Tian, Guozheng; Zhang, Chi; Zhou, Yifeng; Liu, Xiaopeng; Wang, Haiyang; Fan, Di; Wang, Bangjun; Luo, Keming

    2017-05-01

    The roles of most MYB transcription factors (TFs) in the poplar remain unclear. Here, we demonstrate that PtrSSR1, a salt-stress-regulator in the Populus trichocarpa R2R3 MYB gene family, mediates the tolerance of transgenic Arabidopsis plants to salt stress. The transcripts of PtrSSR1 could be induced by salt stress rapidly in poplar. Subcellular localization and yeast assays indicated that PtrSSR1 encoded a nuclear protein with transactivation activity. The Arabidopsis transformants overexpressing PtrSSR1 clearly displayed lateral root emergence (LRE) inhibition compared with wild-type (Wt) under normal conditions; while upon NaCl treatment, the transformants showed improved tolerance, and the LRs emerged faster from salt-induced inhibition. A strong correlation could exist between the LRE mediated by PtrSSR1 and abscisic acid (ABA), mainly because the transformants displayed more sensitivity to exogenous ABA during both seed germination and LRE, and had a distinctly increased level of endogenous ABA. Furthermore, several ABA- and salt-related genes, such as NCED3, ABI1 and CBL1, were up-regulated. Thus, our results suggest that elevation in the endogenous ABA content bring alteration of plant LR development, and that the poplar R2R3 MYB TF PtrSSR1 vitally improve salt stress tolerance by integrating the regulation of LRE and ABA signaling in Arabidopsis. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  1. Pathway analysis of the transcriptome and metabolome of salt sensitive and tolerant poplar species reveals evolutionary adaption of stress tolerance mechanisms

    Directory of Open Access Journals (Sweden)

    Schmitt-Kopplin Philippe

    2010-07-01

    Full Text Available Abstract Background Populus euphratica is a salt tolerant and Populus × canescens a salt sensitive poplar species. Because of low transcriptional responsiveness of P. euphratica to salinity we hypothesized that this species exhibits an innate activation of stress protective genes compared with salt sensitive poplars. To test this hypothesis, the transcriptome and metabolome of mature unstressed leaves of P. euphratica and P. × canescens were compared by whole genome microarray analyses and FT-ICR-MS metabolite profiling. Results Direct cross-species comparison of the transcriptomes of the two poplar species from phylogenetically different sections required filtering of the data set. Genes assigned to the GO slim categories 'mitochondria', 'cell wall', 'transport', 'energy metabolism' and 'secondary metabolism' were significantly enriched, whereas genes in the categories 'nucleus', 'RNA or DNA binding', 'kinase activity' and 'transcription factor activity' were significantly depleted in P. euphratica compared with P. × canescens. Evidence for a general activation of stress relevant genes in P. euphratica was not detected. Pathway analyses of metabolome and transcriptome data indicated stronger accumulation of primary sugars, activation of pathways for sugar alcohol production, and faster consumption of secondary metabolites in P. euphratica compared to P. × canescens. Physiological measurements showing higher respiration, higher tannin and soluble phenolic contents as well as enrichment of glucose and fructose in P. euphratica compared to P. × canescens corroborated the results of pathway analyses. Conclusion P. euphratica does not rely on general over-expression of stress pathways to tolerate salt stress. Instead, it exhibits permanent activation of control mechanisms for osmotic adjustment (sugar and sugar alcohols, ion compartmentalization (sodium, potassium and other metabolite transporters and detoxification of reactive oxygen species

  2. The Cotton WRKY Gene GhWRKY41 Positively Regulates Salt and Drought Stress Tolerance in Transgenic Nicotiana benthamiana.

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    Xiaoqian Chu

    Full Text Available WRKY transcription factors constitute a very large family of proteins in plants and participate in modulating plant biological processes, such as growth, development and stress responses. However, the exact roles of WRKY proteins are unclear, particularly in non-model plants. In this study, Gossypium hirsutum WRKY41 (GhWRKY41 was isolated and transformed into Nicotiana benthamiana. Our results showed that overexpression of GhWRKY41 enhanced the drought and salt stress tolerance of transgenic Nicotiana benthamiana. The transgenic plants exhibited lower malondialdehyde content and higher antioxidant enzyme activity, and the expression of antioxidant genes was upregulated in transgenic plants exposed to osmotic stress. A β-glucuronidase (GUS staining assay showed that GhWRKY41 was highly expressed in the stomata when plants were exposed to osmotic stress, and plants overexpressing GhWRKY41 exhibited enhanced stomatal closure when they were exposed to osmotic stress. Taken together, our findings demonstrate that GhWRKY41 may enhance plant tolerance to stress by functioning as a positive regulator of stoma closure and by regulating reactive oxygen species (ROS scavenging and the expression of antioxidant genes.

  3. Effects of salt stress on wild type and vte4 mutant Arabidopsis thaliana: Model plant to engineer tolerance towards salinity

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    Khalatbari Amir Ali

    2013-01-01

    Full Text Available One of the major environmental constraints impairing plant distribution and yield is believed to be salt stress. Additionally, engineered abiotic stress resistance or/and tolerance is considered as an indispensable target in order to enhance plant productivity. In this study, the effects of salinity on physiological and morphological of wild type (Columbia-0 and vte4 mutant Arabidopsis thaliana were investigated under different NaCl concentrations. These salt treatments, including control condition, 50mM and 100mM NaCl were imposed on the plants. Each salt treatment was replicated three times in a complete randomized design with factorial arrangement. Wild type and mutant A.thaliana plants were subjected to the abiotic stress (salinity for up to 11 days to evaluate the parameters of growth, development and water relations. As a result, the performance of wild type plants was stronger than vte4 mutant under different salt treatments. Under control condition, rosette dry weight, maximum quantum efficiency (PSII and specific leaf area obtained the highest values of 13.85 mg, considered, wild type A.thaliana recorded higher value of 0.82 gW/gFW for relative water content (RWC under 50mM NaCl whereas mutant plants gained the value of 0.78 gW/gFW under the same condition. However, root mass fraction indicated an increase for both wild type and vte4 mutant plants after 11 days of salt stress onset. The reduction of water potential was observed for wild type and mutant A.thaliana where it scored -1.3 MPa and -1.4, respectively. As a conclusion, these findings implied that under different salt treatments morphological and physiological responses of wild type and vte4 mutant were affected in which wild type plants showed more tolerance. Lack of γ-tocopherol methyltransferase (γ -TMT gene in vte4 seemed to impair defence mechanism of this mutant against salinity.

  4. comparative study with commercial rootstocks to determine the tolerance to heavy metal (Pb in the drought and salt stress tolerant eggplant breeding lines

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    Mevlüde Nur TOPAL

    2017-06-01

    Full Text Available Negative effects of heavy metals on plants are peroxidation of lipids in cell membranes, production of free oxygen radicals, disorders in photosynthesis, damages in DNAs and as a result death of the cell. Plant development, productivity and quality of the fruits are decreased in the plants that are exposed to Pb stress which is one of the most toxic heavy metals. Usage of rootstocks which is mainly used against biotic stress conditions also seems to be defined as a solution to abiotic stress conditions such as heavy metal stresses. In eggplant production, wild species and hybrids are used as rootstocks against soil based pathogens and nematode. Reactions of improvement lines derived from local gene resources for rootstock improvement to heavy metal stress which is one of the abiotic stresses were determined. While determining the resistance against Pb stress, commercially used eggplant rootstocks are compared. In this study 4 eggplant cultivars (S. melongena: Burdur Bucak, Mardin Kızıltepe, Artvin Hopa and Kemer whose resistance potential against salt and drought stresses had been previously revealed and 6 rootstocks of wild eggplant species or hybrids (AGR-703, Doyran, Hawk, Hikyaku, Köksal-F1 and Vista-306 were tested against Pb stress. Eggplant seedlings were applied to 0, 150 and 300 ppm Pb solutions (Pb(NO32 during 4-5 true leaf stage. 20 days after the stress application wet and dry weight of green parts and roots, height of the body part and leaf areas were measured. Pb tolerance of Köksal F1 and AGR703 rootstocks were higher than other commercial rootstocks. Mardin Kızıltepe and Burdur Merkez genotypes which have high tolerances against abiotic stress gave lower values with respect to Artvin Hopa and Kemer which are sensitive genotypes and many other rootstocks while comparing the reduction ratios of stress signs such as shoot fresh weight and shoot length according to control under Pb stress.

  5. Overexpression of S-Adenosyl-l-Methionine Synthetase 2 from Sugar Beet M14 Increased Arabidopsis Tolerance to Salt and Oxidative Stress

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    Chunquan Ma

    2017-04-01

    Full Text Available The sugar beet monosomic addition line M14 is a unique germplasm that contains genetic materials from Beta vulgaris L. and Beta corolliflora Zoss, and shows tolerance to salt stress. Our study focuses on exploring the molecular mechanism of the salt tolerance of the sugar beet M14. In order to identify differentially expressed genes in M14 under salt stress, a subtractive cDNA library was generated by suppression subtractive hybridization (SSH. A total of 36 unique sequences were identified in the library and their putative functions were analyzed. One of the genes, S-adenosylmethionine synthetase (SAMS, is the key enzyme involved in the biosynthesis of S-adenosylmethionine (SAM, a precursor of polyamines. To determine the potential role of SAMS in salt tolerance, we isolated BvM14-SAMS2 from the salt-tolerant sugar beet M14. The expression of BvM14-SAMS2 in leaves and roots was greatly induced by salt stress. Overexpression of BvM14-SAMS2 in Arabidopsis resulted in enhanced salt and H2O2 tolerance. Furthermore, we obtained a knock-down T-DNA insertion mutant of AtSAMS3, which shares the highest homology with BvM14-SAMS2. Interestingly, the mutant atsam3 showed sensitivity to salt and H2O2 stress. We also found that the antioxidant system and polyamine metabolism play an important role in salt and H2O2 tolerance in the BvM14-SAMS2-overexpressed plants. To our knowledge, the function of the sugar beet SAMS has not been reported before. Our results have provided new insights into SAMS functions in sugar beet.

  6. The Solanum lycopersicum WRKY3 Transcription Factor SlWRKY3 Is Involved in Salt Stress Tolerance in Tomato

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    Imène Hichri

    2017-07-01

    Full Text Available Salinity threatens productivity of economically important crops such as tomato (Solanum lycopersicum L.. WRKY transcription factors appear, from a growing body of knowledge, as important regulators of abiotic stresses tolerance. Tomato SlWRKY3 is a nuclear protein binding to the consensus CGTTGACC/T W box. SlWRKY3 is preferentially expressed in aged organs, and is rapidly induced by NaCl, KCl, and drought. In addition, SlWRKY3 responds to salicylic acid, and 35S::SlWRKY3 tomatoes showed under salt treatment reduced contents of salicylic acid. In tomato, overexpression of SlWRKY3 impacted multiple aspects of salinity tolerance. Indeed, salinized (125 mM NaCl, 20 days 35S::SlWRKY3 tomato plants displayed reduced oxidative stress and proline contents compared to WT. Physiological parameters related to plant growth (shoot and root biomass and photosynthesis (stomatal conductance and chlorophyll a content were retained in transgenic plants, together with lower Na+ contents in leaves, and higher accumulation of K+ and Ca2+. Microarray analysis confirmed that many stress-related genes were already up-regulated in transgenic tomatoes under optimal conditions of growth, including genes coding for antioxidant enzymes, ion and water transporters, or plant defense proteins. Together, these results indicate that SlWRKY3 is an important regulator of salinity tolerance in tomato.

  7. Cadmium hampers salt tolerance of Sesuvium portulacastrum.

    Science.gov (United States)

    Wali, Mariem; Martos, Soledad; Pérez-Martín, Laura; Abdelly, Chedly; Ghnaya, Tahar; Poschenrieder, Charlotte; Gunsé, Benet

    2017-06-01

    It is well known that salinity reduces cadmium toxicity in halophytes. However, the possible interference of Cd with the mechanisms of salt tolerance is poorly explored. The aim of this study was to see whether Cd affects salt tolerance mechanisms in the halophyte Sesuvium portulacastrum. S. portulacastrum plants obtained from cuttings were grown in hydroponics for 3 weeks and then exposed to low (0.09 mM) or moderate (200 mM) NaCl concentrations, alone or in combination with 25 μM CdCl 2 . Microscopy observation revealed two strategies of salt tolerance: euhalophytism and secretion of salt by bladder cells. Cadmium exposure hardly influenced the total leaf Na + concentrations. However, Cd supply delayed the salt-induced upregulation of AHA1 (plasma membrane H + -ATPase 1) and SOS1 (plasma membrane Na + transporter "Salt Overly Sensitive 1"), genes that are essential for salt tolerance. Moreover, Cd induced the activation of BADH, coding for betaine aldehyde dehydrogenase, indicating enhanced osmotic stress due to Cd. Sodium-green fluorescence in protoplasts from plants grown with low or high NaCl, alone or in combination with Cd, revealed higher Na + concentrations in the cytoplasm of Cd-exposed plants. Taken together the results indicate interference of Cd with salt tolerance mechanisms in S. portulacastrum. This may have consequences for the efficient use of halophytes in phytoremediation of Cd-contaminated saline soils. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  8. Salt and oxidative stress tolerance in Debaryomyces hansenii and Debaryomyces fabryi

    Czech Academy of Sciences Publication Activity Database

    Michán, C.; Martínez, J.L.; Alvarez, M.C.; Turk, M.; Sychrová, Hana; Ramos, J.

    2013-01-01

    Roč. 13, č. 2 (2013), s. 180-188 ISSN 1567-1356 R&D Projects: GA MŠk(CZ) OC10012; GA ČR(CZ) GAP503/10/0307 Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M200110901 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : Debaryomyces * stress tolerance * ROS content * sodium content * membrane fluidity Subject RIV: EE - Microbiology, Virology Impact factor: 2.436, year: 2013

  9. A Novel Stress-Induced Sugarcane Gene Confers Tolerance to Drought, Salt and Oxidative Stress in Transgenic Tobacco Plants

    Science.gov (United States)

    Begcy, Kevin; Mariano, Eduardo D.; Gentile, Agustina; Lembke, Carolina G.; Zingaretti, Sonia Marli; Souza, Glaucia M.; Menossi, Marcelo

    2012-01-01

    Background Drought is a major abiotic stress that affects crop productivity worldwide. Sugarcane can withstand periods of water scarcity during the final stage of culm maturation, during which sucrose accumulation occurs. Meanwhile, prolonged periods of drought can cause severe plant losses. Methodology/Principal Findings In a previous study, we evaluated the transcriptome of drought-stressed plants to better understand sugarcane responses to drought. Among the up-regulated genes was Scdr1 (sugarcane drought-responsive 1). The aim of the research reported here was to characterize this gene. Scdr1 encodes a putative protein containing 248 amino acids with a large number of proline (19%) and cysteine (13%) residues. Phylogenetic analysis showed that ScDR1is in a clade with homologs from other monocotyledonous plants, separate from those of dicotyledonous plants. The expression of Scdr1 in different varieties of sugarcane plants has not shown a clear association with drought tolerance. Conclusions/Significance The overexpression of Scdr1 in transgenic tobacco plants increased their tolerance to drought, salinity and oxidative stress, as demonstrated by increased photosynthesis, water content, biomass, germination rate, chlorophyll content and reduced accumulation of ROS. Physiological parameters, such as transpiration rate (E), net photosynthesis (A), stomatal conductance (gs) and internal leaf CO2 concentration, were less affected by abiotic stresses in transgenic Scdr1 plants compared with wild-type plants. Overall, our results indicated that Scdr1 conferred tolerance to multiple abiotic stresses, highlighting the potential of this gene for biotechnological applications. PMID:22984543

  10. Expression of chickpea CIPK25 enhances root growth and tolerance to dehydration and salt stress in transgenic tobacco

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    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.

  11. Alleviation of salt stress in citrus seedlings inoculated with arbuscular mycorrhizal fungi depends on the rootstock salt tolerance.

    Science.gov (United States)

    Navarro, Josefa M; Pérez-Tornero, Olaya; Morte, Asunción

    2014-01-01

    Seedlings of Cleopatra mandarin (Citrus reshni Hort. ex Tan.) and Alemow (Citrus macrophylla Wester) were inoculated with a mixture of AM fungi (Rhizophagus irregularis and Funneliformis mosseae) (+AM), or left non-inoculated (-AM). From forty-five days after fungal inoculation onwards, half of +AM or -AM plants were irrigated with nutrient solution containing 50 mM NaCl. Three months later, AM significantly increased plant growth in both Cleopatra mandarin and Alemow rootstocks. Plant growth was higher in salinized +AM plants than in non-salinized -AM plants, demonstrating that AM compensates the growth limitations imposed by salinity. Whereas AM-inoculated Cleopatra mandarin seedlings had a very good response under saline treatment, inoculation in Alemow did not alleviate the negative effect of salinity. The beneficial effect of mycorrhization is unrelated with protection against the uptake of Na or Cl and the effect of AM on these ions did not explain the different response of rootstocks. This response was related with the nutritional status since our findings confirm that AM fungi can alter host responses to salinity stress, improving more the P, K, Fe and Cu plant nutrition in Cleopatra mandarin than in Alemow plants. AM inoculation under saline treatments also increased root Mg concentration but it was higher in Cleopatra mandarin than in Alemow. This could explain why AM fungus did not completely recovered chlorophyll concentrations in Alemow and consequently it had lower photosynthesis rate than control plants. AM fungi play an essential role in citrus rootstock growth and biomass production although the intensity of this response depends on the rootstock salinity tolerance. Copyright © 2013 Elsevier GmbH. All rights reserved.

  12. Over-expression of the peroxisomal ascorbate peroxidase (SbpAPX) gene cloned from halophyte Salicornia brachiata confers salt and drought stress tolerance in transgenic tobacco.

    Science.gov (United States)

    Singh, Natwar; Mishra, Avinash; Jha, Bhavanath

    2014-06-01

    Salicornia brachiata Roxb., an extreme halophyte, is a naturally adapted higher plant model for additional gene resources to engineer salt tolerance in plants. Ascorbate peroxidase (APX) plays a key role in protecting plants against oxidative stress and thus confers abiotic stress tolerance. A full-length SbpAPX cDNA, encoding peroxisomal ascorbate peroxidase, was cloned from S. brachiata. The open reading frame encodes for a polypeptide of 287 amino acid residues (31.3-kDa protein). The deduced amino acid sequence of the SbpAPX gene showed characteristic peroxisomal targeting sequences (RKRAI) and a C-terminal hydrophobic region of 39 amino acid residues containing a transmembrane domain (TMD) of 23 amino acid residues. Northern blot analysis showed elevated SbpAPX transcript in response to salt, cold, abscisic acid and salicylic acid stress treatments. The SbpAPX gene was transformed to tobacco for their functional validation under stresses. Transgenic plants over-expressing SbpAPX gene showed enhanced salt and drought stress tolerance compared to wild-type plants. Transgenic plants showed enhanced vegetative growth and germination rate both under normal and stressed conditions. Present study revealed that the SbpAPX gene is a potential candidate, which not only confers abiotic stress tolerance to plants but also seems to be involved in plant growth.

  13. Evaluation of Saccharomyces cerevisiae GAS1 with respect to its involvement in tolerance to low pH and salt stress.

    Science.gov (United States)

    Matsushika, Akinori; Suzuki, Toshihiro; Goshima, Tetsuya; Hoshino, Tamotsu

    2017-08-01

    We previously showed that overexpression of IoGAS1, which was isolated from the multiple stress-tolerant yeast Issatchenkia orientalis, endows Saccharomyces cerevisiae cells with the ability to grow and ferment under acidic and high-salt conditions. The deduced amino acid sequence of the IoGAS1 gene product exhibits 60% identity with the S. cerevisiae Gas1 protein, a glycosylphosphatidylinositol-anchored protein essential for maintaining cell wall integrity. However, the functional roles of ScGAS1 in stress tolerance and pH regulation remain unclear. In the present study, we characterized ScGAS1 regarding its roles in tolerance to low pH and high salt concentrations. Transcriptional analysis indicated that, as for the IoGAS1 gene, ScGAS1 expression was pH dependent, with maximum expression at pH 3.0; the presence of salt increased endogenous expression of both GAS1 genes at almost all pH levels. These results suggested that ScGAS1, like IoGAS1, is involved in a novel acid- and salt-stress adaptation mechanism in S. cerevisiae. Overexpression of ScGAS1 in S. cerevisiae improved growth and ethanol production from glucose under acid stress without added salt, although the stress tolerance of the ScGAS1-overexpressing strain was inferior to that of the IoGAS1-overexpressing strain. However, overexpression of ScGAS1 did not result in increased tolerance of S. cerevisiae to combined acid and salt stress, even though ScGAS1 appears to be a salt-responsive gene. Thus, ScGAS1 is directly implicated in tolerance to low pH but does not confer salinity tolerance, supporting the view that ScGAS1 and IoGAS1 have overlapping yet distinct roles in stress tolerance in yeast. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  14. Overexpression of an Arabidopsis heterogeneous nuclear ribonucleoprotein gene, AtRNP1, affects plant growth and reduces plant tolerance to drought and salt stresses

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhenyu, E-mail: wzy72609@163.com [Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730030 (China); Zhao, Xiuyang, E-mail: xiuzh@psb.vib-ugent.be [Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730030 (China); Wang, Bing, E-mail: wangbing@ibcas.ac.cn [Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730030 (China); Liu, Erlong, E-mail: liuel14@lzu.edu.cn [Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730030 (China); Chen, Ni, E-mail: 63710156@qq.com [Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730030 (China); Zhang, Wei, E-mail: wzhang1216@yahoo.com [Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai 200444 (China); Liu, Heng, E-mail: hengliu@lzu.edu.cn [Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730030 (China)

    2016-04-01

    Heterogeneous nuclear ribonucleoproteins (hnRNPs) participate in diverse regulations of plant growth and environmental stress responses. In this work, an Arabidopsis hnRNP of unknown function, AtRNP1, was investigated. We found that AtRNP1 gene is highly expressed in rosette and cauline leaves, and slightly induced under drought, salt, osmotic and ABA stresses. AtRNP1 protein is localized to both the nucleus and cytoplasm. We performed homologous overexpression of AtRNP1 and found that the transgenic plants showed shortened root length and plant height, and accelerated flowering. In addition, the transgenic plants also showed reduced tolerance to drought, salt, osmotic and ABA stresses. Further studies revealed that under both normal and stress conditions, the proline contents in the transgenic plants are markedly decreased, associated with reduced expression levels of a proline synthase gene and several stress-responsive genes. These results suggested that the overexpression of AtRNP1 negatively affects plant growth and abiotic stress tolerance. - Highlights: • AtRNP1 is a widely expressed gene and its expression is slightly induced under abiotic stresses. • AtRNP1 protein is localized to both the nucleus and cytoplasm. • Overexpression of AtRNP1 affects plant growth. • Overexpression of AtRNP1 reduces plant tolerance to drought and salt stresses. • AtRNP1 overexpression plants show decreased proline accumulation and stress-responsive gene expressions.

  15. Disruption of AtWNK8 Enhances Tolerance of Arabidopsis to Salt and Osmotic Stresses via Modulating Proline Content and Activities of Catalase and Peroxidase

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    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.

  16. The maize AAA-type protein SKD1 confers enhanced salt and drought stress tolerance in transgenic tobacco by interacting with Lyst-interacting protein 5.

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    Zongliang Xia

    Full Text Available ATPase associated with various cellular activities (AAA proteins are important regulators involved in diverse cellular functions. To date, the molecular mechanisms of AAA proteins involved in response to salt and drought stresses in plants are largely unknown. In this study, a putative SKD1 (suppressor of K(+ transport growth defect 1 ortholog from Zea mays (ZmSKD1, which encodes a putative AAA protein, was isolated. The transcript levels of ZmSKD1 were higher in aerial tissues and were markedly up-regulated by salt or drought stress. Over-expression of ZmSKD1 in tobacco plants enhanced their tolerances not only to salt but to drought. Moreover, reactive oxygen species accumulations in ZmSKD1 transgenic lines were relative less than those in wild-type plants during salt or PEG-induced water stress. The interaction between ZmSKD1 and NtLIP5 (Lyst-Interacting Protein 5 homolog from Nicotiana tabacum was confirmed by both yeast two-hybrid and immuno-precipitation assays; moreover, the α-helix-rich domain in the C-terminus of ZmSKD1 was identified to be required for its interaction with NtLIP5 using truncation mutations. Collectively, these data demonstrate that ZmSKD1could be involved in salt and drought stress responses and its over-expression enhances salt or drought stress tolerance possibly through interacting with LIP5 in tobacco. This study may facilitate our understandings of the biological roles of SKD1-mediated ESCRT pathway under stress conditions in higher plants and accelerate genetic improvement of crop plants tolerant to environmental stresses.

  17. The modulation of leaf metabolism plays a role in salt tolerance of Cymodocea nodosa exposed to hypersaline stress in mesocosms

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    Amalia ePiro

    2015-06-01

    Full Text Available By the proteomic approach we tested the physiological responses of the euryhaline seagrass Cymodocea nodosa to deliberate manipulation of salinity in a mesocosm system. Plants were subjected to a chronic hypersaline condition (43 psu to compare their proteins expression and plant photochemistry responses after 15 and 30 days of exposure with those of plants cultured under normal/ambient saline conditions (37 psu. Results showed a general decline in the expression level of leaf proteins in hypersaline stressed plants, with more intense reductions on the long-lasting exposure. Specifically, the carbon-fixing enzyme RuBisCo displayed a lower expression level in stressed plants relative to controls; while contrarily, the key enzymes involve in the regulation of glycolisis, the cytosolic glyceraldehyde-3-phopsphate dehydrogenase, the enolase 2 and triose-phosphate isomerase, showed significant higher expression levels. Responses that suggest a shift of the carbon metabolism in stressed plants. Hypersaline stress also induced a significant alteration of the photosynthetic physiology of the C. nodosa by means of the down-regulation of structural proteins and enzymes of both PSII and PSI; however we found an over-expression of the cytochrome b559 alpha subunit of the PSII initial complex, which is a receptor for the PSII core proteins involved in biogenesis or repair processes and therefore potentially involved in the absence of effects at the photochemical level of stressed plants. As expected hypersalinity also affects the vacuolar metabolism increasing the leaf cell turgor pressure and enhancing the up-take of Na+ by the over-expression of the tonoplast specific intrinsic protein pyrophosphate-energized inorganic pyrophosphatase (H(+-PPase that is coupled with the Na+/H+-antiporter. The modulation of carbon metabolism and the enhancement of vacuole capacity in Na+ sequestration and osmolarity changes are discussed in relation to salt tolerance of C

  18. Bottle gourd rootstock-grafting affects nitrogen metabolism in NaCl-stressed watermelon leaves and enhances short-term salt tolerance.

    Science.gov (United States)

    Yang, Yanjuan; Lu, Xiaomin; Yan, Bei; Li, Bin; Sun, Jin; Guo, Shirong; Tezuka, Takafumi

    2013-05-01

    The plant growth, nitrogen absorption, and assimilation in watermelon (Citrullus lanatus [Thunb.] Mansf.) were investigated in self-grafted and grafted seedlings using the salt-tolerant bottle gourd rootstock Chaofeng Kangshengwang (Lagenaria siceraria Standl.) exposed to 100mM NaCl for 3d. The biomass and NO3(-) uptake rate were significantly increased by rootstock while these values were remarkably decreased by salt stress. However, compared with self-grafted plants, rootstock-grafted plants showed higher salt tolerance with higher biomass and NO3(-) uptake rate under salt stress. Salinity induced strong accumulation of nitrate, ammonium and protein contents and a significant decrease of nitrogen content and the activities of nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), and glutamate synthase (GOGAT) in leaves of self-grafted seedlings. In contrast, salt stress caused a remarkable decrease in nitrate content and the activities of GS and GOGAT, and a significant increase of ammonium, protein, and nitrogen contents and NR activity, in leaves of rootstock-grafted seedlings. Compared with that of self-grafted seedlings, the ammonium content in leaves of rootstock-grafted seedlings was much lower under salt stress. Glutamate dehydrogenase (GDH) activity was notably enhanced in leaves of rootstock-grafted seedlings, whereas it was significantly inhibited in leaves of self-grafted seedlings, under salinity stress. Three GDH isozymes were isolated by native gel electrophoresis and their expressions were greatly enhanced in leaves of rootstock-grafted seedlings than those of self-grafted seedlings under both normal and salt-stress conditions. These results indicated that the salt tolerance of rootstock-grafted seedlings might (be enhanced) owing to the higher nitrogen absorption and the higher activities of enzymes for nitrogen assimilation induced by the rootstock. Furthermore, the detoxification of ammonium by GDH when the GS/GOGAT pathway

  19. Salt and cadmium stress tolerance caused by overexpression of the Glycine Max Na+/H+ Antiporter (GmNHX1) gene in duckweed (Lemna turionifera 5511).

    Science.gov (United States)

    Yang, Lin; Han, Yujie; Wu, Di; Yong, Wang; Liu, Miaomiao; Wang, Sutong; Liu, Wenxin; Lu, Meiyi; Wei, Ying; Sun, Jinsheng

    2017-11-01

    Cadmium (Cd) pollution has aroused increasing attention due to its toxicity. It has been proved that Na+/H+ Antiporter (NHX1) encodes a well-documented protein in Na+/H+ trafficking, which leads to salt tolerance. This study showed that Glycine max Na+/H+ Antiporter (GmNHX1) improved short-term cadmium and salt resistance in Lemna turionifera 5511. Expression of GmNHX1 prevented root from abscission and cell membrane damage, which also can enhance antioxidant system, inhibited of reactive oxygen species (ROS) accumulation and cause a less absorption of Cd under cadmium and salt stress. The cadmium tolerance suggested that NHX1 was involved under the cadmium stress. Copyright © 2017. Published by Elsevier B.V.

  20. The effect of Piriformospora indica inoculation on salt and drought stress tolerance in Stevia rebaudiana under in vitro conditions

    Directory of Open Access Journals (Sweden)

    Fahimeh Seraj

    2016-09-01

    Full Text Available In order to investigate the effect of Piriformospora indica under salt and drought stresses on some vegetative characteristics and physiological parameters of stevia (Stevia rebaudiana Bertoni medicinal plant, an experiment was conducted in factorial arrangement based on completely randomized design with three replicates at Genetics and Agricultural Biotechnology Institute in Sari Agricultural Sciences and Natural Resources University. Factors include three levels of osmatic potential (0, -5, and -10 bar and with three osmotic sources including NaCl (Na, Mannitol (M and NaCl+Mannitol (N+M and inoculation of mycorrhizae like fungi at two levels (non-inoculated and inoculation with fungi. The plantlets were treated for 30 days and then some morphological and physiological parameters were measured. Results of ANOVA showed that there was a significant interaction between osmatic source and levels with fungi inoculation for the most determined parameters. Inoculation of stevia plantlets with P. indica at osmatic level of -5 bar caused either by M or M+Na markedly improved dry weight of leaf (112 and 156%, respectively and aerial parts (49 and 144%, respectively as compared to the uninoculated control. Fungi inoculation positively improved vegetative parameters of stevia plant under most osmatic levels and sources. The most ameliorate effect, however, was observed where M as drought stress or M+Na were adjusted to -5 bar. Therefore, the results of this study represented a positive effect of P. indica inoculation in inproving osmotic tolerance of stevia medicinal plant.

  1. Effects of heat, cold, acid and bile salt adaptations on the stress tolerance and protein expression of kefir-isolated probiotic Lactobacillus kefiranofaciens M1.

    Science.gov (United States)

    Chen, Ming-Ju; Tang, Hsin-Yu; Chiang, Ming-Lun

    2017-09-01

    Lactobacillus kefiranofaciens M1 is a probiotic strain isolated from Taiwanese kefir grains. The present study evaluated the effects of heat, cold, acid and bile salt adaptations on the stress tolerance of L. kefiranofaciens M1. The regulation of protein expression of L. kefiranofaciens M1 under these adaptation conditions was also investigated. The results showed that adaptation of L. kefiranofaciens M1 to heat, cold, acid and bile salts induced homologous tolerance and cross-protection against heterologous challenge. The extent of induced tolerance varied depending on the type and condition of stress. Proteomic analysis revealed that 27 proteins exhibited differences in expression between non-adapted and stress-adapted L. kefiranofaciens M1 cells. Among these proteins, three proteins involved in carbohydrate metabolism (triosephosphate isomerase, enolase and NAD-dependent glycerol-3-phosphate dehydrogenase), two proteins involved in pH homeostasis (ATP synthase subunits AtpA and AtpB), two stress response proteins (chaperones DnaK and GroEL) and one translation-related protein (30S ribosomal protein S2) were up-regulated by three of the four adaptation treatments examined. The increased synthesis of these stress proteins might play a critical protective role in the cellular defense against heat, cold, acid and bile salt stresses. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Constitutive and stress-inducible overexpression of a native aquaporin gene (MusaPIP2;6) in transgenic banana plants signals its pivotal role in salt tolerance.

    Science.gov (United States)

    Sreedharan, Shareena; Shekhawat, Upendra K Singh; Ganapathi, Thumballi R

    2015-05-01

    High soil salinity constitutes a major abiotic stress and an important limiting factor in cultivation of crop plants worldwide. Here, we report the identification and characterization of a aquaporin gene, MusaPIP2;6 which is involved in salt stress signaling in banana. MusaPIP2;6 was firstly identified based on comparative analysis of stressed and non-stressed banana tissue derived EST data sets and later overexpression in transgenic banana plants was performed to study its tangible functions in banana plants. The overexpression of MusaPIP2;6 in transgenic banana plants using constitutive or inducible promoter led to higher salt tolerance as compared to equivalent untransformed control plants. Cellular localization assay performed using transiently transformed onion peel cells indicated that MusaPIP2;6 protein tagged with green fluorescent protein was translocated to the plasma membrane. MusaPIP2;6-overexpressing banana plants displayed better photosynthetic efficiency and lower membrane damage under salt stress conditions. Our results suggest that MusaPIP2;6 is involved in salt stress signaling and tolerance in banana.

  3. A Medicago truncatula EF-hand family gene, MtCaMP1, is involved in drought and salt stress tolerance.

    Directory of Open Access Journals (Sweden)

    Tian-Zuo Wang

    Full Text Available BACKGROUND: Calcium-binding proteins that contain EF-hand motifs have been reported to play important roles in transduction of signals associated with biotic and abiotic stresses. To functionally characterize genes of EF-hand family in response to abiotic stress, an MtCaMP1 gene belonging to EF-hand family from legume model plant Medicago truncatula was isolated and its function in response to drought and salt stress was investigated by expressing MtCaMP1 in Arabidopsis. METHODOLOGY/PRINCIPAL FINDINGS: Transgenic Arabidopsis seedlings expressing MtCaMP1 exhibited higher survival rate than wild-type seedlings under drought and salt stress, suggesting that expression of MtCaMP1 confers tolerance of Arabidopsis to drought and salt stress. The transgenic plants accumulated greater amounts of Pro due to up-regulation of P5CS1 and down-regulation of ProDH than wild-type plants under drought stress. There was a less accumulation of Na(+ in the transgenic plants than in WT plants due to reduced up-regulation of AtHKT1 and enhanced regulation of AtNHX1 in the transgenic plants compared to WT plants under salt stress. There was a reduced accumulation of H2O2 and malondialdehyde in the transgenic plants than in WT plants under both drought and salt stress. CONCLUSIONS/SIGNIFICANCE: The expression of MtCaMP1 in Arabidopsis enhanced tolerance of the transgenic plants to drought and salt stress by effective osmo-regulation due to greater accumulation of Pro and by minimizing toxic Na(+ accumulation, respectively. The enhanced accumulation of Pro and reduced accumulation of Na(+ under drought and salt stress would protect plants from water default and Na(+ toxicity, and alleviate the associated oxidative stress. These findings demonstrate that MtCaMP1 encodes a stress-responsive EF-hand protein that plays a regulatory role in response of plants to drought and salt stress.

  4. Salt Tolerance in Rice: Focus on Mechanisms and Approaches

    Directory of Open Access Journals (Sweden)

    Inja Naga Bheema Lingeswara Reddy

    2017-05-01

    Full Text Available Salt tolerance is an important constrain for rice, which is generally categorized as a typical glycophyte. Soil salinity is one of the major constraints affecting rice production worldwide, especially in the coastal areas. Susceptibility or tolerance of rice plants to high salinity is a coordinated action of multiple stress responsive genes, which also interacts with other components of stress signal transduction pathways. Salt tolerant varieties can be produced by marker-assisted selection or genetic engineering by introducing salt-tolerance genes. In this review, we have updated on mechanisms and genes which can help in transferring of the salt tolerance into high-yielding rice varieties. We have focused on the need for integrating phenotyping, genomics, metabolic profiling and phenomics into transgenic and breeding approaches to develop high-yielding as well as salt tolerant rice varieties.

  5. Evaluation for salt stress tolerance of pepper genotypes to be used as rootstocks

    NARCIS (Netherlands)

    Penella, C.; Nebauer, S.G.; Lopéz-Galarza, S.; SanBautista, A.; Gorbe, E.; Calatayud, A.

    2013-01-01

    Salinity is a major environmental constraint on crop productivity and grafting can be a sustainable strategy to enhance plant tolerance under adverse growth conditions. Screening different graft combinations under field conditions can be a slow and expensive processes. In this study, plants of 18

  6. 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.

  7. Plant salt tolerance: adaptations in halophytes

    National Research Council Canada - National Science Library

    Flowers, Timothy J; Colmer, Timothy D

    2015-01-01

    ..., and to develop salt-tolerant crops. In this Preface to a Special Issue on halophytes and saline adaptations, the evolution of salt tolerance in halophytes, their life-history traits and progress in understanding...

  8. Comparative physiology of salt and water stress.

    Science.gov (United States)

    Munns, R.

    2002-02-01

    Plant responses to salt and water stress have much in common. Salinity reduces the ability of plants to take up water, and this quickly causes reductions in growth rate, along with a suite of metabolic changes identical to those caused by water stress. The initial reduction in shoot growth is probably due to hormonal signals generated by the roots. There may be salt-specific effects that later have an impact on growth; if excessive amounts of salt enter the plant, salt will eventually rise to toxic levels in the older transpiring leaves, causing premature senescence, and reduce the photosynthetic leaf area of the plant to a level that cannot sustain growth. These effects take time to develop. Salt-tolerant plants differ from salt-sensitive ones in having a low rate of Na+ and Cl-- transport to leaves, and the ability to compartmentalize these ions in vacuoles to prevent their build-up in cytoplasm or cell walls and thus avoid salt toxicity. In order to understand the processes that give rise to tolerance of salt, as distinct from tolerance of osmotic stress, and to identify genes that control the transport of salt across membranes, it is important to avoid treatments that induce cell plasmolysis, and to design experiments that distinguish between tolerance of salt and tolerance of water stress.

  9. Transgenic rice expressing a cassava (Manihot esculenta Crantz) plasma membrane gene MePMP3-2 exhibits enhanced tolerance to salt and drought stresses.

    Science.gov (United States)

    Yu, Y; Cui, Y C; Ren, C; Rocha, P S C F; Peng, M; Xu, G Y; Wang, M L; Xia, X J

    2016-02-05

    Plasma membrane proteolipid 3 (PMP3) is a class of small hydrophobic proteins found in many organisms including higher plants. Some plant PMP3 genes have been shown to respond to abiotic stresses and to participate in the processes of plant stress tolerance. In this study, we isolated the cassava (Manihot esculenta Crantz) MePMP3-2 gene and functionally characterized its role in tolerance to abiotic stress by expressing it in rice (Oryza sativa L.). MePMP3-2 encodes a 77-amino acid protein belonging to a subgroup of plant PMP3s that have long hydrophylic C-terminal tails of unknown function. In silico analysis and co-localization studies indicated that MePMP3-2 is a plasma membrane protein with two transmembrane domains, similar to other PMP3s. In cassava leaves, MePMP3-2 expression was up-regulated by salt and drought stresses. Heterologous constitutive expression of MePMP3-2 in rice did not alter plant growth and development but increased tolerance to salt and drought stresses. In addition, under stress conditions MePMP3-2 transgenic plants accumulated less malondialdehyde, had increased levels of proline, and exhibited greater up-regulation of the stress-related genes OsProT and OsP5CS, but led to only minor changes in OsDREB2A and OsLEA3 expression. These findings indicate that MePMP3-2 may play an important role in salt and drought stress tolerance in transgenic rice.

  10. A novel Glycine soja tonoplast intrinsic protein gene responds to abiotic stress and depresses salt and dehydration tolerance in transgenic Arabidopsis thaliana.

    Science.gov (United States)

    Wang, Xi; Li, Yong; Ji, Wei; Bai, Xi; Cai, Hua; Zhu, Dan; Sun, Xiao-Li; Chen, Lian-Jiang; Zhu, Yan-Ming

    2011-07-15

    Tonoplast intrinsic protein (TIP) is a subfamily of the aquaporin (AQP), also known as major intrinsic protein (MIP) family, and regulates water movement across vacuolar membranes. Some reports have implied that TIP genes are associated with plant tolerance to some abiotic stresses that cause water loss, such as drought and high salinity. In our previous work, we found that an expressed sequence tag (EST) representing a TIP gene in our Glycine soja EST library was inducible by abiotic stresses. This TIP was subsequently isolated from G. soja with cDNA library screening, EST assembly and PCR, and named as GsTIP2;1. The expression patterns of GsTIP2;1 in G. soja under low temperature, salt and dehydration stress were different in leaves and roots. Though GsTIP2;1 is a stress-induced gene, overexpression of GsTIP2;1 in Arabidopsis thaliana depressed tolerance to salt and dehydration stress, but did not affect seedling growth under cold or favorable conditions. Higher dehydration speed was detected in Arabidopsis plants overexpressing GsTIP2;1, implying GsTIP2;1 might mediate stress sensitivity by enhancing water loss in the plant. Such a result is not identical to previous reports, providing some new information about the relationship between TIP and plant abiotic stress tolerance. Copyright © 2011 Elsevier GmbH. All rights reserved.

  11. Overexpression of SbSI-1, A Nuclear Protein from Salicornia brachiata Confers Drought and Salt Stress Tolerance and Maintains Photosynthetic Efficiency in Transgenic Tobacco.

    Science.gov (United States)

    Kumari, Jyoti; Udawat, Pushpika; Dubey, Ashish K; Haque, Md Intesaful; Rathore, Mangal S; Jha, Bhavanath

    2017-01-01

    A novel Salicornia brachiata Salt Inducible (SbSI-1) gene was isolated and overexpressed in tobacco for in planta functional validation subjected to drought and salt stress. SbSI-1 is a nuclear protein. The transgenic tobacco overexpressing SbSI-1 gene exhibited better seed germination, growth performances, pigment contents, cell viability, starch accumulation, and tolerance index under drought and salt stress. Overexpression of SbSI-1 gene alleviated the build-up of reactive oxygen species (ROS) and curtailed the ROS-induced oxidative damages thus improved the physiological health of transgenic tobacco under stressed conditions. The higher activities of antioxidant enzymes, lower accumulation of ROS, higher membrane stability, relative water content, and polyphenol contents indicated the better survival of the transgenic tobacco than wild-type (WT) tobacco under stressed conditions. Transgenic tobacco had a higher net photosynthetic rate, PSII operating efficiency, and performance index under drought and salt stress. Higher accumulation of compatible solutes and K+/Na+ ratio in transgenic tobacco than WT showed the better osmotic and redox homeostasis under stressed conditions. The up-regulation of genes encoding antioxidant enzymes (NtSOD, NtAPX, and NtCAT) and transcription factors (NtDREB2 and NtAP2) in transgenic tobacco under stressed conditions showed the role of SbSI-1 in ROS alleviation and involvement of this gene in abiotic stress tolerance. Multivariate data analysis exhibited statistical distinction among growth responses, physiological health, osmotic adjustment, and photosynthetic responses of WT and transgenic tobacco under stressed conditions. The overexpression of SbSI-1 gene curtailed the ROS-induced oxidative damages and maintained the osmotic homeostasis under stress conditions thus improved physiological health and photosynthetic efficiencies of the transgenic tobacco overexpressing SbSI-1 gene.

  12. Overexpression of SbSI-1, A Nuclear Protein from Salicornia brachiata Confers Drought and Salt Stress Tolerance and Maintains Photosynthetic Efficiency in Transgenic Tobacco

    Directory of Open Access Journals (Sweden)

    Jyoti Kumari

    2017-07-01

    Full Text Available A novel SalicorniabrachiataSalt Inducible (SbSI-1 gene was isolated and overexpressed in tobacco for in planta functional validation subjected to drought and salt stress. SbSI-1 is a nuclear protein. The transgenic tobacco overexpressing SbSI-1 gene exhibited better seed germination, growth performances, pigment contents, cell viability, starch accumulation, and tolerance index under drought and salt stress. Overexpression of SbSI-1 gene alleviated the build-up of reactive oxygen species (ROS and curtailed the ROS-induced oxidative damages thus improved the physiological health of transgenic tobacco under stressed conditions. The higher activities of antioxidant enzymes, lower accumulation of ROS, higher membrane stability, relative water content, and polyphenol contents indicated the better survival of the transgenic tobacco than wild-type (WT tobacco under stressed conditions. Transgenic tobacco had a higher net photosynthetic rate, PSII operating efficiency, and performance index under drought and salt stress. Higher accumulation of compatible solutes and K+/Na+ ratio in transgenic tobacco than WT showed the better osmotic and redox homeostasis under stressed conditions. The up-regulation of genes encoding antioxidant enzymes (NtSOD, NtAPX, and NtCAT and transcription factors (NtDREB2 and NtAP2 in transgenic tobacco under stressed conditions showed the role of SbSI-1 in ROS alleviation and involvement of this gene in abiotic stress tolerance. Multivariate data analysis exhibited statistical distinction among growth responses, physiological health, osmotic adjustment, and photosynthetic responses of WT and transgenic tobacco under stressed conditions. The overexpression of SbSI-1 gene curtailed the ROS-induced oxidative damages and maintained the osmotic homeostasis under stress conditions thus improved physiological health and photosynthetic efficiencies of the transgenic tobacco overexpressing SbSI-1 gene.

  13. Differential responses of CO2 assimilation, carbohydrate allocation and gene expression to NaCl stress in perennial ryegrass with different salt tolerance.

    Directory of Open Access Journals (Sweden)

    Tao Hu

    Full Text Available Little is known about the effects of NaCl stress on perennial ryegrass (Lolium perenne L. photosynthesis and carbohydrate flux. The objective of this study was to understand the carbohydrate metabolism and identify the gene expression affected by salinity stress. Seventy-four days old seedlings of two perennial ryegrass accessions (salt-sensitive 'PI 538976' and salt-tolerant 'Overdrive' were subjected to three levels of salinity stress for 5 days. Turf quality in all tissues (leaves, stems and roots of both grass accessions negatively and significantly correlated with GFS (Glu+Fru+Suc content, except for 'Overdrive' stems. Relative growth rate (RGR in leaves negatively and significantly correlated with GFS content in 'Overdrive' (P0.05 for turf quality. A greater up-regulation in the expression of SPS, SS, SI, 6-SFT gene was observed in 'Overdrive' than 'PI 538976'. A higher level of SPS and SS expression in leaves was found in 'PI 538976' relative to 'Overdrive'. Accumulation of hexoses in roots, stems and leaves can induce a feedback repression to photosynthesis in salt-stressed perennial ryegrass and the salt tolerance may be changed with the carbohydrate allocation in leaves and stems.

  14. Vegetative and reproductive growth of salt-stressed chickpea are carbon-limited: sucrose infusion at the reproductive stage improves salt tolerance.

    Science.gov (United States)

    Khan, Hammad A; Siddique, Kadambot H M; Colmer, Timothy D

    2017-04-01

    Reproductive processes of chickpea (Cicer arietinum L.) are particularly sensitive to salinity. We tested whether limited photoassimilate availability contributes to reproductive failure in salt-stressed chickpea. Rupali, a salt-sensitive genotype, was grown in aerated nutrient solution, either with non-saline (control) or 30mM NaCl treatment. At flowering, stems were either infused with sucrose solution (0.44M), water only or maintained without any infusion, for 75 d. The sucrose and water infusion treatments of non-saline plants had no effect on growth or yield, but photosynthesis declined in response to sucrose infusion. Salt stress reduced photosynthesis, decreased tissue sugars by 22-47%, and vegetative and reproductive growth were severely impaired. Sucrose infusion of salt-treated plants increased total sugars in stems, leaves and developing pods, to levels similar to those of non-saline plants. In salt-stressed plants, sucrose infusion increased dry mass (2.6-fold), pod numbers (3.8-fold), seed numbers (6.5-fold) and seed yield (10.4-fold), yet vegetative growth and reproductive failure were not rescued completely by sucrose infusion. Sucrose infusion partly rescued reproductive failure in chickpea by increasing vegetative growth enabling more flower production and by providing sucrose for pod and seed growth. We conclude that insufficient assimilate availability limits yield in salt-stressed chickpea. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  15. 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

    Late embryogenesis abundant (LEA) proteins are closely related to abiotic stress tolerance of plants. In the present study, we identified a novel Em-like gene from lettuce, termed LsEm1, which could be classified into group 1 LEA proteins, and shared high homology with Cynara cardunculus Em protein. The LsEm1 protein contained three different 20-mer conserved elements (C-element, N-element, and M-element) in the C-termini, N-termini, and middle-region, respectively. The LsEm1 mRNAs were accumulated in all examined tissues during the flowering and mature stages, with a little accumulation in the roots and leaves during the seedling stage. Furthermore, the LsEm1 gene was also expressed in response to salt, dehydration, abscisic acid (ABA), and cold stresses in young seedlings. The LsEm1 protein could effectively reduce damage to the lactate dehydrogenase (LDH) and protect LDH activity under desiccation and salt treatments. The Escherichia coli cells overexpressing the LsEm1 gene showed a growth advantage over the control under drought and salt stresses. Moreover, LsEm1-overexpressing rice seeds were relatively sensitive to exogenously applied ABA, suggesting that the LsEm1 gene might depend on an ABA signaling pathway in response to environmental stresses. The transgenic rice plants overexpressing the LsEm1 gene showed higher tolerance to drought and salt stresses than did wild-type (WT) plants on the basis of the germination performances, higher survival rates, higher chlorophyll content, more accumulation of soluble sugar, lower relative electrolyte leakage, and higher superoxide dismutase activity under stress conditions. The LsEm1-overexpressing rice lines also showed less yield loss compared with WT rice under stress conditions. Furthermore, the LsEm1 gene had a positive effect on the expression of the OsCDPK9, OsCDPK13, OsCDPK15, OsCDPK25, and rab21 (rab16a) genes in transgenic rice under drought and salt stress conditions, implying that overexpression of these

  16. The Solanum lycopersicum WRKY3 Transcription Factor SlWRKY3 Is Involved in Salt Stress Tolerance in Tomato

    Czech Academy of Sciences Publication Activity Database

    Hichri, I.; Muhovski, Y.; Žižková, Eva; Dobrev, Petre; Gharbi, E.; Franco-Zorrilla, J.M.; Lopez-Vidriero, I.; Solano, R.; Clippe, A.; Errachid, A.; Motyka, Václav; Lutts, S.

    2017-01-01

    Roč. 8, JUL 31 (2017), č. článku 1343. ISSN 1664-462X R&D Projects: GA ČR(CZ) GA16-14649S Institutional support: RVO:61389030 Keywords : agrobacterium-mediated transformation * transgenic arabidopsis plants * dna-binding * salinity tolerance * defense responses * drought tolerance * abiotic stresses * water-stress * genes * tobacco * Solanum lycopersicum * SlWRKY3 * transcription factor * salinity tolerance * plant physiology Subject RIV: EF - Botanics Impact factor: 4.298, year: 2016

  17. High accumulation of anthocyanins via the ectopic expression of AtDFR confers significant salt stress tolerance in Brassica napus L.

    Science.gov (United States)

    Kim, Jihye; Lee, Won Je; Vu, Tien Thanh; Jeong, Chan Young; Hong, Suk-Whan; Lee, Hojoung

    2017-08-01

    The ectopic expression of AtDFR results in increased accumulation of anthocyanins leading to enhanced salinity and drought stress tolerance in B. napus plants. Flavonoids with antioxidant effects confer many additional benefits to plants. Evidence indicates that flavonoids, including anthocyanins, protect tissues against oxidative stress from various abiotic stressors. We determined whether increases in anthocyanins increased abiotic stress tolerance in Brassica napus, because the values of B. napus L. and its cultivation area are increasing worldwide. We overexpressed Arabidopsis dihydroflavonol-4-reductase (DFR) in B. napus. Increased DFR transcript levels for AtDFR-OX B. shoots correlated with higher anthocyanin accumulation. AtDFR-OX Brassica shoots exhibited lower reactive oxygen species (ROS) accumulation than wild-type (WT) shoots under high NaCl and mannitol concentrations. This was corroborated by 3,3-diaminobenzidine staining for ROS scavenging activity in 1,1-diphenyl-2-picryl-hydrazyl assays. Shoots of the AtDFR-OX B. napus lines grown in a high salt medium exhibited enhanced salt tolerance and higher chlorophyll content than similarly grown WT plants. Our observations suggested that the AtDFR gene can be effectively manipulated to modulate salinity and drought stress tolerance by directing to high accumulation of anthocyanins in oilseed plants.

  18. K+ Efflux and Retention in Response to NaCl Stress Do Not Predict Salt Tolerance in Contrasting Genotypes of Rice (Oryza sativa L.)

    Science.gov (United States)

    Coskun, Devrim; Britto, Dev T.; Jean, Yuel-Kai; Kabir, Imtiaz; Tolay, Inci; Torun, Ayfer A.; Kronzucker, Herbert J.

    2013-01-01

    Sudden elevations in external sodium chloride (NaCl) accelerate potassium (K+) efflux across the plasma membrane of plant root cells. It has been proposed that the extent of this acceleration can predict salt tolerance among contrasting cultivars. However, this proposal has not been considered in the context of plant nutritional history, nor has it been explored in rice (Oryza sativa L.), which stands among the world’s most important and salt-sensitive crop species. Using efflux analysis with 42K, coupled with growth and tissue K+ analyses, we examined the short- and long-term effects of NaCl exposure to plant performance within a nutritional matrix that significantly altered tissue-K+ set points in three rice cultivars that differ in salt tolerance: IR29 (sensitive), IR72 (moderate), and Pokkali (tolerant). We show that total short-term K+ release from roots in response to NaCl stress is small (no more than 26% over 45 min) in rice. Despite strong varietal differences, the extent of efflux is shown to be a poor predictor of plant performance on long-term NaCl stress. In fact, no measure of K+ status was found to correlate with plant performance among cultivars either in the presence or absence of NaCl stress. By contrast, shoot Na+ accumulation showed the strongest correlation (a negative one) with biomass, under long-term salinity. Pharmacological evidence suggests that NaCl-induced K+ efflux is a result of membrane disintegrity, possibly as result of osmotic shock, and not due to ion-channel mediation. Taken together, we conclude that, in rice, K+ status (including efflux) is a poor predictor of salt tolerance and overall plant performance and, instead, shoot Na+ accumulation is the key factor in performance decline on NaCl stress. PMID:23460903

  19. K+ efflux and retention in response to NaCl stress do not predict salt tolerance in contrasting genotypes of rice (Oryza sativa L..

    Directory of Open Access Journals (Sweden)

    Devrim Coskun

    Full Text Available Sudden elevations in external sodium chloride (NaCl accelerate potassium (K(+ efflux across the plasma membrane of plant root cells. It has been proposed that the extent of this acceleration can predict salt tolerance among contrasting cultivars. However, this proposal has not been considered in the context of plant nutritional history, nor has it been explored in rice (Oryza sativa L., which stands among the world's most important and salt-sensitive crop species. Using efflux analysis with (42K, coupled with growth and tissue K(+ analyses, we examined the short- and long-term effects of NaCl exposure to plant performance within a nutritional matrix that significantly altered tissue-K(+ set points in three rice cultivars that differ in salt tolerance: IR29 (sensitive, IR72 (moderate, and Pokkali (tolerant. We show that total short-term K(+ release from roots in response to NaCl stress is small (no more than 26% over 45 min in rice. Despite strong varietal differences, the extent of efflux is shown to be a poor predictor of plant performance on long-term NaCl stress. In fact, no measure of K(+ status was found to correlate with plant performance among cultivars either in the presence or absence of NaCl stress. By contrast, shoot Na(+ accumulation showed the strongest correlation (a negative one with biomass, under long-term salinity. Pharmacological evidence suggests that NaCl-induced K(+ efflux is a result of membrane disintegrity, possibly as result of osmotic shock, and not due to ion-channel mediation. Taken together, we conclude that, in rice, K(+ status (including efflux is a poor predictor of salt tolerance and overall plant performance and, instead, shoot Na(+ accumulation is the key factor in performance decline on NaCl stress.

  20. Identifying salt stress-responsive transcripts from Roselle ( Hibiscus ...

    African Journals Online (AJOL)

    Hibiscus sabdariffa L.). Identifying the potentially novel transcripts responsible for salt stress tolerance in roselle will increase knowledge of the molecular mechanism underlying salt stress responses. In this study, differential display reverse ...

  1. The effect of exogenous spermidine concentration on polyamine metabolism and salt tolerance in zoysiagrass (Zoysia japonica Steud subjected to short-term salinity stress

    Directory of Open Access Journals (Sweden)

    Shucheng Li

    2016-08-01

    Full Text Available Salt stress, and particularly short-term salinity stress, is one of the most serious abiotic factors limiting plant survival and growth in China. It has been established that exogenous spermidine (Spd stimulats tolerance to salt stress in plants. In the present study, two cultivars that are typically grown in China were used. The two zoysiagrass cultivars, exhibiting a sensitive ( cv. Z081 or tolerant ( cv. Z057 salt stress adaptation ability, were subjected to 200 mM salt stress and treated with different exogenous Spd concentrations for 8 days. Polyamine (Put, Spd and Spm contents and polyamine metabolic enzyme (ADC, ODC, SAMDC, PAO and DAO, malondialdehyde (MDA, H2O2 and antioxidant enzyme activities (superoxide dismutase, catalase, and peroxidase were measured. The results showed that salt stress induced increases in Spd and Spm contents and the activity of ornithine decarboxylase (ODC, S-adenosylmethionine decarboxylase (SAMDC and diamine oxidase (DAO in both cultivars. Exogenous Spd application did not compromise polyamine contents through the regulation of polyamine-degrading enzymes, and an increase in PA synthesis enzymes was observed during the experiment. The application resulted in a tendency for the Spd and Spm contents and the activities of ODC, S-adenosylmethionine decarboxylase (SAMDC, DAO, and antioxidant enzymes to first increase and then decrease in both cultivars with an increase in the exogenous Spd concentration. H2O2 and MDA significantly decreased in both cultivars treated with Spd. With an increase in the exogenous Spd concentration, the Spd + Spm level scores showed positive correlations with polyamine synthesis enzymes (ADC, SAMDC, DAO, antioxidant enzymes (SOD, POD, CAT, while showing negative correlations with H2O2 and MDA in both cultivars.

  2. Application of Plant-Growth-Promoting Fungi Trichoderma longibrachiatum T6 Enhances Tolerance of Wheat to Salt Stress through Improvement of Antioxidative Defense System and Gene Expression.

    Science.gov (United States)

    Zhang, Shuwu; Gan, Yantai; Xu, Bingliang

    2016-01-01

    Soil salinity is a serious problem worldwide that reduces agricultural productivity. Trichoderma longibrachiatum T6 (T6) has been shown to promote wheat growth and induce plant resistance to parasitic nematodes, but whether the plant-growth-promoting fungi T6 can enhance plant tolerance to salt stress is unknown. Here, we determined the effect of plant-growth-promoting fungi T6 on wheat seedlings' growth and development under salt stress, and investigated the role of T6 in inducing the resistance to NaCl stress at physiological, biochemical, and molecular levels. Wheat seedlings were inoculated with the strain of T6 and then compared with non-inoculated controls. Shoot height, root length, and shoot and root weights were measured on 15 days old wheat seedlings grown either under 150 mM NaCl or in a controlled setting without any NaCl. A number of colonies were re-isolated from the roots of wheat seedlings under salt stress. The relative water content in the leaves and roots, chlorophyll content, and root activity were significantly increased, and the accumulation of proline content in leaves was markedly accelerated with the plant growth parameters, but the content of leaf malondialdehyde under saline condition was significantly decreased. The antioxidant enzymes-superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in wheat seedlings were increased by 29, 39, and 19%, respectively, with the application of the strain of T6 under salt stress; the relative expression of SOD, POD, and CAT genes in these wheat seedlings were significantly up-regulated. Our results indicated that the strain of T6 ameliorated the adverse effects significantly, protecting the seedlings from salt stress during their growth period. The possible mechanisms by which T6 suppresses the negative effect of NaCl stress on wheat seedling growth may be due to the improvement of the antioxidative defense system and gene expression in the stressed wheat plants.

  3. SALT TOLERANCE OF CROP PLANTS

    Directory of Open Access Journals (Sweden)

    Hamdia, M. A

    2010-09-01

    Full Text Available Several environmental factors adversely affect plant growth and development and final yield performance of a crop. Drought, salinity, nutrient imbalances (including mineral toxicities and deficiencies and extremes of temperature are among the major environmental constraints to crop productivity worldwide. Development of crop plants with stress tolerance, however, requires, among others, knowledge of the physiological mechanisms and genetic controls of the contributing traits at different plant developmental stages. In the past 2 decades, biotechnology research has provided considerable insights into the mechanism of biotic stress tolerance in plants at the molecular level. Furthermore, different abiotic stress factors may provoke osmotic stress, oxidative stress and protein denaturation in plants, which lead to similar cellular adaptive responses such as accumulation of compatible solutes, induction of stress proteins, and acceleration of reactive oxygen species scavenging systems. Recently, the authores try to improve plant tolerance to salinity injury through either chemical treatments (plant hormones, minerals, amino acids, quaternary ammonium compounds, polyamines and vitamins or biofertilizers treatments (Asymbiotic nitrogen-fixing bacteria, symbiotic nitrogen-fixing bacteria and mycorrhiza or enhanced a process used naturally by plants to minimise the movement of Na+ to the shoot, using genetic modification to amplify the process, helping plants to do what they already do - but to do it much better."

  4. 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.

  5. Does Salicylic Acid (SA) Improve Tolerance to Salt Stress in Plants? A Study of SA Effects On Tomato Plant Growth, Water Dynamics, Photosynthesis, and Biochemical Parameters.

    Science.gov (United States)

    Mimouni, Hajer; Wasti, Salma; Manaa, Arafet; Gharbi, Emna; Chalh, Abdellah; Vandoorne, Bertrand; Lutts, Stanley; Ben Ahmed, Hela

    2016-03-01

    Environmental stresses such as salinity directly impact crop growth, and by extension, world food supply and societal prosperity. It is estimated that over 800 million hectares of land throughout the world are salt-affected. In arid and semi-arid regions, salt concentration can be close to that in the seawater. Hence, there are intensive efforts to improve plant tolerance to salinity and other environmental stressors. Salicylic acid (SA) is an important signal molecule for modulating plant responses to stress. In the present study, we examined, on multiple plant growth related endpoints, whether SA applied through the rooting medium could mitigate the adverse effects of salinity on tomato (Solanum lycopersicum) cv. Marmande. The latter is a hitherto understudied tomato plant from the above perspective; it is a classic variety that produces the large ribbed tomatoes in the Mediterranean and consumed worldwide. We found salt stress negatively affected the growth of cv. Marmande tomato plants. However, the SA-treated plants had greater shoot and root dry mass, leaf area compared to untreated plants when exposed to salt stress. Application of SA restores photosynthetic rates and photosynthetic pigment levels under salt (NaCl) exposure. Leaf water, osmotic potential, stomatal conductance transpiration rate, and biochemical parameters were also ameliorated in SA-treated plants under saline stress conditions. Overall, these data illustrate that SA increases cv. Marmande tomato growth by improving photosynthesis, regulation and balance of osmotic potential, induction of compatible osmolyte metabolism, and alleviating membrane damage. We suggest salicylic acid might be considered as a potential growth regulator to improve tomato plant salinity stress resistance, in the current era of global climate change.

  6. Genes and Salt Tolerance: Bringing Them Together

    National Research Council Canada - National Science Library

    Rana Munns

    2005-01-01

    Salinity tolerance comes from genes that limit the rate of salt uptake from the soil and the transport of salt throughout the plant, adjust the ionic and osmotic balance of cells in roots and shoots...

  7. Volatile-Mediated Effects Predominate in Paraburkholderia phytofirmans Growth Promotion and Salt Stress Tolerance of Arabidopsis thaliana

    Science.gov (United States)

    Ledger, Thomas; Rojas, Sandy; Timmermann, Tania; Pinedo, Ignacio; Poupin, María J.; Garrido, Tatiana; Richter, Pablo; Tamayo, Javier

    2016-01-01

    Abiotic stress has a growing impact on plant growth and agricultural activity worldwide. Specific plant growth promoting rhizobacteria have been reported to stimulate growth and tolerance to abiotic stress in plants, and molecular mechanisms like phytohormone synthesis and 1-aminocyclopropane-1-carboxylate deamination are usual candidates proposed to mediate these bacterial effects. Paraburkholderia phytofirmans PsJN is able to promote growth of several plant hosts, and improve their tolerance to chilling, drought and salinity. This work investigated bacterial determinants involved in PsJN stimulation of growth and salinity tolerance in Arabidopsis thaliana, showing bacteria enable plants to survive long-term salinity treatment, accumulating less sodium within leaf tissues relative to non-inoculated controls. Inactivation of specific bacterial genes encoding ACC deaminase, auxin catabolism, N-acyl-homoserine-lactone production, and flagellin synthesis showed these functions have little influence on bacterial induction of salinity tolerance. Volatile organic compound emission from strain PsJN was shown to reproduce the effects of direct bacterial inoculation of roots, increasing plant growth rate and tolerance to salinity evaluated both in vitro and in soil. Furthermore, early exposure to VOCs from P. phytofirmans was sufficient to stimulate long-term effects observed in Arabidopsis growth in the presence and absence of salinity. Organic compounds were analyzed in the headspace of PsJN cultures, showing production of 2-undecanone, 7-hexanol, 3-methylbutanol and dimethyl disulfide. Exposure of A. thaliana to different quantities of these molecules showed that they are able to influence growth in a wide range of added amounts. Exposure to a blend of the first three compounds was found to mimic the effects of PsJN on both general growth promotion and salinity tolerance. To our knowledge, this is the first report on volatile compound-mediated induction of plant abiotic

  8. Hyperspectral imaging to identify salt-tolerant wheat lines

    Science.gov (United States)

    Moghimi, Ali; Yang, Ce; Miller, Marisa E.; Kianian, Shahryar; Marchetto, Peter

    2017-05-01

    In order to address the worldwide growing demand for food, agriculture is facing certain challenges and limitations. One of the important threats limiting crop productivity is salinity. Identifying salt tolerate varieties is crucial to mitigate the negative effects of this abiotic stress in agricultural production systems. Traditional measurement methods of this stress, such as biomass retention, are labor intensive, environmentally influenced, and often poorly correlated to salinity stress alone. In this study, hyperspectral imaging, as a non-destructive and rapid method, was utilized to expedite the process of identifying relatively the most salt tolerant line among four wheat lines including Triticum aestivum var. Kharchia, T. aestivum var. Chinese Spring, (Ae. columnaris) T. aestivum var. Chinese Spring, and (Ae. speltoides) T. aestivum var. Chinese Spring. To examine the possibility of early detection of a salt tolerant line, image acquisition was started one day after stress induction and continued on three, seven, and 12 days after adding salt. Simplex volume maximization (SiVM) method was deployed to detect superior wheat lines in response to salt stress. The results of analyzing images taken as soon as one day after salt induction revealed that Kharchia and (columnaris)Chinese Spring are the most tolerant wheat lines, while (speltoides) Chinese Spring was a moderately susceptible, and Chinese Spring was a relatively susceptible line to salt stress. These results were confirmed with the measuring biomass performed several weeks later.

  9. A Glycine soja ABA-responsive receptor-like cytoplasmic kinase, GsRLCK, positively controls plant tolerance to salt and drought stresses.

    Science.gov (United States)

    Sun, XiaoLi; Sun, Mingzhe; Luo, Xiao; Ding, XiaoDong; Ji, Wei; Cai, Hua; Bai, Xi; Liu, XiaoFei; Zhu, YanMing

    2013-06-01

    Receptor such as protein kinases are proposed to work as sensors to initiate signaling cascades in higher plants. However, little is known about the precise functions of receptor such as protein kinases in abiotic stress response in plants, especially in wild soybean. Here, we focused on characterization of the biological functions of a receptor-like cytoplasmic serine/threonine protein kinase gene, GsRLCK, which was previously identified as a putative salt-alkali stress-related gene from the transcriptome profiles of Glycine soja. Bioinformatic analysis showed that GsRLCK protein contained a conserved kinase catalytic domain and two transmembrane domains at the N-terminus, but no typical extracellular domain. Consistently, GsRLCK-eGFP fusion protein was observed on the plasma membrane, but eGFP alone was distributing throughout the cytoplasm in onion epidermal cells. Quantitative real-time PCR analysis revealed the induced expression of GsRLCK by ABA, salt, alkali, and drought stresses. However, the expression levels of GsRLCK seemed to be similar in different tissues, except soybean pod. Phenotypic assays demonstrated that GsRLCK overexpression decreased ABA sensitivity and altered expression levels of ABA-responsive genes. Furthermore, we also found that GsRLCK conferred increased tolerance to salt and drought stresses and increased expression levels of a handful of stress-responsive genes, when overexpressing in Arabidopsis. In a word, we gave exact evidence that GsRLCK was a novel receptor-like cytoplasmic protein kinase and played a crucial role in plant responses to ABA, salt, and drought stresses.

  10. SlDEAD31, a Putative DEAD-Box RNA Helicase Gene, Regulates Salt and Drought Tolerance and Stress-Related Genes in Tomato.

    Directory of Open Access Journals (Sweden)

    Mingku Zhu

    Full Text Available The DEAD-box RNA helicases are involved in almost every aspect of RNA metabolism, associated with diverse cellular functions including plant growth and development, and their importance in response to biotic and abiotic stresses is only beginning to emerge. However, none of DEAD-box genes was well characterized in tomato so far. In this study, we reported on the identification and characterization of two putative DEAD-box RNA helicase genes, SlDEAD30 and SlDEAD31 from tomato, which were classified into stress-related DEAD-box proteins by phylogenetic analysis. Expression analysis indicated that SlDEAD30 was highly expressed in roots and mature leaves, while SlDEAD31 was constantly expressed in various tissues. Furthermore, the expression of both genes was induced mainly in roots under NaCl stress, and SlDEAD31 mRNA was also increased by heat, cold, and dehydration. In stress assays, transgenic tomato plants overexpressing SlDEAD31 exhibited dramatically enhanced salt tolerance and slightly improved drought resistance, which were simultaneously demonstrated by significantly enhanced expression of multiple biotic and abiotic stress-related genes, higher survival rate, relative water content (RWC and chlorophyll content, and lower water loss rate and malondialdehyde (MDA production compared to wild-type plants. Collectively, these results provide a preliminary characterization of SlDEAD30 and SlDEAD31 genes in tomato, and suggest that stress-responsive SlDEAD31 is essential for salt and drought tolerance and stress-related gene regulation in plants.

  11. 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.

  12. OsLEA3-2, an abiotic stress induced gene of rice plays a key role in salt and drought tolerance.

    Directory of Open Access Journals (Sweden)

    Jianli Duan

    Full Text Available Late embryogenesis abundant (LEA proteins are involved in tolerance to drought, cold and high salinity in many different organisms. In this report, a LEA protein producing full-length gene OsLEA3-2 was identified in rice (Oryza sativa using the Rapid Amplification of cDNA Ends (RACE method. OsLEA3-2 was found to be only expressed in the embryo and can be induced by abiotic stresses. The coding protein localizes to the nucleus and overexpression of OsLEA3-2 in yeast improved growth performance compared with control under salt- and osmotic-stress conditions. OsLEA3-2 was also inserted into pHB vector and overexpressed in Arabidopsis and rice. The transgenic Arabidopsis seedlings showed better growth on MS media supplemented with 150 mM mannitol or 100 mM NaCl as compared with wild type plants. The transgenic rice also showed significantly stronger growth performance than control under salinity or osmotic stress conditions and were able to recover after 20 days of drought stress. In vitro analysis showed that OsLEA3-2 was able to protect LDH from aggregation on freezing and inactivation on desiccation. These results indicated that OsLEA3-2 plays an important role in tolerance to abiotic stresses.

  13. A halotolerant bacterium Bacillus licheniformis HSW-16 augments induced systemic tolerance to salt stress in wheat plant (Triticum aestivum

    Directory of Open Access Journals (Sweden)

    Rajnish Prakash Singh

    2016-12-01

    Full Text Available Certain plant growth promoting bacteria can protect associated plants from harmful effects of salinity. We report the isolation and characterization of 1-aminocyclopropane-1-carboxylic acid (ACC deaminase bacterium Bacillus licheniformis HSW-16 capable of ameliorating salt (NaCl stress in wheat plants. The bacterium was isolated from water of Sambhar salt lake, Rajasthan, India. The presence of ACC deaminase activity was confirmed by enzyme assay and analysis of AcdS gene, a structural gene for ACC deaminase. Inoculation of B. licheniformis HSW-16 protected wheat plants from growth inhibition caused by NaCl and increased plant growth (6-38% in terms of root length, shoot length, fresh weight, and dry weight. Ionic analysis of plant samples showed that the bacterial inoculation decreased accumulation of Na+ content (51%, and increased K+ (68%, and Ca2+ content (32% in plants at different concentration of NaCl. It suggested that bacterial inoculation protected plants from the effect of NaCl by decreasing level of Na+ in plants. Production of exopolysaccharide by the B. licheniformis HSW-16 can also protect from Na+ by binding this ion. Moreover, application of test isolate resulted in an increase in certain osmolytes such as total soluble sugar, total protein content and a decrease in malondialdehyde content, illustrating their role in the protection of plants. The ability of B. licheniformis HSW-16 to colonize plant root surface was examined by staining the bacterium with acridine orange followed by fluorescence microscopy and polymerase chain reaction (PCR-based DNA fingerprinting analysis. These results suggested that B. licheniformis HSW-16 could be used as a bioinoculant to improve the productivity of plants growing under salt stress.

  14. Chrysanthemum WRKY gene CmWRKY17 negatively regulates salt stress tolerance in transgenic chrysanthemum and Arabidopsis plants.

    Science.gov (United States)

    Li, Peiling; Song, Aiping; Gao, Chunyan; Wang, Linxiao; Wang, Yinjie; Sun, Jing; Jiang, Jiafu; Chen, Fadi; Chen, Sumei

    2015-08-01

    CmWRKY17 was induced by salinity in chrysanthemum, and it might negatively regulate salt stress in transgenic plants as a transcriptional repressor. WRKY transcription factors play roles as positive or negative regulators in response to various stresses in plants. In this study, CmWRKY17 was isolated from chrysanthemum (Chrysanthemum morifolium). The gene encodes a 227-amino acid protein and belongs to the group II WRKY family, but has an atypical WRKY domain with the sequence WKKYGEK. Our data indicated that CmWRKY17 was localized to the nucleus in onion epidermal cells. CmWRKY17 showed no transcriptional activation in yeast; furthermore, luminescence assay clearly suggested that CmWRKY17 functions as a transcriptional repressor. DNA-binding assay showed that CmWRKY17 can bind to W-box. The expression of CmWRKY17 was induced by salinity in chrysanthemum, and a higher expression level was observed in the stem and leaf compared with that in the root, disk florets, and ray florets. Overexpression of CmWRKY17 in chrysanthemum and Arabidopsis increased the sensitivity to salinity stress. The activities of superoxide dismutase and peroxidase and proline content in the leaf were significantly lower in transgenic chrysanthemum than those in the wild type under salinity stress, whereas electrical conductivity was increased in transgenic plants. Expression of the stress-related genes AtRD29, AtDREB2B, AtSOS1, AtSOS2, AtSOS3, and AtNHX1 was reduced in the CmWRKY17 transgenic Arabidopsis compared with that in the wild-type Col-0. Collectively, these data suggest that CmWRKY17 may increase the salinity sensitivity in plants as a transcriptional repressor.

  15. Enhancement of growth and salt tolerance of red pepper seedlings (Capsicum annuum L.) by regulating stress ethylene synthesis with halotolerant bacteria containing 1-aminocyclopropane-1-carboxylic acid deaminase activity.

    Science.gov (United States)

    Siddikee, Md Ashaduzzaman; Glick, Bernard R; Chauhan, Puneet S; Yim, Woo jong; Sa, Tongmin

    2011-04-01

    Three 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase-producing halotolerant bacteria were isolated from West Coast soil of Yellow Sea, Incheon, South Korea and evaluated for their efficiency in improving red pepper plant growth under salt stress. The strains RS16, RS656 and RS111 were identified by 16S rRNA gene sequencing as Brevibacterium iodinum, Bacillus licheniformis and Zhihengliuela alba, respectively. Two hour exposure of 100, 150 and 200 mM NaCl stress on 8 day old red pepper seedlings caused 44, 64 and 74% increase ethylene production, while at 150 mM NaCl stress, inoculation of B. licheniformis RS656, Z. alba RS111, and Br. iodinum RS16 reduces ethylene production by 44, 53 and 57%, respectively. Similarly, 3 week old red pepper plants were subjected to salt stress for two weeks and approximately ∼50% reduction in growth recorded at 150 mM NaCl stress compared to negative control whereas bacteria inoculation significantly increase the growth compared to positive control. Salt stress also caused 1.3-fold reduction in the root/shoot dry weight ratio compared to the absence of salt while bacteria inoculation retained the biomass allocation similar to control plants. The salt tolerance index (ratio of biomass of salt stressed to non-stressed plant) was also significantly increased in inoculated plants compared to non-inoculated. Increase nutrient uptakes under salt stress by red pepper further evident that bacteria inoculation ameliorates salt stress effect. In summary, this study indicates that the use of ACC deaminase-producing halotolerant bacteria mitigates the salt stress by reducing salt stress-induced ethylene production on growth of red pepper plants. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  16. Salt Tolerance of Desorption Electrospray Ionization (DESI)

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Ayanna U. [Purdue University; Talaty, Nari [Purdue University; Cooks, R G [Purdue University; Van Berkel, Gary J [ORNL

    2007-01-01

    Suppression of ion intensity in the presence of high salt matrices is common in most mass spectrometry ionization techniques. Desorption electrospray ionization (DESI) is an ionization method that exhibits salt tolerance, and this is investigated. DESI analysis was performed on three different drug mixtures in the presence of 0, 0.2, 2, 5, 10, and 20% NaCl:KCl weight by volume from seven different surfaces. At physiological concentrations individual drugs in each mixture were observed with each surface. Collision-induced dissociation (CID) was used to provide additional confirmation for select compounds. Multiple stage experiments, to MS5, were performed for select compounds. Even in the absence of added salt, the benzodiazepine containing mixture yielded sodium and potassium adducts of carbamazepine which masked the ions of interest. These adducts were eliminated by adding 0.1% 7M ammonium acetate to the standard methanol:water (1:1) spray solvent. Comparison of the salt tolerance of DESI with that of electrospray ionization (ESI) demonstrated much better signal/noise characteristics for DESI in this study. The salt tolerance of DESI was also studied by performing limit of detection and dynamic range experiments. Even at a salt concentration significantly above physiological concentrations, select surfaces were effective in providing spectra that allowed the ready identification of the compounds of interest. The already high salt tolerance of DESI can be optimized further by appropriate choices of surface and spray solution.

  17. Leaf sodium accumulation facilitates salt stress adaptation and preserves photosystem functionality in salt stressed Ocimum basilicum

    NARCIS (Netherlands)

    Mancarella, S.; Orsini, F.; Oosten, van M.J.; Sanoubar, R.; Stanghellini, C.; Kondo, S.; Gianquinto, G.; Maggio, A.

    2016-01-01

    In this study, plant growth, water relations, ABA levels, ion accumulation patterns and chlorophyll fluorescence were functionally linked to salt stress tolerance of two basil cultivars (Napoletano and Genovese) with different stress sensitivity levels. Plants were treated with salty water at 0,

  18. 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.

  19. Does stress induce salt intake?

    Science.gov (United States)

    Torres, Susan J; Turner, Anne I; Nowson, Caryl A

    2010-06-01

    Psychological stress is a common feature of modern day societies, and contributes to the global burden of disease. It was proposed by Henry over 20 years ago that the salt intake of a society reflects the level of stress, and that stress, through its effect on increasing salt intake, is an important factor in the development of hypertension. This review evaluates the evidence from animal and human studies to determine if stress does induce a salt appetite and increase salt consumption in human subjects. Findings from animal studies suggest that stress may drive salt intake, with evidence for a potential mechanism via the sympatho-adrenal medullary system and/or the hypothalamo-pituitary-adrenal axis. In contrast, in the few laboratory studies conducted in human subjects, none has found that acute stress affects salt intake. However, one study demonstrated that life stress (chronic stress) was associated with increased consumption of snack foods, which included, but not specifically, highly salty snacks. Studies investigating the influence of chronic stress on eating behaviours are required, including consumption of salty foods. From the available evidence, we can conclude that in free-living, Na-replete individuals, consuming Na in excess of physiological requirements, stress is unlikely to be a major contributor to salt intake.

  20. The induction of salt stress tolerance by propyl gallate treatment in green microalga Dunaliella bardawil, through enhancing ascorbate pool and antioxidant enzymes activity.

    Science.gov (United States)

    Einali, Alireza

    2017-10-08

    The effect of propyl gallate (PG), a synthetic antioxidant, on antioxidant responses and salinity tolerance was investigated in the cells of the green microalga, Dunaliella bardawil. Algal suspensions grown at three salinity levels of 1, 2, and 3 M NaCl were incubated with 1 mM of PG. The number of cells was significantly lower in all PG-treated cells compared to untreated controls. Despite PG-induced cell death, the fresh weight of all PG-treated cells was considerably higher than controls. PG-treated cells had enhanced antioxidant capacity because of increased levels of Chlorophyll a, β-carotene, reduced ascorbate, protein, and enzymatic activities, but accumulated lower levels of malonyldialdehyde and hydrogen peroxide compared to untreated cells. The results suggest that PG acts as a signal molecule both directly by reducing of free radical oxidants and indirectly by augmenting ascorbate pool levels, β-carotene production, and antioxidant enzymes activity to boost the capacity of antioxidant systems and radical oxygen species scavenging. Therefore, induction of salt stress tolerance by PG in D. bardawil is associated with metabolic adjustments through activation or synthesis of both enzymatic and non-enzymatic molecules involved in antioxidant systems.

  1. THE DETECTION OF APPROPRIATE ORGANIC FERTILIZER AND MYCORRHIZAL METHOD ENHANCING SALT STRESS TOLERANCE IN RICE (Oryza sativa L. UNDER FIELD CONDITIONS

    Directory of Open Access Journals (Sweden)

    Mehmet AYBEKE

    2016-06-01

    Full Text Available This study was performed in order to identify the appropriate organic fertilizer and mycorrhizal methods for promoting rice tolerance in response to salty environmental conditions. For this purpose, some agronomic, biochemical and physiological parameters were investigated in rice under natural salt stress. The plants were grown in saline field conditions from germination to harvest stage and fertilizing consisted of only a mixture of different ratios of mycorrhizal, municipal solid waste (MSW, waste tea leaves, straw, olive manure and chicken manure. Samples of the plants were taken when they reached harvesting stage and their agronomical properties (plant height, number of leaves, leaf sheaths length, tillering, leaf area, panicle length, total and milled rice values and 1000 grain weight were recorded and biochemical (chlorophyll a and b and physiological analysis (Na, K, Ca, Si amounts in roots were performed. The results showed that improvements in vegetative characters except leaf number were obtained with trials with MSW, MSW+waste tea leaves+straw or MSW+waste tea leaves+straw+chicken or olive manure including fertilizers, increase in chlorophyll b content was obtained with trials except with mycorrhiza, and decreased root Na levels and increases in chlorophyll a content (biochemical parameter were obtained particularly with trials with of the mycorrhiza+MSW pair or mycorrhiza+MSW+waste tea leave mixture. The best fertilizing mixture, straw (100kg/decare + MSW (75g / 2,5m2, was in experiment no: 2. Additionally, there was no change in the low yield; but certain additives were necessary. In conclusion, organic waste and mycorrhizal fertilizer applications with specific ratios were determined to have a protective effect on plants against salt stress.

  2. Plant Responses to Salt Stress: Adaptive Mechanisms

    Directory of Open Access Journals (Sweden)

    Jose Ramón Acosta-Motos

    2017-02-01

    Full Text Available This review deals with the adaptive mechanisms that plants can implement to cope with the challenge of salt stress. Plants tolerant to NaCl implement a series of adaptations to acclimate to salinity, including morphological, physiological and biochemical changes. These changes include increases in the root/canopy ratio and in the chlorophyll content in addition to changes in the leaf anatomy that ultimately lead to preventing leaf ion toxicity, thus maintaining the water status in order to limit water loss and protect the photosynthesis process. Furthermore, we deal with the effect of salt stress on photosynthesis and chlorophyll fluorescence and some of the mechanisms thought to protect the photosynthetic machinery, including the xanthophyll cycle, photorespiration pathway, and water-water cycle. Finally, we also provide an updated discussion on salt-induced oxidative stress at the subcellular level and its effect on the antioxidant machinery in both salt-tolerant and salt-sensitive plants. The aim is to extend our understanding of how salinity may affect the physiological characteristics of plants.

  3. Can elevated CO(2) improve salt tolerance in olive trees?

    Science.gov (United States)

    Melgar, Juan Carlos; Syvertsen, James P; García-Sánchez, Francisco

    2008-04-18

    We compared growth, leaf gas exchange characteristics, water relations, chlorophyll fluorescence, and Na(+) and Cl(-) concentration of two cultivars ('Koroneiki' and 'Picual') of olive (Olea europaea L.) trees in response to high salinity (NaCl 100mM) and elevated CO(2) (eCO(2)) concentration (700microLL(-1)). The cultivar 'Koroneiki' is considered to be more salt sensitive than the relatively salt-tolerant 'Picual'. After 3 months of treatment, the 9-month-old cuttings of 'Koroneiki' had significantly greater shoot growth, and net CO(2) assimilation (A(CO(2))) at eCO(2) than at ambient CO(2), but this difference disappeared under salt stress. Growth and A(CO(2)) of 'Picual' did not respond to eCO(2) regardless of salinity treatment. Stomatal conductance (g(s)) and leaf transpiration were decreased at eCO(2) such that leaf water use efficiency (WUE) increased in both cultivars regardless of saline treatment. Salt stress increased leaf Na(+) and Cl(-) concentration, reduced growth and leaf osmotic potential, but increased leaf turgor compared with non-salinized control plants of both cultivars. Salinity decreased A(CO(2)), g(s), and WUE, but internal CO(2) concentrations in the mesophyll were not affected. eCO(2) increased the sensitivity of PSII and chlorophyll concentration to salinity. eCO(2) did not affect leaf or root Na(+) or Cl(-) concentrations in salt-tolerant 'Picual', but eCO(2) decreased leaf and root Na(+) concentration and root Cl(-) concentration in the more salt-sensitive 'Koroneiki'. Na(+) and Cl(-) accumulation was associated with the lower water use in 'Koroneiki' but not in 'Picual'. Although eCO(2) increased WUE in salinized leaves and decreased salt ion uptake in the relatively salt-tolerant 'Koroneiki', growth of these young olive trees was not affected by eCO(2).

  4. Genetic diversity of salt tolerance in Miscanthus

    NARCIS (Netherlands)

    Chen, Charlie; Schoot, van der Hanneke; Dehghan, Shiva; Alvim Kamei, Claire L.; Schwarz, Kai Uwe; Meyer, Heike; Visser, Richard G.F.; Linden, van der Gerard

    2017-01-01

    Miscanthus is a woody rhizomatous C4 grass that can be used as a CO2 neutral biofuel resource. It has potential to grow in marginal areas such as saline soils, avoiding competition for arable lands with food crops. This study explored genetic diversity for salt tolerance in Miscanthus and discovered

  5. Increased tolerance to salt stress in OPDA-deficient rice ALLENE OXIDE CYCLASE mutants is linked to an increased ROS-scavenging activity

    Science.gov (United States)

    Hazman, Mohamed; Hause, Bettina; Eiche, Elisabeth; Nick, Peter; Riemann, Michael

    2015-01-01

    Salinity stress represents a global constraint for rice, the most important staple food worldwide. Therefore the role of the central stress signal jasmonate for the salt response was analysed in rice comparing the responses to salt stress for two jasmonic acid (JA) biosynthesis rice mutants (cpm2 and hebiba) impaired in the function of ALLENE OXIDE CYCLASE (AOC) and their wild type. The aoc mutants were less sensitive to salt stress. Interestingly, both mutants accumulated smaller amounts of Na+ ions in their leaves, and showed better scavenging of reactive oxygen species (ROS) under salt stress. Leaves of the wild type and JA mutants accumulated similar levels of abscisic acid (ABA) under stress conditions, and the levels of JA and its amino acid conjugate, JA–isoleucine (JA-Ile), showed only subtle alterations in the wild type. In contrast, the wild type responded to salt stress by strong induction of the JA precursor 12-oxophytodienoic acid (OPDA), which was not observed in the mutants. Transcript levels of representative salinity-induced genes were induced less in the JA mutants. The absence of 12-OPDA in the mutants correlated not only with a generally increased ROS-scavenging activity, but also with the higher activity of specific enzymes in the antioxidative pathway, such as glutathione S-transferase, and fewer symptoms of damage as, for example, indicated by lower levels of malondialdehyde. The data are interpreted in a model where the absence of OPDA enhanced the antioxidative power in mutant leaves. PMID:25873666

  6. Complex molecular mechanisms underlying seedling salt tolerance in rice revealed by comparative transcriptome and metabolomic profiling

    Science.gov (United States)

    Wang, Wen-Sheng; Zhao, Xiu-Qin; Li, Min; Huang, Li-Yu; Xu, Jian-Long; Zhang, Fan; Cui, Yan-Ru; Fu, Bin-Ying; Li, Zhi-Kang

    2016-01-01

    To understand the physiological and molecular mechanisms underlying seedling salt tolerance in rice (Oryza sativa L.), the phenotypic, metabolic, and transcriptome responses of two related rice genotypes, IR64 and PL177, with contrasting salt tolerance were characterized under salt stress and salt+abscisic acid (ABA) conditions. PL177 showed significantly less salt damage, lower Na+/K+ ratios in shoots, and Na+ translocation from roots to shoots, attributed largely to better salt exclusion from its roots and salt compartmentation of its shoots. Exogenous ABA was able to enhance the salt tolerance of IR64 by selectively decreasing accumulation of Na+ in its roots and increasing K+ in its shoots. Salt stress induced general and organ-specific increases of many primary metabolites in both rice genotypes, with strong accumulation of several sugars plus proline in shoots and allantoin in roots. This was due primarily to ABA-mediated repression of genes for degradation of these metabolites under salt. In PL177, salt specifically up-regulated genes involved in several pathways underlying salt tolerance, including ABA-mediated cellular lipid and fatty acid metabolic processes and cytoplasmic transport, sequestration by vacuoles, detoxification and cell-wall remodeling in shoots, and oxidation–reduction reactions in roots. Combined genetic and transcriptomic evidence shortlisted relatively few candidate genes for improved salt tolerance in PL177. PMID:26512058

  7. The BEACH Domain Protein SPIRRIG Is Essential for Arabidopsis Salt Stress Tolerance and Functions as a Regulator of Transcript Stabilization and Localization.

    Directory of Open Access Journals (Sweden)

    Alexandra Steffens

    2015-07-01

    Full Text Available Members of the highly conserved class of BEACH domain containing proteins (BDCPs have been established as broad facilitators of protein-protein interactions and membrane dynamics in the context of human diseases like albinism, bleeding diathesis, impaired cellular immunity, cancer predisposition, and neurological dysfunctions. Also, the Arabidopsis thaliana BDCP SPIRRIG (SPI is important for membrane integrity, as spi mutants exhibit split vacuoles. In this work, we report a novel molecular function of the BDCP SPI in ribonucleoprotein particle formation. We show that SPI interacts with the P-body core component DECAPPING PROTEIN 1 (DCP1, associates to mRNA processing bodies (P-bodies, and regulates their assembly upon salt stress. The finding that spi mutants exhibit salt hypersensitivity suggests that the local function of SPI at P-bodies is of biological relevance. Transcriptome-wide analysis revealed qualitative differences in the salt stress-regulated transcriptional response of Col-0 and spi. We show that SPI regulates the salt stress-dependent post-transcriptional stabilization, cytoplasmic agglomeration, and localization to P-bodies of a subset of salt stress-regulated mRNAs. Finally, we show that the PH-BEACH domains of SPI and its human homolog FAN (Factor Associated with Neutral sphingomyelinase activation interact with DCP1 isoforms from plants, mammals, and yeast, suggesting the evolutionary conservation of an association of BDCPs and P-bodies.

  8. What molecular mechanism is adapted by plants during salt stress ...

    African Journals Online (AJOL)

    Salt stress harmfully shocks agricultural yield throughout the world affecting production whether it is for subsistence or economic outcomes. The plant response to salinity consists of numerous processes that must function in coordination to alleviate both cellular hyper-osmolarity and ion disequilibrium. Salt tolerance and ...

  9. Osmotic stress tolerance in semi-terrestrial tardigrades

    DEFF Research Database (Denmark)

    Heidemann, Nanna W T; Smith, Daniel K.; Hygum, Thomas L.

    2016-01-01

    Little is known about ionic and osmotic stress tolerance in tardigrades. Here, we examine salt stress tolerance in Ramazzottius oberhaeuseri and Echiniscus testudo from Nivå (Denmark) and address whether limno-terrestrial tardigrades can enter a state of quiescence (osmobiosis) in the face of high...

  10. An Alcohol Dehydrogenase Gene fromSynechocystissp. Confers Salt Tolerance in Transgenic Tobacco.

    Science.gov (United States)

    Yi, So Young; Ku, Seong Sub; Sim, Hee-Jung; Kim, Sang-Kyu; Park, Ji Hyun; Lyu, Jae Il; So, Eun Jin; Choi, So Yeon; Kim, Jonghyun; Ahn, Myung Suk; Kim, Suk Weon; Park, Hyunwoo; Jeong, Won Joong; Lim, Yong Pyo; Min, Sung Ran; Liu, Jang Ryol

    2017-01-01

    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 C 6 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.

  11. Molecular markers associated with salt tolerance in Egyptian wheats ...

    African Journals Online (AJOL)

    Salinity affects plant growth by the osmotic stress of the salt around the roots, as well as by toxicity caused by excessive accumulation of salt in leaves. In the present study, seven common (Triticum aestivum) and two durum (T. turgidum ssp. Durum) wheat genotypes were subjected to salt stress for 2 weeks. Salt stress ...

  12. Isolation of genes conferring salt tolerance from Piriformospora indica by random overexpression in Escherichia coli.

    Science.gov (United States)

    Gahlot, Sunayna; Joshi, Amita; Singh, Pratap; Tuteja, Renu; Dua, Meenakshi; Jogawat, Abhimanyu; Kumar, Manoj; Raj, Sumit; Dayaman, Vikram; Johri, Atul Kumar; Tuteja, Narendra

    2015-08-01

    Piriformospora indica, a root endophytic fungus identified in the Indian Thar desert, colonizes the roots of plants and provides resistance towards biotic stress as well as tolerance to abiotic stress in the plants. Despite its positive impact on the host, little is known about the P. indica genes that are involved in salt stress tolerance. Therefore this study was conducted to identify and isolate high salinity-tolerance genes from P. indica. Thirty-six salinity-tolerance genes were obtained by functional screening, based on random over expression of a P. indica cDNA library in Escherichia coli grown on medium supplemented with 0.6 M NaCl. The salinity tolerance conferred by these 36 genes in bacteria was further confirmed by using another strain of E. coli (DH5α) transformants. However when the expression of these 36 genes was analysed in P. indica using quantitative RT-PCR, we found only six genes were up-regulated by salt stress. These six genes are involved in different cellular processes, such as metabolism, energy and biosynthetic processes, DNA repair, regulation of protein turnover, transport and salt stress tolerance. This work presents the basis for further molecular analyses of the mechanisms of salt tolerance in P. indica and for the use of this endophyte to confer salt tolerance to plants.

  13. 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.

  14. Diversity and Evolution of Salt Tolerance in the Genus Vigna.

    Directory of Open Access Journals (Sweden)

    Kohtaro Iseki

    Full Text Available Breeding salt tolerant plants is difficult without utilizing a diversity of wild crop relatives. Since the genus Vigna (family Fabaceae is comprised of many wild relatives adapted to various environmental conditions, we evaluated the salt tolerance of 69 accessions of this genus, including that of wild and domesticated accessions originating from Asia, Africa, Oceania, and South America. We grew plants under 50 mM and 200 mM NaCl for two weeks and then measured the biomass, relative quantum yield of photosystem II, leaf Na+ concentrations, and leaf K+ concentrations. The accessions were clustered into four groups: the most tolerant, tolerant, moderately susceptible, and susceptible. From the most tolerant group, we selected six accessions, all of which were wild accessions adapted to coastal environments, as promising sources of salt tolerance because of their consistently high relative shoot biomass and relative quantum yield. Interestingly, variations in leaf Na+ concentration were observed between the accessions in the most tolerant group, suggesting different mechanisms were responsible for their salt tolerance. Phylogenetic analysis with nuclear DNA sequences revealed that salt tolerance had evolved independently at least four times in the genus Vigna, within a relatively short period. The findings suggested that simple genetic changes in a few genes might have greatly affected salt tolerances. The elucidation of genetic mechanisms of salt tolerances in the selected accessions may contribute to improving the poor salt tolerance in legume crops.

  15. Transcriptomic analysis of salt stress responsive genes in Rhazya stricta.

    Directory of Open Access Journals (Sweden)

    Nahid H Hajrah

    Full Text Available Rhazya stricta is an evergreen shrub that is widely distributed across Western and South Asia, and like many other members of the Apocynaceae produces monoterpene indole alkaloids that have anti-cancer properties. This species is adapted to very harsh desert conditions making it an excellent system for studying tolerance to high temperatures and salinity. RNA-Seq analysis was performed on R. stricta exposed to severe salt stress (500 mM NaCl across four time intervals (0, 2, 12 and 24 h to examine mechanisms of salt tolerance. A large number of transcripts including genes encoding tetrapyrroles and pentatricopeptide repeat (PPR proteins were regulated only after 12 h of stress of seedlings grown in controlled greenhouse conditions. Mechanisms of salt tolerance in R. stricta may involve the upregulation of genes encoding chaperone protein Dnaj6, UDP-glucosyl transferase 85a2, protein transparent testa 12 and respiratory burst oxidase homolog protein b. Many of the highly-expressed genes act on protecting protein folding during salt stress and the production of flavonoids, key secondary metabolites in stress tolerance. Other regulated genes encode enzymes in the porphyrin and chlorophyll metabolic pathway with important roles during plant growth, photosynthesis, hormone signaling and abiotic responses. Heme biosynthesis in R. stricta leaves might add to the level of salt stress tolerance by maintaining appropriate levels of photosynthesis and normal plant growth as well as by the participation in reactive oxygen species (ROS production under stress. We speculate that the high expression levels of PPR genes may be dependent on expression levels of their targeted editing genes. Although the results of PPR gene family indicated regulation of a large number of transcripts under salt stress, PPR actions were independent of the salt stress because their RNA editing patterns were unchanged.

  16. Transcriptomic analysis of salt stress responsive genes in Rhazya stricta

    Science.gov (United States)

    Hajrah, Nahid H.; Obaid, Abdullah Y.; Atef, Ahmed; Ramadan, Ahmed M.; Arasappan, Dhivya; Nelson, Charllotte A.; Edris, Sherif; Mutwakil, Mohammed Z.; Alhebshi, Alawia; Gadalla, Nour O.; Makki, Rania M.; Al-Kordy, Madgy A.; El-Domyati, Fotouh M.; Sabir, Jamal S. M.; Khiyami, Mohammad A.; Hall, Neil; Bahieldin, Ahmed

    2017-01-01

    Rhazya stricta is an evergreen shrub that is widely distributed across Western and South Asia, and like many other members of the Apocynaceae produces monoterpene indole alkaloids that have anti-cancer properties. This species is adapted to very harsh desert conditions making it an excellent system for studying tolerance to high temperatures and salinity. RNA-Seq analysis was performed on R. stricta exposed to severe salt stress (500 mM NaCl) across four time intervals (0, 2, 12 and 24 h) to examine mechanisms of salt tolerance. A large number of transcripts including genes encoding tetrapyrroles and pentatricopeptide repeat (PPR) proteins were regulated only after 12 h of stress of seedlings grown in controlled greenhouse conditions. Mechanisms of salt tolerance in R. stricta may involve the upregulation of genes encoding chaperone protein Dnaj6, UDP-glucosyl transferase 85a2, protein transparent testa 12 and respiratory burst oxidase homolog protein b. Many of the highly-expressed genes act on protecting protein folding during salt stress and the production of flavonoids, key secondary metabolites in stress tolerance. Other regulated genes encode enzymes in the porphyrin and chlorophyll metabolic pathway with important roles during plant growth, photosynthesis, hormone signaling and abiotic responses. Heme biosynthesis in R. stricta leaves might add to the level of salt stress tolerance by maintaining appropriate levels of photosynthesis and normal plant growth as well as by the participation in reactive oxygen species (ROS) production under stress. We speculate that the high expression levels of PPR genes may be dependent on expression levels of their targeted editing genes. Although the results of PPR gene family indicated regulation of a large number of transcripts under salt stress, PPR actions were independent of the salt stress because their RNA editing patterns were unchanged. PMID:28520766

  17. A novel α/β-hydrolase gene IbMas enhances salt tolerance in transgenic sweetpotato.

    Directory of Open Access Journals (Sweden)

    Degao Liu

    Full Text Available Salt stress is one of the major environmental stresses in agriculture worldwide and affects crop productivity and quality. The development of crops with elevated levels of salt tolerance is therefore highly desirable. In the present study, a novel maspardin gene, named IbMas, was isolated from salt-tolerant sweetpotato (Ipomoea batatas (L. Lam. line ND98. IbMas contains maspardin domain and belongs to α/β-hydrolase superfamily. Expression of IbMas was up-regulated in sweetpotato under salt stress and ABA treatment. The IbMas-overexpressing sweetpotato (cv. Shangshu 19 plants exhibited significantly higher salt tolerance compared with the wild-type. Proline content was significantly increased, whereas malonaldehyde content was significantly decreased in the transgenic plants. The activities of superoxide dismutase (SOD and photosynthesis were significantly enhanced in the transgenic plants. H2O2 was also found to be significantly less accumulated in the transgenic plants than in the wild-type. Overexpression of IbMas up-regulated the salt stress responsive genes, including pyrroline-5-carboxylate synthase, pyrroline-5-carboxylate reductase, SOD, psbA and phosphoribulokinase genes, under salt stress. These findings suggest that overexpression of IbMas enhances salt tolerance of the transgenic sweetpotato plants by regulating osmotic balance, protecting membrane integrity and photosynthesis and increasing reactive oxygen species scavenging capacity.

  18. Citeromyces matritensis M37 is a salt-tolerant yeast that produces ethanol from salted algae.

    Science.gov (United States)

    Okai, Masahiko; Betsuno, Ayako; Shirao, Ayaka; Obara, Nobuo; Suzuki, Kotaro; Takei, Toshinori; Takashio, Masachika; Ishida, Masami; Urano, Naoto

    2017-01-01

    Algae are referred to as a third-generation biomass for ethanol production. However, salinity treatment is a problem that needs to be solved, because algal hydrolysates often contain high salt. Here, we isolated the salt-tolerant ethanol-producing yeast Citeromyces matritensis M37 from the east coast of Miura Peninsula in Japan. This yeast grew under osmotic stress conditions (20% NaCl or 60% glucose). It produced 6.55 g/L ethanol from YPD medium containing 15% NaCl after 48 h, and the ethanol accumulation was observed even at 20% NaCl. Using salted Undaria pinnatifida (wakame), we obtained 6.33 g/L glucose from approx. 150 g/L of the salted wakame powder with acidic and heat pretreatment followed by enzymatic saccharification, and the ethanol production reached 2.58 g/L for C. matritensis M37. The ethanol concentration was 1.4 times higher compared with that using the salt-tolerant ethanol-producing yeast Zygosaccharomyces rouxii S11.

  19. A ROP2-RIC1 pathway fine-tunes microtubule reorganization for salt tolerance in Arabidopsis.

    Science.gov (United States)

    Li, Changjiang; Lu, Hanmei; Li, Wei; Yuan, Ming; Fu, Ying

    2017-07-01

    The reorganization of microtubules induced by salt stress is required for Arabidopsis survival under high salinity conditions. RIC1 is an effector of Rho-related GTPase from plants (ROPs) and a known microtubule-associated protein. In this study, we demonstrated that RIC1 expression decreased with long-term NaCl treatment, and ric1-1 seedlings exhibited a higher survival rate under salt stress. We found that RIC1 reduced the frequency of microtubule transition from shortening to growing status and knockout of RIC1 improved the reassembly of depolymerized microtubules caused by either oryzalin treatment or salt stress. Further investigation showed that constitutively active ROP2 promoted the reassembly of microtubules and the survival of seedlings under salt stress. A rop2-1 ric1-1 double mutant rescued the salt-sensitive phenotype of rop2-1, indicating that ROP2 functions in salt tolerance through RIC1. Although ROP2 did not regulate RIC1 expression upon salt stress, a quick but mild increase of ROP2 activity was induced, led to reduction of RIC1 on microtubules. Collectively, our study reveals an ROP2-RIC1 pathway that fine-tunes microtubule dynamics in response to salt stress in Arabidopsis. This finding not only reveals a new regulatory mechanism for microtubule reorganization under salt stress but also the importance of ROP signalling for salinity tolerance. © 2017 John Wiley & Sons Ltd.

  20. Metabolic Profiles Reveal Changes in Wild and Cultivated Soybean Seedling Leaves under Salt Stress.

    Directory of Open Access Journals (Sweden)

    Jing Zhang

    Full Text Available Clarification of the metabolic mechanisms underlying salt stress responses in plants will allow further optimization of crop breeding and cultivation to obtain high yields in saline-alkali land. Here, we characterized 68 differential metabolites of cultivated soybean (Glycine max and wild soybean (Glycine soja under neutral-salt and alkali-salt stresses using gas chromatography-mass spectrometry (GC-MS-based metabolomics, to reveal the physiological and molecular differences in salt tolerance. According to comparisons of growth parameters under the two kinds of salt stresses, the level of inhibition in wild soybean was lower than in cultivated soybean, especially under alkali-salt stress. Moreover, wild soybean contained significantly higher amounts of phenylalanine, asparagine, citraconic acid, citramalic acid, citric acid and α-ketoglutaric acid under neutral-salt stress, and higher amounts of palmitic acid, lignoceric acid, glucose, citric acid and α-ketoglutaric acid under alkali-salt stress, than cultivated soybean. Further investigations demonstrated that the ability of wild soybean to salt tolerance was mainly based on the synthesis of organic and amino acids, and the more active tricarboxylic acid cycle under neutral-salt stress. In addition, the metabolite profiling analysis suggested that the energy generation from β-oxidation, glycolysis and the citric acid cycle plays important roles under alkali-salt stress. Our results extend the understanding of mechanisms involved in wild soybean salt tolerance and provide an important reference for increasing yields and developing salt-tolerant soybean cultivars.

  1. Comparison of Salt Tolerance in Soja Based on Metabolomics of Seedling Roots

    Directory of Open Access Journals (Sweden)

    Mingxia Li

    2017-06-01

    Full Text Available Soybean is an important economic crop that is continually threatened by abiotic stresses, especially salt stress. Wild soybean is an important germplasm resource for the breeding of cultivated soybean. The root system plays a very important role in plant salt tolerance. To explore the salt tolerance-related mechanisms among Soja, we have demonstrated the seedling roots' growth and metabolomics in wild soybean, semi-wild soybean, and cultivated soybean under two types of salt stress by using gas chromatography-mass spectrometry. We characterized 47 kinds of differential metabolites under neutral salt stress, and isoleucine, serine, l-allothreonine, glutamic acid, phenylalanine, asparagines, aspartic acid, pentadecanoic acid, lignoceric acid, oleic acid, galactose, tagatose, d-arabitol, dihydroxyacetone, 3-hydroxybutyric acid, and glucuronic acid increased significantly in the roots of wild soybean seedlings. However, these metabolites were suppressed in semi-wild and cultivated soybeans. Amino acid, fatty acid, sugars, and organic acid synthesis and the secondary metabolism of antioxidants increased significantly in the roots of wild soybean seedling. Under alkaline salt stress, wild soybean contained significantly higher amounts of proline, glutamic acid, aspartic acid, l-allothreonine, isoleucine, serine, alanine, arachidic acid, oleic acid, cis-gondoic acid, fumaric acid, l-malic acid, citric acid, malonic acid, gluconic acid, 5-methoxytryptamine, salicylic acid, and fluorene than semi-wild and cultivated soybeans. Our study demonstrated that carbon and nitrogen metabolism, and the tricarboxylic acid (TCA cycle and receiver operating characteristics (especially the metabolism of phenolic substances of the seedling roots were important to resisting salt stress and showed a regular decreasing trend from wild soybean to cultivated soybean. The metabolomics's changes were critical factors in the evolution of salt tolerance among Soja. This study

  2. Comparison of Salt Tolerance in Soja Based on Metabolomics of Seedling Roots.

    Science.gov (United States)

    Li, Mingxia; Guo, Rui; Jiao, Yang; Jin, Xiaofei; Zhang, Haiyan; Shi, Lianxuan

    2017-01-01

    Soybean is an important economic crop that is continually threatened by abiotic stresses, especially salt stress. Wild soybean is an important germplasm resource for the breeding of cultivated soybean. The root system plays a very important role in plant salt tolerance. To explore the salt tolerance-related mechanisms among Soja, we have demonstrated the seedling roots' growth and metabolomics in wild soybean, semi-wild soybean, and cultivated soybean under two types of salt stress by using gas chromatography-mass spectrometry. We characterized 47 kinds of differential metabolites under neutral salt stress, and isoleucine, serine, l-allothreonine, glutamic acid, phenylalanine, asparagines, aspartic acid, pentadecanoic acid, lignoceric acid, oleic acid, galactose, tagatose, d-arabitol, dihydroxyacetone, 3-hydroxybutyric acid, and glucuronic acid increased significantly in the roots of wild soybean seedlings. However, these metabolites were suppressed in semi-wild and cultivated soybeans. Amino acid, fatty acid, sugars, and organic acid synthesis and the secondary metabolism of antioxidants increased significantly in the roots of wild soybean seedling. Under alkaline salt stress, wild soybean contained significantly higher amounts of proline, glutamic acid, aspartic acid, l-allothreonine, isoleucine, serine, alanine, arachidic acid, oleic acid, cis-gondoic acid, fumaric acid, l-malic acid, citric acid, malonic acid, gluconic acid, 5-methoxytryptamine, salicylic acid, and fluorene than semi-wild and cultivated soybeans. Our study demonstrated that carbon and nitrogen metabolism, and the tricarboxylic acid (TCA) cycle and receiver operating characteristics (especially the metabolism of phenolic substances) of the seedling roots were important to resisting salt stress and showed a regular decreasing trend from wild soybean to cultivated soybean. The metabolomics's changes were critical factors in the evolution of salt tolerance among Soja. This study provides new

  3. Overexpression of a Vesicle Trafficking Gene, OsRab7, Enhances Salt Tolerance in Rice

    Directory of Open Access Journals (Sweden)

    Xiaojue Peng

    2014-01-01

    Full Text Available High soils salinity is a main factor affecting agricultural production. Studying the function of salt-tolerance-related genes is essential to enhance crop tolerance to stress. Rab7 is a small GTP-binding protein that is distributed widely among eukaryotes. Endocytic trafficking mediated by Rab7 plays an important role in animal and yeast cells, but the current understanding of Rab7 in plants is still very limited. Herein, we isolated a vesicle trafficking gene, OsRab7, from rice. Transgenic rice over-expressing OsRab7 exhibited enhanced seedling growth and increased proline content under salt-treated conditions. Moreover, an increased number of vesicles was observed in the root tip of OsRab7 transgenic rice. The OsRab7 over-expression plants showed enhanced tolerance to salt stress, suggesting that vacuolar trafficking is important for salt tolerance in plants.

  4. Overexpression of pigeonpea stress-induced cold and drought regulatory gene (CcCDR) confers drought, salt, and cold tolerance in Arabidopsis.

    Science.gov (United States)

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

    2014-09-01

    A potent cold and drought regulatory protein-encoding gene (CcCDR) was isolated from the subtractive cDNA library of pigeonpea plants subjected to drought stress. CcCDR was induced by different abiotic stress conditions in pigeonpea. Overexpression of CcCDR in Arabidopsis thaliana imparted enhanced tolerance against major abiotic stresses, namely drought, salinity, and low temperature, as evidenced by increased biomass, root length, and chlorophyll content. Transgenic plants also showed increased levels of antioxidant enzymes, proline, and reducing sugars under stress conditions. Furthermore, CcCDR-transgenic plants showed enhanced relative water content, osmotic potential, and cell membrane stability, as well as hypersensitivity to abscisic acid (ABA) as compared with control plants. Localization studies confirmed that CcCDR could enter the nucleus, as revealed by intense fluorescence, indicating its possible interaction with various nuclear proteins. Microarray analysis revealed that 1780 genes were up-regulated in CcCDR-transgenics compared with wild-type plants. Real-time PCR analysis on selected stress-responsive genes, involved in ABA-dependent and -independent signalling networks, revealed higher expression levels in transgenic plants, suggesting that CcCDR acts upstream of these genes. The overall results demonstrate the explicit role of CcCDR in conferring multiple abiotic stress tolerance at the whole-plant level. The multifunctional CcCDR seems promising as a prime candidate gene for enhancing abiotic stress tolerance in diverse plants. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  5. Effects of salt stress on germination of some maize (Zea mays L ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-05

    Oct 5, 2009 ... This study was conducted to investigate the effects of salt stress on germination of six maize (Zea mays L.) cultivars ... Key words: Maize, NaCl, germination percentage, stress tolerance ındex, germination ındex. INTRODUCTION ... Salt tolerance at germination stage is important factor, where soil salinity is ...

  6. Improving abiotic stress tolerance of quinoa

    DEFF Research Database (Denmark)

    Yang, Aizheng

    other crops, its productivity declines under severe drought, high salt conditions and harsh climate conditions. Different management approaches including water-saving irrigation methods (such as deficit irrigation, DI and alternate root-zone drying irrigation, ARD), inoculating crop seeds with plant......Global food security faces the challenges of rapid population growth and shortage of water resources. Drought, heat waves and soil salinity are becoming more frequent and extreme due to climatic changes in many regions of the world, and resulting in yield reduction of many crops. It is hypothesized...... that quinoa has the potential to grow under a range of abiotic stresses, tolerating levels regarded as stresses in other crop species. Therefore cultivation of quinoa (Chenopodium quinoa Willd.) could be an alternative option in such regions. Even though quinoa is more tolerant to abiotic stress than most...

  7. A Raf-like MAPKKK gene, GhRaf19, negatively regulates tolerance to drought and salt and positively regulates resistance to cold stress by modulating reactive oxygen species in cotton.

    Science.gov (United States)

    Jia, Haihong; Hao, Lili; Guo, Xulei; Liu, Shuchang; Yan, Yan; Guo, Xingqi

    2016-11-01

    Mitogen-activated protein kinase kinase kinases (MAPKKKs) function at the top level of MAPK cascades and play important roles in plant development and stress responses. Although MAPKKKs comprise the largest family in the MAPK cascades, very few Raf-like MAPKKKs have been functionally identified, especially in the economically important crop cotton. In this study, a Raf-like MAPKKK gene, GhRaf19, was characterized for the first time in cotton. Our data show that the expression of GhRaf19 was inhibited by PEG and NaCl and induced by cold (4°C) and H2O2. Furthermore, when GhRaf19 was silenced in cotton using virus-induced gene silencing (VIGS), tolerance to drought and salt stress were enhanced, the accumulation of reactive oxygen species (ROS) was reduced, and ROS-related gene expression was increased. Consistent with these results, in N. benthamiana, overexpressing-GhRaf19 reduced tolerance to drought and salt. However, GhRaf19-silenced plants showed lowered resistance to cold in cotton, and this effect was correlated with the accumulation of ROS. In contrast, overexpressing GhRaf19 in N. benthamiana increased resistance to cold by inducing higher levels of expression and activity of ROS-related antioxidant genes/enzymes. These results indicate that GhRaf19 negatively regulates tolerance to drought and salt and positively regulates resistance to cold stress by modulating cellular ROS in cotton. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  8. Genetic Approaches to Develop Salt Tolerant Germplasm

    KAUST Repository

    Tester, Mark A.

    2015-08-19

    ://www.plantphenomics.org.au/). New genetic loci for previously under-studied components of salinity tolerance discovered using this new approach will be presented. The application of these technologies provides opportunities to significantly increase abiotic stress tolerance of crops, and thus contribute to increasing agricultural production in many regions, especially in the face of global environmental change. However, this needs to be tested in the field, such as done by Munns et al (2012) and Schilling et al. (2014). To this end, work will be described where mapping populations are grown in the field, and also grown in the Accelerator, and loci for traits are being compared with loci for tolerance in the field.

  9. Influence of salicylic acid on in vitro propagation and salt tolerance ...

    African Journals Online (AJOL)

    Influence of salicylic acid on in vitro propagation and salt tolerance in Hibiscus acetosella and Hibiscus moscheutos (cv 'Luna Red'). HF Sakhanokho, RY Kelley. Abstract. Salicylic acid (SA) has been reported to improve in vitro regeneration as well as induce abiotic stress tolerance in plants. The effects of varying SA ...

  10. Expression Profiling of Ribosomal Protein Gene Family in Dehydration Stress Responses and Characterization of Transgenic Rice Plants Overexpressing RPL23A for Water-Use Efficiency and Tolerance to Drought and Salt Stresses

    Directory of Open Access Journals (Sweden)

    Mazahar Moin

    2017-11-01

    Full Text Available Our previous findings on the screening of a large-pool of activation tagged rice plants grown under limited water conditions revealed the activation of Ribosomal Protein Large (RPL subunit genes, RPL6 and RPL23A in two mutants that exhibited high water-use efficiency (WUE with the genes getting activated by the integrated 4x enhancers (Moin et al., 2016a. In continuation of these findings, we have comprehensively characterized the Ribosomal Protein (RP gene family including both small (RPS and large (RPL subunits, which have been identified to be encoded by at least 70 representative genes; RP-genes exist as multiple expressed copies with high nucleotide and amino acid sequence similarity. The differential expression of all the representative genes in rice was performed under limited water and drought conditions at progressive time intervals in the present study. More than 50% of the RP genes were upregulated in both shoot and root tissues. Some of them exhibited an overlap in upregulation under both the treatments indicating that they might have a common role in inducing tolerance under limited water and drought conditions. Among the genes that became significantly upregulated in both the tissues and under both the treatments are RPL6, 7, 23A, 24, and 31 and RPS4, 10 and 18a. To further validate the role of RP genes in WUE and inducing tolerance to other stresses, we have raised transgenic plants overexpressing RPL23A in rice. The high expression lines of RPL23A exhibited low Δ13C, increased quantum efficiency along with suitable growth and yield parameters with respect to negative control under the conditions of limited water availability. The constitutive expression of RPL23A was also associated with transcriptional upregulation of many other RPL and RPS genes. The seedlings of RPL23A high expression lines also showed a significant increase in fresh weight, root length, proline and chlorophyll contents under simulated drought and salt

  11. Classification and salt tolerance analysis of barley varieties

    NARCIS (Netherlands)

    Katerji, N.; Hoorn, van J.W.; Hamdy, A.; Mastrorilli, M.; Fares, C.; Ceccarelli, S.; Grando, S.; Oweis, T.

    2006-01-01

    Six varieties of barley (Hordeum vulgare), five of which were provided by ICARDA, were tested in a green house experiment for their salt tolerance. Afterwards the ICARDA variety Melusine, selected from this experiment for its combination of high yield and salt tolerance, was compared in a lysimeter

  12. Atmospheric application of trace amounts of nitric oxide enhances tolerance to salt stress and improves nutritional quality in spinach (Spinacia oleracea L.).

    Science.gov (United States)

    Du, Shao-Ting; Liu, Yue; Zhang, Peng; Liu, Hui-Jun; Zhang, Xue-Qing; Zhang, Ran-Ran

    2015-04-15

    The increased salinity in greenhouses has become a problem of great concern. In this study, it was observed that the salt-induced oxidative damages (indicated by MDA, H2O2 and antioxidant enzymes, including POD, SOD and CAT) could be alleviated by application of NO gas. Consequently, although both photosynthesis and growth in plants were inhibited by NaCl stress, they were restored by NO gas application, and the fresh and dry biomasses of edible parts increased by 60% and 27% over NaCl stress treatment, respectively. Furthermore, gaseous NO application also significantly elevated the levels of several antioxidation-associated compounds such as proline, ascorbate, glutathione, total phenolics and flavonoids, as well as the total antioxidant capacity (indicated by DPPH scavenging activity) in NaCl-treated plants. Keeping in mind all of the above, we concluded that atmospheric application of trace amounts of nitric oxide gas could be an effective strategy for improving both biomass production and nutrition quality in spinach under salt stress. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. A computational systems biology study for understanding salt tolerance mechanism in rice.

    Directory of Open Access Journals (Sweden)

    Juexin Wang

    Full Text Available Salinity is one of the most common abiotic stresses in agriculture production. Salt tolerance of rice (Oryza sativa is an important trait controlled by various genes. The mechanism of rice salt tolerance, currently with limited understanding, is of great interest to molecular breeding in improving grain yield. In this study, a gene regulatory network of rice salt tolerance is constructed using a systems biology approach with a number of novel computational methods. We developed an improved volcano plot method in conjunction with a new machine-learning method for gene selection based on gene expression data and applied the method to choose genes related to salt tolerance in rice. The results were then assessed by quantitative trait loci (QTL, co-expression and regulatory binding motif analysis. The selected genes were constructed into a number of network modules based on predicted protein interactions including modules of phosphorylation activity, ubiquity activity, and several proteinase activities such as peroxidase, aspartic proteinase, glucosyltransferase, and flavonol synthase. All of these discovered modules are related to the salt tolerance mechanism of signal transduction, ion pump, abscisic acid mediation, reactive oxygen species scavenging and ion sequestration. We also predicted the three-dimensional structures of some crucial proteins related to the salt tolerance QTL for understanding the roles of these proteins in the network. Our computational study sheds some new light on the mechanism of salt tolerance and provides a systems biology pipeline for studying plant traits in general.

  14. Haplotyping of Rice Genotypes Using Simple Sequence Repeat Markers Associated with Salt Tolerance

    Directory of Open Access Journals (Sweden)

    A.D. Chowdhury

    2016-11-01

    Full Text Available Salt stress is a major problem in most of the rice growing areas in the world. A major QTL Saltol associated with salt tolerance at the seedling stage has been mapped on chromosome 1 in rice. This study aimed to characterize the haplotype diversity at Saltol and additional QTLs associated with salt tolerance. Salt tolerance at the seedling stage was assessed in 54 rice genotypes in the scale of 1 to 9 score at EC = 10 dSm-1 under controlled environmental conditions. Seven new breeding lines including three KMR3/O. rufipogon introgression lines showed similar salt tolerant ability as FL478 and can be good sources of new genes/alleles for salt tolerance. Simple sequence repeat (SSR marker RM289 showed only two alleles and RM8094 showed seven alleles. Polymorphic information content value varied from 0.55 for RM289 to 0.99 for RM8094 and RM493. Based on 14 SSR markers, the 54 lines were clearly separated into two major clusters. Fourteen haplotypes were identified based on Saltol linked markers with FL478 as the reference. Alleles of RM8094 and RM3412 can discriminate between the salt tolerant and susceptible genotypes clearly and hence can be useful in marker-assisted selection at the seedling stage. Other markers RM10720 on chromosome 1 and RM149 and RM264 on chromosome 8 can also distinguish tolerant and susceptible lines but with lesser stringency.

  15. Brassinosteroid Action in Plant Abiotic Stress Tolerance.

    Science.gov (United States)

    Krishna, Priti; Prasad, Bishun D; Rahman, Tawhidur

    2017-01-01

    Brassinosteroids (BRs) are a class of plant steroidal hormones that play essential roles in plant growth and development. Systematic studies had first been undertaken concomitantly to determine both the effects of exogenous BR on stress phenotypes of Arabidopsis thaliana and Brassica napus (rapeseed) seedlings and the expression of stress marker genes in BR-treated and untreated seedlings. When reproducible and convincing evidence of the role of BR in stress tolerance had been obtained, molecular mechanisms underlying the ability of BR to confer tolerance against heat, cold, drought, and salt stress, as well as pathogen resistance were studied with several molecular approaches and tools. The results of these studies have together provided valuable insights into how BRs, through their control of many basic cellular processes and stress responses, promote vigor in plants and prepare the plant to mount a dynamic response upon environmental challenges. Protocols to assess BR effects on abiotic stress tolerance in Arabidopsis and rapeseed seedlings are described here and they can be fine-tuned and adapted for other plant species.

  16. RAS1, a quantitative trait locus for salt tolerance and ABA sensitivity in Arabidopsis

    KAUST Repository

    Ren, Zhonghai

    2010-03-08

    Soil salinity limits agricultural production and is a major obstacle for feeding the growing world population. We used natural genetic variation in salt tolerance among different Arabidopsis accessions to map a major quantitative trait locus (QTL) for salt tolerance and abscisic acid (ABA) sensitivity during seed germination and early seedling growth. A recombinant inbred population derived from Landsberg erecta (Ler; salt and ABA sensitive) x Shakdara (Sha; salt and ABA resistant) was used for QTL mapping. High-resolution mapping and cloning of this QTL, Response to ABA and Salt 1 (RAS1), revealed that it is an ABA- and salt stress-inducible gene and encodes a previously undescribed plant-specific protein. A premature stop codon results in a truncated RAS1 protein in Sha. Reducing the expression of RAS1 by transfer-DNA insertion in Col or RNA interference in Ler leads to decreased salt and ABA sensitivity, whereas overexpression of the Ler allele but not the Sha allele causes increased salt and ABA sensitivity. Our results suggest that RAS1 functions as a negative regulator of salt tolerance during seed germination and early seedling growth by enhancing ABA sensitivity and that its loss of function contributes to the increased salt tolerance of Sha.

  17. Global Metabolic Responses to Salt Stress in Fifteen Species.

    Directory of Open Access Journals (Sweden)

    Daniel C Sévin

    Full Text Available Cells constantly adapt to unpredictably changing extracellular solute concentrations. A cornerstone of the cellular osmotic stress response is the metabolic supply of energy and building blocks to mount appropriate defenses. Yet, the extent to which osmotic stress impinges on the metabolic network remains largely unknown. Moreover, it is mostly unclear which, if any, of the metabolic responses to osmotic stress are conserved among diverse organisms or confined to particular groups of species. Here we investigate the global metabolic responses of twelve bacteria, two yeasts and two human cell lines exposed to sustained hyperosmotic salt stress by measuring semiquantitative levels of hundreds of cellular metabolites using nontargeted metabolomics. Beyond the accumulation of osmoprotectants, we observed significant changes of numerous metabolites in all species. Global metabolic responses were predominantly species-specific, yet individual metabolites were characteristically affected depending on species' taxonomy, natural habitat, envelope structure or salt tolerance. Exploiting the breadth of our dataset, the correlation of individual metabolite response magnitudes across all species implicated lower glycolysis, tricarboxylic acid cycle, branched-chain amino acid metabolism and heme biosynthesis to be generally important for salt tolerance. Thus, our findings place the global metabolic salt stress response into a phylogenetic context and provide insights into the cellular phenotype associated with salt tolerance.

  18. Salt tolerance at single cell level in giant-celled Characeae

    Directory of Open Access Journals (Sweden)

    Mary Jane eBeilby

    2015-04-01

    Full Text Available Characean plants provide an excellent experimental system for electrophysiology and physiology due to: (i very large cell size, (ii position on phylogenetic tree near the origin of land plants and (iii continuous spectrum from very salt sensitive to very salt tolerant species. A range of experimental techniques is described, some unique to characean plants. Application of these methods provided electrical characteristics of membrane transporters, which dominate the membrane conductance under different outside conditions. With this considerable background knowledge the electrophysiology of salt sensitive and salt tolerant genera can be compared under salt and/or osmotic stress. Both salt tolerant and salt sensitive Characeae show a rise in membrane conductance and simultaneous increase in Na+ influx upon exposure to saline medium. Salt tolerant Chara longifolia and Lamprothamnium sp. exhibit proton pump stimulation upon both turgor decrease and salinity increase, allowing the membrane PD to remain negative. The turgor is regulated through the inward K+ rectifier and 2H+/Cl- symporter. Lamprothamnium plants can survive in hypersaline media up to twice seawater strength and withstand large sudden changes in salinity. Salt-sensitive Chara australis succumbs to 50 - 100 mM NaCl in few days. Cells exhibit no pump stimulation upon turgor decrease and at best transient pump stimulation upon salinity increase. Turgor is not regulated. The membrane PD exhibits characteristic noise upon exposure to salinity. Depolarization of membrane PD to excitation threshold sets off trains of action potentials, leading to further loses of K+ and Cl-. In final stages of salt damage the H+/OH- channels are thought to become the dominant transporter, dissipating the proton gradient and bringing the cell PD close to 0. The differences in transporter electrophysiology and their synergy under osmotic and/or saline stress in salt sensitive and salt tolerant characean cells

  19. Overexpression of AtSTO1 leads to improved salt tolerance in Populus tremula × P. alba

    Science.gov (United States)

    Shaneka S. Lawson; Charles H. Michler

    2014-01-01

    One of the major abiotic stress conditions limiting healthy growth of trees is salinity stress. The use of gene manipulation for increased tolerance to abiotic stress has been successful in many plant species. Overexpression of the Arabidopsis SALT TOLERANT1 (STO1) gene leads to increased concentrations of 9-cis-epoxycarotenoid dioxygenase3, a vital...

  20. The plant-growth-promoting bacterium Klebsiella sp. SBP-8 confers induced systemic tolerance in wheat (Triticum aestivum) under salt stress.

    Science.gov (United States)

    Singh, Rajnish Prakash; Jha, Prameela; Jha, Prabhat Nath

    2015-07-20

    Plant-growth-promoting bacteria (PGPB) with 1-aminocyclopropane-1-carboxylatedeaminase (ACCD) activity can protect plants from the deleterious effects of abioticstressors. An ACCD bacterial strain, SBP-8, identified as Klebsiella sp., also having other plant-growth-promoting activities, was isolated from Sorghum bicolor growing in the desertregion of Rajasthan, India. ACCD activity of SBP-8 was characterized at biochemical, physiological, and molecular levels. The presence of AcdS, a structural gene for ACCD, was confirmed by the polymerase chain reaction. Strain SBP-8 showed optimum growth and ACCD activity at increased salt (NaCl) concentrations of up to 6%, indicating its potential to survive and associate with plants growing in saline soil. Inoculation of wheat plants with SBP-8 when grow in the presence of salt (150-200 mM) and temperature (30-40 °C) stressors resulted inamelioration of stress conditions by increasing plant biomass and chlorophyll content, and are duction in plant growth inhibition (10-100%) occurred due to salt and temperature stressors. Moreover, strain SBP-8 also caused Na(+) exclusion (65%) and increased uptake of K(+) (84.21%) in the host plant. This property can protect plants from adverse effects of Na(+) on plant growth and physiology. Thus, SBP-8 improves growth of the host plant and protects from salt stressors through more than one mechanism including an effect of ACCD activity and on K(+)/Na(+) ratio in plants. The colonization efficiency of strain SBP-8 was confirmedby CFU (colony-forming unit) count, microscopy, and ERIC-PCR based DNA-finger-printing approach. Therefore, and the use of efficient colonizing plant-growth-promoting bacteria may provideinsights into possible biotechnological approaches to decrease the impact of salinity and other stressors. Copyright © 2015 Elsevier GmbH. All rights reserved.

  1. Identification of salt-tolerant Sinorhizobium sp. strain BL3 membrane proteins based on proteomics

    DEFF Research Database (Denmark)

    Tanthanuch, Waraporn; Tittabutr, Panlada; Mohammed, Shabaz

    2010-01-01

    Sinorhizobium sp. BL3 is a salt-tolerant strain that can fix atmospheric nitrogen in symbiosis with leguminous host plants under salt-stress conditions. Since cell membranes are the first barrier to environmental change, it is interesting to explore the membrane proteins within this protective ba......-line SCX fractionation coupled to nanoLC-MS/MS. These techniques would be useful for further comparative analysis of membrane proteins that function in the response to environmental stress....

  2. Salt-induced root protein profile changes in seedlings of maize inbred lines with differing salt tolerances

    Directory of Open Access Journals (Sweden)

    Yujing Cheng

    2014-12-01

    Full Text Available Salt stress is one of the severest growth limited-factors to agriculture production. To gain in-depth knowledge of salt-stress response mechanisms, the proteomics analysis from two maize (Zea mays L. inbred lines was carried out using two-dimensional gel electrophoresis (2-DGE and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/TOF-MS. There were 57 salt-regulated proteins identified, 21 and 36 proteins were differentially regulated in inbred lines 'Nongda 1145' (salt-resistant and 'D340' (salt-sensitive, respectively. The identified proteins were distributed in 11 biological processes and seven molecular functions. Under salt stress, proteins related to antioxidation and lignin synthesis were increased in both inbred lines. The relative abundance of proteins involved in translation initiation, elongation, and protein proteolysis increased in 'Nongda 1145' and decreased in 'D340'. In addition, the abundance of proteins involved in carbohydrate metabolism, protein refolding, ATP synthase and transcription differed between the two inbred lines. Our results suggest that the enhanced ability of salt-tolerant inbred line 'Nongda 1145' to combat salt stress occurs via regulation of transcription factors promoting increased antioxidation and lignin biosynthesis, enhanced energy production, and acceleration of protein translation and protein proteolysis.

  3. Overexpression of DgWRKY4 Enhances Salt Tolerance in Chrysanthemum Seedlings

    Science.gov (United States)

    Wang, Ke; Wu, Yin-Huan; Tian, Xiao-Qin; Bai, Zhen-Yu; Liang, Qian-Yu; Liu, Qing-Lin; Pan, Yuan-Zhi; Zhang, Lei; Jiang, Bei-Bei

    2017-01-01

    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. PMID:28959270

  4. 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.

  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. Field Observed Salt Tolerance of California Pistachios

    Science.gov (United States)

    Sanden, Blake; Fergusion, Lousie; Kallsen, Craig

    2017-04-01

    The general concept of crop salt tolerance is over simplified: consisting of a single soil saturation extract salinity threshold with a "% relative yield" decline function. This approach minimizes the real world variability in actual tree growth and yield due to additional specific ion toxicity and soil texture/anoxia. The current salinity tolerance function for California pistachios is essentially the same as cotton. It was developed from a small plot study in an 8 to 13 year old orchard in northwestern Kern County from 1997-2002 with a threshold of 9.4 dS/m ECe and an 8.4% relative yield decline above that level. These values were confirmed for seedling growth in saline sand-tank studies at the USDA Salinity Lab in Riverside, California. A second large scale field study applied fresh and saline irrigation treatments (0.5 to 5.2 dS/m EC) from planting through 10th leaf. Trees were commercially harvested starting in 2011. Average 2011-14 root zone salinity ranged from 2.5 to 13.2 dS/m and caused a significant edible inshell yield reduction of 108 to 264 kg/ha (depending on rootstock) in the combined 4 year yield: a 1 to 3% decline for every unit EC (dS/m) increase over 6 ds/m. A greatly expanded salinity survey including 10 commercial fields (9th - 15th leaf) in western Kern County with 140 individual tree data points ranging from an average root zone (1.5 m depth) salinity of 1.6 to 20.5 dS/m resulted in a similar yield reduction of 162 to 394 kg/ha (3 year cumulative inshell yield) for every unit ECe > 6.5 dS/m.

  7. 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.

  8. Stress tolerant plants

    OpenAIRE

    Rubio, Vicente; Iniesto Sánchez, Elisa; Irigoyen Miguel, María Luisa

    2014-01-01

    [EN] The invention relates to transgenic plants and methods for modulating abscisic acid (ABA) perception and signal transduction in plants. The plants find use in increasing yield in plants, particularly under abiotic stress.

  9. Transcriptome Analysis of Salt Stress Responsiveness in the Seedlings of Dongxiang Wild Rice (Oryza rufipogon Griff.)

    Science.gov (United States)

    Zhou, Yi; Yang, Ping; Cui, Fenglei; Zhang, Fantao; Luo, Xiangdong; Xie, Jiankun

    2016-01-01

    Dongxiang wild rice (Oryza rufipogon Griff.) is the progenitor of cultivated rice (Oryza sativa L.), and is well known for its superior level of tolerance against cold, drought and diseases. To date, however, little is known about the salt-tolerant character of Dongxiang wild rice. To elucidate the molecular genetic mechanisms of salt-stress tolerance in Dongxiang wild rice, the Illumina HiSeq 2000 platform was used to analyze the transcriptome profiles of the leaves and roots at the seedling stage under salt stress compared with those under normal conditions. The analysis results for the sequencing data showed that 6,867 transcripts were differentially expressed in the leaves (2,216 up-regulated and 4,651 down-regulated) and 4,988 transcripts in the roots (3,105 up-regulated and 1,883 down-regulated). Among these differentially expressed genes, the detection of many transcription factor genes demonstrated that multiple regulatory pathways were involved in salt stress tolerance. In addition, the differentially expressed genes were compared with the previous RNA-Seq analysis of salt-stress responses in cultivated rice Nipponbare, indicating the possible specific molecular mechanisms of salt-stress responses for Dongxiang wild rice. A large number of the salt-inducible genes identified in this study were co-localized onto fine-mapped salt-tolerance-related quantitative trait loci, providing candidates for gene cloning and elucidation of molecular mechanisms responsible for salt-stress tolerance in rice. PMID:26752408

  10. A MAPK gene from Dead Sea fungus confers stress tolerance to lithium salt and freezing–thawing: Prospects for saline agriculture

    Science.gov (United States)

    Jin, Yan; Weining, Song; Nevo, Eviatar

    2005-01-01

    The Dead Sea is one of the most saline lakes on earth (≈340 g/liter salinity) and is ≈10 times saltier than the oceans. Eurotium herbariorum, a common fungal species, was isolated from its water. EhHOG gene, encoding a mitogen-activated protein kinase (MAPK) that plays an essential role in the osmoregulatory pathway in yeast and many other eukaryotes, was isolated from E. herbariorum. The deduced amino acid sequences of EhHOG indicated high similarity with homologous genes from Aspergillus nidulans, Saccharomyces cerevisiae, and Schizosaccharomyces pombe and contained a TGY motif for phosphorylation by MAPK kinase. When EhHOG was expressed in S. cerevisiae hog1Δ mutant, the growth and aberrant morphology of hog1Δ mutant was restored under high osmotic stress condition. Moreover, intracellular glycerol content in the transformant increased to a much higher level than that in the mutant during salt-stress situations. hog1Δ mutant complemented by EhHOG outperformed the wild type or had higher genetic fitness under high Li+ and freezing–thawing conditions. The present study revealed the putative presence of a high-osmolarity glycerol response (HOG) pathway in E. herbariorum and the significance of EhHOG in osmotic regulation, heat stress, freeze stress, and oxidative stress. The Dead Sea is becoming increasingly more saline while the fungi living in it evolutionarily adapt to its high-saline environment, particularly with the extraordinarily high Li+ concentration. The Dead Sea is potentially an excellent model for studies of evolution under extreme environments and is an important gene pool for future agricultural genetic engineering prospects. PMID:16365289

  11. Tissue metabolic responses to salt stress in wild and cultivated barley.

    Directory of Open Access Journals (Sweden)

    Dezhi Wu

    Full Text Available A thorough understanding of the mechanisms underlying barley salt tolerance and exploitation of elite genetic resource are essential for utilizing wild barley germplasm in developing barley varieties with salt tolerance. In order to reveal the physiological and molecular difference in salt tolerance between Tibetan wild barley (Hordeum spontaneum and cultivated barley (Hordeum vulgare, profiles of 82 key metabolites were studies in wild and cultivated barley in response to salinity. According to shoot dry biomass under salt stress, XZ16 is a fast growing and salt tolerant wild barley. The results of metabolite profiling analysis suggested osmotic adjustment was a basic mechanism, and polyols played important roles in developing salt tolerance only in roots, and high level of sugars and energy in roots and active photosynthesis in leaves were important for barley to develop salt tolerance. The metabolites involved in tolerance enhancement differed between roots and shoots, and also between genotypes. Tibetan wild barley, XZ16 had higher chlorophyll content and higher contents of compatible solutes than CM72, while the cultivated barley, CM72 probably enhanced its salt tolerance mainly through increasing glycolysis and energy consumption, when the plants were exposed to high salinity. The current research extends our understanding of the mechanisms involved in barley salt tolerance and provides possible utilization of Tibetan wild barley in developing barley cultivars with salt tolerance.

  12. [Salt tolerance evaluation of cotton (Gossypium hirsutum) at its germinating and seedling stages and selection of related indices].

    Science.gov (United States)

    Zhang, Guo-wei; Lu, Hai-ling; Zhang, Lei; Chen, Bing-lin; Zhou, Zhi-guo

    2011-08-01

    A sand culture experiment was conducted to study the salt tolerance of 13 cotton cultivars at their germinating and seedling stages under the stress of different concentration NaCl, and a cluster analysis was made on the salt tolerance, according to the subjection values of salt toxicity coefficients of multi-indices and the sum subjection value. It was observed that the appropriate concentration of NaCl for the evaluation of salt tolerance was 150 mmol x L(-1). The salt tolerance differed with cultivar and growth stage. Among the 13 cultivars, the CCRI-44 and CCRI-177 were steadily salt-tolerant at both germinating and seedling stages, the CCRI-103, Dexiamian 1, and NuCOTN 33B were steadily and moderately salt-tolerant, while the CCRI-102, Sumian 12, and Simian 3 were steadily salt-sensitive. Germination rate, germination potential, germination index, vigor index, and fresh mass could be served as the indicators to evaluate the salt tolerance of the cultivars at germinating stage, while plant height, leaf expansion rate, shoot dry mass, root dry mass, root vigor, and net photosynthetic rate could be applied to assess the salt tolerance at seedling stage.

  13. Evaluation of rice genotypes to salt stress in different growth stages ...

    African Journals Online (AJOL)

    Tolerant genotypes were tested in young seedling stage in hydroponic system and then reproductive stage in 2010. Results show that vegetative growth was less affected by salt stress comparison to reproductive stage. Na and Na-K ratio in tolerant genotypes were lower than suspectible genotypes in salt condition in ...

  14. Over‐expression of an Na+‐ and K+‐permeable HKT transporter in barley improves salt tolerance

    National Research Council Canada - National Science Library

    Mian, Afaq; Oomen, Ronald J.F.J; Isayenkov, Stanislav; Sentenac, Hervé; Maathuis, Frans J.M; Véry, Anne‐Aliénor

    2011-01-01

    ... + uptake, translocation and compartmentalization. Na + transporters belonging to the HKT family have been shown to be involved in tolerance to mild salt stress in glycophytes such as Arabidopsis, wheat and rice by contributing to Na...

  15. Polyamine biosynthesis in rice cultivars under salt stress and comparison with observations under drought stress

    Directory of Open Access Journals (Sweden)

    Phuc Thi Do

    2014-05-01

    Full Text Available Soil salinity affects a large proportion of rural area and limits agricultural productivity. To investigate differential adaptation to soil salinity, we studied salt tolerance of 18 varieties of Oryza sativa using a hydroponic culture system. Based on visual inspection and photosynthetic parameters, cultivars were classified according to their tolerance level. Additionally, biomass parameters were correlated with salt tolerance. Polyamines have frequently been demonstrated to be involved in plant stress responses and therefore soluble leaf polyamines were measured. Under salinity, putrescine (Put content was unchanged or increased in tolerant, while dropped in sensitive cultivars. Spermidine (Spd content was unchanged at lower NaCl concentrations in all, while reduced at 100 mM NaCl in sensitive cultivars. Spermine (Spm content was increased in all cultivars. A comparison with data from 21 cultivars under long-term, moderate drought stress revealed an increase of Spm under both stress conditions. While Spm became the most prominent polyamine under drought, levels of all three polyamines were relatively similar under salt stress. Put levels were reduced under both, drought and salt stress, while changes in Spd were different under drought (decrease or salt (unchanged conditions. Regulation of polyamine metabolism at the transcript level during exposure to salinity was studied for genes encoding enzymes involved in the biosynthesis of polyamines and compared to expression under drought stress. Based on expression profiles, investigated genes were divided into generally stress-induced genes (ADC2, SPD/SPM2, SPD/SPM3, one generally stress-repressed gene (ADC1, constitutively expressed genes (CPA1, CPA2, CPA4, SAMDC1, SPD/SPM1, specifically drought-induced genes (SAMDC2, AIH, one specifically drought-repressed gene (CPA3 and one specifically salt-stress repressed gene (SAMDC4, revealing both overlapping and specific stress responses under these

  16. Fungicide, antibiotic, heavy metal resistance and salt tolerance of ...

    African Journals Online (AJOL)

    Fungicide, antibiotic, heavy metal resistance and salt tolerance of root nodule isolates from Vicia palaestina. ... African Journal of Biotechnology ... The objective of this study was to investigate the effects of fungicides, antibiotics, heavy metal and salt on growth of Rhizobium isolates which isolated from the Vicia palaestina ...

  17. Arbuscular mycorrhizal fungi in alleviation of salt stress: a review.

    Science.gov (United States)

    Evelin, Heikham; Kapoor, Rupam; Giri, Bhoopander

    2009-12-01

    Salt stress has become a major threat to plant growth and productivity. Arbuscular mycorrhizal fungi colonize plant root systems and modulate plant growth in various ways. This review addresses the significance of arbuscular mycorrhiza in alleviation of salt stress and their beneficial effects on plant growth and productivity. It also focuses on recent progress in unravelling biochemical, physiological and molecular mechanisms in mycorrhizal plants to alleviate salt stress. The role of arbuscular mycorrhizal fungi in alleviating salt stress is well documented. This paper reviews the mechanisms arbuscular mycorrhizal fungi employ to enhance the salt tolerance of host plants such as enhanced nutrient acquisition (P, N, Mg and Ca), maintenance of the K(+) : Na(+) ratio, biochemical changes (accumulation of proline, betaines, polyamines, carbohydrates and antioxidants), physiological changes (photosynthetic efficiency, relative permeability, water status, abscissic acid accumulation, nodulation and nitrogen fixation), molecular changes (the expression of genes: PIP, Na(+)/H(+) antiporters, Lsnced, Lslea and LsP5CS) and ultra-structural changes. Theis review identifies certain lesser explored areas such as molecular and ultra-structural changes where further research is needed for better understanding of symbiosis with reference to salt stress for optimum usage of this technology in the field on a large scale. This review paper gives useful benchmark information for the development and prioritization of future research programmes.

  18. A retrotransposon in an HKT1 family sodium transporter causes variation of leaf Na+ exclusion and salt tolerance in maize.

    Science.gov (United States)

    Zhang, Ming; Cao, Yibo; Wang, Zhiping; Wang, Zhi-Qiang; Shi, Junpeng; Liang, Xiaoyan; Song, Weibin; Chen, Qijun; Lai, Jinsheng; Jiang, Caifu

    2017-11-15

    Soil salinity is one of several major abiotic stresses that constrain maize productivity worldwide. An improved understanding of salt-tolerance mechanisms will thus enhance the breeding of salt-tolerant maize and boost productivity. Previous studies have indicated that the maintenance of leaf Na+ concentration is essential for maize salt tolerance, and the difference in leaf Na+ exclusion has previously been associated with variation in salt tolerance between maize varieties. Here, we report the identification and functional characterization of a maize salt-tolerance quantitative trait locus (QTL), Zea mays Na+ Content1 (ZmNC1), which encodes an HKT-type transporter (designated as ZmHKT1). We show that a natural ZmHKT1 loss-of-function allele containing a retrotransposon insertion confers increased accumulation of Na+ in leaves, and salt hypersensitivity. We next show that ZmHKT1 encodes a plasma membrane-localized Na+ -selective transporter, and is preferentially expressed in root stele (including the parenchyma cells surrounding the xylem vessels). We also show that loss of ZmHKT1 function increases xylem sap Na+ concentration and causes increased root-to-shoot Na+ delivery, indicating that ZmHKT1 promotes leaf Na+ exclusion and salt tolerance by withdrawing Na+ from the xylem sap. We conclude that ZmHKT1 is a major salt-tolerance QTL and identifies an important new gene target in breeding for improved maize salt tolerance. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  19. Identification of a major QTL allele from wild soybean (Glycine soja Sieb. & Zucc.) for increasing alkaline salt tolerance in soybean.

    Science.gov (United States)

    Tuyen, D D; Lal, S K; Xu, D H

    2010-07-01

    Salt-affected soils are generally classified into two main categories, sodic (alkaline) and saline. Our previous studies showed that the wild soybean accession JWS156-1 (Glycine soja) from the Kinki area of Japan was tolerant to NaCl salt, and the quantitative trait locus (QTL) for NaCl salt tolerance was located on soybean linkage group N (chromosome 3). Further investigation revealed that the wild soybean accession JWS156-1 also had a higher tolerance to alkaline salt stress. In the present study, an F(6) recombinant inbred line mapping population (n = 112) and an F(2) population (n = 149) derived from crosses between a cultivated soybean cultivar Jackson and JWS156-1 were used to identify QTL for alkaline salt tolerance in soybean. Evaluation of soybean alkaline salt tolerance was carried out based on salt tolerance rating (STR) and leaf chlorophyll content (SPAD value) after treatment with 180 mM NaHCO(3) for about 3 weeks under greenhouse conditions. In both populations, a significant QTL for alkaline salt tolerance was detected on the molecular linkage group D2 (chromosome 17), which accounted for 50.2 and 13.0% of the total variation for STR in the F(6) and the F(2) populations, respectively. The wild soybean contributed to the tolerance allele in the progenies. Our results suggest that QTL for alkaline salt tolerance is different from the QTL for NaCl salt tolerance found previously in this wild soybean genotype. The DNA markers closely associated with the QTLs might be useful for marker-assisted selection to pyramid tolerance genes in soybean for both alkaline and saline stresses.

  20. A comparative study of salt tolerance parameters in 11 wild relatives of Arabidopsis thaliana.

    Science.gov (United States)

    Orsini, Francesco; D'Urzo, Matilde Paino; Inan, Gunsu; Serra, Sara; Oh, Dong-Ha; Mickelbart, Michael V; Consiglio, Federica; Li, Xia; Jeong, Jae Cheol; Yun, Dae-Jin; Bohnert, Hans J; Bressan, Ray A; Maggio, Albino

    2010-08-01

    Salinity is an abiotic stress that limits both yield and the expansion of agricultural crops to new areas. In the last 20 years our basic understanding of the mechanisms underlying plant tolerance and adaptation to saline environments has greatly improved owing to active development of advanced tools in molecular, genomics, and bioinformatics analyses. However, the full potential of investigative power has not been fully exploited, because the use of halophytes as model systems in plant salt tolerance research is largely neglected. The recent introduction of halophytic Arabidopsis-Relative Model Species (ARMS) has begun to compare and relate several unique genetic resources to the well-developed Arabidopsis model. In a search for candidates to begin to understand, through genetic analyses, the biological bases of salt tolerance, 11 wild relatives of Arabidopsis thaliana were compared: Barbarea verna, Capsella bursa-pastoris, Hirschfeldia incana, Lepidium densiflorum, Malcolmia triloba, Lepidium virginicum, Descurainia pinnata, Sisymbrium officinale, Thellungiella parvula, Thellungiella salsuginea (previously T. halophila), and Thlaspi arvense. Among these species, highly salt-tolerant (L. densiflorum and L. virginicum) and moderately salt-tolerant (M. triloba and H. incana) species were identified. Only T. parvula revealed a true halophytic habitus, comparable to the better studied Thellungiella salsuginea. Major differences in growth, water transport properties, and ion accumulation are observed and discussed to describe the distinctive traits and physiological responses that can now be studied genetically in salt stress research.

  1. A comparative study of salt tolerance parameters in 11 wild relatives of Arabidopsis thaliana

    KAUST Repository

    Orsini, Francesco

    2010-07-01

    Salinity is an abiotic stress that limits both yield and the expansion of agricultural crops to new areas. In the last 20 years our basic understanding of the mechanisms underlying plant tolerance and adaptation to saline environments has greatly improved owing to active development of advanced tools in molecular, genomics, and bioinformatics analyses. However, the full potential of investigative power has not been fully exploited, because the use of halophytes as model systems in plant salt tolerance research is largely neglected. The recent introduction of halophytic Arabidopsis-Relative Model Species (ARMS) has begun to compare and relate several unique genetic resources to the well-developed Arabidopsis model. In a search for candidates to begin to understand, through genetic analyses, the biological bases of salt tolerance, 11 wild relatives of Arabidopsis thaliana were compared: Barbarea verna, Capsella bursa-pastoris, Hirschfeldia incana, Lepidium densiflorum, Malcolmia triloba, Lepidium virginicum, Descurainia pinnata, Sisymbrium officinale, Thellungiella parvula, Thellungiella salsuginea (previously T. halophila), and Thlaspi arvense. Among these species, highly salt-tolerant (L. densiflorum and L. virginicum) and moderately salt-tolerant (M. triloba and H. incana) species were identified. Only T. parvula revealed a true halophytic habitus, comparable to the better studied Thellungiella salsuginea. Major differences in growth, water transport properties, and ion accumulation are observed and discussed to describe the distinctive traits and physiological responses that can now be studied genetically in salt stress research. 2010 The Author.

  2. Evaluation of salt tolerance in almond [Prunus dulcis (L.) Batsch ...

    African Journals Online (AJOL)

    user

    2012-07-12

    Jul 12, 2012 ... al., 2006; Jafarzadeh and Aliasgarzad, 2007). Woody plants are usually relatively salt-tolerant during the seed germination stage but much more sensitive during the young seedling stage and progressively more tolerant with increasing age through the reproductive stage (Najafian et al., 2008). Temperate ...

  3. Trifolium isthmocarpum Brot, a salt-tolerant wild leguminous forage crop in salt-affected soils

    Directory of Open Access Journals (Sweden)

    Kawtar Bennani

    2013-08-01

    Full Text Available Plant scientists are investigating the potential of previously unexploited legume species where environmental and biological stresses constrain the use of more conventional forage crops or where these species are better suited to the needs of sustainable agriculture. Trifolium isthmocarpum Brot., Moroccan clover, occurs as a weed in different habitats in Morocco. It grows in moderately saline areas, where traditional forage legumes cannot be cultivated; however, it has not been widely studied despite its good palatability. The salt tolerance was studied between natural field conditions and glasshouse. The extensive field studies have recorded the species in many different habitats ranging from healthy agricultural lands to abandoned saline areas. The plants maintained high nodulation capacity (ranging between 60% and 97% and nitrogenase activities (average 2.04 µmol C2H4 plant-1 h-1 in different habitats. Shoot systems of plants collected from salt-affected soils exhibited higher concentrations of Na+ and Cl- than those collected from healthy soils. Greenhouse experiments showed that germination percentage and vigor value of the studied species was not significantly (P > 0.05 affected at 160 mM NaCl, and that 25% of the germination ability was maintained when growing on substrats containing 240 mM NaCl. The growth rate of seedlings was not signicantly affected by 160 mM NaCl but was reduced by 38% under 240 mM NaCl. Leaf succulence and indices of leaf water status did not differ among the salt treatments, whereas relative water content was reduced by only 8% and water content at saturation increased by about 12% at high salt concentrations in the growing medium. This study suggest recommending the cultivation of T. isthmocarpum in salt-affected soils, which are widespread and pose a problem for the farmers of Morocco and other countries in the world’s arid belt.

  4. Improvement of Salinity Stress Tolerance in Rice: Challenges and Opportunities

    Directory of Open Access Journals (Sweden)

    Thi My Linh Hoang

    2016-10-01

    Full Text Available Rice (Oryza sativa L. is an important staple crop that feeds more than one half of the world’s population and is the model system for monocotyledonous plants. However, rice is very sensitive to salinity and is the most salt sensitive cereal crop with a threshold of 3 dSm−1 for most cultivated varieties. Despite many attempts using different strategies to improve salinity tolerance in rice, the achievements so far are quite modest. This review aims to discuss challenges that hinder the improvement of salinity stress tolerance in rice as well as potential opportunities for enhancing salinity stress tolerance in this important crop.

  5. Physical chemistry and evolution of salt tolerance in halobacteria

    Science.gov (United States)

    Lanyi, J. K.

    1980-01-01

    The cellular constituents of extremely halophilic bacteria not only tolerate high salt concentration, but in many cases require it for optical functioning. The characteristics affected by salt include enzyme activity, stability, allosteric regulation, conformation and subunit association. The salt effects are of two major kinds: electrostatic shielding of negative charges by cations at low salt concentration, and hydrophobic stabilization by salting-out type salts at high salt concentration. The composition of halobacterial proteins shows an excess of acidic amino acids and a deficiency of nonpolar amino acids, which accounts for these effects. Since the cohesive forces are weaker and the repulsing forces are stronger in these proteins, preventing aggregation in salt, these structures are no longer suited for functioning in the absence of high salt concentrations. Unlike these nonspecific effects, ribosomes in halobacteria show marked preference for potassium over sodium ions. To ensure the proper intracellular ionic composition, powerful ion transport systems have evolved in the halobacteria, resulting in the extrusion of sodium ions and their replacement by potassium. It is likely that such membrane transport system for ionic movements is a necessary requisite for salt tolerance.

  6. Review on sugar beet salt stress studies in Iran

    Science.gov (United States)

    Khayamim, S.; Noshad, H.; Jahadakbar, M. R.; Fotuhi, K.

    2017-07-01

    Increase of saline lands in most regions of the world and Iran, limit of production increase based on land enhancement and also threat of saline water and soils for crop production make related researches and production of salt tolerant variety to be more serious. There have been many researches about salt stress in Sugar Beet Seed Institute of Iran (SBSI) during several years. Accordingly, the new screening methods for stress tolerance to be continued based on these researches. Previous researches in SBSI were reviewed and results concluded to this study which is presented in this article in three categories including: Agronomy, Breeding and Biotechnology. In agronomy researches, suitable planting medium, EC, growth stage and traits for salinity tolerance screening were determined and agronomic technique such as planting date, planting method and suitable nutrition for sugar beet under salt stress were introduced. Sand was salinizied by saline treatments two times more than Perlit so large sized Perlit is suitable medium for saline studies. Sugar beet genotypes screening for salt tolerance and should be conducted at EC=20 in laboratory and EC= 16 dS/M in greenhouse. Although sugar beet seed germination has been known as more susceptible stage to salinity, it seems establishment is more susceptible than germination in which salinity will cause 70-80% decrease in plant establishment. Measurements of leaves Na, K and total carbohydrate at establishment stage would be useful for faster screening of genotypes, based on high and significant correlation of these traits at establishment with yield at harvest time. In breeding section, SBSI genotypes with drought tolerance background would be useful for salinity stress studies and finally there is a need for more research in the field of biotechnology in Iran.

  7. (SeNHX1) gene in tobacco improves tolerance to salt

    African Journals Online (AJOL)

    use

    2011-11-21

    Nov 21, 2011 ... stress, transgenic plants over-expressing SeNHX1 accumulated 1.2 mg g-1 FW Na+ greater than wild type in old ... malondialdehyde (MDA) content in transgenic plants was significantly lower, but proline content and activity of ..... Evaluation of salt tolerance in cultivated and wild tomato species through in ...

  8. Drought and salt tolerances in wild relatives for wheat and barley improvement.

    Science.gov (United States)

    Nevo, Eviatar; Chen, Guoxiong

    2010-04-01

    Drought and salinity are the major abiotic stresses that dramatically threaten the food supply in the world. Tribe Triticeae, including wheat and barley, possesses tremendous potential for drought and salt tolerance that has been extensively and practically identified, tested, and transferred to wheat cultivars with proven expression of tolerance in experimental trials. Triticum dicoccoides and Hordeum spontaneum, the progenitors of cultivated wheat and barley, have adapted to a broad range of environments and developed rich genetic diversities for drought and salt tolerances. Drought- and salt-tolerant genes and quantitative trait loci (QTLs) have been identified in T. dicoccoides and H. spontaneum and have great potential in wheat and barley improvement. Advanced backcross QTL analysis, the introgression libraries based on wild wheat and wild barley as donors, and positional cloning of natural QTLs will play prevailing roles in elucidating the molecular control of drought and salt tolerance. Combining tolerant genes and QTLs in crop breeding programs aimed at improving tolerance to drought and salinity will be achieved within a multidisciplinary context. Wild genetic resistances to drought and salinity will be shifted in the future from field experiments to the farmer.

  9. Morpho- biochemical evaluation of Brassica rapa sub-species for salt tolerance

    Directory of Open Access Journals (Sweden)

    Jan Sohail Ahmad

    2016-01-01

    Full Text Available Salt stress is one of the key abiotic stresses that affect both the qualitative and quantitative characters of many Brassica rapa sub-species by disturbing its normal morphobiochemical processes. Therefore, the present research work was designed to study the effect of different NaCl events (0, 50,100 and 150 mmol on morphological and biochemical characters and to screen salt tolerant genotypes among brown, yellow and toria types of B. rapa sub-species. The plants were grown in test tubes with addition of four level of NaCl (0, 50,100 and 150 mmol. The effect of salinity on shoot and root length, shoot/ root fresh and dry weight, relative water content (RWC, proline and chlorophyll a, b, a+b contents was recorded after 4 weeks of sowing. The genotype 22861 (brown type showed excellent morphological and biochemical performance at all stress levels followed by Toria-Sathi and Toria-A respectively as compared to Check variety TS-1. The genotype 26158 (yellow type gave very poor performance and retard growth. The %RWC values and chlorophyll a, b and a+b contents were decreased several folds with the increase of salt concentration. While, the proline contents was increased with raising of salt stress. The brown and toria types showed maximum tolerance to salt stress at early germination stages as compare to yellows one. The present study will serve as model to develop quick salt tolerant genotypes among different plant sub-species against salt stress.

  10. Evaluation and Exploration of Favorable QTL Alleles for Salt Stress Related Traits in Cotton Cultivars (G. hirsutum L..

    Directory of Open Access Journals (Sweden)

    Lei Du

    Full Text Available Soil salinization is one of the major problems in global agricultural production. Cotton is a pioneer crop with regard to salt stress tolerance, and can be used for saline-alkali land improvement. The large-scale detection of salt tolerance traits in cotton accessions, and the identification of elite quantitative trait loci (QTLs/genes for salt-tolerance have been very important in salt tolerance breeding. Here, 43 advanced salt-tolerant and 31 highly salt-sensitive cultivars were detected by analyzing ten salt tolerance related traits in 304 upland cotton cultivars. Among them, 11 advanced salt-tolerance and eight highly salt-sensitive cultivars were consistent with previously reported results. Association analysis of ten salt-tolerance related traits and 145 SSRs was performed, and a total of 95 significant associations were detected; 17, 41, and 37 of which were associated with germinative index, seedling stage physiological index, and four seedling stage biochemical indexes, respectively. Of these associations, 20 SSR loci were simultaneously associated with two or more traits. Furthermore, we detected 117 elite alleles associated with salt-tolerance traits, 4 of which were reported previously. Among these loci, 44 (37.60% were rare alleles with a frequency of less than 5%, 6 only existed in advanced salt-tolerant cultivars, and 2 only in highly salt-sensitive cultivars. As a result, 13 advanced salt-tolerant cultivars were selected to assemble the optimal cross combinations by computer simulation for the development of salt-tolerant accessions. This study lays solid foundations for further improvements in cotton salt-tolerance by referencing elite germplasms, alleles associated with salt-tolerance traits, and optimal crosses.

  11. The validity of using juvenile stages for evaluation of salt stress ...

    African Journals Online (AJOL)

    Triticum durum) on the basis of their salt stress tolerance. The effect of this abiotic constraint was investigated at tillering stage using hydroponic culture. Some growth and development parameters were measured between three and six leaves stages ...

  12. A role for antioxidants in acclimation of marine derived pathogenic fungus (NIOCC 1) to salt stress

    Digital Repository Service at National Institute of Oceanography (India)

    Ravindran, C.; Varatharajan, G.R.; Rajasabapathy, R.; Vijayakanth, S.; HarishKumar, A; Meena, R.M.

    Salinity tolerance a key factor helps in understanding the ionic homeostasis in general is a fundamental cellular phenomenon in all living cells. A marine derived pathogenic fungus was examined for its adaptation under salt stress using antioxidant...

  13. Salt stress change chlorophyll fluorescence in mango

    Directory of Open Access Journals (Sweden)

    Cicero Cartaxo de Lucena

    2012-12-01

    Full Text Available This study evaluated the tolerance of mango cultivars 'Haden', 'Palmer', 'Tommy Atkins' and 'Uba' grafted on rootstock 'Imbú' to salt stress using chlorophyll fluorescence. Plants were grown in modified Hoagland solution containing 0, 15, 30, and 45 mmol L-1 NaCl. At 97 days the parameters of the chlorophyll fluorescence (F0, Fm, Fv, F0/Fm, Fv/Fm, Fv'/Fm', ΦPSII = [(Fm'-Fs/(Fm'], D = (1- Fv'/Fm' and ETR = (ΦPSII×PPF×0,84×0,5 were determined. At 100 days, the leaf emission and leaf area, toxicity and leaf abscission indexes were determined. In all cultivars evaluated, in different degree, there were decreases in photochemical efficiency of photosystem II, enhanced concentrations from 15 mmol L-1 NaCl. The decreases in the potential quantum yield of photosystem II (Fv/Fm were 27.9, 18.7, 20.5, and 27.4%, for cultivars 'Haden', 'Palmer', 'Tommy Atkins', and 'Uba', respectively, when grown in 45 mmol L-1 NaCl. It was found decreases in leaf emission and mean leaf area in all cultivars from 15 mmol L-1 NaCl. There were increases in leaf toxicity of 33.0, 67.5, 41.6 and 80.8% and in leaf abscission of 71.8, 29.2, 32.5, and 67.9% for the cultivars 'Haden', 'Palmer', 'Tommy Atkins', and 'Uba' respectively, when grown in 45 mmol L-1 NaCl. Leaf toxicity and leaf abscission were not observed in 15 mmol L-1 NaCl. The decrease in Fv/Fm ratio were accompanied by decreasing in leaf emission and increased leaf toxicity index, showing, therefore, the potential of chlorophyll fluorescence in the early detection of salt stress in mango tree.

  14. IMPROVEMENT OF SALT TOLERANCE IN DURUM WHEAT BY ASCORBIC ACID APPLICATION

    Directory of Open Access Journals (Sweden)

    Fercha Azzedine

    2011-03-01

    Full Text Available The main objective of this study is to examine whether exogenously applied Ascorbic acid (AsA may enhance the salt tolerance in durum wheat (Triticum durum Desf. var. Waha. Two weeks old seedling, grown in plastic pots of 1kg, were subjected to salt stress by adding 25ml of NaCl (150mm, and treated or not with the addition of ascorbic acid (0.7 mM. Two weeks after salt stress, plants were harvested and the various measures were recorded.The effects of salt stress, in the presence and absence of vitamin C, on the leaf growth, leaf area (LA and some physiological and biochemical changes were investigated. It was established that the application of vitamin C mitigate to variable extent the adverse effect of salt stress on plant growth, may be due, in part, to increased leaf area, improved chlorophyll and carotenoid contents, enhanced proline accumulation and decreased H2O2 content.In conclusion, we can say that treatment with ascorbic acid improve salt tolerance in durum wheat through the enhancement of multiple processes.

  15. Molecular design of modified polyacrylamide for the salt tolerance.

    Science.gov (United States)

    Yao, Lin; Chen, Panke; Ding, Bin; Luo, Jianhui; Jiang, Bo; Zhou, Ge

    2012-09-01

    In our work, three kinds of functional monomers were selected to modify polyacrylamide (PAM) or partially hydrolyzed polyacrylamide (HPAM) by molecular dynamics simulation so as to achieve the stronger salt-tolerance of modified HM-HPAM. The radius of gyration (R (g)), the hydrodynamic radius (R (H)), the effective length (L (ef)) and the intrinsic viscosity ([η]) for modified PAM or HPAM were studied in aqueous solutions with different ionic strength at 298 K. The results showed that modified HM-HPAM has a stronger salt tolerance and the salt tolerance increases gradually from HM-HPAM1 to HM-HPAM3 because the monomers with different steric hindrance would reduce the curliness of molecular chains and, consequently, improve the salt tolerance. So, introducing the steric hindrance monomer into polymer will increase the salt tolerance of the polymer and it is indicated that the simulated results agree with the experimental results very well. Furthermore, the radial distribution function (RDF) has been used to investigate the effect of NaCl on the hydration of the -COO- groups of the HM-HPAM from microscopic view.

  16. Triterpenoid modulates the salt tolerance of lanosterol synthase deficientSaccharomyces cerevisiae, GIL77.

    Science.gov (United States)

    Inafuku, Masashi; Basyuni, Mohammad; Oku, Hirosuke

    2018-01-01

    This study examined the effect of triterpenoid on the salt tolerance of lanosterol synthase deficient yeast mutant GIL77. The expression of the triterpenoid synthase gene under GAL1 promoter in GIL77 increased the triterpenoid concentration of both whole cell and plasma membrane fractions. Without the induction of the genes, the growth curve of BgbAS or RsM1 transformant depicted patterns similar to control cells in both the presence and absence of salt with growth inhibition at 500 mM NaCl. The induction of BgbAS and RsM1 gene expression slightly repressed growth compared with control cells in the absence of NaCl. The growth of GIL77 was significantly suppressed by the expression of BgbAS or RsM1 under salinity conditions. Of the triterpenoid synthase genes, BgbAS rather than RsM1 was found to strongly inhibit the growth of GIL77 cells under salt stressed conditions. The expression of the triterpenoid synthase gene in GIL77 also influenced their tolerance to other abiotic stresses. In contrast to the endogenous synthesis, the exogenous supply of triterpenoid in the culture medium appeared to occur in the plasma membrane fraction and enhanced the salt tolerance of GIL77. This study thus discussed the physiological significance of triterpenoid in relation to its possible role in modulating salt tolerance.

  17. Triterpenoid modulates the salt tolerance of lanosterol synthase deficient Saccharomyces cerevisiae, GIL77

    Directory of Open Access Journals (Sweden)

    Masashi Inafuku

    2018-01-01

    Full Text Available This study examined the effect of triterpenoid on the salt tolerance of lanosterol synthase deficient yeast mutant GIL77. The expression of the triterpenoid synthase gene under GAL1 promoter in GIL77 increased the triterpenoid concentration of both whole cell and plasma membrane fractions. Without the induction of the genes, the growth curve of BgbAS or RsM1 transformant depicted patterns similar to control cells in both the presence and absence of salt with growth inhibition at 500 mM NaCl. The induction of BgbAS and RsM1 gene expression slightly repressed growth compared with control cells in the absence of NaCl. The growth of GIL77 was significantly suppressed by the expression of BgbAS or RsM1 under salinity conditions. Of the triterpenoid synthase genes, BgbAS rather than RsM1 was found to strongly inhibit the growth of GIL77 cells under salt stressed conditions. The expression of the triterpenoid synthase gene in GIL77 also influenced their tolerance to other abiotic stresses. In contrast to the endogenous synthesis, the exogenous supply of triterpenoid in the culture medium appeared to occur in the plasma membrane fraction and enhanced the salt tolerance of GIL77. This study thus discussed the physiological significance of triterpenoid in relation to its possible role in modulating salt tolerance.

  18. Signal transduction during cold, salt, and drought stresses in plants.

    Science.gov (United States)

    Huang, Guo-Tao; Ma, Shi-Liang; Bai, Li-Ping; Zhang, Li; Ma, Hui; Jia, Ping; Liu, Jun; Zhong, Ming; Guo, Zhi-Fu

    2012-02-01

    Abiotic stresses, especially cold, salinity and drought, are the primary causes of crop loss worldwide. Plant adaptation to environmental stresses is dependent upon the activation of cascades of molecular networks involved in stress perception, signal transduction, and the expression of specific stress-related genes and metabolites. Plants have stress-specific adaptive responses as well as responses which protect the plants from more than one environmental stress. There are multiple stress perception and signaling pathways, some of which are specific, but others may cross-talk at various steps. In this review article, we first expound the general stress signal transduction pathways, and then highlight various aspects of biotic stresses signal transduction networks. On the genetic analysis, many cold induced pathways are activated to protect plants from deleterious effects of cold stress, but till date, most studied pathway is ICE-CBF-COR signaling pathway. The Salt-Overly-Sensitive (SOS) pathway, identified through isolation and study of the sos1, sos2, and sos3 mutants, is essential for maintaining favorable ion ratios in the cytoplasm and for tolerance of salt stress. Both ABA-dependent and -independent signaling pathways appear to be involved in osmotic stress tolerance. ROS play a dual role in the response of plants to abiotic stresses functioning as toxic by-products of stress metabolism, as well as important signal transduction molecules and the ROS signaling networks can control growth, development, and stress response. Finally, we talk about the common regulatory system and cross-talk among biotic stresses, with particular emphasis on the MAPK cascades and the cross-talk between ABA signaling and biotic signaling.

  19. Screening of Purslane (Portulaca oleracea L. Accessions for High Salt Tolerance

    Directory of Open Access Journals (Sweden)

    Md. Amirul Alam

    2014-01-01

    Full Text Available Purslane (Portulaca oleracea L. is an herbaceous leafy vegetable crop, comparatively more salt-tolerant than any other vegetables with high antioxidants, minerals, and vitamins. Salt-tolerant crop variety development is of importance due to inadequate cultivable land and escalating salinity together with population pressure. In this view a total of 25 purslane accessions were initially selected from 45 collected purslane accessions based on better growth performance and subjected to 5 different salinity levels, that is, 0.0, 10.0, 20.0, 30.0, and 40.0 dS m−1 NaCl. Plant height, number of leaves, number of flowers, and dry matter contents in salt treated purslane accessions were significantly reduced (P≤0.05 and the enormity of reduction increased with increasing salinity stress. Based on dry matter yield reduction, among all 25 purslane accessions 2 accessions were graded as tolerant (Ac7 and Ac9, 6 accessions were moderately tolerant (Ac3, Ac5, Ac6, Ac10, Ac11, and Ac12, 5 accessions were moderately susceptible (Ac1, Ac2, Ac4, Ac8, and Ac13, and the remaining 12 accessions were susceptible to salinity stress and discarded from further study. The selected 13 purslane accessions could assist in the identification of superior genes for salt tolerance in purslane for improving its productivity and sustainable agricultural production.

  20. New Insights on plant salt tolerance mechanisms and their potential use for breeding

    Directory of Open Access Journals (Sweden)

    Moez HANIN

    2016-11-01

    Full Text Available Soil salinization is a major threat to agriculture in arid and semi-arid regions, where water scarcity and inadequate drainage of irrigated lands severely reduce crop yield. Salt accumulation inhibits plant growth and reduces the ability to uptake water and nutrients, leading to osmotic or water-deficit stress. Salt is also causing injury of the young photosynthetic leaves and acceleration of their senescence, as the Na+ cation is toxic when accumulating in cell cytosol resulting in ionic imbalance and toxicity of transpiring leaves. To cope with salt stress, plants have evolved mainly two types of tolerance mechanisms based on either limiting the entry of salt by the roots, or controlling its concentration and distribution. Understanding the overall control of Na+ accumulation and functional studies of genes involved in transport processes, will provide a new opportunity to improve the salinity tolerance of plants relevant to food security in arid regions. A better understanding of these tolerance mechanisms can be used to breed crops with improved yield performance under salinity stress. Moreover, associations of cultures with nitrogen-fixing bactéria and arbuscular mycorrhizal fungi could serve as an alternative and sustainable strategy to increase crop yields in salt affected fields.

  1. Identification of Rice Accessions Associated with K+/Na+ Ratio and Salt Tolerance Based on Physiological and Molecular Responses

    Directory of Open Access Journals (Sweden)

    Inja Naga Bheema Lingeswara Reddy

    2017-11-01

    Full Text Available The key for rice plant survival under NaCl salt stress is maintaining a high K+/Na+ ratio in its cells. Selection for salt tolerance rice genotypes based on phenotypic performance alone will delay in progress in breeding. Use of molecular markers in tandem with physiological studies will help in better identification of salt tolerant rice accessions. Eight rice accessions along with the check Dongjin were screened using 1/2 Yoshida solution with 50 mmol/L NaCl at the seedling stage. The accessions IT001158, IT246674, IT260533 and IT291341 were classified as salt tolerant based on their K+/Na+ ratios. Seventeen SSR markers reported to be associated with K+/Na+ ratio were used to screen the accessions. Five SSR markers (RM8053, RM345, RM318, RM253 and RM7075 could differentiate accessions classified based on their K+/Na+ ratios. Banding pattern of the accessions was scored compared to the banding pattern of Dongjin. The study differentiated accessions based on their association of K+/Na+ ratio with molecular markers which are very reliable. These markers can play a significant role in screening large set of rice germplasms for salt tolerance and also help in identification of high-yielding varieties with better salt tolerance. The salt tolerant accessions can be taken forward into developing better varieties by conventional breeding and exploring genes for salt tolerance.

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

    OpenAIRE

    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 from S. habrochaites LA1777, S. pennellii LA716 and S. lycopersicoides LA2951 were employed to identify quantitative trait loci (QTL). For B. cinerea resistance twenty four QTLs were identified in S....

  3. Evaluation of salt tolerance in almond [Prunus dulcis (L.) Batsch ...

    African Journals Online (AJOL)

    user

    2012-07-12

    Jul 12, 2012 ... stone fruit trees and almond are sensitive to salt stresses and their productivity gradually reduces at salt concen- ... order to improve stone fruit and almond rootstocks through hybridization between peach × almond, apricot × ..... J. Forest Poplar Res. 11(1): p. 202. Ranjbar A, Lemeur R, Damme P (2005).

  4. Assessment of rice genotypes for salt tolerance using microsatellite ...

    African Journals Online (AJOL)

    Phenotypic response of the genotypes to salt stress with EC=12 was assessed under controlled environmental conditions at seedling stage using a visual score of 1 to 9 scale. Thirty three polymorphic SSR markers located on chromosome 1 were also used to determine the impact of these markers associated with salt ...

  5. Integrating Classical with Emerging Concepts for Better Understanding of Salinity Stress Tolerance Mechanisms in Rice

    Directory of Open Access Journals (Sweden)

    Navdeep Kaur

    2017-07-01

    Full Text Available Rice is an important cereal crop responsible for world's food security. The sensitivity of rice plants toward a range of abiotic stresses is a prime challenge for its overall growth and productivity. Among these, salinity is a major stress which results in a significant loss of global rice yield annually. For finding straightforward and strict future solutions in order to assure the food security to growing world population, understanding of the various mechanisms responsible for salt stress tolerance in rice is of paramount importance. In classical studies, identification of salt tolerant cultivars and the genetic markers linked to salt tolerance and breeding approaches have been given emphasis. It further affirmed on the identification of various pathways regulating the complex process of salt stress adaptation. However, only limited success has been achieved in these approaches as salt tolerance is a complex process and is governed by multiple factors. Hence, for better understanding of salt tolerance mechanisms, a comprehensive approach involving physiological, biochemical and molecular studies is much warranted. Modern experimental and genetic resources have provided a momentum in this direction and have provided molecular insights into different salt stress responsive pathways at the signaling and regulatory level. The integrative knowledge of classical and modern research of the understanding of salt stress adaptive pathways can help the researchers for designing effective strategies to fight against salt stress. Hence, the present review is focused on the understanding of the salt stress tolerance mechanisms in rice through the consolidative knowledge of classical and modern concepts. It further highlights the emerging new trends of salt stress adaptive pathways in rice.

  6. Characterization of Salt-Induced Epigenetic Segregation by Genome-Wide Loss of Heterozygosity and its Association with Salt Tolerance in Rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Min Li

    2017-06-01

    Full Text Available In a breeding effort to develop salt tolerant (ST rice varieties by designed QTL pyramiding, large numbers of progenies derived from four crosses between salt- or drought- tolerant BC2F5 IR64 introgression lines, were subjected to severe salt stress, resulting in 422 ST plants. The progeny testing of the selected F3 lines under more severe salt stress resulted in identification of 16 promising homozygous lines with high levels of ST. Genetic characterization of the 422 ST F3 progeny and 318 random F2 plants from the same four crosses using 105 segregating SSR markers lead to three interesting discoveries: (1 salt stress can induce genome-wide epigenetic segregation (ES characterized by complete loss of heterozygosity (LOH and nearly complete loss of an allele (LOA in the F3 progenies of four rice populations in a single generation; (2 ∼25% of the stress-induced ES loci were transgenerational and inherited from their salt- and drought- selected parents; and (3 the salt-induced LOH and LOA loci (regions appeared to contain genes/alleles associated with ST and/or drought tolerance. 32 genomic regions that showed one or more types of salt-induced ES in the random and salt-selected progenies from these crosses. The same or different types of ES were detected with two large genomic regions on chromosomes 1 and 6 where more and the strongest ES were found across different populations. 14 genomic regions were found where the salt-induced ES regions were overlapping with QTL affecting ST related traits. The discovery of the three types of salt-induced ES showed several interesting characteristics and had important implications in evolution and future breeding for developing stress-resilient rice and crops.

  7. Salt stress induces changes in the proteomic profile of micropropagated sugarcane shoots

    Science.gov (United States)

    Reis, Ricardo S.; Heringer, Angelo S.; Rangel, Patricia L.; Santa-Catarina, Claudete; Grativol, Clícia; Veiga, Carlos F. M.; Souza-Filho, Gonçalo A.

    2017-01-01

    Salt stress is one of the most common stresses in agricultural regions worldwide. In particular, sugarcane is affected by salt stress conditions, and no sugarcane cultivar presently show high productivity accompanied by a tolerance to salt stress. Proteomic analysis allows elucidation of the important pathways involved in responses to various abiotic stresses at the biochemical and molecular levels. Thus, this study aimed to analyse the proteomic effects of salt stress in micropropagated shoots of two sugarcane cultivars (CB38-22 and RB855536) using a label-free proteomic approach. The mass spectrometry proteomics data are available via ProteomeXchange with identifier PXD006075. The RB855536 cultivar is more tolerant to salt stress than CB38-22. A quantitative label-free shotgun proteomic analysis identified 1172 non-redundant proteins, and 1160 of these were observed in both cultivars in the presence or absence of NaCl. Compared with CB38-22, the RB855536 cultivar showed a greater abundance of proteins involved in non-enzymatic antioxidant mechanisms, ion transport, and photosynthesis. Some proteins, such as calcium-dependent protein kinase, photosystem I, phospholipase D, and glyceraldehyde-3-phosphate dehydrogenase, were more abundant in the RB855536 cultivar under salt stress. Our results provide new insights into the response of sugarcane to salt stress, and the changes in the abundance of these proteins might be important for the acquisition of ionic and osmotic homeostasis during exposure to salt stress. PMID:28419154

  8. Uncoupling the Effects of Abscisic Acid on Plant Growth and Water Relations. Analysis of sto1/nced3, an Abscisic Acid-Deficient but Salt Stress-Tolerant Mutant in Arabidopsis1

    Science.gov (United States)

    Ruggiero, Bruno; Koiwa, Hisashi; Manabe, Yuzuki; Quist, Tanya M.; Inan, Gunsu; Saccardo, Franco; Joly, Robert J.; Hasegawa, Paul M.; Bressan, Ray A.; Maggio, Albino

    2004-01-01

    We have identified a T-DNA insertion mutation of Arabidopsis (ecotype C24), named sto1 (salt tolerant), that results in enhanced germination on both ionic (NaCl) and nonionic (sorbitol) hyperosmotic media. sto1 plants were more tolerant in vitro than wild type to Na+ and K+ both for germination and subsequent growth but were hypersensitive to Li+. Postgermination growth of the sto1 plants on sorbitol was not improved. Analysis of the amino acid sequence revealed that STO1 encodes a 9-cis-epoxicarotenoid dioxygenase (similar to 9-cis-epoxicarotenoid dioxygenase GB:AAF26356 [Phaseolus vulgaris] and to NCED3 GB:AB020817 [Arabidopsis]), a key enzyme in the abscisic acid (ABA) biosynthetic pathway. STO1 transcript abundance was substantially reduced in mutant plants. Mutant sto1 plants were unable to accumulate ABA following a hyperosmotic stress, although their basal ABA level was only moderately altered. Either complementation of the sto1 with the native gene from the wild-type genome or supplementation of ABA to the growth medium restored the wild-type phenotype. Improved growth of sto1 mutant plants on NaCl, but not sorbitol, medium was associated with a reduction in both NaCl-induced expression of the ICK1 gene and ethylene accumulation. Osmotic adjustment of sto1 plants was substantially reduced compared to wild-type plants under conditions where sto1 plants grew faster. The sto1 mutation has revealed that reduced ABA can lead to more rapid growth during hyperionic stress by a signal pathway that apparently is at least partially independent of signals that mediate nonionic osmotic responses. PMID:15466233

  9. Assessing the role of endophytic bacteria in the halophyte Arthrocnemum macrostachyum salt tolerance.

    Science.gov (United States)

    Navarro-Torre, S; Barcia-Piedras, J M; Mateos-Naranjo, E; Redondo-Gómez, S; Camacho, M; Caviedes, M A; Pajuelo, E; Rodríguez-Llorente, I D

    2017-03-01

    There is an increasing interest to use halophytes for revegetation of salt affected ecosystems, as well as in understanding their mechanisms of salt tolerance. We hypothesized that bacteria from the phyllosphere of these plants might play a key role in its high tolerance to excessive salinity. Eight endophytic bacteria belonging to Bacillus and closely related genera were isolated from phyllosphere of the halophyte Arthrocnemum macrostachyum growing in salty agricultural soils. The presence of plant-growth promoting (PGP) properties, enzymatic activities and tolerance towards NaCl was determined. Effects of inoculation on seeds germination and adult plant growth under experimental NaCl treatments (0, 510 and 1030 mM NaCl) were studied. Inoculation with a consortium including the best performing bacteria improved considerably the kinetics of germination and the final germination percentage of A. macrostachyum seeds. At high NaCl concentrations (1030 mM), inoculation of plants mitigated the effects of high salinity on plant growth and physiological performance and, in addition, this consortium appears to have increased the potential of A. macrostachyum to accumulate Na+ in its shoots, thus improving sodium phytoextraction capacity. Bacteria isolated from A. macrostachyum phyllosphere seem to play an important role in plant salt tolerance under stressing salt concentrations. The combined use of A. macrostachyum and its microbiome can be an adequate tool to enhance plant adaptation and sodium phytoextraction during restoration of salt degraded soils. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  10. Deciphering the salinity adaptation mechanism in Penicilliopsis clavariiformis AP, a rare salt tolerant fungus from mangrove.

    Science.gov (United States)

    Kashyap, Prem Lal; Rai, Anuradha; Singh, Ruchi; Chakdar, Hillol; Kumar, Sudheer; Srivastava, Alok Kumar

    2016-07-01

    Penicilliopsis clavariiformis AP, a rare salt tolerant fungus reported for the first time from India was identified through polyphasic taxonomy. Scanning electron microscopy showed that the fungus has unique features such as biverticillate penicilli bearing masses of oval to ellipsoidal conidia. The fungus has been characterized for salt tolerance and to understand the relevance of central carbon metabolism in salt stress adaptation. It showed optimal growth at 24 °C and able to tolerate up to 10% (w/v) NaCl. To understand the mechanism of adaptation to high salinity, activities of the key enzymes regulating glycolysis, pentose phosphate pathway, and tricarboxylic acid cycle were investigated under normal (0% NaCl) and saline stress environment (10% NaCl). The results revealed a re-routing of carbon metabolism away from glycolysis to the pentose phosphate pathway (PPP), served as a cellular stress-resistance mechanism in fungi under saline environment. The detection and significant expression of fungus genes (Hsp98, Hsp60, HTB, and RHO) under saline stress suggest that these halotolerance conferring genes from the fungus could have a role in fungus protection and adaptation under saline environment. Overall, the present findings indicate that the rearrangement of the metabolic fluxes distribution and stress related genes play an important role in cell survival and adaptation under saline environment. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. A comparison of hydroponic and soil-based screening methods to identify salt tolerance in the field in barley

    Science.gov (United States)

    Tavakkoli, Ehsan; Fatehi, Foad; Rengasamy, Pichu; McDonald, Glenn K.

    2012-01-01

    Success in breeding crops for yield and other quantitative traits depends on the use of methods to evaluate genotypes accurately under field conditions. Although many screening criteria have been suggested to distinguish between genotypes for their salt tolerance under controlled environmental conditions, there is a need to test these criteria in the field. In this study, the salt tolerance, ion concentrations, and accumulation of compatible solutes of genotypes of barley with a range of putative salt tolerance were investigated using three growing conditions (hydroponics, soil in pots, and natural saline field). Initially, 60 genotypes of barley were screened for their salt tolerance and uptake of Na+, Cl–, and K+ at 150 mM NaCl and, based on this, a subset of 15 genotypes was selected for testing in pots and in the field. Expression of salt tolerance in saline solution culture was not a reliable indicator of the differences in salt tolerance between barley plants that were evident in saline soil-based comparisons. Significant correlations were observed in the rankings of genotypes on the basis of their grain yield production at a moderately saline field site and their relative shoot growth in pots at ECe 7.2 [Spearman’s rank correlation (rs)=0.79] and ECe 15.3 (rs=0.82) and the crucial parameter of leaf Na+ (rs=0.72) and Cl– (rs=0.82) concentrations at ECe 7.2 dS m−1. This work has established screening procedures that correlated well with grain yield at sites with moderate levels of soil salinity. This study also showed that both salt exclusion and osmotic tolerance are involved in salt tolerance and that the relative importance of these traits may differ with the severity of the salt stress. In soil, ion exclusion tended to be more important at low to moderate levels of stress but osmotic stress became more important at higher stress levels. Salt exclusion coupled with a synthesis of organic solutes were shown to be important components of salt

  12. A comparison of hydroponic and soil-based screening methods to identify salt tolerance in the field in barley.

    Science.gov (United States)

    Tavakkoli, Ehsan; Fatehi, Foad; Rengasamy, Pichu; McDonald, Glenn K

    2012-06-01

    Success in breeding crops for yield and other quantitative traits depends on the use of methods to evaluate genotypes accurately under field conditions. Although many screening criteria have been suggested to distinguish between genotypes for their salt tolerance under controlled environmental conditions, there is a need to test these criteria in the field. In this study, the salt tolerance, ion concentrations, and accumulation of compatible solutes of genotypes of barley with a range of putative salt tolerance were investigated using three growing conditions (hydroponics, soil in pots, and natural saline field). Initially, 60 genotypes of barley were screened for their salt tolerance and uptake of Na(+), Cl(-), and K(+) at 150 mM NaCl and, based on this, a subset of 15 genotypes was selected for testing in pots and in the field. Expression of salt tolerance in saline solution culture was not a reliable indicator of the differences in salt tolerance between barley plants that were evident in saline soil-based comparisons. Significant correlations were observed in the rankings of genotypes on the basis of their grain yield production at a moderately saline field site and their relative shoot growth in pots at EC(e) 7.2 [Spearman's rank correlation (rs)=0.79] and EC(e) 15.3 (rs=0.82) and the crucial parameter of leaf Na(+) (rs=0.72) and Cl(-) (rs=0.82) concentrations at EC(e) 7.2 dS m(-1). This work has established screening procedures that correlated well with grain yield at sites with moderate levels of soil salinity. This study also showed that both salt exclusion and osmotic tolerance are involved in salt tolerance and that the relative importance of these traits may differ with the severity of the salt stress. In soil, ion exclusion tended to be more important at low to moderate levels of stress but osmotic stress became more important at higher stress levels. Salt exclusion coupled with a synthesis of organic solutes were shown to be important components of

  13. Knocking Down the Expression of GMPase Gene OsVTC1-1 Decreases Salt Tolerance of Rice at Seedling and Reproductive Stages.

    Science.gov (United States)

    Qin, Hua; Wang, Yayun; Wang, Juan; Liu, Hai; Zhao, Hui; Deng, Zaian; Zhang, Zhili; Huang, Rongfeng; Zhang, Zhijin

    2016-01-01

    Salinity is a severe environmental stress that greatly impairs production of crops worldwide. Previous studies have shown that GMPase plays an important role in tolerance of plants to salt stress at vegetative stage. However, the function of GMPase in plant responses to salt stress at reproductive stage remains unclear. Studies have shown that heterologous expression of rice GMPase OsVTC1-1 enhanced salt tolerance of tobacco seedlings, but the native role of OsVTC1-1 in salt stress tolerance of rice is unknown. To illustrate the native function of GMPase in response of rice to salt stress, OsVTC1-1 expression was suppressed using RNAi-mediated gene silencing. Suppressing OsVTC1-1 expression obviously decreased salt tolerance of rice varieties at vegetative stage. Intriguingly, grain yield of OsVTC1-1 RNAi rice was also significantly reduced under salt stress, indicating that OsVTC1-1 plays an important role in salt tolerance of rice at both seedling and reproductive stages. OsVTC1-1 RNAi rice accumulated more ROS under salt stress, and supplying exogenous ascorbic acid restored salt tolerance of OsVTC1-1 RNAi lines, suggesting that OsVTC1-1 is involved in salt tolerance of rice through the biosynthesis regulation of ascorbic acid. Altogether, results of present study showed that rice GMPase gene OsVTC1-1 plays a critical role in salt tolerance of rice at both vegetative and reproductive stages through AsA scavenging of excess ROS.

  14. Genetic transformation of Populus tomentosa to improve salt tolerance

    Science.gov (United States)

    Ningxia Du; Xin Liu; Yun Li; Shouyi Chen; Jinsong Zhang; Da Ha; Wenguang Deng; Chunkui Sun; Yingzhi Zhang; Paula M Pijut

    2012-01-01

    Soil salinity can be a limiting factor for productivity in agriculture and forestry. In order to fully utilize saline lands productively in plantation forestry for pulp production, the genetic modification of tree species for salt tolerance may be required. The AhDREB1 gene, a DREB-like transcription factor gene, was transferred into ...

  15. Pleiotropic phenotypes of the salt-tolerant and cytosine ...

    Indian Academy of Sciences (India)

    Abstract. In Catharanthus roseus, three morphological cum salt-tolerant chemically induced mutants of Mendelian inheritance and their wild-type parent cv Nirmal were characterized for overall cytosine methylation at DNA repeats, expression of 119 protein- coding and seven miRNA-coding genes and 50 quantitative traits.

  16. Association mapping of salt tolerance in barley (Hordeum vulgare L.)

    NARCIS (Netherlands)

    Nguyen Viet Long, L.; Dolstra, O.; Malosetti, M.; Kilian, B.; Graner, A.; Visser, R.G.F.; Linden, van der C.G.

    2013-01-01

    A spring barley collection of 192 genotypes from a wide geographical range was used to identify quantitative trait loci (QTLs) for salt tolerance traits by means of an association mapping approach using a thousand SNP marker set. Linkage disequilibrium (LD) decay was found with marker distances

  17. genotypes for salt-tolerance using multivariate cluster analysis

    African Journals Online (AJOL)

    USER

    2010-07-26

    Jul 26, 2010 ... classification of Kumuangluang (KML), Khao Dawk Mali (KDML), Pokkali (POK), HJ, DPY, Chewmaejan 1. (CMJ1), CMJ2, UR1 and .... selection criteria. However, the effective criteria for identification of salt tolerant genotypes still need to be investigated, especially in mass population of a breeding program.

  18. Assessment of rice genotypes for salt tolerance using microsatellite ...

    African Journals Online (AJOL)

    SERVER

    2008-03-18

    Mar 18, 2008 ... A major quantitative trait locus (QTL) for salt tolerance named Saltol was mapped on chromosome 1 using F8 recombinant ... Key words: Rice, salinity, SSR markers, Saltol, chromosome 1, haplotype diversity. INTRODUCTION .... CA). Data analysis. For each of the defined loci, SSR allelic composition was.

  19. Liquid salt environment stress-rupture testing

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Weiju; Holcomb, David E.; Muralidharan, Govindarajan; Wilson, Dane F.

    2016-03-22

    Disclosed herein are systems, devices and methods for stress-rupture testing selected materials within a high-temperature liquid salt environment. Exemplary testing systems include a load train for holding a test specimen within a heated inert gas vessel. A thermal break included in the load train can thermally insulate a load cell positioned along the load train within the inert gas vessel. The test specimen can include a cylindrical gage portion having an internal void filled with a molten salt during stress-rupture testing. The gage portion can have an inner surface area to volume ratio of greater than 20 to maximize the corrosive effect of the molten salt on the specimen material during testing. Also disclosed are methods of making a salt ingot for placement within the test specimen.

  20. Yeast functional screen to identify genetic determinants capable of conferring abiotic stress tolerance in Jatropha curcas

    Directory of Open Access Journals (Sweden)

    Kumar G Raja

    2010-03-01

    Full Text Available Abstract Background Environmentally inflicted stresses such as salinity and drought limit the plant productivity both in natural and agricultural system. Increasing emphasis has been directed to molecular breeding strategies to enhance the intrinsic ability of plant to survive stress conditions. Functional screens in microorganisms with heterologous genes are a rapid, effective and powerful tool to identify stress tolerant genes in plants. Jatropha curcas (Physic nut has been identified as a potential source of biodiesel plant. In order to improve its productivity under stress conditions to benefit commercial plantations, we initiated prospecting of novel genes expressed during stress in J. curcas that can be utilized to enhance stress tolerance ability of plant. Results To identify genes expressed during salt tolerance, cDNA expression libraries were constructed from salt-stressed roots of J. curcas, regulated under the control of the yeast GAL1 system. Using a replica based screening, twenty thousand yeast transformants were screened to identify transformants expressing heterologous gene sequences from J. curcas with enhanced ability to tolerate stress. From the screen we obtained 32 full length genes from J. curcas [GenBank accession numbers FJ489601-FJ489611, FJ619041-FJ619057 and FJ623457-FJ623460] that can confer abiotic stress tolerance. As a part of this screen, we optimized conditions for salt stress in J. curcas, defined parameters for salt stress in yeast, as well as isolated three salt hypersensitive yeast strains shs-2, shs-6 and shs-8 generated through a process of random mutagenesis, and exhibited growth retardation beyond 750 mM NaCl. Further, we demonstrated complementation of the salt sensitive phenotypes in the shs mutants, and analyzed the expression patterns for selected J. curcas genes obtained from the screen in both leaf and root tissues after salt stress treatments. Conclusions The approach described in this report

  1. MORPHO-MOLECULAR SCREENING OF RICE (ORYZA SATIVA L. GENOTYPES AT SEEDLING STAGE FOR SALT TOLERANCE

    Directory of Open Access Journals (Sweden)

    Ali Julfiker Md. Masud

    2014-10-01

    Full Text Available Providing adequate food to meet an escalating population is one of the gravest problems the humankind is now facing. To resolve this crisis identification of salt tolerant rice variety is very vital. So, in this research, ten rice genotypes were used to screen salinity tolerance at the seedling stage in hydroponic system using SSR markers. Salinity screening was done at glasshouse following IRRI standard protocol using two setups of salinized and non-salinized conditions. Genotypes under controlled condition had longer root and shoot length then salt stress genotypes. Parental polymorphism survey was done with ten SSR markers viz., RM336, RM510, RM7075, RM407, RM3201b, RM10748, AP3206f, RM3412, RM585, RM11504 and all were selected to evaluate salt tolerance in rice genotypes. The number of alleles per locus ranged from 3 (AP3206f to 9 (RM336, with an average of 6.1 alleles across 10 loci obtained in the study. The polymorphic information content values ranged from of 0.54 (AP3206f to a high of 0.86 (RM336 with an average of 0.74. The pair-wise comparisons of Nei’s (1973 genetic distance (D between varieties were computed from combined data for the 10 primers, ranged from 0.30 to 0.90 with an average of 0.86, while the similarity index based analysis ranged from 0.00 to 0.70. Finally, the FL-478, FL-378, Binadhan-8 and Binadhan-10 were selected as salt tolerant because they showed tolerance in phenotypic analysis. These phenotypically selected tolerant genotypes could be used for the selection of suitable parents and development of salt tolerant rice varieties.

  2. Transcriptome Analysis of Salt Stress Responsiveness in the Seedlings of Dongxiang Wild Rice (Oryza rufipogon Griff..

    Directory of Open Access Journals (Sweden)

    Yi Zhou

    Full Text Available Dongxiang wild rice (Oryza rufipogon Griff. is the progenitor of cultivated rice (Oryza sativa L., and is well known for its superior level of tolerance against cold, drought and diseases. To date, however, little is known about the salt-tolerant character of Dongxiang wild rice. To elucidate the molecular genetic mechanisms of salt-stress tolerance in Dongxiang wild rice, the Illumina HiSeq 2000 platform was used to analyze the transcriptome profiles of the leaves and roots at the seedling stage under salt stress compared with those under normal conditions. The analysis results for the sequencing data showed that 6,867 transcripts were differentially expressed in the leaves (2,216 up-regulated and 4,651 down-regulated and 4,988 transcripts in the roots (3,105 up-regulated and 1,883 down-regulated. Among these differentially expressed genes, the detection of many transcription factor genes demonstrated that multiple regulatory pathways were involved in salt stress tolerance. In addition, the differentially expressed genes were compared with the previous RNA-Seq analysis of salt-stress responses in cultivated rice Nipponbare, indicating the possible specific molecular mechanisms of salt-stress responses for Dongxiang wild rice. A large number of the salt-inducible genes identified in this study were co-localized onto fine-mapped salt-tolerance-related quantitative trait loci, providing candidates for gene cloning and elucidation of molecular mechanisms responsible for salt-stress tolerance in rice.

  3. Effects of salt stress on germination of some maize ( Zea mays L ...

    African Journals Online (AJOL)

    This study was conducted to investigate the effects of salt stress on germination of six maize (Zea mays L.) cultivars (ADA-523, Bora, C-955, PR 3394, Progen 1150 and Trebbia). The degrees of salinity tolerance among these cultivars were evaluated at seed germination stage at six different salt concentrations (0, 50, 100, ...

  4. Effects of salt stress on germination of some maize (Zea mays L ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-05

    Oct 5, 2009 ... This study was conducted to investigate the effects of salt stress on germination of six maize (Zea mays L.) cultivars (ADA-523, Bora, .... In addition 15 ml of distilled water without NaCl was used as control. Dishes ..... Salt Tolerance During Seed Germination in Tomato: Analysis of. Response and Correlated ...

  5. Thinopyrum ponticum Chromatin-Integrated Wheat Genome Shows Salt-Tolerance at Germination Stage

    Directory of Open Access Journals (Sweden)

    Wen-Ye Yuan

    2015-02-01

    Full Text Available A wild wheatgrass, Thinopyrum ponticum (2n = 10x = 70, which exhibits substantially higher levels of salt tolerance than cultivated wheat, was employed to transfer its salt tolerance to common wheat by means of wide hybridization. A highly salt-tolerant wheat line S148 (2n = 42 was obtained from the BC3F2 progenies between Triticum aestivum (2n = 42 and Th. ponticum. In the cross of S148 × salt-sensitive wheat variety Chinese Spring, the BC4F2 seeds at germination stage segregated into a ratio of 3 salt tolerant to 1 salt sensitive, indicating that the salt tolerance was conferred by a dominant gene block. Genomic in situ hybridization analysis revealed that S148 had a single pair of Th. ponticum–T. aestivum translocated chromosomes bearing the salt-tolerance. This is an initial step of molecular breeding for salt-tolerant wheat.

  6. Thinopyrum ponticum chromatin-integrated wheat genome shows salt-tolerance at germination stage.

    Science.gov (United States)

    Yuan, Wen-Ye; Tomita, Motonori

    2015-02-26

    A wild wheatgrass, Thinopyrum ponticum (2n = 10x = 70), which exhibits substantially higher levels of salt tolerance than cultivated wheat, was employed to transfer its salt tolerance to common wheat by means of wide hybridization. A highly salt-tolerant wheat line S148 (2n = 42) was obtained from the BC3F2 progenies between Triticum aestivum (2n = 42) and Th. ponticum. In the cross of S148 × salt-sensitive wheat variety Chinese Spring, the BC4F2 seeds at germination stage segregated into a ratio of 3 salt tolerant to 1 salt sensitive, indicating that the salt tolerance was conferred by a dominant gene block. Genomic in situ hybridization analysis revealed that S148 had a single pair of Th. ponticum-T. aestivum translocated chromosomes bearing the salt-tolerance. This is an initial step of molecular breeding for salt-tolerant wheat.

  7. Thinopyrum ponticum chromatin-integrated wheat genome shows salt-tolerance at germination stage

    National Research Council Canada - National Science Library

    Yuan, Wen-Ye; Tomita, Motonori

    2015-01-01

    A wild wheatgrass, Thinopyrum ponticum (2n = 10x = 70), which exhibits substantially higher levels of salt tolerance than cultivated wheat, was employed to transfer its salt tolerance to common wheat by means of wide hybridization...

  8. A Novel Thylakoid Ascorbate Peroxidase from Jatrophacurcas Enhances Salt Tolerance in Transgenic Tobacco

    Directory of Open Access Journals (Sweden)

    Zhibin Liu

    2013-12-01

    Full Text Available Ascorbate peroxidase (APX plays an important role in the metabolism of hydrogen peroxide in higher plants. In the present study, a novel APX gene (JctAPX was cloned from Jatropha curcas L. The deduced amino acid sequence was similar to that of APX of some other plant species. JctAPX has a chloroplast transit peptide and was localized to the chloroplasts by analysis with a JctAPX-green fluorescent protein (GFP fusion protein. Quantitative polymerase chain reaction (qPCR analysis showed that JctAPX was constitutively expressed in different tissues from J. curcas and was upregulated by NaCl stress. To characterize its function in salt tolerance, the construct p35S: JctAPX was created and successfully introduced into tobacco by Agrobacterium-mediated transformation. Compared with wild type (WT, the transgenic plants exhibited no morphological abnormalities in the no-stress condition. However, under 200 mM NaCl treatment, JctAPX over-expressing plants showed increased tolerance to salt during seedling establishment and growth. In addition, the transgenic lines showed higher chlorophyll content and APX activity, which resulted in lower H2O2 content than WT when subjected to 400 mM NaCl stress. These results suggest that the increased APX activity in the chloroplasts from transformed plants increased salt tolerance by enhancing reactive oxygen species (ROS-scavenging capacity under short-term NaCl stress conditions.

  9. Physiological, Biochemical, Epigenetic and Molecular Analyses of Wheat (Triticum aestivum Genotypes with Contrasting Salt Tolerance

    Directory of Open Access Journals (Sweden)

    Suresh Kumar

    2017-06-01

    Full Text Available Abiotic stress exerts significant impact on plant’s growth, development, and productivity. Productivity of crop plants under salt stress is lagging behind because of our limited knowledge about physiological, biochemical, epigenetic, and molecular mechanisms of salt tolerance in plants. This study aimed to investigate physio-biochemical, molecular indices and defense responses of selected wheat cultivars to identify the most contrasting salt-responsive genotypes and the mechanisms associated with their differential responses. Physio-biochemical traits specifically membrane stability index, antioxidant potential, osmoprotectants and chlorophyll contents, measured at vegetative stage, were used for multivariate analysis to identify the most contrasting genotypes. Genetic and epigenetic analyses indicated the possible mechanisms associated with differential response of the wheat genotypes under salt stress. Better antioxidant potential, membrane stability, increased accumulation of osmolytes/phytophenolics, and higher K+/Na+ ratio under 200 mM NaCl stress identified Kharchia-65 to be the most salt-tolerant cultivar. By contrast, increased MDA level, reduced soluble sugar, proline, total chlorophyll, total phenolics contents, and lower antioxidant potential in HD-2329 marked it to be sensitive to the stress. Genetic and bioinformatics analyses of HKT1;4 of contrasting genotypes (Kharchia-65 and HD-2329 revealed deletions, transitions, and transversions resulting into altered structure, loss of conserved motifs (Ser-Gly-Gly-Gly and Gly-Arg and function in salt-sensitive (HD-2329 genotype. Expression analysis of HKTs rationalized the observed responses. Epigenetic variations in cytosine methylation explained tissue- and genotype-specific differential expression of HKT2;1 and HKT2;3.

  10. An Ipomoea batatas iron-sulfur cluster scaffold protein gene, IbNFU1, is involved in salt tolerance.

    Directory of Open Access Journals (Sweden)

    Degao Liu

    Full Text Available Iron-sulfur cluster biosynthesis involving the nitrogen fixation (Nif proteins has been proposed as a general mechanism acting in various organisms. NifU-like protein may play an important role in protecting plants against abiotic and biotic stresses. An iron-sulfur cluster scaffold protein gene, IbNFU1, was isolated from a salt-tolerant sweetpotato (Ipomoea batatas (L. Lam. line LM79 in our previous study, but its role in sweetpotato stress tolerance was not investigated. In the present study, the IbNFU1 gene was introduced into a salt-sensitive sweetpotato cv. Lizixiang to characterize its function in salt tolerance. The IbNFU1-overexpressing sweetpotato plants exhibited significantly higher salt tolerance compared with the wild-type. Proline and reduced ascorbate content were significantly increased, whereas malonaldehyde (MDA content was significantly decreased in the transgenic plants. The activities of superoxide dismutase (SOD and photosynthesis were significantly enhanced in the transgenic plants. H2O2 was also found to be significantly less accumulated in the transgenic plants than in the wild-type. Overexpression of IbNFU1 up-regulated pyrroline-5-carboxylate synthase (P5CS and pyrroline-5-carboxylate reductase (P5CR genes under salt stress. The systemic up-regulation of reactive oxygen species (ROS scavenging genes was found in the transgenic plants under salt stress. These findings suggest that IbNFU1gene is involved in sweetpotato salt tolerance and enhances salt tolerance of the transgenic sweetpotato plants by regulating osmotic balance, protecting membrane integrity and photosynthesis and activating ROS scavenging system.

  11. Overexpression of AtSTO1 leads to improved salt tolerance in Populus tremula × P. alba.

    Science.gov (United States)

    Lawson, Shaneka S; Michler, Charles H

    2014-10-01

    One of the major abiotic stress conditions limiting healthy growth of trees is salinity stress. The use of gene manipulation for increased tolerance to abiotic stress has been successful in many plant species. Overexpression of the Arabidopsis SALT TOLERANT1 (STO1) gene leads to increased concentrations of 9-cis-epoxycarotenoid dioxygenase3, a vital enzyme in Arabidopsis abscisic acid biosynthesis. In the present work, the Arabidopsis STO1 gene (AtSTO1) was overexpressed in poplar to determine if the transgene would confer enhanced salt tolerance to the generated transgenics. The results of multiple greenhouse trials indicated that the transgenic poplar lines had greater levels of resistance to NaCl than wild-type plants. Analysis using RT-PCR indicated a variation in the relative abundance of the STO1 transcript in the transgenics that coincided with tolerance to salt. Several physiological and morphological changes such as greater overall biomass, greater root biomass, improved photosynthesis, and greater pith size were observed in the transgenics when compared to controls undergoing salt stress. These results indicated overexpression of AtSTO1 improved salt tolerance in poplar.

  12. DCA1 Acts as a Transcriptional Co-activator of DST and Contributes to Drought and Salt Tolerance in Rice.

    Directory of Open Access Journals (Sweden)

    Long-Gang Cui

    2015-10-01

    Full Text Available Natural disasters, including drought and salt stress, seriously threaten food security. In previous work we cloned a key zinc finger transcription factor gene, Drought and Salt Tolerance (DST, a negative regulator of drought and salt tolerance that controls stomatal aperture in rice. However, the exact mechanism by which DST regulates the expression of target genes remains unknown. In the present study, we demonstrated that DST Co-activator 1 (DCA1, a previously unknown CHY zinc finger protein, acts as an interacting co-activator of DST. DST was found to physically interact with itself and to form a heterologous tetramer with DCA1. This transcriptional complex appears to regulate the expression of peroxidase 24 precursor (Prx 24, a gene encoding an H2O2 scavenger that is more highly expressed in guard cells. Downregulation of DCA1 significantly enhanced drought and salt tolerance in rice, and overexpression of DCA1 increased sensitivity to stress treatment. These phenotypes were mainly influenced by DCA1 and negatively regulated stomatal closure through the direct modulation of genes associated with H2O2 homeostasis. Our findings establish a framework for plant drought and salt stress tolerance through the DCA1-DST-Prx24 pathway. Moreover, due to the evolutionary and functional conservation of DCA1 and DST in plants, engineering of this pathway has the potential to improve tolerance to abiotic stress in other important crop species.

  13. Microbial stress tolerance for biofuels. Systems biology

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zonglin Lewis (ed.) [National Center for Agricultural Utilization Research, USDA-ARS, Peoria, IL (United States)

    2012-07-01

    The development of sustainable and renewable biofuels is attracting growing interest. It is vital to develop robust microbial strains for biocatalysts that are able to function under multiple stress conditions. This Microbiology Monograph provides an overview of methods for studying microbial stress tolerance for biofuels applications using a systems biology approach. Topics covered range from mechanisms to methodology for yeast and bacteria, including the genomics of yeast tolerance and detoxification; genetics and regulation of glycogen and trehalose metabolism; programmed cell death; high gravity fermentations; ethanol tolerance; improving biomass sugar utilization by engineered Saccharomyces; the genomics on tolerance of Zymomonas mobilis; microbial solvent tolerance; control of stress tolerance in bacterial host organisms; metabolomics for ethanologenic yeast; automated proteomics work cell systems for strain improvement; and unification of gene expression data for comparable analyses under stress conditions. (orig.)

  14. Salt tolerant plants increase nitrogen removal from biofiltration systems affected by saline stormwater.

    Science.gov (United States)

    Szota, Christopher; Farrell, Claire; Livesley, Stephen J; Fletcher, Tim D

    2015-10-15

    Biofiltration systems are used in urban areas to reduce the concentration and load of nutrient pollutants and heavy metals entering waterways through stormwater runoff. Biofilters can, however be exposed to salt water, through intrusion of seawater in coastal areas which could decrease their ability to intercept and retain pollutants. We measured the effect of adding saline stormwater on pollutant removal by six monocotyledonous species with different levels of salt-tolerance. Carex appressa, Carex bichenoviana, Ficinia nodosa, Gahnia filum, Juncus kraussii and Juncus usitatus were exposed to six concentrations of saline stormwater, equivalent to electrical conductivity readings of: 0.09, 2.3, 5.5, 10.4, 20.0 and 37.6 mS cm(-1). Salt-sensitive species: C. appressa, C. bichenoviana and J. usitatus did not survive ≥10.4 mS cm(-1), removing their ability to take up nitrogen (N). Salt-tolerant species, such as F. nodosa and J. kraussii, maintained N-removal even at the highest salt concentration. However, their levels of water stress and stomatal conductance suggest that N-removal would not be sustained at concentrations ≥10.4 mS cm(-1). Increasing salt concentration indirectly increased phosphorus (P) removal, by converting dissolved forms of P to particulate forms which were retained by filter media. Salt concentrations ≥10 mS cm(-1) also reduced removal efficiency of zinc, manganese and cadmium, but increased removal of iron and lead, regardless of plant species. Our results suggest that biofiltration systems exposed to saline stormwater ≤10 mS cm(-1) can only maintain N-removal when planted with salt-tolerant species, while P removal and immobilisation of heavy metals is less affected by species selection. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. The proteome response of salt-resistant and salt-sensitive barley genotypes to long-term salinity stress

    NARCIS (Netherlands)

    Fatehi, F.; Hosseinzadeh, A.; Alizadeh, H.; Brimavandi, T.; Struik, P.C.

    2012-01-01

    Responses of plants to salinity stress and the development of salt tolerance are extremely complex. Proteomics is a powerful technique to identify proteins associated with a particular environmental or developmental signal. We employed a proteomic approach to further understand the mechanism of

  16. Transcriptomic Analysis Reveals Genes Mediating Salt Tolerance through Calcineurin/CchA-Independent Signaling in Aspergillus nidulans

    Directory of Open Access Journals (Sweden)

    Sha Wang

    2017-01-01

    Full Text Available Adaptation to changes in the environment is crucial for the viability of all organisms. Although the importance of calcineurin in the stress response has been highlighted in filamentous fungi, little is known about the involvement of ion-responsive genes and pathways in conferring salt tolerance without calcium signaling. In this study, high-throughput RNA-seq was used to investigate salt stress-induced genes in the parent, ΔcnaB, and ΔcnaBΔcchA strains of Aspergillus nidulans, which differ greatly in salt adaption. In total, 2,884 differentially expressed genes including 1,382 up- and 1,502 downregulated genes were identified. Secondary transporters, which were upregulated to a greater extent in ΔcnaBΔcchA than in the parent or ΔcnaB strains, are likely to play important roles in response to salt stress. Furthermore, 36 genes were exclusively upregulated in the ΔcnaBΔcchA under salt stress. Functional analysis of differentially expressed genes revealed that genes involved in transport, heat shock protein binding, and cell division processes were exclusively activated in ΔcnaBΔcchA. Overall, our findings reveal that secondary transporters and stress-responsive genes may play crucial roles in salt tolerance to bypass the requirement for the CchA-calcineurin pathway, contributing to a deeper understanding of the mechanisms that influence fungal salt stress adaption in Aspergillus.

  17. A comparative study of salt tolerance parameters in 11 wild relatives of Arabidopsis thaliana

    OpenAIRE

    Orsini, Francesco; D'Urzo, Matilde Paino; Inan, Gunsu; Serra, Sara; Oh, Dong-Ha; Mickelbart, Michael V.; Consiglio, Federica; Li, Xia; Jeong, Jae Cheol; Yun, Dae-Jin; Bohnert, Hans J.; Bressan, Ray A.; Maggio, Albino

    2010-01-01

    Salinity is an abiotic stress that limits both yield and the expansion of agricultural crops to new areas. In the last 20 years our basic understanding of the mechanisms underlying plant tolerance and adaptation to saline environments has greatly improved owing to active development of advanced tools in molecular, genomics, and bioinformatics analyses. However, the full potential of investigative power has not been fully exploited, because the use of halophytes as model systems in plant salt ...

  18. Arabidopsis phosphoinositide-specific phospholipase C 4 negatively regulates seedling salt tolerance.

    Science.gov (United States)

    Xia, Keke; Wang, Bo; Zhang, Jiewei; Li, Yuan; Yang, Hailian; Ren, Dongtao

    2017-08-01

    Previous physiological and pharmacological studies have suggested that the activity of phosphoinositide-specific phospholipase C (PI-PLC) plays an important role in regulating plant salt stress responses by altering the intracellular Ca2+ concentration. However, the individual members of plant PLCs involved in this process need to be identified. Here, the function of AtPLC4 in the salt stress response of Arabidopsis seedlings was analysed. plc4 mutant seedlings showed hyposensitivity to salt stress compared with Col-0 wild-type seedlings, and the salt hyposensitive phenotype could be complemented by the expression of native promoter-controlled AtPLC4. Transgenic seedlings with AtPLC4 overexpression (AtPLC4 OE) exhibited a salt-hypersensitive phenotype, while transgenic seedlings with its inactive mutant expression (AtPLC4m OE) did not exhibit this phenotype. Using aequorin as a Ca2+ indicator in plc4 mutant and AtPLC4 OE seedlings, AtPLC4 was shown to positively regulate the salt-induced Ca2+ increase. The salt-hypersensitive phenotype of AtPLC4 OE seedlings was partially rescued by EGTA. An analysis of salt-responsive genes revealed that the transcription of RD29B, MYB15 and ZAT10 was inversely regulated in plc4 mutant and AtPLC4 OE seedlings. Our findings suggest that AtPLC4 negatively regulates the salt tolerance of Arabidopsis seedlings, and Ca2+ may be involved in regulating this process. © 2017 John Wiley & Sons Ltd.

  19. High efficiency transformation of banana [Musa acuminata L. cv. Matti (AA)] for enhanced tolerance to salt and drought stress through overexpression of a peanut salinity-induced pathogenesis-related class 10 protein.

    Science.gov (United States)

    Rustagi, Anjana; Jain, Shalu; Kumar, Deepak; Shekhar, Shashi; Jain, Mukesh; Bhat, Vishnu; Sarin, Neera Bhalla

    2015-01-01

    Bananas and plantains (Musa spp. L.) are important subsistence crops and premium export commodity in several countries, and susceptible to a wide range of environmental and biotic stress conditions. Here, we report efficient, rapid, and reproducible Agrobacterium-mediated transformation and regeneration of an Indian niche cultivar of banana [M. acuminata cv. Matti (AA)]. Apical meristem-derived highly proliferative multiple shoot clump (MSC) explants were transformed with the Agrobacterium strain EHA105 harboring a binary vector pCAMBIA-1301 carrying hptII and uidA. Sequential agro-infiltration (10 min, 400 mmHg), infection (additional 35 min, Agrobacterium density A 600 = 0.8) and co-cultivation (18 h) regimen in 100 µM acetosyringone containing liquid medium were critical factors yielding high transformation efficiency (~81 %) corroborated by transient GUS expression assay. Stable transgenic events were recovered following two cycles of meristem initiation and selection on hygromycin containing medium. Histochemical GUS assay in several tissues of transgenic plants and molecular analyses confirmed stable integration and expression of transgene. The protocol described here allowed recovery of well-established putative transgenic plantlets in as little as 5 months. The transgenic banana plants could be readily acclimatized under greenhouse conditions, and were phenotypically similar to the wild-type untransformed control plants (WT). Transgenic plants overexpressing Salinity-Induced Pathogenesis-Related class 10 protein gene from Arachis hypogaea (AhSIPR10) in banana cv. Matti (AA) showed better photosynthetic efficiency and less membrane damage (P < 0.05) in the presence of NaCl and mannitol in comparison to WT plants suggesting the role of AhSIPR10 in better tolerance of salt stress and drought conditions.

  20. Silicon improves salt tolerance by increasing root water uptake in Cucumis sativus L.

    Science.gov (United States)

    Zhu, Yong-Xing; Xu, Xuan-Bin; Hu, Yan-Hong; Han, Wei-Hua; Yin, Jun-Liang; Li, Huan-Li; Gong, Hai-Jun

    2015-09-01

    Silicon enhances root water uptake in salt-stressed cucumber plants through up-regulating aquaporin gene expression. Osmotic adjustment is a genotype-dependent mechanism for silicon-enhanced water uptake in plants. Silicon can alleviate salt stress in plants. However, the mechanism is still not fully understood, and the possible role of silicon in alleviating salt-induced osmotic stress and the underlying mechanism still remain to be investigated. In this study, the effects of silicon (0.3 mM) on Na accumulation, water uptake, and transport were investigated in two cucumber (Cucumis sativus L.) cultivars ('JinYou 1' and 'JinChun 5') under salt stress (75 mM NaCl). Salt stress inhibited the plant growth and photosynthesis and decreased leaf transpiration and water content, while added silicon ameliorated these negative effects. Silicon addition only slightly decreased the shoot Na levels per dry weight in 'JinYou 1' but not in 'JinChun 5' after 10 days of stress. Silicon addition reduced stress-induced decreases in root hydraulic conductivity and/or leaf-specific conductivity. Expressions of main plasma membrane aquaporin genes in roots were increased by added silicon, and the involvement of aquaporins in water uptake was supported by application of aquaporin inhibitor and restorative. Besides, silicon application decreased the root xylem osmotic potential and increased root soluble sugar levels in 'JinYou 1.' Our results suggest that silicon can improve salt tolerance of cucumber plants through enhancing root water uptake, and silicon-mediated up-regulation of aquaporin gene expression may in part contribute to the increase in water uptake. In addition, osmotic adjustment may be a genotype-dependent mechanism for silicon-enhanced water uptake in plants.

  1. Silicon alleviates salt stress, decreases malondialdehyde content ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-04-20

    Apr 20, 2009 ... Hernandez JA, Corpass FJ, Gomez M, del Río LA, Sevilla F (1993). Salt-induced oxidative stress mediated by active oxygen species in pen leaf mitochondria, Physiol. Plant. 89: 103-110. Hwang SJ, Hamayun M, Kim HY, Na CI, Kim KU, Shin DH, Kim SY, Lee. IJ (2008). Effect of nitrogen and silicon nutrition ...

  2. Salt Tolerance and Polyphyly in the Cyanobacterium Chroococcidiopsis (Pleurocapsales)1

    Science.gov (United States)

    Cumbers, John Robert; Rothschild, Lynn J.

    2014-01-01

    Chroococcidiopsis Geitler (Geitler 1933) is a genus of cyanobacteria containing desiccation and radiation resistant species. Members of the genus live in habitats ranging from hot and cold deserts to fresh and saltwater environments. Morphology and cell division pattern have historically been used to define the genus. To better understand the genetic and phenotypic diversity of the genus, 15 species were selected that had been previously isolated from different locations, including salt and freshwater environments. Four markers were sequenced from these 15 species, the 16S rRNA, rbcL, desC1 and gltX genes. Phylogenetic trees were generated which identified two distinct clades, a salt-tolerant clade and a freshwater clade. This study demonstrates that the genus is polyphyletic based on saltwater and freshwater phenotypes. To understand the resistance to salt in more details, species were grown on a range of sea salt concentrations which demonstrated that the freshwater species were salt-intolerant whilst the saltwater species required salt for growth. This study shows an increased resolution of the phylogeny of Chroococcidiopsis and provides further evidence that the genus is polyphyletic and should be reclassified to improve clarity in the literature.

  3. Bacterial exopolysaccharide and biofilm formation stimulate chickpea growth and soil aggregation under salt stress

    Directory of Open Access Journals (Sweden)

    Aisha Waheed Qurashi

    2012-09-01

    Full Text Available To compensate for stress imposed by salinity, biofilm formation and exopolysaccharide production are significant strategies of salt tolerant bacteria to assist metabolism. We hypothesized that two previously isolated salt-tolerant strains Halomonas variabilis (HT1 and Planococcus rifietoensis (RT4 have an ability to improve plant growth, These strains can form biofilm and accumulate exopolysacharides at increasing salt stress. These results showed that bacteria might be involved in developing microbial communities under salt stress and helpful in colonizing of bacterial strains to plant roots and soil particles. Eventually, it can add to the plant growth and soil structure. We investigated the comparative effect of exopolysacharide and biofilm formation in two bacterial strains Halomonas variabilis (HT1 and Planococcus rifietoensis (RT4 in response to varying salt stress. We found that biofilm formation and exopolysaccharide accumulation increased at higher salinity. To check the effect of bacterial inoculation on the plant (Cicer arietinum Var. CM-98 growth and soil aggregation, pot experiment was conducted by growing seedlings under salt stress. Inoculation of both strains increased plant growth at elevated salt stress. Weight of soil aggregates attached with roots and present in soil were added at higher salt concentrations compared to untreated controls. Soil aggregation was higher at plant roots under salinity. These results suggest the feasibility of using above strains in improving plant growth and soil fertility under salinity.

  4. [Selection and identification of salt tolerant line of sainfoin from the seeds of first post-flight plants].

    Science.gov (United States)

    Xu, Y Y; Wang, M G; Jia, J F

    2001-03-01

    Seeds of sainfoin (Onobrychis vicaefolia Scop.) were carried in the recoverable satellite 940703 and recovered from earth orbit from China in 1994. The progeny seeds were obtained by producing in field. The salt tolerant calluses were selected by screening seedling and callus on 1.5% NaCl-containing medium, reviving growth on NaCl- free medium and selecting callus on 1.2% NaCl-containing medium. The salt tolerant line callus maintained the normal ability to regenerate plant. The salt tolerant line callus exhibited cross-resistance to PEG stress. The variant appeared higher efficiency than control to accumulate proline under salt stress, however, under nonstress condition it had lower proline level than control, which suggested that the higher efficiency to synthesize proline under stress condition may be more important than higher level in tissue under nonstress condition. The mechanism of proline synthesis in the selected callus was considered to result from the alteration in gene sensitivity to water regulation at transcription level. Acrylamide gradient electrophoresis showed that new isoenzyme form with MW 175 kD and 75 kD of superoxide dismutase and esterase respectively appeared in salt torlerant callus. It was indicated that the combination of space mutagenesis with tissue culture could be used for the selection of salt tolerant sainfoin line in vitro.

  5. Mechanisms of silicon-mediated alleviation of drought and salt stress in plants: a review.

    Science.gov (United States)

    Rizwan, Muhammad; Ali, Shafaqat; Ibrahim, Muhammad; Farid, Mujahid; Adrees, Muhammad; Bharwana, Saima Aslam; Zia-Ur-Rehman, Muhammad; Qayyum, Muhammad Farooq; Abbas, Farhat

    2015-10-01

    Drought and salinity are the main abiotic stresses limiting crop yield and quality worldwide. Improving food production in drought- and salt-prone areas is the key to meet the increasing food demands in near future. It has been widely reported that silicon (Si), a second most abundant element in soil, could reduce drought and salt stress in plants. Here, we reviewed the emerging role of Si in enhancing drought and salt tolerance in plants and highlighted the mechanisms through which Si could alleviate both drought and salt stress in plants. Silicon application increased plant growth, biomass, photosynthetic pigments, straw and grain yield, and quality under either drought or salt stress. Under both salt and drought stress, the key mechanisms evoked are nutrient elements homeostasis, modification of gas exchange attributes, osmotic adjustment, regulating the synthesis of compatible solutes, stimulation of antioxidant enzymes, and gene expression in plants. In addition, Si application decreased Na(+) uptake and translocation while increased K(+) uptake and translocation under salt stress. However, these mechanisms vary with plant species, genotype, growth conditions, duration of stress imposed, and so on. This review article highlights the potential for improving plant resistance to drought and salt stress by Si application and provides a theoretical basis for application of Si in saline soils and arid and semiarid regions worldwide. This review article also highlights the future research needs about the role of Si under drought stress and in saline soils.

  6. Physiological Response to Salinity and Alkalinity of Rice Genotypes of Varying Salt Tolerance Grown in Field Lysimeters

    Directory of Open Access Journals (Sweden)

    Surekha Rao, P.

    2013-02-01

    Full Text Available Soil salinity and alkalinity seriously threaten rice production in south Asia. Improving screening methodologies to identify sources of tolerance for improved breeding for salt tolerant rice is of continuing importance. Rice genotypes of varying salt tolerance, such as tolerant (T, semi-tolerant (ST, and sensitive (S, were grown in field lysimeters in saline soil of ECe 4 and 8 mS cm-1 and alkali soil of pH 9.5 and 9.8 in North India and analyzed for chlorophyll (Chl, sugar, starch and proline in leaves. Chlorophyll a and b decreased due to salinity in all the tolerance groups. However, Chl a was not much affected but chl b increased with alkalinity. Under high stress both at ECe 8 and pH 9.8 Chl a and b were more in tolerant than in sensitive genotypes. The ratio of Chl a/b was similar in T, ST and S genotypes under salinity stress. Sugar accumulation was higher in T compared to S under normal conditions but under salinity or alkalinity stress the differences were not significant. Leaf starch was highest in T, intermediate in ST and lowest in S genotypes in normal as well as under salinity and alkalinity stress. There was decrease in starch with salinity and alkalinity stress only in T group but not in ST and S group. Proline increased significantly in all the tolerance groups even at low salinity of ECe 4 mS cm -1 or pH 9.5. The salt tolerant genotypes of rice maintained higher levels of Chl a and b, starch and proline under high salinity and alkalinity stress and are the robust criteria for tolerating high salinity and alkalinity.

  7. Salt stress responsiveness of a wild cotton species (Gossypium klotzschianum) based on transcriptomic analysis.

    Science.gov (United States)

    Wei, Yangyang; Xu, Yanchao; Lu, Pu; Wang, Xingxing; Li, Zhenqing; Cai, Xiaoyan; Zhou, Zhongli; Wang, Yuhong; Zhang, Zhenmei; Lin, Zhongxu; Liu, Fang; Wang, Kunbo

    2017-01-01

    Cotton is a pioneer of saline land crop, while salt stress still causes its growth inhibition and fiber production decrease. Phenotype identification showed better salt tolerance of a wild diploid cotton species Gossypium klotzschianum. To elucidate the salt-tolerant mechanisms in G. klotzschianum, we firstly detected the changes in hormones, H2O2 and glutathione (GSSH and GSH), then investigated the gene expression pattern of roots and leaves treated with 300 mM NaCl for 0, 3, 12, 48 h, and each time control by RNA-seq on the Illumina-Solexa platform. Physiological determination proved that the significant increase in hormone ABA at 48 h, while that in H2O2 was at 12 h, likewise, the GSH content decrease at 48 h and the GSSH content increase at 48 h, under salt stress. In total, 37,278 unigenes were identified from the transcriptome data, 8,312 and 6,732 differentially expressed genes (DEGs) were discovered to be involved in salt stress tolerance in roots and leaves, respectively. Gene function annotation and expression analysis elucidated hormone biosynthesis and signal transduction, reactive oxygen species (ROS), and salt overly sensitive (SOS) signal transduction related genes revealed the important roles of them in signal transmission, oxidation balance and ion homeostasis in response to salinity stress. This is a report which focuses on primary response to highly salty stress (upto 300 mM NaCl) in cotton using a wild diploid Gossypium species, broadening our understanding of the salt tolerance mechanism in cotton and laying a solid foundation of salt resistant for the genetic improvement of upland cotton with the resistance to salt stress.

  8. Assessment of rice genotypes for salt tolerance using microsatellite ...

    African Journals Online (AJOL)

    SERVER

    2008-03-18

    Mar 18, 2008 ... homeostasis in the rice shoots. To test the usefulness of microsatellite (SSR) markers associated with Saltol QTL, a collection of 36 diverse rice genotypes were used. Phenotypic response of the genotypes to salt stress with EC=12 was assessed under controlled environmental conditions at seedling stage ...

  9. Salt tolerance in red clover (Trifolium pratense L.) seedlings

    African Journals Online (AJOL)

    Jane

    2011-08-15

    Aug 15, 2011 ... This study was conducted to investigate the effect of salt stress on germination of 28 red clover. (Trifolium pratense L.) populations collected from Black Sea Region of Turkey. Seeds were germinated in 0, 60, 120, 180 and 240 mM NaCl concentration. Germination percentage (%), mean germination time.

  10. Salt tolerance in red clover ( Trifolium pratense L.) seedlings | Asci ...

    African Journals Online (AJOL)

    This study was conducted to investigate the effect of salt stress on germination of 28 red clover (Trifolium pratense L.) populations collected from Black Sea Region of Turkey. Seeds were germinated in 0, 60, 120, 180 and 240 mM NaCl concentration. Germination percentage (%), mean germination time (MGT), promptness ...

  11. Overexpression of Populus trichocarpa Mitogen-Activated Protein Kinase Kinase4 Enhances Salt Tolerance in Tobacco

    Directory of Open Access Journals (Sweden)

    Chengjun Yang

    2017-10-01

    Full Text Available Mitogen-activated protein kinase (MAPK is one of the factors of cascade reactions affecting responses to signal pathway of environmental stimuli. Throughout the life of plants, MAPK family members participate in signal transduction pathways and regulate various intracellular physiological and metabolic reactions. To gain insights into regulatory function of MAPK kinase (MAPKK in Populus trichocarpa under salt stress, we obtained full-length cDNA of PtMAPKK4 and analyzed different expression levels of PtMAPKK4 gene in leaves, stems, and root organs. The relationship between PtMAPKK4 and salt stress was studied by detecting expression characteristics of mRNA under 150 mM NaCl stress using real-time quantitative polymerase chain reaction. The results showed that expression of PtMAPKK4 increased under salt (NaCl stress in leaves but initially reduced and then increased in roots. Thus, salt stress failed to induce PtMAPKK4 expression in stems. PtMAPKK4 possibly participates in regulation of plant growth and metabolism, thereby improving its salt tolerance. We used Saccharomyces cerevisiae strain INVScI to verify subcellular localization of PtMAPKK4 kinase. The yeast strains containing pYES2-PtMAPKK4-GFP plasmid expressed GFP fusion proteins under the induction of d-galactose, and the products were located in nucleus. These results were consistent with network prediction and confirmed location of PtMAPKK4 enzyme in the nucleus. We tested NaCl tolerance in transgenic tobacco lines overexpressing PtMAPKK4 under the control of 35S promoter at germination stage to detect salt tolerance function of PtMAPKK4. Compared withK326 (a wild-type tobacco, lines overexpressing PtMAPKK4 showed a certain degree of improvement in tolerance, germination, and growth. NaCl inhibited growth of overexpressed line and K326 at the seedling stage. However, statistical analysis showed longer root length, higher fresh weight, and lower MDA content in transgenic lines in

  12. Proteome of Abiotic Stress Tolerance in Date Palm.

    Science.gov (United States)

    El Rabey, Haddad A

    2017-01-01

    This protocol describes the analysis of date palm proteome under salinity and drought stress conditions to possibly identify proteins involved in stress tolerance. Three-month-old date palm seedlings are subjected to drought (27.5 g/L polyethylene glycol 6000) and salinity stress conditions (16 g/L NaCl) for 1 month prior to leaf sample analysis. Differential in gel electrophoresis (DIGE) analysis of protein extracts identifies the sensitive proteins that respond to abiotic stress. Mass spectrometric analysis identifies the significantly changed proteins under both salt and drought stress. This chapter provides techniques for analyzing the proteome of date palm under salinity and drought stress.

  13. Salt tolerance research in date palm tree (Phoenix dactylifera L.), past, present, and future perspectives.

    Science.gov (United States)

    Yaish, Mahmoud W; Kumar, Prakash P

    2015-01-01

    The date palm can adapt to extreme drought, to heat, and to relatively high levels of soil salinity. However, excessive amounts of salt due to irrigation with brackish water lead to a significant reduction in the productivity of the fruits as well as marked decrease in the viable numbers of the date palm trees. It is imperative that the nature of the existing salt-adaptation mechanism be understood in order to develop future date palm varieties that can tolerate excessive soil salinity. In this perspective article, several research strategies, obstacles, and precautions are discussed in light of recent advancements accomplished in this field and the properties of this species. In addition to a physiological characterization, we propose the use of a full range of OMICS technologies, coupled with reverse genetics approaches, aimed toward understanding the salt-adaption mechanism in the date palm. Information generated by these analyses should highlight transcriptional and posttranscriptional modifications controlling the salt-adaptation mechanisms. As an extremophile with a natural tolerance for a wide range of abiotic stresses, the date palm may represent a treasure trove of novel genetic resources for salinity tolerance.

  14. Salt Tolerance Research in Date Palm Tree (Phoenix dactylifera L., Past, Present and Future Perspectives

    Directory of Open Access Journals (Sweden)

    Mahmoud W Yaish

    2015-05-01

    Full Text Available The date palm can adapt to extreme drought, to heat, and to relatively high levels of soil salinity. However, excessive amounts of salt due to irrigation with brackish water lead to a significant reduction in the productivity of the fruits as well as marked decrease in the viable numbers of the date palm trees. It is imperative that the nature of the existing salt adaptation mechanism be understood in order to develop future date palm varieties that can tolerate excessive soil salinity. In this perspective article, several research strategies, obstacles, and precautions are discussed in light of recent advancements accomplished in this field and the properties of this species. In addition to a physiological characterization, we propose the use of a full range of OMICS technologies, coupled with reverse genetics approaches, aimed towards understanding the salt-adaption mechanism in the date palm. Information generated by these analyses should highlight transcriptional and posttranscriptional modifications controlling the salt-adaptation mechanisms. As an extremophile with a natural tolerance for a wide range of abiotic stresses, the date palm may represent a treasure trove of novel genetic resources for salinity tolerance.

  15. Biochar soil amendment on alleviation of drought and salt stress in plants: a critical review.

    Science.gov (United States)

    Ali, Shafaqat; Rizwan, Muhammad; Qayyum, Muhammad Farooq; Ok, Yong Sik; Ibrahim, Muhammad; Riaz, Muhammad; Arif, Muhammad Saleem; Hafeez, Farhan; Al-Wabel, Mohammad I; Shahzad, Ahmad Naeem

    2017-05-01

    Drought and salt stress negatively affect soil fertility and plant growth. Application of biochar, carbon-rich material developed from combustion of biomass under no or limited oxygen supply, ameliorates the negative effects of drought and salt stress on plants. The biochar application increased the plant growth, biomass, and yield under either drought and/or salt stress and also increased photosynthesis, nutrient uptake, and modified gas exchange characteristics in drought and salt-stressed plants. Under drought stress, biochar increased the water holding capacity of soil and improved the physical and biological properties of soils. Under salt stress, biochar decreased Na+ uptake, while increased K+ uptake by plants. Biochar-mediated increase in salt tolerance of plants is primarily associated with improvement in soil properties, thus increasing plant water status, reduction of Na+ uptake, increasing uptake of minerals, and regulation of stomatal conductance and phytohormones. This review highlights both the potential of biochar in alleviating drought and salt stress in plants and future prospect of the role of biochar under drought and salt stress in plants.

  16. Reduction of GIGANTEA expression in transgenic Brassica rapa enhances salt tolerance.

    Science.gov (United States)

    Kim, Jin A; Jung, Ha-Eun; Hong, Joon Ki; Hermand, Victor; Robertson McClung, C; Lee, Yeon-Hee; Kim, Joo Yeol; Lee, Soo In; Jeong, Mi-Jeong; Kim, Jungsun; Yun, DaeJin; Kim, WeoYeon

    2016-09-01

    Here we report the enhancement of tolerance to salt stress in Brassica rapa (Chinese cabbage) through the RNAi-mediated reduction of GIGANTEA ( GI ) expression. Circadian clocks integrate environmental signals with internal cues to coordinate diverse physiological outputs. The GIGANTEA (GI) gene was first discovered due to its important contribution to photoperiodic flowering and has since been shown to be a critical component of the plant circadian clock and to contribute to multiple environmental stress responses. We show that the GI gene in Brassica rapa (BrGI) is similar to Arabidopsis GI in terms of both expression pattern and function. BrGI functionally rescued the late-flowering phenotype of the Arabidopsis gi-201 loss-of-function mutant. RNAi-mediated suppression of GI expression in Arabidopsis Col-0 and in the Chinese cabbage, B. rapa DH03, increased tolerance to salt stress. Our results demonstrate that the molecular functions of GI described in Arabidopsis are conserved in B. rapa and suggest that manipulation of gene expression through RNAi and transgenic overexpression could enhance tolerance to abiotic stresses and thus improve agricultural crop production.

  17. Piriformospora indica rescues growth diminution of rice seedlings during high salt stress.

    Science.gov (United States)

    Jogawat, Abhimanyu; Saha, Shreya; Bakshi, Madhunita; Dayaman, Vikram; Kumar, Manoj; Dua, Meenakshi; Varma, Ajit; Oelmüller, Ralf; Tuteja, Narendra; Johri, Atul Kumar

    2013-10-01

    Piriformospora indica association has been reported to increase biotic as well as abiotic stress tolerance of its host plants. We analyzed the beneficial effect of P. indica association on rice seedlings during high salt stress conditions (200 and 300 mM NaCl). The growth parameters of rice seedlings such as root and shoot lengths or fresh and dry weights were found to be enhanced in P. indica-inoculated rice seedlings as compared with non-inoculated control seedlings, irrespective of whether they are exposed to salt stress or not. However, salt-stressed seedlings performed much better in the presence of the fungus compared with non-inoculated control seedlings. The photosynthetic pigment content [chlorophyll (Chl) a, Chl b, and carotenoids] was significantly higher in P. indica-inoculated rice seedlings under high salt stress conditions as compared with salt-treated non-inoculated rice seedlings, in which these pigments were found to be decreased. Proline accumulation was also observed during P. indica colonization, which may help the inoculated plants to become salt tolerant. Taken together, P. indica rescues growth diminution of rice seedlings under salt stress.

  18. Piriformospora indica rescues growth diminution of rice seedlings during high salt stress

    Science.gov (United States)

    Jogawat, Abhimanyu; Saha, Shreya; Bakshi, Madhunita; Dayaman, Vikram; Kumar, Manoj; Dua, Meenakshi; Varma, Ajit; Oelmüller, Ralf; Tuteja, Narendra; Johri, Atul Kumar

    2013-01-01

    Piriformospora indica association has been reported to increase biotic as well as abiotic stress tolerance of its host plants. We analyzed the beneficial effect of P. indica association on rice seedlings during high salt stress conditions (200 and 300 mM NaCl). The growth parameters of rice seedlings such as root and shoot lengths or fresh and dry weights were found to be enhanced in P. indica-inoculated rice seedlings as compared with non-inoculated control seedlings, irrespective of whether they are exposed to salt stress or not. However, salt-stressed seedlings performed much better in the presence of the fungus compared with non-inoculated control seedlings. The photosynthetic pigment content [chlorophyll (Chl) a, Chl b, and carotenoids] was significantly higher in P. indica-inoculated rice seedlings under high salt stress conditions as compared with salt-treated non-inoculated rice seedlings, in which these pigments were found to be decreased. Proline accumulation was also observed during P. indica colonization, which may help the inoculated plants to become salt tolerant. Taken together, P. indica rescues growth diminution of rice seedlings under salt stress.

  19. Salt stress alters physiological indicators in cotton (Gossypium hirsutum L.

    Directory of Open Access Journals (Sweden)

    Basel Saleh

    2012-11-01

    Full Text Available A pot experiment was conducted to evaluate performance of four upland cotton (Gossypium hirsutum L. varieties, Deir-Ezzor22, Niab78, Aleppo118 and Deltapine50 grown under non-saline conditions (control and salt stress (200 mol m-3 NaCl for 7 weeks. Results showed that seedling height, root length, leaf number, leaf area, leaf chlorophyll a and b, osmotic potential, chlorophyll content index (CCI, dry biomass and root/shoot weight ratio were significantly reduced with salinity treatment. This reduction was more pronounced in Deltapine50 and Aleppo118 than Niab78 and Deir-Ezzor22. Leaf relative water content (RWC was strongly reduced for Deltapine50 and Aleppo118, while, it was slightly increased for Niab78 and Deir-Ezzor22. In conclusion, osmotic potential, RWC, CCI, dry biomass and root/shoot weight ratio could be considered as useful indictors for salt tolerance screening among cotton varieties.

  20. Transcript profile analysis reveals important roles of jasmonic acid signalling pathway in the response of sweet potato to salt stress.

    Science.gov (United States)

    Zhang, Huan; Zhang, Qian; Zhai, Hong; Li, Yan; Wang, Xiangfeng; Liu, Qingchang; He, Shaozhen

    2017-01-13

    Sweet potato is an important food and bio-energy crop, and investigating the mechanisms underlying salt tolerance will provide information for salt-tolerant breeding of this crop. Here, the root transcriptomes of the salt-sensitive variety Lizixiang and the salt-tolerant line ND98 were compared to identify the genes and pathways involved in salt stress responses. In total, 8,744 and 10,413 differentially expressed genes (DEGs) in Lizixiang and ND98, respectively, were involved in salt responses. A lower DNA methylation level was detected in ND98 than in Lizixiang. In both genotypes, the DEGs, which function in phytohormone synthesis and signalling and ion homeostasis, may underlie the different degrees of salt tolerance. Significant up-regulations of the genes involved in the jasmonic acid (JA) biosynthesis and signalling pathways and ion transport, more accumulation of JA, a higher degree of stomatal closure and a lower level of Na + were found in ND98 compared to Lizixiang. This is the first report on transcriptome responses to salt tolerance in sweet potato. These results reveal that the JA signalling pathway plays important roles in the response of sweet potato to salt stress. This study provides insights into the mechanisms and genes involved in the salt tolerance of sweet potato.

  1. Transcript profile analysis reveals important roles of jasmonic acid signalling pathway in the response of sweet potato to salt stress

    Science.gov (United States)

    Zhang, Huan; Zhang, Qian; Zhai, Hong; Li, Yan; Wang, Xiangfeng; Liu, Qingchang; He, Shaozhen

    2017-01-01

    Sweet potato is an important food and bio-energy crop, and investigating the mechanisms underlying salt tolerance will provide information for salt-tolerant breeding of this crop. Here, the root transcriptomes of the salt-sensitive variety Lizixiang and the salt-tolerant line ND98 were compared to identify the genes and pathways involved in salt stress responses. In total, 8,744 and 10,413 differentially expressed genes (DEGs) in Lizixiang and ND98, respectively, were involved in salt responses. A lower DNA methylation level was detected in ND98 than in Lizixiang. In both genotypes, the DEGs, which function in phytohormone synthesis and signalling and ion homeostasis, may underlie the different degrees of salt tolerance. Significant up-regulations of the genes involved in the jasmonic acid (JA) biosynthesis and signalling pathways and ion transport, more accumulation of JA, a higher degree of stomatal closure and a lower level of Na+ were found in ND98 compared to Lizixiang. This is the first report on transcriptome responses to salt tolerance in sweet potato. These results reveal that the JA signalling pathway plays important roles in the response of sweet potato to salt stress. This study provides insights into the mechanisms and genes involved in the salt tolerance of sweet potato. PMID:28084460

  2. Molecular Karyotyping and Exome Analysis of Salt-Tolerant Rice Mutant from Somaclonal Variation

    Directory of Open Access Journals (Sweden)

    Thanikarn Udomchalothorn

    2014-11-01

    Full Text Available LPT123-TC171 is a salt-tolerant (ST and drought-tolerant (DT rice line that was selected from somaclonal variation of the original Leuang Pratew 123 (LPT123 rice cultivar. The objective of this study was to identify the changes in the rice genome that possibly lead to ST and/or DT characteristics. The genomes of LPT123 and LPT123-TC171 were comparatively studied at the four levels of whole chromosomes (chromosome structure including telomeres, transposable elements, and DNA sequence changes by using next-generation sequencing analysis. Compared with LPT123, the LPT123-TC171 line displayed no changes in the ploidy level, but had a significant deficiency of chromosome ends (telomeres. The functional genome analysis revealed new aspects of the genome response to the in vitro cultivation condition, where exome sequencing revealed the molecular spectrum and pattern of changes in the somaclonal variant compared with the parental LPT123 cultivar. Mutation detection was performed, and the degree of mutations was evaluated to estimate the impact of mutagenesis on the protein functions. Mutations within the known genes responding to both drought and salt stress were detected in 493 positions, while mutations within the genes responding to only salt stress were found in 100 positions. The possible functions of the mutated genes contributing to salt or drought tolerance were discussed. It was concluded that the ST and DT characteristics in the somaclonal variegated line resulted from the base changes in the salt- and drought-responsive genes rather than the changes in chromosome structure or the large duplication or deletion in the specific region of the genome.

  3. Research Paper Silicon alleviates salt stress, decreases ...

    African Journals Online (AJOL)

    A greenhouse experiment was conducted to investigate the effects of different levels of silicon (Si) application on cut rose (Rosa xhybrida L.) 'Hot Lady' under two levels of salt stress. Four Si concentrations (0, 50, 100 and 150 ppm) as Si were combined with a 25 mM NaCl (EC 3.8) level in the nutrient solution supplied to ...

  4. Effectiveness of halo-tolerant, auxin producing Pseudomonas and Rhizobium strains to improve osmotic stress tolerance in mung bean (Vigna radiata L.).

    Science.gov (United States)

    Ahmad, Maqshoof; Zahir, Zahir A; Nazli, Farheen; Akram, Fareeha; Arshad, Muhammad; Khalid, Muhammad

    2013-12-01

    Halo-tolerant, auxin producing bacteria could be used to induce salt tolerance in plants. A number of Rhizobium and auxin producing rhizobacterial strains were assessed for their ability to tolerate salt stress by conducting osmoadaptation assay. The selected strains were further screened for their ability to induce osmotic stress tolerance in mung bean seedlings under salt-stressed axenic conditions in growth pouch/jar trials. Three most effective strains of Rhizobium and Pseudomonas containing ACC-deaminase were evaluated in combination, for their ability to induce osmotic stress tolerance in mung bean at original, 4, and 6 dS m(-1) under axenic conditions. Results showed that sole inoculation of Rhizobium and Pseudomonas strains improved the total dry matter up to 1.4, and 1.9 fold, respectively, while the increase in salt tolerance index was improved up to 1.3 and 2.0 fold by the Rhizobium and Pseudomonas strains, respectively. However, up to 2.2 fold increase in total dry matter and salt tolerance index was observed due to combined inoculation of Rhizobium and Pseudomonas strains. So, combined application of Rhizobium and Pseudomonas strains could be explored as an effective strategy to induce osmotic stress tolerance in mung bean.

  5. Bacterial growth tolerance to concentrations of chlorate and perchlorate salts relevant to Mars

    Science.gov (United States)

    Al Soudi, Amer F.; Farhat, Omar; Chen, Fei; Clark, Benton C.; Schneegurt, Mark A.

    2017-07-01

    The Phoenix lander at Mars polar cap found appreciable levels of (per)chlorate salts, a mixture of perchlorate and chlorate salts of Ca, Fe, Mg and Na at levels of ~0.6% in regolith. These salts are highly hygroscopic and can form saturated brines through deliquescence, likely producing aqueous solutions with very low freezing points on Mars. To support planetary protection efforts, we have measured bacterial growth tolerance to (per)chlorate salts. Existing bacterial isolates from the Great Salt Plains of Oklahoma (NaCl-rich) and Hot Lake in Washington (MgSO4-rich) were tested in high concentrations of Mg, K and Na salts of chlorate and perchlorate. Strong growth was observed with nearly all of these salinotolerant isolates at 1% (~0.1 M) (per)chlorate salts, similar to concentrations observed in bulk soils on Mars. Growth in perchlorate salts was observed at concentrations of at least 10% (~1.0 M). Greater tolerance was observed for chlorate salts, where growth was observed to 2.75 M (>25%). Tolerance to K salts was greatest, followed by Mg salts and then Na salts. Tolerances varied among isolates, even among those within the same phylogenetic clade. Tolerant bacteria included genera that also are found in spacecraft assembly facilities. Substantial microbial tolerance to (per)chlorate salts is a concern for planetary protection since tolerant microbes contaminating spacecraft would have a greater chance for survival and proliferation, despite the harsh chemical conditions found near the surface of Mars.

  6. Integrated RNA Sequencing and QTL Mapping to Identify Candidate Genes from Oryza rufipogon Associated with Salt Tolerance at the Seedling Stage

    Directory of Open Access Journals (Sweden)

    Shanshan Wang

    2017-08-01

    Full Text Available Soil salinity is a common abiotic stress affecting crop productivity. To identify favorable alleles from wild rice (Oryza rufipogon Griff. that enhance salinity tolerance of rice (O. sativa L., a set of introgression lines (ILs were developed. The ILs were derived from an O. rufipogon accession collected from Chaling (Hunan Province, China as the donor, and a widely grown O. sativa indica cultivar 93-11 as the recipient. Through evaluating the salt tolerance of 285 ILs at the seedling stage, a total of 10 quantitative trait loci (QTLs related to salt tolerance were identified on chromosomes 1, 5, 7 and 9–12, with individual QTLs explaining 2–8% of phenotypic variance. The O. rufipogon-derived alleles at four QTLs improved salt tolerance in the 93-11 background. At the same time, a salt-tolerant IL, 9L136, was identified and characterized. Compared with the recipient parent 93-11, a total of 1,391 differentially expressed genes (DEGs were detected specifically in 9L136 between salt stress and normal condition through genome-wide expression analysis. Of these, four DEGs located in the QTL regions carried by 9L136, suggesting that the four genes might be candidates associated with salt tolerance. Both the highly salt-tolerant ILs and the favorable O. rufipogon-derived QTLs identified in the present study will provide new genetic resources for improving the resistance of cultivated rice against salinity stress using molecular breeding strategies in the future.

  7. Integrated RNA Sequencing and QTL Mapping to Identify Candidate Genes from Oryza rufipogon Associated with Salt Tolerance at the Seedling Stage

    Science.gov (United States)

    Wang, Shanshan; Cao, Meng; Ma, Xin; Chen, Weikang; Zhao, Jie; Sun, Chuanqing; Tan, Lubin; Liu, Fengxia

    2017-01-01

    Soil salinity is a common abiotic stress affecting crop productivity. To identify favorable alleles from wild rice (Oryza rufipogon Griff.) that enhance salinity tolerance of rice (O. sativa L.), a set of introgression lines (ILs) were developed. The ILs were derived from an O. rufipogon accession collected from Chaling (Hunan Province, China) as the donor, and a widely grown O. sativa indica cultivar 93-11 as the recipient. Through evaluating the salt tolerance of 285 ILs at the seedling stage, a total of 10 quantitative trait loci (QTLs) related to salt tolerance were identified on chromosomes 1, 5, 7 and 9–12, with individual QTLs explaining 2–8% of phenotypic variance. The O. rufipogon-derived alleles at four QTLs improved salt tolerance in the 93-11 background. At the same time, a salt-tolerant IL, 9L136, was identified and characterized. Compared with the recipient parent 93-11, a total of 1,391 differentially expressed genes (DEGs) were detected specifically in 9L136 between salt stress and normal condition through genome-wide expression analysis. Of these, four DEGs located in the QTL regions carried by 9L136, suggesting that the four genes might be candidates associated with salt tolerance. Both the highly salt-tolerant ILs and the favorable O. rufipogon-derived QTLs identified in the present study will provide new genetic resources for improving the resistance of cultivated rice against salinity stress using molecular breeding strategies in the future. PMID:28861103

  8. Assessment of rice genotypes for salt tolerance using microsatellite ...

    African Journals Online (AJOL)

    The results of phenotypic response of rice genotypes to salinity stress at the seedling stage indicated the varied genotypic responses. The genotypes were classified into five groups from highly tolerant (score 1) to highly sensitive (score 9). Number of alleles of the SSR markers ranged from 3 for RM10702 to 14 for RM8094.

  9. Discovery and characterization of two novel salt-tolerance genes in Puccinellia tenuiflora.

    Science.gov (United States)

    Li, Ying; Takano, Tetsuo; Liu, Shenkui

    2014-09-18

    Puccinellia tenuiflora is a monocotyledonous halophyte that is able to survive in extreme saline soil environments at an alkaline pH range of 9-10. In this study, we transformed full-length cDNAs of P. tenuiflora into Saccharomyces cerevisiae by using the full-length cDNA over-expressing gene-hunting system to identify novel salt-tolerance genes. In all, 32 yeast clones overexpressing P. tenuiflora cDNA were obtained by screening under NaCl stress conditions; of these, 31 clones showed stronger tolerance to NaCl and were amplified using polymerase chain reaction (PCR) and sequenced. Four novel genes encoding proteins with unknown function were identified; these genes had no homology with genes from higher plants. Of the four isolated genes, two that encoded proteins with two transmembrane domains showed the strongest resistance to 1.3 M NaCl. RT-PCR and northern blot analysis of P. tenuiflora cultured cells confirmed the endogenous NaCl-induced expression of the two proteins. Both of the proteins conferred better tolerance in yeasts to high salt, alkaline and osmotic conditions, some heavy metals and H2O2 stress. Thus, we inferred that the two novel proteins might alleviate oxidative and other stresses in P. tenuiflora.

  10. Response of Tomato Genotypes to Induced Salt Stress | Agong ...

    African Journals Online (AJOL)

    Thirteen tomato (Lycopersicon esculentum L.) genotypes were subjected to salt treatment under hydroponics and their responses monitored in a set of two experiments with the objective of advancing them as potential salt tolerant tomato scion and/or rootstocks. Salt applications ranged from 0 to 2% NaCl, with the resultant ...

  11. SALT-RESPONSIVE ERF1 Regulates Reactive Oxygen Species–Dependent Signaling during the Initial Response to Salt Stress in Rice[W

    Science.gov (United States)

    Schmidt, Romy; Mieulet, Delphine; Hubberten, Hans-Michael; Obata, Toshihiro; Hoefgen, Rainer; Fernie, Alisdair R.; Fisahn, Joachim; San Segundo, Blanca; Guiderdoni, Emmanuel; Schippers, Jos H.M.; Mueller-Roeber, Bernd

    2013-01-01

    Early detection of salt stress is vital for plant survival and growth. Still, the molecular processes controlling early salt stress perception and signaling are not fully understood. Here, we identified SALT-RESPONSIVE ERF1 (SERF1), a rice (Oryza sativa) transcription factor (TF) gene that shows a root-specific induction upon salt and hydrogen peroxide (H2O2) treatment. Loss of SERF1 impairs the salt-inducible expression of genes encoding members of a mitogen-activated protein kinase (MAPK) cascade and salt tolerance–mediating TFs. Furthermore, we show that SERF1-dependent genes are H2O2 responsive and demonstrate that SERF1 binds to the promoters of MAPK KINASE KINASE6 (MAP3K6), MAPK5, DEHYDRATION-RESPONSIVE ELEMENT BINDING2A (DREB2A), and ZINC FINGER PROTEIN179 (ZFP179) in vitro and in vivo. SERF1 also directly induces its own gene expression. In addition, SERF1 is a phosphorylation target of MAPK5, resulting in enhanced transcriptional activity of SERF1 toward its direct target genes. In agreement, plants deficient for SERF1 are more sensitive to salt stress compared with the wild type, while constitutive overexpression of SERF1 improves salinity tolerance. We propose that SERF1 amplifies the reactive oxygen species–activated MAPK cascade signal during the initial phase of salt stress and translates the salt-induced signal into an appropriate expressional response resulting in salt tolerance. PMID:23800963

  12. De Novo Transcriptome Sequencing of Desert Herbaceous Achnatherum splendens (Achnatherum Seedlings and Identification of Salt Tolerance Genes

    Directory of Open Access Journals (Sweden)

    Jiangtao Liu

    2016-03-01

    Full Text Available Achnatherum splendens is an important forage herb in Northwestern China. It has a high tolerance to salinity and is, thus, considered one of the most important constructive plants in saline and alkaline areas of land in Northwest China. However, the mechanisms of salt stress tolerance in A. splendens remain unknown. Next-generation sequencing (NGS technologies can be used for global gene expression profiling. In this study, we examined sequence and transcript abundance data for the root/leaf transcriptome of A. splendens obtained using an Illumina HiSeq 2500. Over 35 million clean reads were obtained from the leaf and root libraries. All of the RNA sequencing (RNA-seq reads were assembled de novo into a total of 126,235 unigenes and 36,511 coding DNA sequences (CDS. We further identified 1663 differentially-expressed genes (DEGs between the salt stress treatment and control. Functional annotation of the DEGs by gene ontology (GO, using Arabidopsis and rice as references, revealed enrichment of salt stress-related GO categories, including “oxidation reduction”, “transcription factor activity”, and “ion channel transporter”. Thus, this global transcriptome analysis of A. splendens has provided an important genetic resource for the study of salt tolerance in this halophyte. The identified sequences and their putative functional data will facilitate future investigations of the tolerance of Achnatherum species to various types of abiotic stress.

  13. Simultaneous Improvement and Genetic Dissection of Salt Tolerance of Rice (Oryza sativa L. by Designed QTL Pyramiding

    Directory of Open Access Journals (Sweden)

    Yunlong Pang

    2017-07-01

    Full Text Available Breeding of multi-stress tolerant rice varieties with higher grain yields is the best option to enhance the rice productivity of abiotic stresses prone areas. It also poses the greatest challenge to plant breeders to breed rice varieties for such stress prone conditions. Here, we carried out a designed QTL pyramiding experiment to develop high yielding “Green Super Rice” varieties with significantly improved tolerance to salt stress and grain yield. Using the F4 population derived from a cross between two selected introgression lines, we were able to develop six mostly homozygous promising high yielding lines with significantly improved salt tolerance and grain yield under optimal and/or saline conditions in 3 years. Simultaneous mapping using the same breeding population and tunable genotyping-by-sequencing technology, we identified three QTL affecting salt injury score and leaf chlorophyll content. By analyzing 32M SNP data of the grandparents and graphical genotypes of the parents, we discovered 87 positional candidate genes for salt tolerant QTL. According to their functional annotation, we inferred the most likely candidate genes. We demonstrated that designed QTL pyramiding is a powerful strategy for simultaneous improvement and genetic dissection of complex traits in rice.

  14. Overexpression of Glycerol-3-Phosphate Acyltransferase from Suaeda salsa Improves Salt Tolerance in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Na Sui

    2017-08-01

    Full Text Available Glycerol-3-phosphate acyltransferase is the first acyl esterifying enzyme in phosphatidylglycerol (PG synthesis process. In this study, we isolated and characterized the glycerol-3-phosphate acyltransferase (GPAT gene from Suaeda salsa (S. salsa and obtained the full length of the GPAT gene from S. salsa (SsGPAT by 5′ and 3′ RACE. The clone contained an open reading frame (ORF of 1167 bp nucleotides that comprised of 388 amino acid residues. Real-time PCR revealed that the mRNA accumulation of GPAT in S. salsa was induced by salt stress. The highest expression levels were observed when S. salsa leaves were exposed to 300 mM NaCl treatment. At the germination stage, the germination rate and root length of overexpressed Arabidopsis strains were significantly higher than WT under different concentrations of NaCl treatments, while the inhibitory effect was significantly severe in T-DNA insertion mutant strains. In the seedling stage, chlorophyll content, the photochemical efficiency of PSII, PSI oxidoreductive activity (ΔI/Io, and the unsaturated fatty acid content of PG decreased less in overexpressed strains and more in mutant strains than that in WT under salt stress. These results suggest that the overexpression of SsGPAT in Arabidopsis enhances salt tolerance and alleviates the photoinhibition of PSII and PSI under salt stress by improving the unsaturated fatty acid content of PG.

  15. Identification of genes induced by salt stress from Medicago ...

    African Journals Online (AJOL)

    In order to identify genes induced during the salt stress response in barrel medic (Medicago truncatula L) seedlings, a cDNA library by salt stress was constructed by suppression subtractive hybridization (SSH). Total RNA from 15-day-old seedlings was used as a 'driver', and total RNA from seedlings induced by salt was ...

  16. A cellulose synthase-like protein is required for osmotic stress tolerance in Arabidopsis

    KAUST Repository

    Zhu, Jianhua

    2010-04-16

    Osmotic stress imposed by soil salinity and drought stress significantly affects plant growth and development, but osmotic stress sensing and tolerance mechanisms are not well understood. Forward genetic screens using a root-bending assay have previously identified salt overly sensitive (sos) mutants of Arabidopsis that fall into five loci, SOS1 to SOS5. These loci are required for the regulation of ion homeostasis or cell expansion under salt stress, but do not play a major role in plant tolerance to the osmotic stress component of soil salinity or drought. Here we report an additional sos mutant, sos6-1, which defines a locus essential for osmotic stress tolerance. sos6-1 plants are hypersensitive to salt stress and osmotic stress imposed by mannitol or polyethylene glycol in culture media or by water deficit in the soil. SOS6 encodes a cellulose synthase-like protein, AtCSLD5. Only modest differences in cell wall chemical composition could be detected, but we found that sos6-1 mutant plants accumulate high levels of reactive oxygen species (ROS) under osmotic stress and are hypersensitive to the oxidative stress reagent methyl viologen. The results suggest that SOS6/AtCSLD5 is not required for normal plant growth and development but has a critical role in osmotic stress tolerance and this function likely involves its regulation of ROS under stress. © 2010 Blackwell Publishing Ltd.

  17. Evaluation of a Simple Method to Screen Soybean Genotypes for Salt Tolerance

    Science.gov (United States)

    Excessive salt can reduce soybean yield in grower fields. Salt tolerant cultivars are needed to prevent field yield losses where excess salt is a problem. Soybean genotypes have primarily been evaluated for reaction to salt in the greenhouse using a labor intensive and costly hydroponics method. ...

  18. Prospects for improving the salt tolerance of forest trees: A review

    Science.gov (United States)

    Allen, J.A.; Chambers, J.L.; Stine, M.

    1994-01-01

    Three major themes related to the improvement of salt tolerance in forest tree species are examined. First, evidence demonstrating that substantial intraspecific variation in salt tolerance exists in many species is presented. This evidence is important because it suggests that efforts to improve salt tolerance through conventional plant breeding techniques are justified. Second, the physiological and genetic mechanisms controlling salt tolerance are discussed briefly. Although salt tolerance involves the integration of numerous physiological processes, there is considerable evidence that differences in the ability to exclude Na+ and Cl- from leaves are the most important factors underlying intraspecific differences in tolerance. It is also becoming apparent that, although salt tolerance is a multigenic trait, major genes play an important role. Third, progress to date in improving salt tolerance of forest tree species is assessed. Compared with agricultural crops, relatively little progress has been made with either conventional or biotechnological methods, but field trials designed to test clones identified as salt tolerant in screening trials are underway now in several countries. We conclude that there is justification for cautious optimism about the prospects for improving salt tolerance in forest tree species.

  19. Protocols for Pre-Field Screening of Mutants for Salt Tolerance in Rice, Wheat and Barley

    National Research Council Canada - National Science Library

    Bado, Souleymane; Forster, Brian P; Ghanim, Abdelbagi M.A; Jankowicz-Cieslak, Joanna; Berthold, Günter; Luxiang, Liu

    2016-01-01

    .... It presents simple methods for measuring soil salinity, including soil sampling and the analysis of water-soluble salts, and describes a detailed, but simple, screening test for salt tolerance...

  20. Salt tolerance and regulation of gas exchange and hormonal homeostasis by auxin-priming in wheat

    Directory of Open Access Journals (Sweden)

    Muhammad Iqbal

    2013-09-01

    Full Text Available The objective of this work was to assess the regulatory effects of auxin-priming on gas exchange and hormonal homeostasis in spring wheat subjected to saline conditions. Seeds of MH-97 (salt-intolerant and Inqlab-91 (salt-tolerant cultivars were subjected to 11 priming treatments (three hormones x three concentrations + two controls and evaluated under saline (15 dS m-1 and nonsaline (2.84 dS m-1 conditions. The priming treatments consisted of: 5.71, 8.56, and 11.42 × 10-4 mol L-1 indoleacetic acid; 4.92, 7.38, and 9.84 × 10-4 mol L-1 indolebutyric acid; 4.89, 7.34, and 9.79 × 10-4 mol L-1 tryptophan; and a control with hydroprimed seeds. A negative control with nonprimed seeds was also evaluated. All priming agents diminished the effects of salinity on endogenous abscisic acid concentration in the salt-intolerant cultivar. Grain yield was positively correlated with net CO2 assimilation rate and endogenous indoleacetic acid concentration, and it was negatively correlated with abscisic acid and free polyamine concentrations. In general, the priming treatment with tryptophan at 4.89 × 10-4 mol L-1 was the most effective in minimizing yield losses and reductions in net CO2 assimilation rate, under salt stress conditions. Hormonal homeostasis increases net CO2 assimilation rate and confers tolerance to salinity on spring wheat.

  1. An ABRE-binding factor, OSBZ8, is highly expressed in salt tolerant cultivars than in salt sensitive cultivars of indica rice

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    Gupta Sudhiranjan

    2006-08-01

    Full Text Available Abstract Background The bZIP class Abscisic acid Responsive Element (ABRE-binding factor, OSBZ8 (38.5 kD has been considered to regulate ABA-mediated transcription in the suspension cultured cells of japonica rice. Still, nothing is known about the expression of OSBZ8 at protein level in vegetative tissue of salt sensitive and salt tolerant rice plants. In our previous study, Electrophoretic Mobility Shift Assay (EMSA of [32P]ABRE-DNA and nuclear extracts prepared from the lamina of Pokkali rice plants has detected the presence of an ABRE-binding factor. Northern analysis has also detected salinity stress induced accumulation of transcripts for bZIP class of factor. Therefore, OSBZ8 was considered to play an important role in the regulation of transcription in the vegetative tissue of rice. The aim of this study is to find out whether OSBZ8 has any role in regulating the NaCl-stress induced gene expression in vegetative tissue and whether the expression of OSBZ8 factor directly correlates with the stress tolerance of different varieties of indica type rice. Results Northern analysis of total RNA from roots and lamina of salt-sensitive M-I-48 and salt-tolerant Nonabokra, when probed with the N-terminal unique region of OSBZ8 (OSBZ8p, without the highly conserved basic region, a transcript of 1.3 kb hybridized and its level was much higher in tolerant cultivar. EMSA with Em1a, the strongest ABA Responsive Element till reported from the upstream of EmBP1, and the nuclear extracts from laminar tissue of untreated and salt-treated seedlings of three salt sensitive, one moderately sensitive and two salt tolerant indica rice cultivars showed specific binding of nuclear factor to ABRE element. Intensity of binding was low and inducible in salt sensitive rice cultivars while high and constitutive in salt tolerant cultivars. EMSA with 300 bp 5'upstream region of Rab16A gene, a well known salt stress and ABA-inducible gene of rice, showed formation of two

  2. An ABRE-binding factor, OSBZ8, is highly expressed in salt tolerant cultivars than in salt sensitive cultivars of indica rice

    Science.gov (United States)

    Mukherjee, Kakali; Choudhury, Aryadeep Roy; Gupta, Bhaskar; Gupta, Sudhiranjan; Sengupta, Dibyendu N

    2006-01-01

    Background The bZIP class Abscisic acid Responsive Element (ABRE)-binding factor, OSBZ8 (38.5 kD) has been considered to regulate ABA-mediated transcription in the suspension cultured cells of japonica rice. Still, nothing is known about the expression of OSBZ8 at protein level in vegetative tissue of salt sensitive and salt tolerant rice plants. In our previous study, Electrophoretic Mobility Shift Assay (EMSA) of [32P]ABRE-DNA and nuclear extracts prepared from the lamina of Pokkali rice plants has detected the presence of an ABRE-binding factor. Northern analysis has also detected salinity stress induced accumulation of transcripts for bZIP class of factor. Therefore, OSBZ8 was considered to play an important role in the regulation of transcription in the vegetative tissue of rice. The aim of this study is to find out whether OSBZ8 has any role in regulating the NaCl-stress induced gene expression in vegetative tissue and whether the expression of OSBZ8 factor directly correlates with the stress tolerance of different varieties of indica type rice. Results Northern analysis of total RNA from roots and lamina of salt-sensitive M-I-48 and salt-tolerant Nonabokra, when probed with the N-terminal unique region of OSBZ8 (OSBZ8p, without the highly conserved basic region), a transcript of 1.3 kb hybridized and its level was much higher in tolerant cultivar. EMSA with Em1a, the strongest ABA Responsive Element till reported from the upstream of EmBP1, and the nuclear extracts from laminar tissue of untreated and salt-treated seedlings of three salt sensitive, one moderately sensitive and two salt tolerant indica rice cultivars showed specific binding of nuclear factor to ABRE element. Intensity of binding was low and inducible in salt sensitive rice cultivars while high and constitutive in salt tolerant cultivars. EMSA with 300 bp 5'upstream region of Rab16A gene, a well known salt stress and ABA-inducible gene of rice, showed formation of two complexes, again very

  3. Oxidative stress tolerance in plants

    Science.gov (United States)

    Krishnamurthy, Aparna; Rathinasabapathi, Bala

    2013-01-01

    Biotic and abiotic stress conditions produce reactive oxygen species (ROS) in plants causing oxidative stress damage. At the same time, ROS have additional signaling roles in plant adaptation to the stress. It is not known how the two seemingly contrasting functional roles of ROS between oxidative damage to the cell and signaling for stress protection are balanced. Research suggests that the plant growth regulator auxin may be the connecting link regulating the level of ROS and directing its role in oxidative damage or signaling in plants under stress. The objective of this review is to highlight some of the recent research on how auxin’s role is intertwined to that of ROS, more specifically H2O2, in plant adaptation to oxidative stress conditions. PMID:23887492

  4. Transcriptome analysis of salt tolerant common bean (Phaseolus vulgaris L. under saline conditions.

    Directory of Open Access Journals (Sweden)

    Mahmut Can Hiz

    Full Text Available Salinity is one of the important abiotic stress factors that limit crop production. Common bean, Phaseolus vulgaris L., a major protein source in developing countries, is highly affected by soil salinity and the information on genes that play a role in salt tolerance is scarce. We aimed to identify differentially expressed genes (DEGs and related pathways by comprehensive analysis of transcriptomes of both root and leaf tissues of the tolerant genotype grown under saline and control conditions in hydroponic system. We have generated a total of 158 million high-quality reads which were assembled into 83,774 all-unigenes with a mean length of 813 bp and N50 of 1,449 bp. Among the all-unigenes, 58,171 were assigned with Nr annotations after homology analyses. It was revealed that 6,422 and 4,555 all-unigenes were differentially expressed upon salt stress in leaf and root tissues respectively. Validation of the RNA-seq quantifications (RPKM values was performed by qRT-PCR (Quantitative Reverse Transcription PCR analyses. Enrichment analyses of DEGs based on GO and KEGG databases have shown that both leaf and root tissues regulate energy metabolism, transmembrane transport activity, and secondary metabolites to cope with salinity. A total of 2,678 putative common bean transcription factors were identified and classified under 59 transcription factor families; among them 441 were salt responsive. The data generated in this study will help in understanding the fundamentals of salt tolerance in common bean and will provide resources for functional genomic studies.

  5. Transcriptome analysis of salt tolerant common bean (Phaseolus vulgaris L.) under saline conditions.

    Science.gov (United States)

    Hiz, Mahmut Can; Canher, Balkan; Niron, Harun; Turet, Muge

    2014-01-01

    Salinity is one of the important abiotic stress factors that limit crop production. Common bean, Phaseolus vulgaris L., a major protein source in developing countries, is highly affected by soil salinity and the information on genes that play a role in salt tolerance is scarce. We aimed to identify differentially expressed genes (DEGs) and related pathways by comprehensive analysis of transcriptomes of both root and leaf tissues of the tolerant genotype grown under saline and control conditions in hydroponic system. We have generated a total of 158 million high-quality reads which were assembled into 83,774 all-unigenes with a mean length of 813 bp and N50 of 1,449 bp. Among the all-unigenes, 58,171 were assigned with Nr annotations after homology analyses. It was revealed that 6,422 and 4,555 all-unigenes were differentially expressed upon salt stress in leaf and root tissues respectively. Validation of the RNA-seq quantifications (RPKM values) was performed by qRT-PCR (Quantitative Reverse Transcription PCR) analyses. Enrichment analyses of DEGs based on GO and KEGG databases have shown that both leaf and root tissues regulate energy metabolism, transmembrane transport activity, and secondary metabolites to cope with salinity. A total of 2,678 putative common bean transcription factors were identified and classified under 59 transcription factor families; among them 441 were salt responsive. The data generated in this study will help in understanding the fundamentals of salt tolerance in common bean and will provide resources for functional genomic studies.

  6. 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

  7. Comparative Effects of Salt Stress and Extreme pH Stress Combined on Glycinebetaine Accumulation, Photosynthetic Abilities and Growth Characters of Two Rice Genotypes

    Directory of Open Access Journals (Sweden)

    Suriyan CHA-UM

    2009-12-01

    Full Text Available Glycinebetaine (Glybet accumulation, photosynthetic efficiency and growth performance in indica rice cultivated under salt stress and extreme pH stress were investigated. Betaine aldehyde dehydrogenase (BADH activity and Glybet accumulation in the seedlings of salt-tolerant and salt-sensitive rice varieties grown under saline and acidic conditions peaked after treatment for 72 h and 96 h, respectively, and were higher than those grown under neutral pH and alkaline salt stress. A positive correlation was found between BADH activity and Glybet content in both salt-tolerant (r2 = 0.71 and salt-sensitive (r2 = 0.86 genotypes. The chlorophyll a, chlorophyll b, total chlorophyll and total carotenoids contents in the stressed seedlings significantly decreased under both acidic and alkaline stresses, especially in the salt-sensitive genotype. Similarly, the maximum quantum yield of PSII (Fv/Fm, photon yield of PSII (ΦPSII, non-photochemical quenching (NPQ and net photosynthetic rate (Pn in the stressed seedlings were inhibited, leading to overall growth reduction. The positive correlations between chlorophyll a content and Fv/Fm, total chlorophyll content and ΦPSII, ΦPSII and Pn as well as Pn and leaf area in both salt-tolerant and salt-sensitive genotypes were found. Saline acidic and saline alkaline soils may play a key role affecting vegetative growth prior to the reproductive stage in rice plants.

  8. Sequence-specific ¹H, ¹³C and ¹⁵N NMR assignments of Cyclophilin A like protein from Piriformospora indica involved in salt stress tolerance.

    Science.gov (United States)

    Trivedi, Dipesh Kumar; Bhatt, Harshesh; Johri, Atul; Tuteja, Narendra; Bhavesh, Neel Sarovar

    2013-10-01

    Cyclophilins are omnipresent proteins found in eukaryotes and prokaryotes, with presence in cytoplasm as well as in nucleus. Primary role of Cyclophilins is of peptidyl-prolyl cis-trans isomerase, a molecular chaperon action. Here, we report sequence-specific (1)H, (13)C and (15)N resonance assignments for a Cyclophilin A like protein from Piriformospora indica. This protein is up-regulated during salt stress conditions.

  9. Seed priming with hormones does not alleviate induced oxidative stress in maize seedlings subjected to salt stress

    Directory of Open Access Journals (Sweden)

    Rogério Falleiros Carvalho

    2011-10-01

    Full Text Available Seed priming with hormones has been an efficient method for increasing seed vigor as well as seedling growth under stressful conditions. These responses have in the past been attributed to the activation of antioxidant systems in a range of crops. The results described in this work show that hormonal priming with methyl jasmonate, salicylic acid or CEPA (chloroethylphosphonic acid, an ethylene (ET releaser, does not induce the antioxidant activity of superoxide dismutase, catalase, ascorbate peroxidase or glutathione reductase in maize seedlings subjected to salt stress. The enhanced biomass of maize seedlings under salt stress that was observed only from ET priming indicates that the stress tolerance in maize from ethylene priming is a fundamental process for stress tolerance acquisition, which is explained, however, by other biochemical mechanisms but not by changes in the antioxidant system.

  10. Inducing salt tolerance in sweet corn by magnetic priming

    Directory of Open Access Journals (Sweden)

    Soheil Karimi

    2017-01-01

    Full Text Available This study evaluates seed germination and growth of sweet corn under NaCl stress (0, 50, and 100 mM, after exposing the seeds to weak (15 mT or strong (150 mT magnetic fields (MF for different durations (0, 6, 12, and 24 hours. Salinity reduced seed germination and plant growth. MF treatments enhanced rate and percentage of germination and improved plant growth, regardless of salinity. Higher germination rate was obtained by the stronger MF, however, the seedling were more vigorous after priming with 15 mT MF. Proline accumulation was observed in parallel with the loss of plant water content under 100 mM NaCl stress. MF prevented proline accumulation by improving water absorption. Positive correlation between H2O2 accumulation and membrane thermostability (MTI was found after MF treatments, which revealed that MF primed the plant for salinity by H2O2 signaling. However, over-accumulation of H2O2 after prolonged MF exposure adversely affected MTI under severe salt stress. In conclusion, magnetic priming for 6 hours was suggested for enhancing germination and growth of sweet corn under salt stress.

  11. Proteomic comparison reveals the contribution of chloroplast to salt tolerance of a wheat introgression line

    Science.gov (United States)

    Xu, Wenjing; Lv, Hongjun; Zhao, Mingming; Li, Yongchao; Qi, Yueying; Peng, Zhenying; Xia, Guangmin; Wang, Mengcheng

    2016-01-01

    We previously bred a salt tolerant wheat cv. SR3 with bread wheat cv. JN177 as the parent via asymmetric somatic hybridization, and found that the tolerance is partially attributed to the superior photosynthesis capacity. Here, we compared the proteomes of two cultivars to unravel the basis of superior photosynthesis capacity. In the maps of two dimensional difference gel electrophoresis (2D-DIGE), there were 26 differentially expressed proteins (DEPs), including 18 cultivar-based and 8 stress-responsive ones. 21 of 26 DEPs were identified and classified into four categories, including photosynthesis, photosynthesis system stability, linolenic acid metabolism, and protein synthesis in chloroplast. The chloroplast localization of some DEPs confirmed that the identified DEPs function in the chloroplast. The overexpression of a DEP enhanced salt tolerance in Arabidopsis thaliana. In line with these data, it is concluded that the contribution of chloroplast to high salinity tolerance of wheat cv. SR3 appears to include higher photosynthesis efficiency by promoting system protection and ROS clearance, stronger production of phytohormone JA by enhancing metabolism activity, and modulating the in chloroplast synthesis of proteins. PMID:27562633

  12. Soybean NIMA-Related Kinase1 Promotes Plant Growth and Improves Salt and Cold Tolerance.

    Science.gov (United States)

    Pan, Wen-Jia; Tao, Jian-Jun; Cheng, Tong; Shen, Ming; Ma, Jin-Biao; Zhang, Wan-Ke; Lin, Qin; Ma, Biao; Chen, Shou-Yi; Zhang, Jin-Song

    2017-07-01

    NEK (NIMA-related kinase) is known as a family of serine/threonine kinases which mainly participate in microtubule-related mitotic events in fungi, mammals and other eukaryotes. Our previous studies found that Arabidopsis NEK6 plays an important role in plant response to abiotic stress. We further investigated roles of the NEK family in soybean and found that at least eight members can respond to abiotic stresses. Among them, only GmNEK1, a novel NEK member which is distantly related to Arabidopsis NEK6, enhanced plant growth and promoted salt and cold tolerance in transgenic Arabidopsis plants. The growth of soybean plants harboring GmNEK1-overexpressing hairy roots under saline condition was also improved. A series of stress-related genes including RH3, CORI3 and ALDH10A8 were found to be up-regulated in GmNEK1-overexpressing Arabidopsis plants and soybean hairy roots. Moreover, soybean plants with GmRH3-overexpressing hairy roots exhibited increased salt tolerance, while soybean plants with GmRH3-RNAi (RNA interference) roots were more sensitive to salt stress than the wild-type plants. Our study uncovers a novel role for GmNEK1 in promoting plant adaptive growth under adverse conditions at least partially through up-regulation of GmRH3. Manipulation of these genes in soybean or other crops may improve growth and production under stress conditions. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  13. Differentially delayed root proteome responses to salt stress in sugar cane varieties.

    Science.gov (United States)

    Pacheco, Cinthya Mirella; Pestana-Calsa, Maria Clara; Gozzo, Fabio Cesar; Mansur Custodio Nogueira, Rejane Jurema; Menossi, Marcelo; Calsa, Tercilio

    2013-12-06

    Soil salinity is a limiting factor to sugar cane crop development, although in general plants present variable mechanisms of tolerance to salinity stress. The molecular basis underlying these mechanisms can be inferred by using proteomic analysis. Thus, the objective of this work was to identify differentially expressed proteins in sugar cane plants submitted to salinity stress. For that, a greenhouse experiment was established with four sugar cane varieties and two salt conditions, 0 mM (control) and 200 mM NaCl. Physiological and proteomics analyses were performed after 2 and 72 h of stress induction by salt. Distinct physiological responses to salinity stress were observed in the varieties and linked to tolerance mechanisms. In proteomic analysis, the roots soluble protein fraction was extracted, quantified, and analyzed through bidimensional electrophoresis. Gel images analyses were done computationally, where in each contrast only one variable was considered (salinity condition or variety). Differential spots were excised, digested by trypsin, and identified via mass spectrometry. The tolerant variety RB867515 showed the highest accumulation of proteins involved in growth, development, carbohydrate and energy metabolism, reactive oxygen species metabolization, protein protection, and membrane stabilization after 2 h of stress. On the other hand, the presence of these proteins in the sensitive variety was verified only in stress treatment after 72 h. These data indicate that these stress responses pathways play a role in the tolerance to salinity in sugar cane, and their effectiveness for phenotypical tolerance depends on early stress detection and activation of the coding genes expression.

  14. Unraveling Salt Tolerance Mechanisms in Halophytes: A Comparative Study on Four Mediterranean Limonium Species with Different Geographic Distribution Patterns

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    Mohamad Al Hassan

    2017-08-01

    Full Text Available We have performed an extensive study on the responses to salt stress in four related Limonium halophytes with different geographic distribution patterns, during seed germination and early vegetative growth. The aims of the work were twofold: to establish the basis for the different chorology of these species, and to identify relevant mechanisms of salt tolerance dependent on the control of ion transport and osmolyte accumulation. Seeds were germinated in vitro, in the presence of increasing NaCl concentrations, and subjected to “recovery of germination” tests; germination percentages and velocity were determined to establish the relative tolerance and competitiveness of the four Limonium taxa. Salt treatments were also applied to young plants, by 1-month irrigation with NaCl up to 800 mM; then, growth parameters, levels of monovalent and divalent ions (in roots and leaves, and leaf contents of photosynthetic pigments and common osmolytes were determined in control and stressed plants of the four species. Seed germination is the most salt-sensitive developmental phase in Limonium. The different germination behavior of the investigated species appears to be responsible for their geographical range size: L. narbonense and L. virgatum, widespread throughout the Mediterranean, are the most tolerant and the most competitive at higher soil salinities; the endemic L. santapolense and L. girardianum are the most sensitive and more competitive only at lower salinities. During early vegetative growth, all taxa showed a strong tolerance to salt stress, although slightly higher in L. virgatum and L. santapolense. Salt tolerance is based on the efficient transport of Na+ and Cl− to the leaves and on the accumulation of fructose and proline for osmotic adjustment. Despite some species-specific quantitative differences, the accumulation patterns of the different ions were similar in all species, not explaining differences in tolerance, except for the

  15. Metabolic variation in rice cultivars of contrasting salt tolerance and its improvement by zinc in sodic soil.

    Science.gov (United States)

    Singh, H P; Singh, T N

    2006-07-01

    The severity of Zn deficiency increased with increase in soil exchangeable sodium percentage (ESP) with salt sensitive variety M1-48 scoring 6 at ESP 62 as against only score 3 by salt tolerant variety Pokkali under similar soil conditions. Strikingly, zinc contents were much higher in salt tolerant variety than in salt sensitive one. Zinc application increased zinc concentration in the roots by a factor of 2.85 to 3.87 in Pokkali whereas it rose from 2.37 to 4.35 times in M1-48 depending upon ESP but in the leaves it registered increase of 1.5 to 1.8 times only. In general, the concentrations of reducing sugar were less (about 2.2%) than that of non-reducing (about 3.8%) in both the varieties under normal soil conditions. However, the concentration of reducing sugar doubled (4.2-4.4%) at the highest ESP 62, whereas the concentration of non-reducing sugar though increased (4.1 to 5.1%) but not as vigorously as reducing one. Zinc application reduced the concentration of reducing sugar but not that of non-reducing at similar ESP values. In Pokkali, the concentrations of total sugar increased from 6% at ESP 20 to 9.34% at ESP 62, whereas it registered enhancements of 5.98 to 8.6% in M1-48 under similar conditions. The nitrate reductase (NR) activity decreased with increase in soil sodicity however, the varietal differences in NR activity were wider under Zn-stress than under conditions of applied zinc with Pokkali registering higher NR activities. Carbonic anhydrase activities were higher in salt tolerant variety. Inhibition in carbonic anhydrase activity amounted to 23 and 45% in salt-sensitive variely M1-48 whereas only 19 and 33% in salt-tolerant variety Pokkali at ESP 41 and 62, respectively. The effects of zinc application at higher soil sodicity were more obvious in salt-sensitive variety than in salt-tolerant one. The findings suggest that the tolerance to Zn stress runs parallel to salt tolerance abilities of rice varieties.

  16. Identification and Selection for Salt Tolerance in Alfalfa (Medicago sativa L. Ecotypes via Physiological Traits

    Directory of Open Access Journals (Sweden)

    Hassan MONIRIFAR

    2009-12-01

    Full Text Available Salt stress is a serious environmental problem throughout the world which may be partially relieved by breeding cultivars that can tolerate salt stress. Plant breeding may provide a relatively cost effective short-term solution to the salinity problem by producing cultivars able to remain productive at low to moderate levels of salinity. Five alfalfa cultivars, �Seyah-Roud�, �Ahar-Hourand�, �Oskou�, �Malekan� and �Sefida-Khan� were assessed for salt tolerance at mature plant stage. A greenhouse screening system was used to evaluate individual alfalfa plants grown in perlit medium, and irrigated with water containing different amounts of NaCl. Three salt levels were achieved by adding 0, 100 and 200 mM NaCl to Hoagland nutrient solution, respectively. Forage yield, sodium and potassium contents and K/Na ratio was determined. Also, leaf samples were analyzed for proline and chlorophyll contents. The ecotypes Seyha-Roud and �Sefida-Khan� had comparatively less sodium contents than �Oskou�, �Ahar-Hourand� and �Malekan� ecotypes, also potassium content increased under saline condition. Forage yield of different alfalfa ecotypes was significantly influenced by the salinity. The ecotypes �Malekan�, Ahar- Hourand and �Oskou� were successful in maintaining forage yield under salinity stress. Sodium contents increased due to salinity in all alfalfa ecotypes however ecotypes �Ahar-Hourand� and �Malekan� maintained the highest leaf Na concentration. They showed higher content of K than other ecotypes but had lower K/Na ratio. It was concluded that, two ecotypes �Malekan� and �Ahar-Hourand� were better.

  17. The Expression of Millettia pinnata Chalcone Isomerase in Saccharomyces cerevisiae Salt-Sensitive Mutants Enhances Salt-Tolerance

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    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.

  18. Salinity tolerance of 'Valencia' orange trees on rootstocks with contrasting salt tolerance is not improved by moderate shade.

    Science.gov (United States)

    García-Sánchez, F; Syvertsen, J P; Martínez, V; Melgar, J C

    2006-01-01

    The effects of shading in combination with salinity treatments were studied in citrus trees on two rootstocks with contrasting salt tolerance to determine if shading could reduce the negative effects of salinity stress. Well-nourished 2-year-old 'Valencia' orange trees grafted on Cleopatra mandarin (Cleo, relatively salt tolerant) or Carrizo citrange (Carr, relatively salt sensitive), were grown either under a 50% shade cloth or left unshaded in full sunlight. Half the trees received no salinity treatment and half were salinized with 50 mM Cl- during two 9 week salinity periods in the spring and autumn interrupted by an 11 week rainy period. The shade treatment reduced midday leaf temperature and leaf-to-air vapour pressure deficit regardless of salinity treatments. In non-salinized trees, shade increased midday CO2 assimilation rate (A(CO2)) and stomatal conductance, but had no effect on leaf transpiration (E(lf)). Shade also increased leaf chlorophyll and photosynthetic water use efficiency (A(CO2)/E(lf)) in leaves on both rootstocks and increased total plant dry weight in Cleo. The salinity treatment reduced leaf growth and leaf gas exchange parameters. Shade decreased Cl- concentrations in leaves of salinized Carr trees, but had no effect on leaf or root Cl- of trees on Cleo. There were no significant differences in leaf gas exchange parameters of shaded and unshaded salinized plants but the growth reduction from salinity stress was actually greater for shaded than for unshaded trees. Shaded trees on both rootstocks had higher leaf Na+ than unshaded trees after the first salinity period, and this shade-induced elevated leaf Na+ persisted after the second salinity period in trees on Carr. Thus, shading did not alleviate the negative effects of salinity on growth and Na+ accumulation.

  19. Inhibition of ethylene synthesis reduces salt-tolerance in tomato wild relative species Solanum chilense.

    Science.gov (United States)

    Gharbi, Emna; Martínez, Juan-Pablo; Benahmed, Hela; Lepoint, Gilles; Vanpee, Brigitte; Quinet, Muriel; Lutts, Stanley

    2017-03-01

    Exposure to salinity induces a burst in ethylene synthesis in the wild tomato halophyte plant species Solanum chilense. In order to gain information on the role of ethylene in salt adaptation, plants of Solanum chilense (accession LA4107) and of cultivated glycophyte Solanum lycopersicum (cv. Ailsa Craig) were cultivated for 7days in nutrient solution containing 0 or 125mM NaCl in the presence or absence of the inhibitor of ethylene synthesis (aminovinylglycine (AVG) 2μM). Salt-induced ethylene synthesis in S. chilense occurred concomitantly with an increase in stomatal conductance, an efficient osmotic adjustment and the maintenance of carbon isotope discrimination value (Δ13C). In contrast, in S. lycopersicum, salt stress decreased stomatal conductance and Δ13C values while osmotic potential remained higher than in S. chilense. Inhibition of stress-induced ethylene synthesis by AVG decreased stomatal conductance and Δ13C in S. chilense and compromised osmotic adjustment. Solanum chilense behaved as an includer and accumulated high amounts of Na in the shoot but remained able to maintain K nutrition in the presence of NaCl. This species however did not stimulate the expression of genes coding for high-affinity K transport but genes coding for ethylene responsive factor ERF5 and JREF1 were constitutively more expressed in S. chilense than in S. lycopersicum. It is concluded that ethylene plays a key role in salt tolerance of S. chilense. Copyright © 2016. Published by Elsevier GmbH.

  20. Integrating role of ethylene and ABA in tomato plants adaptation to salt stress

    DEFF Research Database (Denmark)

    Amjad, Muhammad; Akhtar, Javaid; Anwar-ul-Haq, Muhammad

    2014-01-01

    Saline stress seriously disrupts the growth and physiology of plants, whereas phytohormones play an important role in regulating plant responses to salinity stress. The involvement of phytohormones in salt tolerance of tomato and the interaction between potassium and phytohormones was studied...... the negative impact of salinity stress and thus increased the hormone concentration. Enhanced concentration of hormones in salt-tolerant genotype positively affected plant physiology and thus better chlorophyll content index (CCI), stomatal conductance and ion homeostasis that is higher K+/Na+ ratio...... concentrations of ABA and ethylene under saline conditions compared to control (0mM NaCl) and salt-sensitive genotype. The concentration of hormones was significantly higher in the treatment where no K was applied and it was lower in treatments where K was applied indicating that K application reduced...

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

    Science.gov (United States)

    Wang, Shiwen; Liu, Peng; Chen, Daoqian; Yin, Lina; Li, Hongbing; Deng, Xiping

    2015-01-01

    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 2 weeks were exposed to 65 mM NaCl solution for another 1 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. PMID:26442072

  2. Breeding vegetables tolerant to environmental stress

    Energy Technology Data Exchange (ETDEWEB)

    Stoner, A.K.

    1978-12-01

    Much progress has been made in breeding vegetables tolerant to environmental stresses. However, in many cases the authors have only begun to exploit the potential of germplasm collections. Progress in breeding for stress tolerance will probably always be slow, but it can be maximized by improved support and better cooperation within and outside organizations. Better cooperation is needed among breeders and scientists of other disciplines and among breeders from different organizations. Vegetable breeders must also be willing to tackle and follow through on difficult problems. Many of the easier breeding problems have been solved. In instances where breeders are discouraged from working on difficult problems, the system needs to be changed to encourage and reward breeders. More effort must be devoted to developing stress tolerant vegetable cultivars if the US vegetable industry is to continue to meet consumer demands for reasonable priced, high-quality vegetables.

  3. Relative contribution of Na+/K+homeostasis, photochemical efficiency and antioxidant defense system to differential salt tolerance in cotton (Gossypium hirsutum L.) cultivars.

    Science.gov (United States)

    Wang, Ning; Qiao, Wenqing; Liu, Xiaohong; Shi, Jianbin; Xu, Qinghua; Zhou, Hong; Yan, Gentu; Huang, Qun

    2017-10-01

    In this study, the role of specific components of different coping strategies to salt load were identified. A pot experiment was conducted with four cotton (Gossypium hirsutum L.) cultivars (differing in salt-sensitivity) under salinity stress. Based on observed responses in growth performance and physiological characteristics, CZ91 was the most tolerant of the four cultivars, followed by cultivars CCRI44 and CCRI49, with Z571 being much more sensitive to salt stress. To perform this tolerant response, they implement different adaptative mechanisms to cope with salt-stress. The superior salt tolerance of CZ91 was conferred by at least three complementary physiological mechanisms: its ability to regulate K + and Na + transport more effectively, its higher photochemical efficiency and better antioxidant defense capacity. However, only one or a few specific components of these defense systems play crucial roles in moderately salt tolerant CCRI44 and CCRI49. Lower ROS load in CCRI44 may be attributed to simultaneous induction of antioxidant defenses by maintaining an unusually high level of SOD, and higher activities of CAT, APX, and POD during salt stress. CCRI49 could reduce the excess generation of ROS not only by maintaining a higher selective absorption of K + over Na + in roots across the membranes through SOS1, AKT1, and HAK5, but also by displaying higher excess-energy dissipation (e.g., higher ETR, P R and qN) during salt stress. Overall, our data provide a mechanistic explanation for differential salt stress tolerance among these cultivars and shed light on the different strategies employed by cotton cultivars to minimize the ill effects of stress. Copyright © 2017. Published by Elsevier Masson SAS.

  4. Salt tolerance is evolutionarily labile in a diverse set of angiosperm families.

    Science.gov (United States)

    Moray, Camile; Hua, Xia; Bromham, Lindell

    2015-05-19

    Salt tolerance in plants is rare, yet it is found across a diverse set of taxonomic groups. This suggests that, although salt tolerance often involves a set of complex traits, it has evolved many times independently in different angiosperm lineages. However, the pattern of evolution of salt tolerance can vary dramatically between families. A recent phylogenetic study of the Chenopodiaceae (goosefoot family) concluded that salt tolerance has a conserved evolutionary pattern, being gained early in the evolution of the lineage then retained by most species in the family. Conversely, a phylogenetic study of the Poaceae (grass family) suggested over 70 independent gains of salt tolerance, most giving rise to only one or a few salt tolerant species. Here, we use a phylogenetic approach to explore the macroevolutionary patterns of salt tolerance in a sample of angiosperm families, in order to ask whether either of these two patterns - deep and conserved or shallow and labile - represents a common mode of salt tolerance evolution. We analyze the distribution of halophyte species across the angiosperms and identify families with more or less halophytes than expected under a random model. Then, we explore the phylogenetic distribution of halophytes in 22 families using phylogenetic comparative methods. We find that salt tolerance species have been reported from over one-third of angiosperm families, but that salt tolerant species are not distributed evenly across angiosperm families. We find that salt tolerance has been gained hundreds of times over the history of the angiosperms. In a few families, we find deep and conserved gains of salt tolerance, but in the majority of families analyzed, we find that the pattern of salt tolerant species is best explained by multiple independent gains that occur near the tips of the phylogeny and often give rise to only one or a few halophytes. Our results suggest that the pattern of many independent gains of salt tolerance near the tips

  5. 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.

  6. Comparing salt tolerance of beet cultivars and their halophytic ancestor: consequences of domestication and breeding programs

    NARCIS (Netherlands)

    Rozema, J.; Cornelisse, D.; Zhang, Y.; Li, H.; Bruning, B.; Katschnig, D.; Broekman, R.A.; Ji, B.; van Bodegom, P.M.

    2015-01-01

    Salt tolerance of higher plants is determined by a complex set of traits, the timing and rate of evolution of which are largely unknown. We compared the salt tolerance of cultivars of sugar beet and their ancestor, sea beet, in hydroponic studies and evaluated whether traditional domestication and

  7. Salt tolerance analysis of chickpea, faba bean and durum wheat varieties. II. Durum wheat

    NARCIS (Netherlands)

    Katerji, N.; Hoorn, van J.W.; Hamdy, A.; Mastrorilli, M.; Nachit, M.M.; Oweis, T.

    2005-01-01

    Seven varieties of durum wheat (Triticum turgidum), provided by ICARDA, were tested in a greenhouse experiment for their salt tolerance. Afterwards two varieties, differing in salt tolerance, were irrigated with waters of three different salinity levels in a lysimeter experiment to analyse their

  8. Improvement of salt tolerance in transgenic potato plants by glyceraldehyde-3 phosphate dehydrogenase gene transfer.

    Science.gov (United States)

    Jeong, M J; Park, S C; Byun, M O

    2001-10-31

    In the previous experiment, we isolated and characterized glyceraldehyde-3-phosphate dehydrogenase (GPD) gene of the oyster mushroom, Pleurotus sajor-caju. Expression levels of the GPD gene in the mycelia of P sajor-caju was significantly increased by exposing the mycelia to abiotic stresses, such as salt, cold, heat, and drought. We also showed that GPD confers abiotic stress resistance when introduced into yeast cells. The survival rate of the transgenic yeast cell that harbored the GPD gene was significantly higher when the yeast cells were subjected to salt, cold, heat, and drought stresses, compared with the yeast that was transformed with the pYES2 vector alone. In order to investigate the functional role of the P. sajor-caju GPD gene in higher plant cells, the complete P. sajor-caju GPD cDNA was fused into the CaMV35S promoter and then introduced into potato plants. Putative potato transformants were screened by using PCR. Twenty-one transformants were further analyzed with RT-PCR to confirm the expression of P. sajor-caju GPD. A RT-PCR Southern blot analysis revealed that 12 transgenics induced the P. sajor-caju GPD gene expression. A bioassay of these transformants revealed that the P. sajor-caju GPD gene was enough to confer salt stress resistance in the potato plant cell system. Results showed that P. sajor-caju GPD, which was continuously expressed in transgenic potato plants under normal growing conditions, resulted in improved tolerance against salt loading.

  9. Salt tolerance traits increase the invasive success of Acacia longifolia in Portuguese coastal dunes.

    Science.gov (United States)

    Morais, Maria Cristina; Panuccio, Maria Rosaria; Muscolo, Adele; Freitas, Helena

    2012-06-01

    Salt tolerance of two co-occurring legumes in coastal areas of Portugal, a native species--Ulex europaeus, and an invasive species--Acacia longifolia, was evaluated in relation to plant growth, ion content and antioxidant enzyme activities. Plants were submitted to four concentrations of NaCl (0, 50, 100 and 200 mM) for three months, under controlled conditions. The results showed that NaCl affects the growth of both species in different ways. Salt stress significantly reduced the plant height and the dry weight in Acacia longifolia whereas in U. europaeus the effect was not significant. Under salt stress, the root:shoot ratio (W(R):W(S)) and root mass ratio (W(R):W(RS)) increased as a result of increasing salinity in A. longifolia but the same was not observed in U. europaeus. In addition, salt stress caused a significant accumulation of Na+, especially in U. europaeus, and a decrease in K+ content and K+/Na+ ratio. The activities of antioxidant enzymes were higher in A. longifolia compared to U. europaeus. In A. longifolia, catalase (CAT, EC 1.11.1.6) and glutathione reductase (GR, EC 1.6.4.2.) activities increased significantly, while ascorbate peroxidase (APX, EC 1.11.1.11) and peroxidase (POX, EC 1.11.1.7) activities remained unchanged in comparison with the control. In U. europaeus, NaCl concentration significantly reduced APX activity but did not significantly affect CAT, GR and POX activities. Our results suggest that the invasive species copes better with salinity stress in part due to a higher rates of CAT and GR activities and a higher K+/Na+ ratio, which may represent an additional advantage when competing with native species in co-occurring salty habitats. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  10. Anastatica hierochuntica, an Arabidopsis Desert Relative, Is Tolerant to Multiple Abiotic Stresses and Exhibits Species-Specific and Common Stress Tolerance Strategies with Its Halophytic Relative, Eutrema (Thellungiella) salsugineum

    Science.gov (United States)

    Eshel, Gil; Shaked, Ruth; Kazachkova, Yana; Khan, Asif; Eppel, Amir; Cisneros, Aroldo; Acuna, Tania; Gutterman, Yitzhak; Tel-Zur, Noemi; Rachmilevitch, Shimon; Fait, Aaron; Barak, Simon

    2017-01-01

    The search for novel stress tolerance determinants has led to increasing interest in plants native to extreme environments – so called “extremophytes.” One successful strategy has been comparative studies between Arabidopsis thaliana and extremophyte Brassicaceae relatives such as the halophyte Eutrema salsugineum located in areas including cold, salty coastal regions of China. Here, we investigate stress tolerance in the desert species, Anastatica hierochuntica (True Rose of Jericho), a member of the poorly investigated lineage III Brassicaceae. We show that A. hierochuntica has a genome approximately 4.5-fold larger than Arabidopsis, divided into 22 diploid chromosomes, and demonstrate that A. hierochuntica exhibits tolerance to heat, low N and salt stresses that are characteristic of its habitat. Taking salt tolerance as a case study, we show that A. hierochuntica shares common salt tolerance mechanisms with E. salsugineum such as tight control of shoot Na+ accumulation and resilient photochemistry features. Furthermore, metabolic profiling of E. salsugineum and A. hierochuntica shoots demonstrates that the extremophytes exhibit both species-specific and common metabolic strategies to cope with salt stress including constitutive up-regulation (under control and salt stress conditions) of ascorbate and dehydroascorbate, two metabolites involved in ROS scavenging. Accordingly, A. hierochuntica displays tolerance to methyl viologen-induced oxidative stress suggesting that a highly active antioxidant system is essential to cope with multiple abiotic stresses. We suggest that A. hierochuntica presents an excellent extremophyte Arabidopsis relative model system for understanding plant survival in harsh desert conditions. PMID:28144244

  11. Isolation and functional characterization of salt-stress induced RCI2-like genes from Medicago sativa and Medicago truncatula.

    Science.gov (United States)

    Long, Ruicai; Zhang, Fan; Li, Zhenyi; Li, Mingna; Cong, Lili; Kang, Junmei; Zhang, Tiejun; Zhao, Zhongxiang; Sun, Yan; Yang, Qingchuan

    2015-07-01

    Salt stress is one of the most significant adverse abiotic factors, causing crop failure worldwide. So far, a number of salt stress-induced genes, and genes improving salt tolerance have been characterized in a range of plants. Here, we report the isolation and characterization of a salt stress-induced Medicago sativa (alfalfa) gene (MsRCI2A), which showed a high similarity to the yeast plasma membrane protein 3 gene (PMP3) and Arabidopsis RCI2A. The sequence comparisons revealed that five genes of MtRCI2(A-E) showed a high similarity to MsRCI2A in the Medicago truncatula genome. MsRCI2A and MtRCI2(A-E) encode small, highly hydrophobic proteins containing two putative transmembrane domains, predominantly localized in the plasma membrane. The transcript analysis results suggest that MsRCI2A and MtRCI2(A-D) genes are highly induced by salt stress. The expression of MsRCI2A and MtRCI2(A-C) in yeast mutants lacking the PMP3 gene can functionally complement the salt sensitivity phenotype resulting from PMP3 deletion. Overexpression of MsRCI2A in Arabidopsis plants showed improved salt tolerance suggesting the important role of MsRCI2A in salt stress tolerance in alfalfa.

  12. Plant glutathione transferase-mediated stress tolerance

    NARCIS (Netherlands)

    Nianiou-Obeidat, Irini; Madesis, Panagiotis; Kissoudis, Christos; Voulgari, Georgia; Chronopoulou, Evangelia; Tsaftaris, Athanasios; Labrou, Nikolaos E.

    2017-01-01

    Plant glutathione transferases (EC 2.5.1.18, GSTs) are an ancient, multimember and diverse enzyme class. Plant GSTs have diverse roles in plant development, endogenous metabolism, stress tolerance, and xenobiotic detoxification. Their study embodies both fundamental aspects and agricultural

  13. Thinopyrum ponticum Chromatin-Integrated Wheat Genome Shows Salt-Tolerance at Germination Stage

    OpenAIRE

    Wen-Ye Yuan; Motonori Tomita

    2015-01-01

    A wild wheatgrass, Thinopyrum ponticum (2n = 10x = 70), which exhibits substantially higher levels of salt tolerance than cultivated wheat, was employed to transfer its salt tolerance to common wheat by means of wide hybridization. A highly salt-tolerant wheat line S148 (2n = 42) was obtained from the BC3F2 progenies between Triticum aestivum (2n = 42) and Th. ponticum. In the cross of S148 × salt-sensitive wheat variety Chinese Spring, the BC4F2 seeds at germination stage segregated into a ...

  14. Poaceae vs. Abiotic Stress: Focus on Drought and Salt Stress, Recent Insights and Perspectives

    Directory of Open Access Journals (Sweden)

    Simone Landi

    2017-07-01

    Full Text Available Poaceae represent the most important group of crops susceptible to abiotic stress. This large family of monocotyledonous plants, commonly known as grasses, counts several important cultivated species, namely wheat (Triticum aestivum, rice (Oryza sativa, maize (Zea mays, and barley (Hordeum vulgare. These crops, notably, show different behaviors under abiotic stress conditions: wheat and rice are considered sensitive, showing serious yield reduction upon water scarcity and soil salinity, while barley presents a natural drought and salt tolerance. During the green revolution (1940–1960, cereal breeding was very successful in developing high-yield crops varieties; however, these cultivars were maximized for highest yield under optimal conditions, and did not present suitable traits for tolerance under unfavorable conditions. The improvement of crop abiotic stress tolerance requires a deep knowledge of the phenomena underlying tolerance, to devise novel approaches and decipher the key components of agricultural production systems. Approaches to improve food production combining both enhanced water use efficiency (WUE and acceptable yields are critical to create a sustainable agriculture in the future. This paper analyzes the latest results on abiotic stress tolerance in Poaceae. In particular, the focus will be directed toward various aspects of water deprivation and salinity response efficiency in Poaceae. Aspects related to cell wall metabolism will be covered, given the importance of the plant cell wall in sensing environmental constraints and in mediating a response; the role of silicon (Si, an important element for monocots' normal growth and development, will also be discussed, since it activates a broad-spectrum response to different exogenous stresses. Perspectives valorizing studies on landraces conclude the survey, as they help identify key traits for breeding purposes.

  15. Proteome Analysis of Date Palm (Phoenix dactylifera L.) under Severe Drought and Salt Stress.

    Science.gov (United States)

    El Rabey, Haddad A; Al-Malki, Abdulrahman L; Abulnaja, Khalid O

    2016-01-01

    Date palm cultivars differently tolerate salinity and drought stress. This study was carried out to study the response of date palm to severe salinity and drought based on leaf proteome analysis. Eighteen-month-old date palm plants were subjected to severe salt (48 g/L NaCl) and drought (82.5 g/L PEG or no irrigation) conditions for one month. Using a protein 2D electrophoresis method, 55 protein spots were analyzed using mass spectrometry. ATP synthase CF1 alpha chains were significantly upregulated under all three stress conditions. Changes in the abundance of RubisCO activase and one of the RubisCO fragments were significant in the same spots only for salt stress and drought stress with no irrigation, and oxygen-evolving enhancer protein 2 was changed in different spots. Transketolase was significantly changed only in drought stress with PEG. The expression of salt and drought stress genes of the chosen protein spots was either overexpressed or downexpressed as revealed by the high or low protein abundance, respectively. In addition, all drought tolerance genes due to no irrigation were downregulated. In conclusion, the proteome analysis of date palm under salinity and drought conditions indicated that both salinity and drought tolerance genes were differentially expressed resulting in high or low protein abundance of the chosen protein spots as a result of exposure to drought and salinity stress condition.

  16. Tobacco OPBP1 Enhances Salt Tolerance and Disease Resistance of Transgenic Rice

    Directory of Open Access Journals (Sweden)

    Xujun Chen

    2008-12-01

    Full Text Available Osmotin promoter binding protein 1 (OPBP1, an AP2/ERF transcription factor of tobacco, has been demonstrated to function in disease resistance and salt tolerance in tobacco. To increase stress tolerant capability of rice, we generated rice plants with an OPBP1 overexpressing construct. Salinity shock treatment with 250 mM NaCl indicated that most of the OPBP1 transgenic plants can survive, whereas the control seedlings cannot. Similar recovery was found by using the seedlings grown in 200 mM NaCl for two weeks. The OPBP1 transgenic and control plants were also studied for oxidative stress tolerance by treatment with paraquat, showing the transgenic lines were damaged less in comparison with the control plants. Further, the OPBP1 overexpression lines exhibited enhanced resistance to infections of Magnaporthe oryzae and Rhizoctonia solani pathogens. Gene expressing analysis showed increase in mRNA accumulation of several stress related genes. These results suggest that expression of OPBP1 gene increase the detoxification capability of rice.

  17. The Effects of Cation Ratios on Root Lamella Suberization in Rice (Oryza sativa L. with Contrasting Salt Tolerance

    Directory of Open Access Journals (Sweden)

    M. R. Momayezi

    2012-01-01

    Full Text Available Rice is an important produced cereal in the world. We evaluated the effect of salt compositions including NaCl and Na2SO4 on suberin lamellae as a major barrier to radial ion and water movements in two rice genotypes representing contrasting salt tolerance levels under salinity stress. Two rice genotypes, Fajr as salt tolerant and Khazar as salt sensitive, were transplanted in sand culture under glasshouse condition. Rice seedlings were treated with five salt compositions including NaCl, Na2SO4, 1 : 1, 1 : 2, and 2 : 1 molar ratios for 40 days. It was proven that suberin lamellae in endodermis of root cell wall were thickened with Na2SO4 treatment. The results demonstrated that the number of passage cells was higher in Fajr genotype than that in Khazar genotype under saline condition. Calcium concentration in root tissue decreased as the SO42- concentration in root media increased. It can be concluded that Fajr genotype is able to keep some passage cells open to maintain Ca2+ uptake. The Ca2+/Na+ ratio in shoot tissue can be also a reliable index for the early recognition of salt stress in these rice genotypes.

  18. Effects of salt stress on micropropagation of potato (Solanum ...

    African Journals Online (AJOL)

    Jane

    2011-08-01

    Aug 1, 2011 ... African Journal of Biotechnology Vol. 10(40), pp. ... Plants of this cultivar had greater shoot length than other cultivars at all salt concentrations tested. The results indicated that cultivar "Bartina" is more salt tolerant than other cultivars studied. Key words: Potato .... Breeding for salinity resistance in crop. Plant ...

  19. Salt tolerance of a wild ecotype of vetiver grass (Vetiveria zizanioides L.) in southern China.

    Science.gov (United States)

    Liu, Wan-Gou; Liu, Jin-Xiang; Yao, Mei-Ling; Ma, Qi-Fu

    2016-12-01

    Vetiver grass (Vetiveria zizanioides L.) is widely used in more than 120 countries for land management (e.g. rehabilitation of saline lands). A wild ecotype of vetiver grass was found in southern China in the 1950s, but little is known about its adaptability to saline stress. For the purpose of understanding its tolerance to salinity as well as corresponding tolerance mechanisms, in a greenhouse with natural lighting, seedlings were grown in culture solutions and subjected to a range of NaCl concentrations for 18 days. Compared to no NaCl treatment, 200 mM NaCl significantly reduced leaf water potential, leaf water content, leaf elongation rate, leaf photosynthetic rate and plant relative growth rate and increased leaf malondialdehyde (MDA) content, but the parameters showed only slight reduction at 150 mM NaCl. In addition, salinity caused an increase in the activity of antioxidant enzymes in leaves. Moreover, increasing NaCl levels significantly increased Na+ but decreased K+ concentrations in both roots and leaves. The leaves had higher K+ concentrations at all NaCl levels, but lower Na+ concentrations compared to the roots, thereby maintaining higher K+/Na+ ratio in leaves. Our results showed that the salinity threshold of this wild vetiver grass is about 100 mM NaCl, i.e. highly tolerant to salt stress. This wild vetiver grass has a high ability to exclude Na+ and retain K+ in its leaves, which is a critical strategy for salt tolerance.

  20. Phosphate-dependent root system architecture responses to salt stress

    KAUST Repository

    Kawa, Dorota

    2016-05-20

    Nutrient availability and salinity of the soil affect growth and development of plant roots. Here, we describe how phosphate availability affects root system architecture (RSA) of Arabidopsis and how phosphate levels modulate responses of the root to salt stress. Phosphate (Pi) starvation reduced main root length and increased the number of lateral roots of Arabidopsis Col-0 seedlings. In combination with salt, low Pi dampened the inhibiting effect of mild salt stress (75mM) on all measured RSA components. At higher NaCl concentrations, the Pi deprivation response prevailed over the salt stress only for lateral root elongation. The Pi deprivation response of lateral roots appeared to be oppositely affected by abscisic acid (ABA) signaling compared to the salt stress response. Natural variation in the response to the combination treatment of salt and Pi starvation within 330 Arabidopsis accessions could be grouped into four response patterns. When exposed to double stress, in general lateral roots prioritized responses to salt, while the effect on main root traits was additive. Interestingly, these patterns were not identical for all accessions studied and multiple strategies to integrate the signals from Pi deprivation and salinity were identified. By Genome Wide Association Mapping (GWAS) 13 genomic loci were identified as putative factors integrating responses to salt stress and Pi starvation. From our experiments, we conclude that Pi starvation interferes with salt responses mainly at the level of lateral roots and that large natural variation exists in the available genetic repertoire of accessions to handle the combination of stresses.

  1. Comparative effects of neutral salt and alkaline salt stress on seed ...

    African Journals Online (AJOL)

    Comparative effects of neutral salt and alkaline salt stress on seed germination, early seedling growth and physiological response of a halophyte species Chenopodium glaucum. ... No obvious increase of osmolytes (proline, soluble sugar, betaine) was detected under lower concentration of NaCl and NaHCO3 stress.

  2. FTIR Spectroscopy of Protein Isolates of Salt-Tolerant Soybean Mutants

    Science.gov (United States)

    Akyuz, S.; Akyuz, T.; Celik, O.; Atak, C.

    2018-01-01

    The effect of salinity on the conformation of proteins of four salt-tolerant M2 generation mutants of soybean plants (S04-05/150-2, S04-05/150-8, S04-05/150-106, and S04-05/150-114) was investigated using Fourier transform infrared (FTIR) spectroscopy. Salinity is one of the important abiotic stress factors that limits growth and productivity of plants. The mutants belonging to the M2 generation were determined as tolerant to 90 mM NaCl. The relative contents of α-helix, β-sheet, turn, and irregular conformations for the soybean protein isolates were determined depending on the analysis of the amide I region. The comparison of the secondary structures of soybean proteins of the mutants with those of the control group indicated that the α-helix structure percentage was diminished while β-turn and disordered structures were increased as a result of the salt stress.

  3. The cyclic nucleotide-gated channel, AtCNGC10, influences salt tolerance in Arabidopsis.

    Science.gov (United States)

    Guo, Kun-Mei; Babourina, Olga; Christopher, David A; Borsics, Tamas; Rengel, Zed

    2008-11-01

    Cyclic nucleotide-gated channels (CNGCs) in the plasma membrane transport K+ and other cations; however, their roles in the response and adaptation of plants to environmental salinity are unclear. Growth, cation contents, salt tolerance and K+ fluxes were assessed in wild-type and two AtCNGC10 antisense lines (A2 and A3) of Arabidopsis thaliana (L.) Heynh. Compared with the wild-type, mature plants of both antisense lines had altered K+ and Na+ concentrations in shoots and were more sensitive to salt stress, as assessed by biomass and Chl fluorescence. The shoots of A2 and A3 plants contained higher Na+ concentrations and significantly higher Na+/K+ ratios compared with wild-type, whereas roots contained higher K+ concentrations and lower Na+/K+ ratios. Four-day-old seedlings of both antisense lines exposed to salt stress had smaller Na+/K+ ratios and longer roots than the wild-type. Under sudden salt treatment, the Na+ efflux was higher and the K+ efflux was smaller in the antisense lines, indicating that AtCNGC10 might function as a channel providing Na+ influx and K+ efflux at the root/soil interface. We conclude that the AtCNGC10 channel is involved in Na+ and K+ transport during cation uptake in roots and in long-distance transport, such as phloem loading and/or xylem retrieval. Mature A2 and A3 plants became more salt sensitive than wild-type plants because of impaired photosynthesis induced by a higher Na+ concentration in the leaves.

  4. Regulation of some salt defense-related genes in relation to physiological and biochemical changes in three sugarcane genotypes subjected to salt stress.

    Science.gov (United States)

    Poonsawat, Wasinee; Theerawitaya, Cattarin; Suwan, Therapatt; Mongkolsiriwatana, Chareerat; Samphumphuang, Thapanee; Cha-um, Suriyan; Kirdmanee, Chalermpol

    2015-01-01

    Sugarcane (Saccharum officinale L.; Poaceae) is a sugar-producing plant widely grown in tropic. Being a glycophytic species, it is very sensitive to salt stress, and salinity severely reduces growth rate and cane yield. The studies investigating the regulation of salt defense metabolite-related genes in relation to final biochemical products in both susceptible and tolerant genotypes of sugarcane are largely lacking. We therefore investigated the expression levels of sugarcane shaggy-like kinase (SuSK), sucrose transporter (SUT), proline biosynthesis (pyrolline-5-carboxylate synthetase; P5CS), ion homeostasis (NHX1), and catalase (CAT2) mRNAs, and contents of Na(+), soluble sugar, and free proline in three sugarcane genotypes (A19 mutant, K88-92, and K92-80) when subjected to salt stress (200 mM NaCl). The relative expression levels of salt defense-related genes in salt-stressed plantlets of sugarcane cv. K88-92 were upregulated in relation to salt exposure times when compared with glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as housekeeping gene. In addition, final biochemical products, i.e., low Na(+), sucrose enrichment, and free proline accumulation, were evidently demonstrated in salt-stressed plantlets. Chlorophyll b, total chlorophyll, total carotenoid concentrations, and maximum quantum yield of PSII (F v/F m) in positive check (K88-92) were maintained under salt stress, leading to high net photosynthetic rate (P n) and growth retention (root length, fresh weight, and leaf area). In contrast, photosynthetic abilities in negative check, K92-80, and A19 mutant lines grown under salt stress declined significantly in comparison to control, leading to a reduction in P n and an inhibition of overall growth characters. The study concludes that the genetic background of sugarcane cv. K88-92 may further be exploited to play a key role as parental clone for sugarcane breeding program for salt-tolerant purposes.

  5. Effect of salt stress on growth, inorganic ion and proline ...

    African Journals Online (AJOL)

    PRECIOUS

    2010-01-11

    Jan 11, 2010 ... 4Institute of Molecular Bio Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand. Accepted 26 March ... cultures of KDML105 rice were exposed to salt stress by placing on Murashige and Skoog (MS) medium ... Key word: Aromatic rice, osmoprotectant, callus culture, salt stress.

  6. Effect of salt stress on growth, inorganic ion and proline ...

    African Journals Online (AJOL)

    The inhibitory effect of salt stress in rice is complex and is one of the main reasons for reduction of plant growth and crop productivity. In the present study, the response of rice callus cultivar Khao Dawk Mali 105 (KDML105), commonly known as Thai jasmine rice, to salt stress was examined. Callus cultures of KDML105 rice ...

  7. Increased sensitivity to salt stress in tocopherol-deficient Arabidopsis mutants growing in a hydroponic system

    Science.gov (United States)

    Ellouzi, Hasna; Hamed, Karim Ben; Cela, Jana; Müller, Maren; Abdelly, Chedly; Munné-Bosch, Sergi

    2013-01-01

    Recent studies suggest that tocopherols could play physiological roles in salt tolerance but the mechanisms are still unknown. In this study, we analyzed changes in growth, mineral and oxidative status in vte1 and vte4 Arabidopsis thaliana mutants exposed to salt stress. vte1 and vte4 mutants lack α-tocopherol, but only the vte1 mutant is additionally deficient in γ-tocopherol. Results showed that a deficiency in vitamin E leads to reduced growth and increased oxidative stress in hydroponically-grown plants. This effect was observed at early stages, not only in rosettes but also in roots. The vte1 mutant was more sensitive to salt-induced oxidative stress than the wild type and the vte4 mutant. Salt sensitivity was associated with (i) high contents of Na+, (ii) reduced efficiency of PSII photochemistry (Fv/Fm ratio) and (iii) more pronounced oxidative stress as indicated by increased hydrogen peroxide and malondialdeyde levels. The vte 4 mutant, which accumulates γ- instead of α-tocopherol showed an intermediate sensitivity to salt stress between the wild type and the vte1 mutant. Contents of abscisic acid, jasmonic acid and the ethylene precursor, 1-aminocyclopropane-1-carboxylic acid were higher in the vte1 mutant than the vte4 mutant and wild type. It is concluded that vitamin E-deficient plants show an increased sensitivity to salt stress both in rosettes and roots, therefore indicating the positive role of tocopherols in stress tolerance, not only by minimizing oxidative stress, but also controlling Na+/K+ homeostasis and hormonal balance. PMID:23299430

  8. Manipulation of alternative oxidase can influence salt tolerance in Arabidopsis thaliana.

    Science.gov (United States)

    Smith, Chevaun Anne; Melino, Vanessa Jane; Sweetman, Crystal; Soole, Kathleen Lydia

    2009-12-01

    The growth and development of plants can be limited by environmental stresses such as salinity. It has been suggested that the non-phosphorylating alternative respiratory pathway in plants, mediated by the NAD(P)H dehydrogenase [NAD(P)H DH] and alternative oxidase (AOX), is important during environmental stresses. The involvement of this alternative pathway in a stress response may be linked to its capacity to uncouple carbon metabolism from adenylate control and/or the minimization of the formation of destructive reactive oxygen species (ROS). Salinity stress is a widespread, adverse environmental stress, which leads to an ionic imbalance, hyperosmotic stress and oxidative stress, the latter being the result of ROS formation. In this study, we show that salinity stress of Arabidopsis thaliana plants resulted in the formation of ROS, increased levels of Na+ in both the shoot and the root and an increase in transcription of Ataox1a, Atndb2 and Atndb4 genes, indicating the formation of an abridged non-phosphorylating electron transport chain in response to salinity stress. Furthermore, plants constitutively over-expressing Ataox1a, with increased AOX capacity, showed lower ROS formation, 30-40% improved growth rates and lower shoot Na+ content compared with controls, when grown under salinity stress conditions. Thus, more active AOX in roots and shoots can improve the salt tolerance of Arabidopsis as defined by its ability to grow more effectively in the presence of NaCl, and maintain lower shoot Na+ content. AOX does have an important role in stress adaptation in plants, and these results provide some validation of the hypothesis that AOX can play a critical role in cell re-programming under salinity stress.

  9. Identification of salt tolerant rice cultivars via phenotypic and marker-assisted procedures.

    Science.gov (United States)

    Bhowmik, Salil Kumar; Islam, Mirza Mofazzal; Emon, Reza Mohammad; Begum, Shamsun Nahar; Siddika, Aysha; Sultana, Sharmin

    2007-12-15

    Eleven genotypes, including the salt tolerant cultivar Pokkali as check, were used to evaluate salinity tolerance phenotypically and genotypically. Three selected SSR primers viz., RM7075, RM336 and RM253 were used to evaluate rice genotypes for salt tolerance. Two setups were maintained for this study viz., the seedling and reproductive stages. Phenotyping at the seedling stage was done in hydroponic system using salinized (EC 12 dS m(-1)) nutrient solution and at the reproductive stage using salinized tap water (EC 6 dS m(-1)). IRRI standard protocol was followed to evaluate salinity tolerance in rice. The genotypes having similar banding pattern with Pokkali were considered as tolerant. Phenotypically, three genotypes Pokkali, THDB and TNDB-100 and five genotypes RD-2586, TNDB-100, Dhol Kochuri, PNR-519 and Pokkali were identified as salt tolerant at the seedling and reproductive stages, respectively. These genotypes were also identified as salt tolerant genotypically (with markers). Through phenotypic and genotypic study, five genotypes viz., Pokkali, Dhol Kochuri, RD-2586, TNDB-100 and PNR-519 were identified as salt tolerant. Therefore, these microsatellite markers used in this study could be efficiently used for identification of salt tolerant rice varieties in marker-assisted breeding and quantitative trait loci analysis.

  10. Genome-Wide Association Study Reveals the Genetic Architecture Underlying Salt Tolerance-Related Traits in Rapeseed (Brassica napus L.)

    OpenAIRE

    Wan, Heping; Chen, Lunlin; Guo, Jianbin; Li, Qun; Wen, Jing; Yi, Bin; Ma, Chaozhi; Tu, Jinxing; Fu, Tingdong; Shen, Jinxiong

    2017-01-01

    Soil salinity is a serious threat to agriculture sustainability worldwide. Salt tolerance at the seedling stage is crucial for plant establishment and high yield in saline soils; however, little information is available on rapeseed (Brassica napus L.) salt tolerance. We evaluated salt tolerance in different rapeseed accessions and conducted a genome-wide association study (GWAS) to identify salt tolerance-related quantitative trait loci (QTL). A natural population comprising 368 B. napus cult...

  11. Comparative Analysis of the Chrysanthemum Leaf Transcript Profiling in Response to Salt Stress.

    Science.gov (United States)

    Wu, Yin-Huan; Wang, Tong; Wang, Ke; Liang, Qian-Yu; Bai, Zhen-Yu; Liu, Qing-Lin; Pan, Yuan-Zhi; Jiang, Bei-Bei; Zhang, Lei

    2016-01-01

    Salt stress has some remarkable influence on chrysanthemum growth and productivity. To understand the molecular mechanisms associated with salt stress and identify genes of potential importance in cultivated chrysanthemum, we carried out transcriptome sequencing of chrysanthemum. Two cDNA libraries were generated from the control and salt-treated samples (Sample_0510_control and Sample_0510_treat) of leaves. By using the Illumina Solexa RNA sequencing technology, 94 million high quality sequencing reads and 161,522 unigenes were generated and then we annotated unigenes through comparing these sequences to diverse protein databases. A total of 126,646 differentially expressed transcripts (DETs) were identified in leaf. Plant hormones, amino acid metabolism, photosynthesis and secondary metabolism were all changed under salt stress after the complete list of GO term and KEGG enrichment analysis. The hormone biosynthesis changing and oxidative hurt decreasing appeared to be significantly related to salt tolerance of chrysanthemum. Important protein kinases and major transcription factor families involved in abiotic stress were differentially expressed, such as MAPKs, CDPKs, MYB, WRKY, AP2 and HD-zip. In general, these results can help us to confirm the molecular regulation mechanism and also provide us a comprehensive resource of chrysanthemum under salt stress.

  12. Comparative Analysis of the Chrysanthemum Leaf Transcript Profiling in Response to Salt Stress.

    Directory of Open Access Journals (Sweden)

    Yin-Huan Wu

    Full Text Available Salt stress has some remarkable influence on chrysanthemum growth and productivity. To understand the molecular mechanisms associated with salt stress and identify genes of potential importance in cultivated chrysanthemum, we carried out transcriptome sequencing of chrysanthemum. Two cDNA libraries were generated from the control and salt-treated samples (Sample_0510_control and Sample_0510_treat of leaves. By using the Illumina Solexa RNA sequencing technology, 94 million high quality sequencing reads and 161,522 unigenes were generated and then we annotated unigenes through comparing these sequences to diverse protein databases. A total of 126,646 differentially expressed transcripts (DETs were identified in leaf. Plant hormones, amino acid metabolism, photosynthesis and secondary metabolism were all changed under salt stress after the complete list of GO term and KEGG enrichment analysis. The hormone biosynthesis changing and oxidative hurt decreasing appeared to be significantly related to salt tolerance of chrysanthemum. Important protein kinases and major transcription factor families involved in abiotic stress were differentially expressed, such as MAPKs, CDPKs, MYB, WRKY, AP2 and HD-zip. In general, these results can help us to confirm the molecular regulation mechanism and also provide us a comprehensive resource of chrysanthemum under salt stress.

  13. High salt and high pH tolerance of new isolated Rhizobium etli strains from Egyptian soils.

    Science.gov (United States)

    Shamseldin, Abdelaal; Werner, Dietrich

    2005-01-01

    Saline and alkaline soils are major problems contributing to the low productivity of common bean (Phaseolus vulgaris) in arid and semi-arid regions such as Egypt. Therefore our study was directed toward selecting strains more tolerant to these environmental stresses. Among seven Rhizobium etli strains isolated from Egyptian soils, we found a high degree of diversity. Strains EBRI 21 and EBRI 26 are highly tolerant to a salt concentration up to 4% NaCl. A positive correlation was found between the salt tolerance and the adaptation to alkaline pH (9). Strains EBRI 2 and EBRI 26 were adapted to elevated temperatures (42 degrees C). The minimum level of low pH for the majority of Rhizobium etli strains from Egypt was pH 4.7 while the Colombian strain Rhizobium tropici CIAT 899 survived well at pH 4. At 0.4% NaCl, the symbiotic efficiency of the salt-tolerant strain EBRI 26 was superior in cultivar Giza 6 compared with the salt-sensitive strain EBRI 2 (18.2 compared with 13.9 nM: C2H4 h(-1) mg(-1) nodule fresh weight). In the bean cultivar Saxa, nitrogen fixation was much more affected by high salt concentration (0.4% NaCl) than in the cultivar Giza 6 with both strains (3.9 and 3.8 nM: C2H4 h(-1) mg(-1) nodule fresh weight, respectively). In general, stress of alkalinity had a less detrimental effect on nodulation and N2 fixation than stress of salinity.

  14. Induction of salt tolerance and up-regulation of aquaporin genes in tropical corn by rhizobacterium Pantoea agglomerans.

    Science.gov (United States)

    Gond, S K; Torres, M S; Bergen, M S; Helsel, Z; White, J F

    2015-04-01

    Bacteria were isolated from surface disinfected seeds of eight modern corn types and an ancestor of corn, 'teosinte' and identified using 16S rDNA sequences. From each of the modern corn types we obtained Bacillus spp. (including, Bacillus amyloliquefaciens and Bacillus subtilis); while from teosinte we obtained only Pantoea agglomerans and Agrobacterium species. Of these bacteria, only P. agglomerans could actively grow under hypersaline conditions and increase salt tolerance of tropical corn seedlings. In laboratory and greenhouse experiments where plants were watered with a 0.2 mol l(-1) NaCl solution, P. agglomerans was found to enhance the capacity of tropical corn to grow compared to uninoculated controls. The total dry biomass was significantly higher in P. agglomerans-treated plants compared to controls under saline water. Gene expression analysis showed the up-regulation of the aquaporin gene family especially plasma membrane integral protein (ZmPIP) genes in P. agglomerans-treated plants. The plasma membrane integral protein type 2 (PIP2-1) gene in tropical corn seedlings was highly up-regulated by P. agglomerans treatment under salt stress conditions. Microscopic examination of P. agglomerans inoculated seedlings revealed that the bacterium colonized root meristems densely, and as roots developed, the bacterium became sparsely located in cell junctions. The enhancement of salt tolerance capacity in tropical corn, an important food crop, has the capacity to increase its cultivation area and yield in saline soils. The application of rhizobacteria to improve salt tolerance of tropical corn is ecofriendly and cost effective. We show that P. agglomerans isolated from teosinte (an ancestor of corn) induces salt tolerance in tropical corn and up-regulation of aquaporin genes. This study shows that microbes that increase salt tolerance may be used to enhance crop growth in saline soils. © 2014 The Society for Applied Microbiology.

  15. Differential Response of Two Scented Indica Rice (Oryza sativa Cultivars under Salt Stress

    Directory of Open Access Journals (Sweden)

    Sunita Danai-Tambhale

    2011-12-01

    Full Text Available Present report deals with the effect of varying (0 – 200 mM NaCl salt stress on two popular scented non-basmati type indica rice cultivars, namely Indrayani and Ambemohar on germination and growth and biochemical parameters. In the present investigation the effect of increasing salt stress was seen on germination, biomass production and biochemical parameters including total protein content, proline accumulation, starch content, polyphenols levels, and reducing and non-reducing sugars. Contrasting behavior was evidenced in both the cultivars in terms of germination rate and biomass production at seedling and early vegetative growth level. Salt stress-induced proline accumulation was observed in both the cultivars, however, with much higher extent of proline accumulation in Ambemohar than Indrayani. A salinity stress of 200 mM NaCl resulted into 305% higher proline content than the control plants of Ambemohar against 222% higher proline in Indrayani at the same stress level. Similarly protein content was also higher in Ambemohar than Indrayani at the highest stress level used in this study. Contrasting results were seen in terms of starch content amongst both the cultivars, where continuous decrease with increasing salt stress was observed in Indrayani, on the other hand, an increase in starch content was evident in Ambemohar under the influence of NaCl-induced salt stress. These finding clearly indicates the comparably higher salt tolerant nature of Ambemohar than Indrayani which might be attributed to higher proline, protein and starch content than Indrayani cultivar under salt stress.

  16. Transcriptome-based gene expression profiling identifies differentially expressed genes critical for salt stress response in radish (Raphanus sativus L.).

    Science.gov (United States)

    Sun, Xiaochuan; Xu, Liang; Wang, Yan; Luo, Xiaobo; Zhu, Xianwen; Kinuthia, Karanja Benard; Nie, Shanshan; Feng, Haiyang; Li, Chao; Liu, Liwang

    2016-02-01

    Transcriptome-based gene expression analysis identifies many critical salt-responsive genes in radish and facilitates further dissecting the molecular mechanism underlying salt stress response. Salt stress severely impacts plant growth and development. Radish, a moderately salt-sensitive vegetable crop, has been studied for decades towards the physiological and biochemical performances under salt stress. However, no systematic study on isolation and identification of genes involved in salt stress response has been performed in radish, and the molecular mechanism governing this process is still indistinct. Here, the RNA-Seq technique was applied to analyze the transcriptomic changes on radish roots treated with salt (200 mM NaCl) for 48 h in comparison with those cultured in normal condition. Totally 8709 differentially expressed genes (DEGs) including 3931 up- and 4778 down-regulated genes were identified. Functional annotation analysis indicated that many genes could be involved in several aspects of salt stress response including stress sensing and signal transduction, osmoregulation, ion homeostasis and ROS scavenging. The association analysis of salt-responsive genes and miRNAs exhibited that 36 miRNA-mRNA pairs had negative correlationship in expression trends. Reverse-transcription quantitative PCR (RT-qPCR) analysis revealed that the expression profiles of DEGs were in line with results from the RNA-Seq analysis. Furthermore, the putative model of DEGs and miRNA-mediated gene regulation was proposed to elucidate how radish sensed and responded to salt stress. This study represents the first comprehensive transcriptome-based gene expression profiling under salt stress in radish. The outcomes of this study could facilitate further dissecting the molecular mechanism underlying salt stress response and provide a valuable platform for further genetic improvement of salt tolerance in radish breeding programs.

  17. Streptomyces sp. strain PGPA39 alleviates salt stress and promotes growth of 'Micro Tom' tomato plants.

    Science.gov (United States)

    Palaniyandi, S A; Damodharan, K; Yang, S H; Suh, J W

    2014-09-01

    To identify an actinobacterial strain that can promote growth and alleviate salinity stress in tomato plants. Actinobacteria were isolated from agricultural soil and screened for ACC deaminase activity, production of indole acetic acid (IAA), solubilization of tricalcium phosphate and sodium chloride (NaCl) salinity tolerance. Among the several strains tested, one strain designated PGPA39 exhibited higher IAA production, and phosphate solubilization in addition to ACC deaminase activity, and tolerance to 1 mol l(-1) NaCl. Strain PGPA39 was identified as a Streptomyces strain based on 16S rDNA sequence and designated Streptomyces sp. strain PGPA39. It promoted the growth of Arabidopsis seedlings in vitro as evidenced by a significant increase in plant biomass and number of lateral roots. Salinity stress-alleviating activity of PGPA39 was evaluated using 'Micro Tom' tomato plants with 180 mmol l(-1) NaCl stress under gnotobiotic condition. A significant increase in plant biomass and chlorophyll content and a reduction in leaf proline content were observed in PGPA39-inoculated tomato plants under salt stress compared with control and salt-stressed noninoculated plants. Streptomyces sp. strain PGPA39 alleviated salt stress and promoted the growth of tomato plants. This study shows the potential of Streptomyces sp. strain PGPA39 in alleviating salinity stress in tomato plants and could be utilized for stress alleviation in crop plants under field conditions. © 2014 The Society for Applied Microbiology.

  18. Assessment of variation in antioxidative defense system in salt-treated pea (Pisum sativum) cultivars and its putative use as salinity tolerance markers.

    Science.gov (United States)

    Noreen, Zahra; Ashraf, Muhammad

    2009-11-01

    The present work describes whether the changes in the activities of antioxidant enzymes and the levels of some non-enzymatic antioxidants could be used as markers of salt tolerance in nine genetically diverse pea (Pisum sativum) cultivars. All cultivars were exposed to four levels of NaCl i.e., 0, 40, 80 and 120mM in sand culture. Plant fresh biomass, total phenolics, total soluble proteins, hydrogen peroxide (H(2)O(2)), malondialdehyde (MDA), superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in leaves while different forms of tocopherols (alpha-, gamma- and Delta-tocopherol) in fresh seed of salt-stressed and non-stressed plants were analyzed. On the basis of percent inhibition in shoot biomass at the highest salt level (120mM) cultivars 2001-35, 2001-55 and Climax were ranked as tolerant (percent inhibition less than 60%), 2001-20, 9800-5 and 9800-10 moderately tolerant (percent inhibition 60-70%), and 2001-40, 9200 and Tere 2 salt sensitive (percent inhibition more than 70%). Salt stress markedly enhanced the activities of SOD and POD, levels of total phenolics and gamma- and Delta-tocopherols, and decreased the total soluble proteins and CAT activity, while the internal levels of H(2)O(2) remained unaffected in all pea cultivars. Although salt-induced oxidative stress occurred in all pea cultivars, the response of salt-tolerant and salt-sensitive cultivars with respect to the generation of enzymatic and non-enzymatic metabolites measured in the present study was not consistent. Of different antioxidant enzymes and metabolites analyzed, only CAT activity was found to be a reliable marker of salt tolerance in the set of pea cultivars examined.

  19. Expression of heterologous transporters in Saccharomyces kudriavzevii: A strategy for improving yeast salt tolerance and fermentation performance.

    Science.gov (United States)

    Dibalova-Culakova, Hana; Alonso-Del-Real, Javier; Querol, Amparo; Sychrova, Hana

    2018-03-02

    S. kudriavzevii has potential for fermentations and other biotechnological applications, but is sensitive to many types of stress. We tried to increase its tolerance and performance via the expression of various transporters from different yeast species. Whereas the overexpression of Z. rouxii fructose uptake systems (ZrFfz1 and ZrFsy1) or a glycerol importer (ZrStl1) did not improve the ability of S. kudriavzevii to consume fructose and survive osmotic stress, the expression of alkali-metal-cation exporters (ScEna1, ScNha1, YlNha2) improved S. kudriavzevii salt tolerance, and that of ScNha1 also the fermentation performance. The level of improvement depended on the type and activity of the transporter suggesting that the natural sensitivity of S. kudriavzevii cells to salts is based on a non-optimal functioning of its own transporters. Copyright © 2018. Published by Elsevier B.V.

  20. Increased salt tolerance with overexpression of cation/proton antiporter 1 genes: a meta-analysis.

    Science.gov (United States)

    Ma, Yuan-Chun; Augé, Robert M; Dong, Chao; Cheng, Zong-Ming Max

    2017-02-01

    Cation/proton antiporter 1 (CPA1) genes encode cellular Na(+) /H(+) exchanger proteins, which act to adjust ionic balance. Overexpression of CPA1s can improve plant performance under salt stress. However, the diversified roles of the CPA1 family and the various parameters used in evaluating transgenic plants over-expressing CPA1s make it challenging to assess the complex functions of CPA1s and their physiological mechanisms in salt tolerance. Using meta-analysis, we determined how overexpression of CPA1s has influenced several plant characteristics involved in response and resilience to NaCl stress. We also evaluated experimental variables that favour or reduce CPA1 effects in transgenic plants. Viewed across studies, overexpression of CPA1s has increased the magnitude of 10 of the 19 plant characteristics examined, by 25% or more. Among the ten moderating variables, several had substantial impacts on the extent of CPA1 influence: type of culture media, donor and recipient type and genus, and gene family. Genes from monocotyledonous plants stimulated root K(+) , root K(+) /Na(+) , total chlorophyll, total dry weight and root length much more than genes from dicotyledonous species. Genes transformed to or from Arabidopsis have led to smaller CPA1-induced increases in plant characteristics than genes transferred to or from other genera. Heterogeneous expression of CPA1s led to greater increases in leaf chlorophyll and root length than homologous expression. These findings should help guide future investigations into the function of CPA1s in plant salt tolerance and the use of genetic engineering for breeding of resistance. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  1. 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.

  2. 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.

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

    Science.gov (United States)

    Habib, Sheikh Hasna; Kausar, Hossain; Saud, Halimi Mohd

    2016-01-01

    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.

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

    OpenAIRE

    Wang, Shiwen; Liu, Peng; Chen, Daoqian; Yin, Lina; Li, Hongbing; Deng, Xiping

    2015-01-01

    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 2 weeks were exposed to 65 mM NaCl solution for another 1 week. The dry weight and shoot/root ratio were reduced by salt stress, but silicon application significantly alleviated these decreases. The chlorophyll concentration, net...

  5. Assimilation and Translocation of Dry Matter and Phosphorus in Rice Genotypes Affected by Salt-Alkaline Stress

    Directory of Open Access Journals (Sweden)

    Zhijie Tian

    2016-06-01

    Full Text Available Salt-alkaline stress generally leads to soil compaction and fertility decline. It also restricts rice growth and phosphorus acquisition. In this pot experiment, two relatively salt-alkaline tolerant (Dongdao-4 and Changbai-9 and sensitive (Changbai-25 and Tongyu-315 rice genotypes were planted in sandy (control and salt-alkaline soil to evaluate the characteristics of dry matter and phosphorus assimilation and translocation in rice. The results showed that dry matter and phosphorus assimilation in rice greatly decreased under salt-alkaline stress as the plants grew. The translocation and contribution of dry matter and phosphorus to the grains also increased markedly; different performances were observed between genotypes under salt-alkaline stress. D4 and C9 showed higher dry matter translocation, translocation efficiency and contribution of dry matter assimilation to panicles than those of C25 and T315. These changes in D4 and C9 indexes occurred at low levels of salt-alkaline treatment. Higher phosphorus acquisition efficiency of D4 and C9 were also found under salt-alkaline conditions. Additionally, the phosphorus translocation significantly decreased in C25 and T315 in the stress treatment. In conclusion, the results indicated that salt-alkaline-tolerant rice genotypes may have stronger abilities to assimilate and transfer biomass and phosphorus than sensitive genotypes, especially in salt-alkaline conditions.

  6. Proteomic analysis of seedling roots of two maize inbred lines that differ significantly in the salt stress response.

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    Dezhou Cui

    Full Text Available Salinity is a major abiotic stress that limits plant productivity and quality throughout the world. Roots are the sites of salt uptake. To better understand salt stress responses in maize, we performed a comparative proteomic analysis of seedling roots from the salt-tolerant genotype F63 and the salt-sensitive genotype F35 under 160 mM NaCl treatment for 2 days. Under salinity conditions, the shoot fresh weight and relative water content were significantly higher in F63 than in F35, while the osmotic potential was significantly lower and the reduction of the K+/Na+ ratio was significantly less pronounced in F63 than in F35. Using an iTRAQ approach, twenty-eight proteins showed more than 2.0- fold changes in abundance and were regarded as salt-responsive proteins. Among them, twenty-two were specifically regulated in F63 but remained constant in F35. These proteins were mainly involved in signal processing, water conservation, protein synthesis and biotic cross-tolerance, and could be the major contributors to the tolerant genotype of F63. Functional analysis of a salt-responsive protein was performed in yeast as a case study to confirm the salt-related functions of detected proteins. Taken together, the results of this study may be helpful for further elucidating salt tolerance mechanisms in maize.

  7. Genetic Adaptation to Salt Stress in Experimental Evolution of Desulfovibrio vulgaris Hildenborough

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Aifen; Hillesland, Kristina; He, Zhili; Joachimiak, Marcin; Zane, Grant; Dehal, Paramvir; Arkin, Adam; Stahl, David; Wall, Judy; Hazen, Terry; Zhou, Jizhong; Baidoo, Edward; Benke, Peter; Mukhopadhyay, Aindrila

    2010-05-17

    High salinity is one of the most common environmental stressors. In order to understand how environmental organisms adapt to salty environment, an experiment evolution with sulfate reducing bacteria Desulfovibrio vugaris Hildenborough was conducted. Control lines and salt-stressed lines (6 lines each) grown in minimal medium LS4D or LS4D + 100 mM NaCl were transferred for 1200 generations. The salt tolerance was tested with LS4D supplemented with 250 mM NaCl. Statistical analysis of the growth data suggested that all lines adapted to their evolutionary environment. In addition, the control lines performed better than the ancestor with faster growth rate, higher biomass yield and shorter lag phase under salty environment they did not evolve in. However, the salt-adapted lines performed better than the control lines on measures of growth rate and yield under salty environment, suggesting that the salt?evolved lines acquired mutations specific to having extra salt in LS4D. Growth data and gene transcription data suggested that populations tended to improve till 1000 generations and active mutations tended to be fixed at the stage of 1000 generations. Point mutations and insertion/deletions were identified in isolated colonies from salt-adapted and control lines via whole genome sequencing. Glu, Gln and Ala appears to be the major osmoprotectant in evolved salt-stressed line. Ongoing studies are now characterizing the contribution of specific mutations identified in the salt-evolved D. vulgaris.

  8. Plant growth-promoting bacteria Bacillus amyloliquefaciens NBRISN13 modulates gene expression profile of leaf and rhizosphere community in rice during salt stress.

    Science.gov (United States)

    Nautiyal, Chandra Shekhar; Srivastava, Suchi; Chauhan, Puneet Singh; Seem, Karishma; Mishra, Aradhana; Sopory, Sudhir Kumar

    2013-05-01

    Growth and productivity of rice and soil inhabiting microbial population is negatively affected by soil salinity. However, some salt resistant, rhizosphere competent bacteria improve plant health in saline stress. Present study evaluated the effect of salt tolerant Bacillus amyloliquefaciens NBRISN13 (SN13) inoculation on rice plants in hydroponic and soil conditions exposed to salinity. SN13 increased plant growth and salt tolerance (NaCl 200 mM) and expression of at least 14 genes under hydroponic and soil conditions in rice. Among these 14 genes 4 (NADP-Me2, EREBP, SOSI, BADH and SERK1) were up-regulated and 2 (GIG and SAPK4) repressed under salt stress in hydroponic condition. In greenhouse experiment, salt stress resulted in accumulation of MAPK5 and down-regulation of the remaining 13 transcripts was observed. SN13 treatment, with or without salt gave similar expression for all tested genes as compared to control. Salt stress caused changes in the microbial diversity of the rice rhizosphere and stimulated population of betaine-, sucrose-, trehalose-, and glutamine-utilizing bacteria in salt-treated rice rhizosphere (SN13 + salt). The observations imply that SN13 confers salt tolerance in rice by modulating differential transcription in a set of at least 14 genes. Stimulation of osmoprotectant utilizing microbial population as a mechanism of inducing salt tolerance in rice is reported for the first time in this study to the best of our knowledge. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  9. Molecular cloning and expression analysis of the MaASR1 gene in banana and functional characterization under salt stress

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    Hongxia Miao

    2014-11-01

    Conclusions: This study demonstrated that overexpression of MaASR1 in Arabidopsis confers salt stress tolerance by reducing the expression of ABA/stress-responsive genes, but does not affect the expression of the ABA-independent pathway and biosynthesis pathway genes.

  10. Tissue specific responses alter the biomass accumulation in wheat under gradual and sudden salt stress

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    Yumurtaci A.

    2012-11-01

    Full Text Available Salinity is one the major limiting environmental factors which has negative side effects on crop production. The purpose of this study was to investigate the differences between the gradual and sudden salt stress effects on biomass accumulation associated with whole plant development in three different tissues of two wheat species ( Triticum aestivum and Triticum durum under hydroponic conditions in the long term. Considering the effects of sudden and gradual stress for biomass accumulation, while importance of salinity x genotype interaction for fresh weights was 5%, association for salinity x tissue type was found as 1% important. Interestingly, root branching and development of lateral roots were much more negatively affected by gradual stress rather than sudden salt application. Our results demonstrated that root and leaf were both critical tissues to test the salt tolerance by physiologically but sheath tissue might be used as an alternative source of variation for solving the interactions between root and leaves in wheat.

  11. Impact of exogenous ascorbic acid on biochemical activities of rice callus treated with salt stress

    Science.gov (United States)

    Alhasnawi, Arshad Naji; Zain, Che Radziah Che Mohd; Kadhimi, Ahsan A.; Isahak, Anizan; Mohamad, Azhar; Ashraf, Mehdi Farshad; Doni, Febri; Yusoff, Wan Mohtar Wan

    2016-11-01

    The application of in vitro systems can lead to new methods of crop amelioration. This method has been widely utilized for breeding tenacities, particularly for stress tolerance selection. Salinity causes oxidative stress in callus by enhancing the production of Reactive Oxygen Species (ROS), resulting in an efficient antioxidant system. The exogenous application of ascorbic acid (AsA) is an important requirement for tolerance. The present study aimed to examine in vitro selection strategy for callus induction in rice mature embryo culture on MS culture medium and to produce salt-tolerant callus under sodium chloride (NaCl) and AsA conditions in callus rice variety, MR269. This study also highlights changes in the activities of proline and antioxidants peroxidase (POD), catalase (CAT) and superoxide dismutase (SOD) of callus under NaCl stress to understand their possible role in salt tolerance. However, various levels of exogenously applied AsA under saline conditions improved callus, and the antioxidant enzyme activities of AsA are related to resistance to oxidative stress. Our results provide strong support for the hypothesis that AsA-dependent antioxidant enzymes play a significant role in the salinity tolerance of callus rice.

  12. Evaluating relative contribution of osmotolerance and tissue tolerance mechanisms toward salinity stress tolerance in three Brassica species.

    Science.gov (United States)

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

    2016-10-01

    Three different species of Brassica, with differential salt sensitivity were used to understand physiological mechanisms of salt tolerance operating in these species and to evaluate the relative contribution of different strategies to cope with salt load. Brassica napus was the most tolerant species in terms of the overall performance, with Brassica juncea and Brassica oleracea being much more sensitive to salt stress with no obvious difference between them. While prominent reduction in net CO2 assimilation was observed in both sensitive species, physiological mechanisms beyond this reduction differed strongly. Brassica juncea plants possessed high osmotolerance and were able to maintain high transpiration rate but showed a significant reduction in leaf chlorophyll content and efficiency of leaf photochemistry. On the contrary, B. oleracea plants possessed the highest (among the three species) tissue tolerance but showed a very significant stomatal limitation of photosynthesis. Electrophysiological experiments revealed that the high tissue tolerance in B. oleracea was related to the ability of leaf mesophyll cells to maintain highly negative membrane potential in the presence of high apoplastic Na(+) . In addition to high osmotolerance, the most tolerant B. napus showed also lesser accumulation of toxic Na(+) and Cl(-) in the leaf, possessed moderate tissue tolerance and had a superior K(+) retention ability. Taken together, the results from this study indicate that the three Brassica species employ very different mechanisms to cope with salinity and, despite its overall sensitivity to salinity, B. oleracea could be recommended as a valuable 'donor' of tissue tolerance genes to confer this trait for marker-assisted breeding programs. © 2016 Scandinavian Plant Physiology Society.

  13. Pleiotropic phenotypes of the salt-tolerant and cytosine ...

    Indian Academy of Sciences (India)

    Keywords. centromeric DNA; DNA hypomethylation; drought tolerance; epigenetic regulation; gene expression changes; microRNA; plant development; ribosomal DNA; salinity tolerance; terpenoid indole alkaloids.

  14. De Novo Transcriptome Characterization, Gene Expression Profiling and Ionic Responses of Nitraria sibirica Pall. under Salt Stress

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    Huanyong Li

    2017-06-01

    Full Text Available Nitraria sibirica Pall., a typical halophyte of great ecological value, is widely distributed in desert, saline, and coastal saline-alkali environments. Consequently, researching the salt tolerance mechanism of N. sibirica Pall. has great significance to the cultivation and utilization of salt-tolerant plants. In this research, RNA-seq, digital gene expression (DGE, and high flux element analysis technologies were used to investigate the molecular and physiological mechanisms related to salt tolerance of N. sibirica Pall. Integrative analysis and de novo transcriptome assembly generated 137,421 unigenes. In total, 58,340 and 34,033 unigenes were annotated with gene ontology (GO terms and mapped in Kyoto Encyclopedia of Genes and Genomes (KEGG pathways, respectively. Three differentially expressed genes (DEGs libraries were subsequently constructed from the leaves of N. sibirica Pall. seedlings under different treatments: control (CK, light short-term salt stress (CL2, and heavy long-term salt stress (CL6. Eight hundred and twenty-six, and 224 differentially expressed genes were identified in CL2 and CL6 compared to CK, respectively. Finally, ionomic analysis of N. sibirica Pall. seedlings treated with 0, 100, 200 or 300 mM concentrations of NaCl for one day showed that the uptake and distribution of Ca, Cu, Fe, Mg and K in different organs of N. sibirica Pall. were significantly affected by salt stress. Our findings have identified potential genes involved in salt tolerance and in the reference transcriptome and have revealed the salt tolerance mechanism in N. sibirica Pall. These findings will provide further insight into the molecular and physiological mechanisms related to salt stress in N. sibirica Pall. and in other halophytes.

  15. Calcium supplementation improves Na+/K+ ratio, antioxidant defense and glyoxalase systems in salt-stressed rice seedlings

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    Anisur eRahman

    2016-05-01

    Full Text Available The present study investigates the regulatory role of exogenous calcium (Ca in developing salt stress tolerance in rice seedlings. Hydroponically grown 13-d-old rice (Oryza sativa L. cv. BRRI dhan47 seedlings were exposed to 200 mM NaCl alone and combined with 2 mM CaCl2 and 2 mM ethylene glycol tetraacetic acid (EGTA, a Ca scavenger for three days. The salt stress caused growth inhibition, chlorosis and water shortage in the rice seedlings. The salt-induced stress disrupted ion homeostasis through Na+ influx and K+ efflux, and decreased other mineral nutrient uptake. Salt-induced stress caused oxidative stress in rice seedlings through lipid peroxidation, loss of plasma membrane integrity, higher reactive oxygen species (ROS production and methylglyoxal (MG formation. The salt-stressed rice seedlings supplemented with exogenous Ca recovered from water loss, chlorosis and growth inhibition. Calcium supplementation in the salt-stressed rice seedlings improved ion homeostasis by inhibition of Na+ influx and K+ leakage. Exogenous Ca also improved ROS and MG detoxification by improving the antioxidant defense and glyoxalase systems, respectively. On the other hand, applying EGTA along with salt and Ca again negatively affected the rice seedlings as EGTA negated Ca activity. It confirms that, the positive responses in salt-stressed rice seedlings to exogenous Ca were for Ca mediated improvement of ion homeostasis, antioxidant defense and glyoxalase system.

  16. Leaf conductance and carbon gain under salt-stressed conditions

    Science.gov (United States)

    Volpe, V.; Manzoni, S.; Marani, M.; Katul, G.

    2011-12-01

    Exposure of plants to salt stress is often accompanied by reductions in leaf photosynthesis and in stomatal and mesophyll conductances. To separate the effects of salt stress on these quantities, a model based on the hypothesis that carbon gain is maximized subject to a water loss cost is proposed. The optimization problem of adjusting stomatal aperture for maximizing carbon gain at a given water loss is solved for both a non-linear and a linear biochemical demand function. A key novel theoretical outcome of the optimality hypothesis is an explicit relationship between the stomatal and mesophyll conductances that can be evaluated against published measurements. The approaches here successfully describe gas-exchange measurements reported for olive trees (Olea europea L.) and spinach (Spinacia oleraceaL.) in fresh water and in salt-stressed conditions. Salt stress affected both stomatal and mesophyll conductances and photosynthetic efficiency of both species. The fresh water/salt water comparisons show that the photosynthetic capacity is directly reduced by 30%-40%, indicating that reductions in photosynthetic rates under increased salt stress are not due only to a limitation of CO2diffusion. An increase in salt stress causes an increase in the cost of water parameter (or marginal water use efficiency) exceeding 100%, analogous in magnitude to findings from extreme drought stress studies. The proposed leaf-level approach can be incorporated into physically based models of the soil-plant-atmosphere system to assess how saline conditions and elevated atmospheric CO2 jointly impact transpiration and photosynthesis.

  17. Physiological and proteomic analyses of Saccharum spp. grown under salt stress.

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    Aline Melro Murad

    Full Text Available Sugarcane (Saccharum spp. is the world most productive sugar producing crop, making an understanding of its stress physiology key to increasing both sugar and ethanol production. To understand the behavior and salt tolerance mechanisms of sugarcane, two cultivars commonly used in Brazilian agriculture, RB867515 and RB855536, were submitted to salt stress for 48 days. Physiological parameters including net photosynthesis, water potential, dry root and shoot mass and malondialdehyde (MDA content of leaves were determined. Control plants of the two cultivars showed similar values for most traits apart from higher root dry mass in RB867515. Both cultivars behaved similarly during salt stress, except for MDA levels for which there was a delay in the response for cultivar RB867515. Analysis of leaf macro- and micronutrients concentrations was performed and the concentration of Mn(2+ increased on day 48 for both cultivars. In parallel, to observe the effects of salt stress on protein levels in leaves of the RB867515 cultivar, two-dimensional gel electrophoresis followed by MS analysis was performed. Four proteins were differentially expressed between control and salt-treated plants. Fructose 1,6-bisphosphate aldolase was down-regulated, a germin-like protein and glyceraldehyde 3-phosphate dehydrogenase showed increased expression levels under salt stress, and heat-shock protein 70 was expressed only in salt-treated plants. These proteins are involved in energy metabolism and defense-related responses and we suggest that they may be involved in protection mechanisms against salt stress in sugarcane.

  18. Global Gene Expression of Kosteletzkya virginica Seedlings Responding to Salt Stress.

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    Xiaoli Tang

    Full Text Available Soil salinization is becoming a serious threat to crop yield all over the world. Nowadays, acquainting the specific molecular mechanisms underlying various abiotic stresses especially to salt stress should be of great importance. While the development of the high-throughout sequencing technology promoted the progress powerfully. The intricate perception, transduction and regulation mechanisms underlying salt stress are being illustrated more and more clearly. As a perennial halophytic plant, Kosteletzkya virginica is able to help us to understand the mechanisms more directly and effectively. We carried out the whole transcriptome analysis on young seedlings with or without salt treatment through high-throughout sequencing technology. The results revealed that the numbers of different expressed transcripts between control and different treatments are 4145 and 9134, respectively. The ORF prediction suggested that there were 94308 ORF out of the 103489 (91.10% total transcripts. We also carried out further differential expression analysis through gene ontology (GO classification, cluster of orthologous groups (COG and Kyoto Encyclopedia of Genes and Genomes (KEGG analysis. In a word, our transcriptome study on Kosteletzkya virginica would provide direct and effective references for researches on molecular mechanisms of salt-tolerance, extending our view of salt tolerance in plant further. Above all, the related report in this paper is the first about Kosteletzkya virginica.

  19. Tissue-Specific Transcriptome Analysis Reveals Multiple Responses to Salt Stress in Populus euphratica Seedlings.

    Science.gov (United States)

    Yu, Le; Ma, Jianchao; Niu, Zhimin; Bai, Xiaotao; Lei, Wenli; Shao, Xuemin; Chen, Ningning; Zhou, Fangfang; Wan, Dongshi

    2017-12-08

    Salt stress is one of the most crucial factors impacting plant growth, development and reproduction. However, information regarding differences in tissue-specific gene expression patterns, which may improve a plant's tolerance to salt stress, is limited. Here, we investigated the gene expression patterns in tissues of Populus euphratica Oliv. seedlings using RNA sequencing (RNA-Seq) technology. A total of 109.3 million, 125bp paired-end clean reads were generated, and 6428, 4797, 2335 and 3358 differentially expressed genes (DEGs) were identified in leaf, phloem, xylem and root tissues, respectively. While the tissue-specific DEGs under salt stress had diverse functions, "membrane transporter activity" was the most significant leaf function, whereas "oxidation-reduction process" was the most significant function in root tissue. Further analysis of the tissue-specific DEGs showed that the expression patterns or functions of gene families, such as SOS, NHX, GolS, GPX, APX, RBOHF and CBL, were diverse, suggesting that calcium signaling, reactive oxygen species (ROS) and salt overly sensitive (SOS) pathways are all involved in ionic homeostasis in tissues from P. euphratica seedlings. The DEGs, for example the up-regulated antioxidant genes, contribute to ROS-scavenging induced by salt stress but result in decreased Na⁺ concentrations in root vasculature cells and in xylem sap, while the down-regulated rbohF leads to the reverse results. These results suggest that the divergence of DEGs expression patterns contribute to maintenance of ionic and ROS homeostasis in tissues and improve plant salinity tolerance. We comprehensively analyzed the response of P. euphratica seedlings to salt stress and provide helpful genetic resources for studying plant-abiotic stress interactions.

  20. Engineering Cold Stress Tolerance in Crop Plants

    Science.gov (United States)

    Sanghera, Gulzar S; Wani, Shabir H; Hussain, Wasim; Singh, N.B

    2011-01-01

    Plants respond with changes in their pattern of gene expression and protein products when exposed to low temperatures. Thus ability to adapt has an impact on the distribution and survival of the plant, and on crop yields. Many species of tropical or subtropical origin are injured or killed by non-freezing low temperatures, and exhibit various symptoms of chilling injury such as chlorosis, necrosis, or growth retardation. In contrast, chilling tolerant species are able to grow at such cold temperatures. Conventional breeding methods have met with limited success in improving the cold tolerance of important crop plants involving inter-specific or inter-generic hybridization. Recent studies involving full genome profiling/ sequencing, mutational and transgenic plant analyses, have provided a deep insight of the complex transcriptional mechanism that operates under cold stress. The alterations in expression of genes in response to cold temperatures are followed by increases in the levels of hundreds of metabolites, some of which are known to have protective effects against the damaging effects of cold stress. Various low temperature inducible genes have been isolated from plants. Most appear to be involved in tolerance to cold stress and the expression of some of them is regulated by C-repeat binding factor/ dehydration-responsive element binding (CBF/DREB1) transcription factors. Numerous physiological and molecular changes occur during cold acclimation which reveals that the cold resistance is more complex than perceived and involves more than one pathway. The findings summarized in this review have shown potential practical applications for breeding cold tolerance in crop and horticultural plants suitable to temperate geographical locations. PMID:21886453

  1. Engineering cold stress tolerance in crop plants.

    Science.gov (United States)

    Sanghera, Gulzar S; Wani, Shabir H; Hussain, Wasim; Singh, N B

    2011-03-01

    Plants respond with changes in their pattern of gene expression and protein products when exposed to low temperatures. Thus ability to adapt has an impact on the distribution and survival of the plant, and on crop yields. Many species of tropical or subtropical origin are injured or killed by non-freezing low temperatures, and exhibit various symptoms of chilling injury such as chlorosis, necrosis, or growth retardation. In contrast, chilling tolerant species are able to grow at such cold temperatures. Conventional breeding methods have met with limited success in improving the cold tolerance of important crop plants involving inter-specific or inter-generic hybridization. Recent studies involving full genome profiling/ sequencing, mutational and transgenic plant analyses, have provided a deep insight of the complex transcriptional mechanism that operates under cold stress. The alterations in expression of genes in response to cold temperatures are followed by increases in the levels of hundreds of metabolites, some of which are known to have protective effects against the damaging effects of cold stress. Various low temperature inducible genes have been isolated from plants. Most appear to be involved in tolerance to cold stress and the expression of some of them is regulated by C-repeat binding factor/ dehydration-responsive element binding (CBF/DREB1) transcription factors. Numerous physiological and molecular changes occur during cold acclimation which reveals that the cold resistance is more complex than perceived and involves more than one pathway. The findings summarized in this review have shown potential practical applications for breeding cold tolerance in crop and horticultural plants suitable to temperate geographical locations.

  2. Influence of salt tolerant Trichoderma spp. on growth of maize (Zea mays) under different salinity conditions.

    Science.gov (United States)

    Kumar, Krishna; Manigundan, K; Amaresan, Natarajan

    2017-02-01

    In the present study, a total of 70 Trichoderma spp. were isolated from the rhizosphere soils of vegetable and spice crops that were grown in Andaman and Nicobar Islands, India. Initial screening of Trichoderma spp. for salt tolerant properties showed 32 isolates were able to tolerate 10% NaCl. Furthermore, these isolates were screened for their potential plant growth-promoting characteristics such as IAA production, phosphate solubilization, and siderophore production. Among 32 isolates, nine isolates were able to produce IAA, siderophore, and solubilize phosphate. Jar trial was carried out on maize under axenic conditions at 1.67, 6.25, 11.25, 17.2, and 22.9 dS m -1 salt stress using the best nine isolates. Three isolates (TRC3, NRT2, and THB3) were effective in improving germination percentage, reducing reduction percentage of germination (RPG) and also in increasing the shoot and root length under axenic conditions. These three isolates were further tested under pot trial at 52 (sea water), 27, 15, 7, and 1.67 dS m -1 . TRC3 was found to be the most effective isolate compared to the other isolates and significantly increased the physiological parameters like shoot, root length, leaf area, total biomass, and stem and leaf fresh weight at all stress levels. Similarly, total chlorophyll content also increased by TRC3 over control. All three isolates, NRT2, TRC3, and THB3 showed lower accumulation of malondialdehyde (MDA) content whereas, proline and phenol content were higher than the uninoculated control plants under both normal and saline conditions. The results suggest that these isolates could be utilized for the alleviation of salinity stress in maize. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Long term salinity stress in relation to lipid peroxidation, super oxide dismutase activity and proline content of salt-sensitive and salt-tolerant wheat cultivars Estrés salino a largo plazo en relación con peroxidación lipídica, actividad superóxido dismutasa y contenido de prolina de cultivares de trigo sensibles y tolerantes a la salinidad

    Directory of Open Access Journals (Sweden)

    Azam Borzouei

    2012-12-01

    Full Text Available Salinity is a widespread root medium problem limiting productivity of cereal crops worldwide. The ability of plants to tolerate salt is determined by multiple biochemical pathways that facilitate retention and/or acquisition of water, protect chloroplast functions, and maintain ion homeostasis. Therefore, the ability of salt-sensitive ('Tajan' and salt-tolerant cultivar ('Bam' of Triticum aestivum L. to adapt to a saline environment were evaluated in a set of greenhouse experiments under salt stress during three growth stages (tillering, 50% anthesis, and 10 d after anthesis. Plants were irrigated by different saline waters with electrical conductivities of 1.3, 6, 8, 10, and 12 dS m-1, which were obtained by adding NaCl:CaCl2 in 10:1 molar ratio to fresh water. Differences in growth parameters, lipid peroxidation, superoxide dismutase (SOD activity, and proline accumulation were tested in order to put forward the relative tolerance or sensitivity of cultivars. Results indicated that both parameters differ according to the cultivar's ability in coping oxidative stress caused by salinity. We observed a greater decline in the growth parameters and grain yield under salt stress in 'Tajan' than in 'Bam'. Malondialdehyde content was also higher in 'Tajan'. The improved performance of the 'Bam' under high salinity was accompanied by an increase in SOD (EC 1.15.1.1 activity and proline content at all growth stages. Growth parameters, lipid peroxidation and proline accumulation results are also in good correlation with supporting this cultivar is being relatively tolerant.La salinidad es un problema del medio radical ampliamente distribuido que limita la productividad de los cultivos de cereal en todo el mundo. La capacidad de las plantas para tolerar la sal está determinada por multiples vías bioquímicas que facilitan la retención y/o adquisición de agua, protegen las funciones del cloroplasto, y mantienen la homeostasis iónica. Por lo tanto, se

  4. Responses of Photosynthesis, Chlorophyll Fluorescence and ROS-Scavenging Systems to Salt Stress During Seedling and Reproductive Stages in Rice

    Science.gov (United States)

    Moradi, Foad; Ismail, Abdelbagi M.

    2007-01-01

    Background and Aims Salinity is a widespread soil problem limiting productivity of cereal crops worldwide. Rice is particularly sensitive to salt stress during the seedling stage, with consequent poor crop establishment, as well as during reproduction where salinity can severely disrupt grain formation and yield. Tolerance at the seedling stage is weakly associated with tolerance during reproduction. Physiological responses to salinity were evaluated for contrasting genotypes, during the seedling and reproductive stages. Methods Three rice genotypes differing in their tolerance of salinity were evaluated in a set of greenhouse experiments under salt stress during both seedling stage and reproduction. Key Results Photosynthetic CO2 fixation, stomatal conductance (gs) and transpiration decreased substantially because of salt stress, but with greater reduction in the sensitive cultivar IR29. The tolerant lines IR651 and IR632 had more responsive stomata that tended to close faster during the first few hours of stress, followed by partial recovery after a brief period of acclimation. However, in the sensitive line, gs continued to decrease for longer duration and with no recovery afterward. Chlorophyll fluorescence measurements revealed that non-photochemical quenching increased, whereas the electron transport rate decreased under salt stress. Salt-tolerant cultivars exhibited much lower lipid peroxidation, maintained elevated levels of reduced ascorbic acid and showed increased activities of the enzymes involved in the reactive oxygen scavenging system during both developmental stages. Conclusions Upregulation of the anti-oxidant system appears to play a role in salt tolerance of rice, with tolerant genotypes also maintaining relatively higher photosynthetic function; during both the vegetative and reproductive stages. PMID:17428832

  5. Inheritance of salt tolerance in wild soybean (Glycine soja Sieb. and Zucc.) accession PI483463.

    Science.gov (United States)

    Lee, Jeong-Dong; Shannon, J Grover; Vuong, Tri D; Nguyen, Henry T

    2009-01-01

    Tolerant soybean (Glycine max [L.] Merr.) cultivars aid in reducing salt damage in problem fields. New genes are important to reduce losses from salt injury. Objectives of this study were to determine inheritance of salt tolerance in wild soybean (Glycine soja Sieb. and Zucc.) PI483463 and to test allelism of tolerance genes from genotypes PI483463 and S-100, a common ancestor of southern in US cultivars. Tolerant (T) PI483463 was crossed to sensitive (S) cultivar Hutcheson to study inheritance. PI483463 (T) was crossed with S-100 (T) to test for allelism. Parents, F(1) plants, F(2) populations, and F(2:3) lines were assayed in a 100 mM salt solution to determine tolerance. F(2) from T x S cross segregated 3(T):1 (S) and the F(2:3) lines responded 1 (T): 2 (segregating):1 (S). F(2) plants from PI483463 (T) x S-100 (T) segregated 15 (T):1 (S) indicating different genes from the 2 sources. Results showed that G. soja line PI483463 had a single dominant gene for salt tolerance, which was different than the gene in G. max line S-100. The symbol, Ncl2, was designated for this new salt tolerance allele.

  6. Co-overexpressing a Plasma Membrane and a Vacuolar Membrane Sodium/Proton Antiporter Significantly Improves Salt Tolerance in Transgenic Arabidopsis Plants

    Science.gov (United States)

    Pehlivan, Necla; Sun, Li; Jarrett, Philip; Yang, Xiaojie; Mishra, Neelam; Chen, Lin; Kadioglu, Asim; Shen, Guoxin; Zhang, Hong

    2016-01-01

    The Arabidopsis gene AtNHX1 encodes a vacuolar membrane-bound sodium/proton (Na+/H+) antiporter that transports Na+ into the vacuole and exports H+ into the cytoplasm. The Arabidopsis gene SOS1 encodes a plasma membrane-bound Na+/H+ antiporter that exports Na+ to the extracellular space and imports H+ into the plant cell. Plants rely on these enzymes either to keep Na+ out of the cell or to sequester Na+ into vacuoles to avoid the toxic level of Na+ in the cytoplasm. Overexpression of AtNHX1 or SOS1 could improve salt tolerance in transgenic plants, but the improved salt tolerance is limited. NaCl at concentration >200 mM would kill AtNHX1-overexpressing or SOS1-overexpressing plants. Here it is shown that co-overexpressing AtNHX1 and SOS1 could further improve salt tolerance in transgenic Arabidopsis plants, making transgenic Arabidopsis able to tolerate up to 250 mM NaCl treatment. Furthermore, co-overexpression of AtNHX1 and SOS1 could significantly reduce yield loss caused by the combined stresses of heat and salt, confirming the hypothesis that stacked overexpression of two genes could substantially improve tolerance against multiple stresses. This research serves as a proof of concept for improving salt tolerance in other plants including crops. PMID:26985021

  7. Genetic engineering of the biosynthesis of glycinebetaine leads to alleviate salt-induced potassium efflux and enhances salt tolerance in tomato plants.

    Science.gov (United States)

    Wei, Dandan; Zhang, Wen; Wang, Cuicui; Meng, Qingwei; Li, Gang; Chen, Tony H H; Yang, Xinghong

    2017-04-01

    Tomato (Solanum lycopersicum cv. 'Moneymaker') was transformed with the choline oxidase gene codA from Arthrobacter globiformis, which was modified to allow for targeting to both chloroplasts and the cytosol. Glycine betaine (GB) was accumulated in transformed plants, while no detectable GB was found in wild-type (WT) plants. Compared to WT plants, transgenic lines showed significantly higher photosynthetic rates (Pn) and antioxidant enzyme activities and lower reactive oxygen species (ROS) accumulation in the leaves when exposed to salt stress. Furthermore, compared with WT plants, K+ efflux decreased and Na+ efflux increased in roots of transgenic plants under salt stress; resulted in lower Na+/K+ ratios in transgenic lines. The exogenous application of GB also significantly reduced NaCl-induced K+ efflux and increased Na+ efflux in WT plants. A qRT-PCR assay indicated that GB enhanced NaCl-induced expression of genes encoding the K+ transporter, Na+/H+ antiporter, and H+-ATPase. These results suggest that the enhanced salt tolerance conferred by codA in transgenic tomato plants might be due to the regulation of ion channel and transporters by GB, which would allow high potassium levels and low sodium levels to be maintained in transgenic plants under salt stress condition. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. 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.

  9. Physio-biochemical and morphological characters of halophyte legume shrub, Acacia ampliceps seedlings in response to salt stress under greenhouse

    Directory of Open Access Journals (Sweden)

    Cattarin eTheerawitaya

    2015-08-01

    Full Text Available Acacia ampliceps (salt wattle, a leguminous shrub, has been introduced in salt-affected areas in northeast of Thailand for remediation of saline soils. However, the defense mechanisms underlying salt tolerance A. ampliceps are unknown. We investigated various physio-biochemical and morphological attributes of A. ampliceps in response to varying levels of salt treatment (200 to 600 mM NaCl. Seedlings of A. ampliceps (252 cm in plant height raised from seeds were treated with 200 mM (mild stress, 400 and 600 mM (extreme stress of salt treatment (NaCl under greenhouse conditions. Na+ and Ca2+ contents in the leaf tissues increased significantly under salt treatment, whereas K+ content declined in salt-stressed plants. Free proline and soluble sugar contents in plant grown under extreme salt stress (600 mM NaCl for 9 days significantly increased by 28.7 (53.33 mol g1 FW and 3.2 (42.11 mg g1 DW folds, respectively over the control, thereby playing a major role as osmotic adjustment. Na+ enrichment in the phyllode tissues of salt-stressed seedlings positively related to total chlorophyll degradation (R2=0.72. Photosynthetic pigments and chlorophyll fluorescence in salt-stressed plants increased under mild salt stress (200 mM NaCl. However, these declined under high level of salinity (400-600 mM NaCl, consequently resulting in reduced net photosynthetic rate (R2=0.81 and plant dry weight (R2= 0.91. The study concludes that A. ampliceps has an osmotic adjustment and Na+ compartmentation as effective salt defense mechanisms, and thus it could be an excellent species to grow in salt-affected soils.

  10. Genome-Wide Association Study Identifies Loci for Salt Tolerance during Germination in Autotetraploid Alfalfa (Medicago sativa L.) Using Genotyping-by-Sequencing.

    Science.gov (United States)

    Yu, Long-Xi; Liu, Xinchun; Boge, William; Liu, Xiang-Ping

    2016-01-01

    Salinity is one of major abiotic stresses limiting alfalfa (Medicago sativa L.) production in the arid and semi-arid regions in US and other counties. In this study, we used a diverse panel of alfalfa accessions previously described by Zhang et al. (2015) to identify molecular markers associated with salt tolerance during germination using genome-wide association study (GWAS) and genotyping-by-sequencing (GBS). Phenotyping was done by germinating alfalfa seeds under different levels of salt stress. Phenotypic data of adjusted germination rates and SNP markers generated by GBS were used for marker-trait association. Thirty six markers were significantly associated with salt tolerance in at least one level of salt treatments. Alignment of sequence tags to the Medicago truncatula genome revealed genetic locations of the markers on all chromosomes except chromosome 3. Most significant markers were found on chromosomes 1, 2, and 4. BLAST search using the flanking sequences of significant markers identified 14 putative candidate genes linked to 23 significant markers. Most of them were repeatedly identified in two or three salt treatments. Several loci identified in the present study had similar genetic locations to the reported QTL associated with salt tolerance in M. truncatula. A locus identified on chromosome 6 by this study overlapped with that by drought in our previous study. To our knowledge, this is the first report on mapping loci associated with salt tolerance during germination in autotetraploid alfalfa. Further investigation on these loci and their linked genes would provide insight into understanding molecular mechanisms by which salt and drought stresses affect alfalfa growth. Functional markers closely linked to the resistance loci would be useful for MAS to improve alfalfa cultivars with enhanced resistance to drought and salt stresses.

  11. Genome-Wide Association Study Identifies Loci for Salt Tolerance during Germination in Autotetraploid Alfalfa (Medicago sativa L.) Using Genotyping-by-Sequencing

    Science.gov (United States)

    Yu, Long-Xi; Liu, Xinchun; Boge, William; Liu, Xiang-Ping

    2016-01-01

    Salinity is one of major abiotic stresses limiting alfalfa (Medicago sativa L.) production in the arid and semi-arid regions in US and other counties. In this study, we used a diverse panel of alfalfa accessions previously described by Zhang et al. (2015) to identify molecular markers associated with salt tolerance during germination using genome-wide association study (GWAS) and genotyping-by-sequencing (GBS). Phenotyping was done by germinating alfalfa seeds under different levels of salt stress. Phenotypic data of adjusted germination rates and SNP markers generated by GBS were used for marker-trait association. Thirty six markers were significantly associated with salt tolerance in at least one level of salt treatments. Alignment of sequence tags to the Medicago truncatula genome revealed genetic locations of the markers on all chromosomes except chromosome 3. Most significant markers were found on chromosomes 1, 2, and 4. BLAST search using the flanking sequences of significant markers identified 14 putative candidate genes linked to 23 significant markers. Most of them were repeatedly identified in two or three salt treatments. Several loci identified in the present study had similar genetic locations to the reported QTL associated with salt tolerance in M. truncatula. A locus identified on chromosome 6 by this study overlapped with that by drought in our previous study. To our knowledge, this is the first report on mapping loci associated with salt tolerance during germination in autotetraploid alfalfa. Further investigation on these loci and their linked genes would provide insight into understanding molecular mechanisms by which salt and drought stresses affect alfalfa growth. Functional markers closely linked to the resistance loci would be useful for MAS to improve alfalfa cultivars with enhanced resistance to drought and salt stresses. PMID:27446182

  12. Marker-assisted backcrossing for identification of salt tolerant rice lines

    Directory of Open Access Journals (Sweden)

    M. Moniruzzaman

    2012-12-01

    Full Text Available SSR or microsatellite markers are proved to be ideal for making genetic maps, assisting selection and studying genetic diversity in germplasm. SSR markers are playing important role to identify gene for salt tolerance that can be helpful for plant breeders to develop new cultivars. The experiment was conducted during the period from July 2009 to November 2010 in the experimental field and Biotechnology Laboratory of Plant Breeding Division, Bangladesh Institute of Nuclear Agriculture (BINA, Mymensingh to identify salt tolerant rice line of BC1F1 progenies of Binadhan-5 x FL-478 using SSR markers. Salt tolerant genotype, FL-478 was crossed with high yielding variety, Binadhan-5. Randomly selected 40 BC1F1 progenies along with their two parents (Binadhan-5, FL-478 and F1 were genotyped with microsatellite or SSR markers for identification of salt tolerant rice lines. Parental polymorphism survey was assayed by 10 SSR markers and three polymorphic SSR markers viz., RM 336, RM 510, and RM 585 were selected to evaluate BC1F1 rice lines for salt tolerance. In respect of Primer RM 336, 11 lines were found as salt tolerant and 25 lines were heterozygous and 3 lines were susceptible. Primer RM 510 identified two tolerant, 14 heterozygous and 22 susceptible lines. And primer RM 585 identified 4 lines as tolerant and 35 lines as susceptible. Thus, these markers could be efficiently used in tagging salt tolerant genes, in marker-assisted selection and quantitative trait loci (QTL mapping. The selected BC1F1 could be used for developing BC2F1 and BC2F2 and mapping genes for salinity tolerance.

  13. Salt stress encourages proline accumulation by regulating proline biosynthesis and degradation in Jerusalem artichoke plantlets.

    Directory of Open Access Journals (Sweden)

    Zengrong Huang

    Full Text Available Proline accumulation is an important mechanism for osmotic regulation under salt stress. In this study, we evaluated proline accumulation profiles in roots, stems and leaves of Jerusalem artichoke (Helianthus tuberosus L. plantlets under NaCl stress. We also examined HtP5CS, HtOAT and HtPDH enzyme activities and gene expression patterns of putative HtP5CS1, HtP5CS2, HtOAT, HtPDH1, and HtPDH2 genes. The objective of our study was to characterize the proline regulation mechanisms of Jerusalem artichoke, a moderately salt tolerant species, under NaCl stress. Jerusalem artichoke plantlets were observed to accumulate proline in roots, stems and leaves during salt stress. HtP5CS enzyme activities were increased under NaCl stress, while HtOAT and HtPDH activities generally repressed. Transcript levels of HtP5CS2 increased while transcript levels of HtOAT, HtPDH1 and HtPDH2 generally decreased in response to NaCl stress. Our results supports that for Jerusalem artichoke, proline synthesis under salt stress is mainly through the Glu pathway, and HtP5CS2 is predominant in this process while HtOAT plays a less important role. Both HtPDH genes may function in proline degradation.

  14. Salt stress encourages proline accumulation by regulating proline biosynthesis and degradation in Jerusalem artichoke plantlets.

    Science.gov (United States)

    Huang, Zengrong; Zhao, Long; Chen, Dandan; Liang, Mingxiang; Liu, Zhaopu; Shao, Hongbo; Long, Xiaohua

    2013-01-01

    Proline accumulation is an important mechanism for osmotic regulation under salt stress. In this study, we evaluated proline accumulation profiles in roots, stems and leaves of Jerusalem artichoke (Helianthus tuberosus L.) plantlets under NaCl stress. We also examined HtP5CS, HtOAT and HtPDH enzyme activities and gene expression patterns of putative HtP5CS1, HtP5CS2, HtOAT, HtPDH1, and HtPDH2 genes. The objective of our study was to characterize the proline regulation mechanisms of Jerusalem artichoke, a moderately salt tolerant species, under NaCl stress. Jerusalem artichoke plantlets were observed to accumulate proline in roots, stems and leaves during salt stress. HtP5CS enzyme activities were increased under NaCl stress, while HtOAT and HtPDH activities generally repressed. Transcript levels of HtP5CS2 increased while transcript levels of HtOAT, HtPDH1 and HtPDH2 generally decreased in response to NaCl stress. Our results supports that for Jerusalem artichoke, proline synthesis under salt stress is mainly through the Glu pathway, and HtP5CS2 is predominant in this process while HtOAT plays a less important role. Both HtPDH genes may function in proline degradation.

  15. Transcriptome analysis of salt tolerant common bean (Phaseolus vulgaris L.) under saline conditions

    National Research Council Canada - National Science Library

    Hiz, Mahmut Can; Canher, Balkan; Niron, Harun; Turet, Muge

    2014-01-01

    .... Common bean, Phaseolus vulgaris L., a major protein source in developing countries, is highly affected by soil salinity and the information on genes that play a role in salt tolerance is scarce...

  16. A study of proline metabolism in canola (Brassica napus L.) seedlings under salt stress.

    Science.gov (United States)

    Saadia, Mubshara; Jamil, Amer; Akram, Nudrat Aisha; Ashraf, Muhammad

    2012-05-16

    Expression analysis of crop plants has improved our knowledge about the veiled underlying mechanisms for salt tolerance. In order to observe the time course effects of salinity stress on gene expression for enzymes regulating proline metabolism, we comparatively analyzed the expression of specific genes for proline metabolism in root and shoot tissues of salt-tolerant (cv. Dunkled) and salt-sensitive (cv. Cyclone) canola (Brassica napus L.) cultivars through reverse-transcriptase polymerase chain reaction (RT-PCR); following the NaCl treatment for various durations. Both lines showed an increase in ∆¹-pyrroline-5-carboxylate synthase1 (P5CS1) gene expression after induction of salt stress with enhanced expression in the root tissue of the tolerant line, while maximum expression was noted in the shoot tissues of the sensitive line. We observed a much reduced proline dehydrogenase (PDH) expression in both the root and shoot tissues of both canola lines, with more marked reduction of PDH expression in the shoot tissues than that in the root ones. To confirm the increase in P5CS1 gene expression, total proline content was also measured in the root and shoot tissues of both the canola lines. The root tissues of canola sensitive line showed a gradually increasing proline concentration pattern with regular increase in salinity treatment, while an increase in proline concentration in the tolerant line was noted at 24 h post salinity treatment after a sudden decrease at 6 h and 12 h of salt treatment. A gradually increasing concentration of free proline content was found in shoot tissues of the tolerant canola line though a remarkable increase in proline concentration was noted in the sensitive canola line at 24 h post salinity treatment, indicating the initiation of proline biosynthesis process in that tissue of sensitive canola.

  17. Hemodynamic responses to mental stress during salt loading

    DEFF Research Database (Denmark)

    Goyal, Maria Gefke; Christensen, Niels Juel; Bech, Per

    2017-01-01

    ) during preparation for a medical exam (prolonged stress) and (ii) outside the exam period (low stress). All subjects consumed a controlled diet for 3 days with low- or high-salt content in randomized order. The subjective stress was measured by Spielberger's State-Trait Anxiety Inventory-Scale, SCL...

  18. Physiological responses of salt stress and osmoprotection with ...

    African Journals Online (AJOL)

    Yomi

    2011-12-21

    Dec 21, 2011 ... Keywords: Salt stress, bacterial growth, osmoregulation, proline, stress protein synthesis. INTRODUCTION. Bacterial cells had ... under osmotic stress increase the proline pool of endo- genous origin by regulation of ... synthesis of proteins involved in the protection and repair of macromolecules. As with ...

  19. of Kidney Bean, Soybean and Alfalfa Under Salt Stress

    African Journals Online (AJOL)

    komla

    kidney bean, soybean and alfalfa under salt stress were investigated in the greenhouse. Growth and ... Continuous irrigation with water loaded with material in the soil, different substances are soluble salts results in ..... alfalfa at 100 mM Na,SO, was observed There appears to be no published work for both composts but ...

  20. Study on salt tolerance with YHem1 transgenic canola (Brassica napus).

    Science.gov (United States)

    Sun, Xin-E; Feng, Xin-Xin; Li, Cui; Zhang, Zhi-Ping; Wang, Liang-Ju

    2015-06-01

    5-Aminolevulinic acid (5-ALA) has been suggested for improving plant salt tolerance via exogenous application. In this study, we used a transgenic canola (Brassica napus), which contained a constituted gene YHem1 and biosynthesized more 5-ALA, to study salt stress responses. In a long-term pot experiment, the transgenic plants produced higher yield under 200 mmol L(-1) NaCl treatment than the wild type (WT). In a short-term experiment, the YHem1 transformation accelerated endogenous 5-ALA metabolism, leading to more chlorophyll accumulation, higher diurnal photosynthetic rates and upregulated expression of the gene encoding Rubisco small subunit. Furthermore, the activities of antioxidant enzymes, including superoxide dismutase, guaiacol peroxidase, catalase and ascorbate peroxidase, were significantly higher in the transgenic plants than the WT, while the levels of O2 ·(-) and malondialdehyde were lower than the latter. Additionally, the Na(+) content was higher in the transgenic leaves than that in the WT under salinity, but K(+) and Cl(-) were significantly lower. The levels of N, P, Cu, and S in the transgenic plants were also significantly lower than those in the WT, but the Fe content was significantly improved. As the leaf Fe content was decreased by salinity, it was suggested that the stronger salt tolerance of the transgenic plants was related to the higher Fe acquisition. Lastly, YHem1 transformation improved the leaf proline content, but salinity decreased rather than increased it. The content of free amino acids and soluble sugars was similarly decreased as salinity increased, but it was higher in the transgenic plants than that in the WT. © 2014 Scandinavian Plant Physiology Society.

  1. Transcriptomic profiling of the salt-stress response in the halophyte Halogeton glomeratus.

    Science.gov (United States)

    Wang, Juncheng; Li, Baochun; Meng, Yaxiong; Ma, Xiaole; Lai, Yong; Si, Erjing; Yang, Ke; Ren, Panrong; Shang, Xunwu; Wang, Huajun

    2015-03-11

    Halogeton glomeratus (H. glomeratus) is an extreme halophyte that is widely distributed in arid regions, including foothills, the Gobi desert of northwest China, and the marginal loess of Central Asia. However, research on the salt-tolerant mechanisms and genes of this species are limited because of a lack of genomic sequences. In the present study, the transcriptome of H. glomeratus was analyzed using next-generation sequencing technology to identify genes involved in salt tolerance and better understand mechanisms of salt response in the halophyte H. glomeratus. Illumina RNA-sequencing was performed in five sequencing libraries that were prepared from samples treated with 200 mM NaCl for 6, 12, 24, and 72 h and a control sample to investigate changes in the H. glomeratus transcriptome in response to salt stress. The de novo assembly of five transcriptomes identified 50,267 transcripts. Among these transcripts, 31,496 (62.66%) were annotated, including 44 Gene Ontology (GO) terms and 128 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Compared with transcriptomes from the control and NaCl-treated samples, there were 2,223, 5,643, 7,510 and 10,908 genes that were differentially expressed after exposure to NaCl for 6, 12, 24, and 72 h, respectively. One hundred and eighteen salt-induced genes were common to at least two stages of salt stress, and 291 up-regulated genes were common to various stages of salt stress. Numerous genes that are related to ion transport, reactive oxygen species scavenging, energy metabolism, hormone-response pathways, and responses to biotic and abiotic stress appear to play a significant role in adaptation to salinity conditions in this species. The detection of expression patterns of 18 salt-induced genes by quantitative real-time polymerase chain reaction were basically consistent with their changes in transcript abundance determined by RNA sequencing. Our findings provide a genomic sequence resource for functional genetic

  2. Proteomic Analysis Reveals Proteins Involved in Seed Imbibition under Salt Stress in Rice.

    Science.gov (United States)

    Xu, Enshun; Chen, Mingming; He, Hui; Zhan, Chengfang; Cheng, Yanhao; Zhang, Hongsheng; Wang, Zhoufei

    2016-01-01

    Enhancement of salinity tolerance during seed germination is very important for direct seeding in rice. In this study, the salt-tolerant japonica landrace Jiucaiqing was used to determine the regulators that are involved in seed imbibition under salt stress. Briefly, the comparative proteomic analysis was conducted between dry (0 h) and imbibed (24 h) seeds with 150 mM NaCl. Under salt stress, the uptake of water increased rapidly before 24 h imbibition (Phase I), followed by a plateau of seed imbibition from 24 to 96 h imbibition (Phase II). We identified 14 proteins involved in seed imbibition, in which the majority of these proteins were involved in energy supply and storage protein. The early imbibition process was mediated by protein catabolism; the most of proteins were down-regulated after 24 h imbibition. Eleven genes in salt stress treated seeds were expressed early during the seed imbibition in comparison to control seeds. By comparison, 2,3-bisphosphoglycerate-independent phosphoglycerate mutase (BPM), glutelin (GLU2.2 and GLU2.3), glucose-1-phosphate adenylyltransferase large subunit (GAS8), and cupin domain containing protein (CDP3.1 and CDP3.2) were near the regions of quantitative trait loci (QTLs) for seed dormancy, seed reserve utilization, and seed germination in Jiucaiqing. In particular, CDP3.1 was co-located in the region of qIR-3 for imbibition rate, and qGP-3 for germination percentage. The role of CDP3.1 was verified in enhancing seed germination under salt stress using T-DNA mutant. The identified proteins might be applicable for the improvement of seed germination under salt stress in rice.

  3. 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 ...

  4. Transcriptional profiling of Medicago truncatula under salt stress identified a novel CBF transcription factor MtCBF4 that plays an important role in abiotic stress responses

    Directory of Open Access Journals (Sweden)

    Su Zhen

    2011-07-01

    Full Text Available Abstract Background Salt stress hinders the growth of plants and reduces crop production worldwide. However, different plant species might possess different adaptive mechanisms to mitigate salt stress. We conducted a detailed pathway analysis of transcriptional dynamics in the roots of Medicago truncatula seedlings under salt stress and selected a transcription factor gene, MtCBF4, for experimental validation. Results A microarray experiment was conducted using root samples collected 6, 24, and 48 h after application of 180 mM NaCl. Analysis of 11 statistically significant expression profiles revealed different behaviors between primary and secondary metabolism pathways in response to external stress. Secondary metabolism that helps to maintain osmotic balance was induced. One of the highly induced transcription factor genes was successfully cloned, and was named MtCBF4. Phylogenetic analysis revealed that MtCBF4, which belongs to the AP2-EREBP transcription factor family, is a novel member of the CBF transcription factor in M. truncatula. MtCBF4 is shown to be a nuclear-localized protein. Expression of MtCBF4 in M. truncatula was induced by most of the abiotic stresses, including salt, drought, cold, and abscisic acid, suggesting crosstalk between these abiotic stresses. Transgenic Arabidopsis over-expressing MtCBF4 enhanced tolerance to drought and salt stress, and activated expression of downstream genes that contain DRE elements. Over-expression of MtCBF4 in M. truncatula also enhanced salt tolerance and induced expression level of corresponding downstream genes. Conclusion Comprehensive transcriptomic analysis revealed complex mechanisms exist in plants in response to salt stress. The novel transcription factor gene MtCBF4 identified here played an important role in response to abiotic stresses, indicating that it might be a good candidate gene for genetic improvement to produce stress-tolerant plants.

  5. The Arabidopsis PLAT domain protein1 is critically involved in abiotic stress tolerance

    DEFF Research Database (Denmark)

    Hyun, Tae Kyung; van der Graaff, Eric; Albacete, Alfonso

    2014-01-01

    Despite the completion of the Arabidopsis genome sequence, for only a relatively low percentage of the encoded proteins experimental evidence concerning their function is available. Plant proteins that harbour a single PLAT (Polycystin, Lipoxygenase, Alpha-toxin and Triacylglycerol lipase) domain...... and belong to the PLAT-plant-stress protein family are ubiquitously present in monocot and dicots. However, the function of PLAT-plant-stress proteins is still poorly understood. Therefore, we have assessed the function of the uncharacterised Arabidopsis PLAT-plant-stress family members through a combination...... of functional genetic and physiological approaches. PLAT1 overexpression conferred increased abiotic stress tolerance, including cold, drought and salt stress, while loss-of-function resulted in opposite effects on abiotic stress tolerance. Strikingly, PLAT1 promoted growth under non-stressed conditions...

  6. Overexpression of TaLEA gene from Tamarix androssowii improves salt and drought tolerance in transgenic poplar (Populus simonii × P. nigra.

    Directory of Open Access Journals (Sweden)

    Weidong Gao

    Full Text Available Late embryogenesis abundant (LEA genes were confirmed to confer resistance to drought and water deficiency. An LEA gene from Tamarixandrossowii (named TaLEA was transformed into Xiaohei poplar (Populussimonii × P. nigra via Agrobacterium. Twenty-five independent transgenic lines were obtained that were resistant to kanamycin, and 11 transgenic lines were randomly selected for further analysis. The polymerase chain reaction (PCR and ribonucleic acid (RNA gel blot indicated that the TaLEA gene had been integrated into the poplar genome. The height growth rate, malondialdehyde (MDA content, relative electrolyte leakage and damages due to salt or drought to transgenic and non-transgenic plants were compared under salt and drought stress conditions. The results showed that the constitutive expression of the TaLEA gene in transgenic poplars could induce an increase in height growth rate and a decrease in number and severity of wilted leaves under the salt and drought stresses. The MDA content and relative electrolyte leakage in transgenic lines under salt and drought stresses were significantly lower compared to those in non-transgenic plants, indicating that the TaLEA gene may enhance salt and drought tolerance by protecting cell membranes from damage. Moreover, amongst the lines analyzed for stress tolerance, the transgenic line 11 (T11 showed the highest tolerance levels under both salinity and drought stress conditions. These results indicated that the TaLEA gene could be a salt and drought tolerance candidate gene and could confer a broad spectrum of tolerance under abiotic stresses in poplars.

  7. Salt tolerance of halophytes, research questions reviewed in the perspective of saline agriculture

    NARCIS (Netherlands)

    Rozema, J.; Schat, H.

    2013-01-01

    Halophytes of the lower coastal salt marsh show increased salt tolerance, and under high salinity they grow faster than upper marsh species. We could not show reduced growth rate of halophytes compared with glycophytes when grown under non-saline conditions. This indicates limited energy costs

  8. Influence of intracellular Na + , K + and Cl - on the salt tolerance in ...

    African Journals Online (AJOL)

    In the process of selection for salt tolerance, it is important to understand the physiological basis of ion management executed by the cells through the exclusion, accumulation or maintenance of ratios of specific ions. Intracellular accumulation of Na+, K+ and Cl- ions in the cells in vitro was studied as a factor in salt ...

  9. An alfalfa (Medicago sativa L.) ethylene response factor gene, MsERF11, enhances salt tolerance in transgenic Arabidopsis.

    Science.gov (United States)

    Chen, Tingting; Yang, Qingchuan; Zhang, Xinquan; Ding, Wang; Gruber, Margaret

    2012-09-01

    A novel orthologue of ethylene response factor gene, MsERF11, was isolated from alfalfa in this study. It has an open reading frame of 807 bp, encoding a predicted polypeptide of 268 amino acids. Sequence similarity analysis clearly suggested that MsERF11 encoded an ethylene response factor protein. The results of transient expression of MsERF11 in onion epidermal cells indicated that MsERF11 is a nuclear protein. The expression pattern of MsERF11 gene was analyzed by real-time quantitative PCR and a higher level of expression was observed in leaves than was observed in roots, stems, flower buds and flowers. Furthermore, the expression was induced by PEG6000, NaCl, Al2(SO4)3 and six different hormones. Over-expressing MsERF11 resulted in enhanced tolerances to salt stress in transgenic Arabidopsis plants. This research indicates that MsERF11 has the potential to be used for improving crop's salt tolerance in areas where salinity is a limiting factor for agricultural productivity. MsERF11 was isolated from alfalfa. Its expression was induced by different abiotic stresses and hormones. Over-expressing MsERF11 resulted in enhanced salt tolerance in transgenic Arabidopsis plants.

  10. 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.

  11. ABA inducible rice protein phosphatase 2C confers ABA insensitivity and abiotic stress tolerance in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Amarjeet Singh

    Full Text Available Arabidopsis PP2C belonging to group A have been extensively worked out and known to negatively regulate ABA signaling. However, rice (Oryza sativa orthologs of Arabidopsis group A PP2C are scarcely characterized functionally. We have identified a group A PP2C from rice (OsPP108, which is highly inducible under ABA, salt and drought stresses and localized predominantly in the nucleus. Genetic analysis revealed that Arabidopsis plants overexpressing OsPP108 are highly insensitive to ABA and tolerant to high salt and mannitol stresses during seed germination, root growth and overall seedling growth. At adult stage, OsPP108 overexpression leads to high tolerance to salt, mannitol and drought stresses with far better physiological parameters such as water loss, fresh weight, chlorophyll content and photosynthetic potential (Fv/Fm in transgenic Arabidopsis plants. Expression profile of various stress marker genes in OsPP108 overexpressing plants revealed interplay of ABA dependent and independent pathway for abiotic stress tolerance. Overall, this study has identified a potential rice group A PP2C, which regulates ABA signaling negatively and abiotic stress signaling positively. Transgenic rice plants overexpressing this gene might provide an answer to the problem of low crop yield and productivity during adverse environmental conditions.

  12. Proteome Analysis for Understanding Abiotic Stress (Salinity and Drought Tolerance in Date Palm (Phoenix dactylifera L.

    Directory of Open Access Journals (Sweden)

    Haddad A. El Rabey

    2015-01-01

    Full Text Available This study was carried out to study the proteome of date palm under salinity and drought stress conditions to possibly identify proteins involved in stress tolerance. For this purpose, three-month-old seedlings of date palm cultivar “Sagie” were subjected to drought (27.5 g/L polyethylene glycol 6000 and salinity stress conditions (16 g/L NaCl for one month. DIGE analysis of protein extracts identified 47 differentially expressed proteins in leaves of salt- and drought-treated palm seedlings. Mass spectrometric analysis identified 12 proteins; three out of them were significantly changed under both salt and drought stress, while the other nine were significantly changed only in salt-stressed plants. The levels of ATP synthase alpha and beta subunits, an unknown protein and some of RubisCO fragments were significantly changed under both salt and drought stress conditions. Changes in abundance of superoxide dismutase, chlorophyll A-B binding protein, light-harvesting complex1 protein Lhca1, RubisCO activase, phosphoglycerate kinase, chloroplast light-harvesting chlorophyll a/b-binding protein, phosphoribulokinase, transketolase, RubisCO, and some of RubisCO fragments were significant only for salt stress.

  13. 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.

  14. Physiological and Proteomic Responses of Diploid and Tetraploid Black Locust (Robinia pseudoacacia L. Subjected to Salt Stress

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    Fanjuan Meng

    2013-10-01

    Full Text Available Tetraploid black locust (Robinia pseudoacacia L. is adaptable to salt stress. Here, we compared morphological, physiological, ultrastructural, and proteomic traits of leaves in tetraploid black locust and its diploid relatives under salt stress. The results showed that diploid (2× plants suffered from greater negative effects than those of tetraploid (4× plants. After salt treatment, plant growth was inhibited, photosynthesis was reduced, reactive oxygen species, malondialdehyde content, and relative electrolyte leakage increased, and defense-related enzyme activities decreased in 2× compared to those in 4×. In addition, salt stress resulted in distorted chloroplasts, swollen thylakoid membranes, accumulation of plastoglobules, and increased starch grains in 2× compared to those in 4×. However, 4× developed diverse responses under salt stress. A comparative proteomic analysis revealed that 41 and 37 proteins were differentially expressed in 2× and 4×, respectively. These proteins were mainly involved in photosynthesis, stress and defense, energy, metabolism, transcription/translation, and transportation. Distinct patterns of protein changes between 2× and 4× were analyzed. Collectively, our results suggest that the plants showed significantly different responses to salt stress based on ploidy level of the plant. The 4× possessed a better salt protection mechanism than that of 2×, suggesting salt tolerance in the polyploid plant.

  15. Advances in functional genomics for investigating salinity stress tolerance mechanisms in cereals

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    Megan C Shelden

    2013-05-01

    Full Text Available Abiotic stresses such as low water availability and high salinity are major causes of cereal crop yield losses and significantly impact on sustainability. Wheat and barley are two of the most important cereal crops (after maize and rice and are grown in increasingly hostile environments with soil salinity and drought both expected to increase this century, reducing the availability of arable land. Barley and wheat are classified as glycophytes (salt-sensitive, yet they are more salt-tolerant than other cereal crops such as rice and so are good models for studying salt-tolerance in cereals. The exploitation of genetic variation of phenotypic traits through plant breeding could significantly improve growth of cereals in salinity-affected regions, thus leading to improved crop yields. Genetic variation in phenotypic traits for abiotic stress tolerance have been identified in land races and wild germplasm but the molecular basis of these differences is often difficult to determine due to the complex genetic nature of these species. High-throughput functional genomics technologies, such as transcriptomics, metabolomics, proteomics and ionomics are powerful tools for investigating the molecular responses of plants to abiotic stress. The advancement of these technologies has allowed for the identification and quantification of transcript /metabolites in specific cell types and/or tissues. Using these new technologies on plants will provide a powerful tool to uncovering genetic traits in more complex species such as wheat and barley and provide novel insights into the molecular mechanisms of salinity stress tolerance.

  16. Germination and growth of white oat genotypes seedlings submitted to salt stress

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    Fabiana Carrett Timm

    2015-10-01

    Full Text Available The white oat is a winter crop used in succession to rice cultivation, subject to salt stress due to the accumulation of salts in the soil, especially in the southern Rio Grande do Sul. The objective of this work was to evaluate the seed germination, initial growth of the nine genotypes seedling of white oat and to identify contrasting genotypes, well as to identify the genotypes contrasting to character for salt tolerance character. For this, the genotypes were submitted to different salt concentrations (0, 25, 50, 75 and 100 mM de NaCl per liter of water, being analyzed the following variables: percentage of germination, first counting germination, index germination speed, length, shoots and roots dry mass of seedlings. The results may imply that seed germination that the percentage of germination was slightly decreased compared to the shoot growth and roots that have been greatly reduced with increasing salt concentrations. The root length and shoot length is in promising variables in the separation of genotypes in relation to different salt concentrations, allowing you to select two contrasting genotypes to salinity, the (URS 22 characterized as tolerant and (UPF 16 as sensitive.

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

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    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.

  18. A meta-analysis of arbuscular mycorrhizal effects on plants grown under salt stress.

    Science.gov (United States)

    Chandrasekaran, Murugesan; Boughattas, Sonia; Hu, Shuijin; Oh, Sang-Hyon; Sa, Tongmin

    2014-11-01

    Salt stress limits crop yield and sustainable agriculture in most arid and semiarid regions of the world. Arbuscular mycorrhizal fungi (AMF) are considered bio-ameliorators of soil salinity tolerance in plants. In evaluating AMF as significant predictors of mycorrhizal ecology, precise quantifiable changes in plant biomass and nutrient uptake under salt stress are crucial factors. Therefore, the objective of the present study was to analyze the magnitude of the effects of AMF inoculation on growth and nutrient uptake of plants under salt stress through meta-analyses. For this, data were compared in the context of mycorrhizal host plant species, plant family and functional group, herbaceous vs. woody plants, annual vs. perennial plants, and the level of salinity across 43 studies. Results indicate that, under saline conditions, AMF inoculation significantly increased total, shoot, and root biomass as well as phosphorous (P), nitrogen (N), and potassium (K) uptake. Activities of the antioxidant enzymes superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase also increased significantly in mycorrhizal compared to nonmycorrhizal plants growing under salt stress. In addition, sodium (Na) uptake decreased significantly in mycorrhizal plants, while changes in proline accumulation were not significant. Across most subsets of the data analysis, identities of AMF (Glomus fasciculatum) and host plants (Acacia nilotica, herbs, woody and perennial) were found to be essential in understanding plant responses to salinity stress. For the analyzed dataset, it is concluded that under salt stress, mycorrhizal plants have extensive root traits and mycorrhizal morphological traits which help the uptake of more P and K, together with the enhanced production of antioxidant enzymes resulting in salt stress alleviation and increased plant biomass.

  19. Development of intermittent drought stress tolerant common bean ...

    African Journals Online (AJOL)

    Development of intermittent drought stress tolerant common bean genotypes in Uganda. ... yielding and drought-tolerant are crucial in coping with the effects of drought, ... Thus, these genotypes could be useful sources of genes for drought ...

  20. No evidence for local adaptation to salt stress in the existing populations of invasive Solidago canadensis in China.

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    Junmin Li

    Full Text Available Local adaptation is an important mechanism underlying the adaptation of plants to environmental heterogeneity, and the toxicity of salt results in strong selection pressure on salt tolerance in plants and different ecotypes. Solidago canadensis, which is invasive in China, has spread widely and has recently colonized alkali sandy loams with a significant salt content. A common greenhouse experiment was conducted to test the role of local adaptation in the successful invasion of S. canadensis into salty habitats. Salt treatment significantly decreased the growth of S. canadensis, including rates of increase in the number of leaves and plant height; the root, shoot, and total biomass. Furthermore, salt stress significantly reduced the net photosynthetic rate, stomatal conductance, transpiration rate and relative chlorophyll content but significantly increased peroxidase activity and the proline content of S. canadensis and the root/shoot ratio. Two-way analysis of variance showed that salt treatment had a significant effect on the physiological traits of S. canadensis, except for the intercellular CO2 concentration, whereas the population and the salt × population interaction had no significant effect on any physiological traits. Most of the variation in plasticity existed within and not among populations, excep for the root/shoot ratio. S. canadensis populations from soil with moderate/high salt levels grew similarly to S. canadensis populations from soils with low salt levels. No significant correlation between salt tolerance indices and soil salinity levels was observed. The plasticity of the proline content, intercellular CO2 concentration and chlorophyll content had significant correlations with the salt tolerance index. These findings indicate a lack of evidence for local adaption in the existing populations of invasive S. canadensis in China; instead, plasticity might be more important than local adaptation in influencing the physiological

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

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    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.

  2. Safety aspects of genetically modified crops with abiotic stress tolerance

    NARCIS (Netherlands)

    Liang, C.; Prins, T.W.; Wiel, van de C.C.M.; Kok, E.J.

    2014-01-01

    Abiotic stress, such as drought, salinity, and temperature extremes, significantly reduce crop yields. Hence, development of abiotic stress-tolerant crops by modern biotechnology may contribute to global food security. Prior to introducing genetically modified crops with abiotic stress tolerance to

  3. ESKIMO1 is a key gene involved in water economy as well as cold acclimation and salt tolerance

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    Yu Agnes

    2008-12-01

    Full Text Available Abstract Background Drought is a major social and economic problem resulting in huge yield reduction in the field. Today's challenge is to develop plants with reduced water requirements and stable yields in fluctuating environmental conditions. Arabidopsis thaliana is an excellent model for identifying potential targets for plant breeding. Drought tolerance in the field was successfully conferred to crops by transferring genes from this model species. While involved in a plant genomics programme, which aims to identify new genes responsible for plant response to abiotic stress, we identified ESKIMO1 as a key gene involved in plant water economy as well as cold acclimation and salt tolerance. Results All esk1 mutants were more tolerant to freezing, after acclimation, than their wild type counterpart. esk1 mutants also showed increased tolerance to mild water deficit for all traits measured. The mutant's improved tolerance to reduced water supply may be explained by its lower transpiration rate and better water use efficiency (WUE, which was assessed by carbon isotope discrimination and gas exchange measurements. esk1 alleles were also shown to be more tolerant to salt stress. Transcriptomic analysis of one mutant line and its wild-type background was carried out. Under control watering conditions a number of genes were differentially expressed between the mutant and the wild type whereas under mild drought stress this list of genes was reduced. Among the genes that were differentially expressed between the wild type and mutant, two functional categories related to the response to stress or biotic and abiotic stimulus were over-represented. Under salt stress conditions, all gene functional categories were represented equally in both the mutant and wild type. Based on this transcriptome analysis we hypothesise that in control conditions the esk1 mutant behaves as if it was exposed to drought stress. Conclusion Overall our findings suggest that the

  4. Dissipation of excess photosynthetic energy contributes to salinity tolerance: a comparative study of salt-tolerant Ricinus communis and salt-sensitive Jatropha curcas.

    Science.gov (United States)

    Lima Neto, Milton C; Lobo, Ana K M; Martins, Marcio O; Fontenele, Adilton V; Silveira, Joaquim Albenisio G

    2014-01-01

    The relationships between salt tolerance and photosynthetic mechanisms of excess energy dissipation were assessed using two species that exhibit contrasting responses to salinity, Ricinus communis (tolerant) and Jatropha curcas (sensitive). The salt tolerance of R. communis was indicated by unchanged electrolyte leakage (cellular integrity) and dry weight in leaves, whereas these parameters were greatly affected in J. curcas. The leaf Na+ content was similar in both species. Photosynthesis was intensely decreased in both species, but the reduction was more pronounced in J. curcas. In this species biochemical limitations in photosynthesis were more prominent, as indicated by increased C(i) values and decreased Rubisco activity. Salinity decreased both the V(cmax) (in vivo Rubisco activity) and J(max) (maximum electron transport rate) more significantly in J. curcas. The higher tolerance in R. communis was positively associated with higher photorespiratory activity, nitrate assimilation and higher cyclic electron flow. The high activity of these alternative electron sinks in R. communis was closely associated with a more efficient photoprotection mechanism. In conclusion, salt tolerance in R. communis, compared with J. curcas, is related to higher electron partitioning from the photosynthetic electron transport chain to alternative sinks. Copyright © 2013 Elsevier GmbH. All rights reserved.

  5. Genome-Wide Association Study Reveals the Genetic Architecture Underlying Salt Tolerance-Related Traits in Rapeseed (Brassica napus L.

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    Jinxiong Shen

    2017-04-01

    Full Text Available Soil salinity is a serious threat to agriculture sustainability worldwide. Salt tolerance at the seedling stage is crucial for plant establishment and high yield in saline soils; however, little information is available on rapeseed (Brassica napus L. salt tolerance. We evaluated salt tolerance in different rapeseed accessions and conducted a genome-wide association study (GWAS to identify salt tolerance-related quantitative trait loci (QTL. A natural population comprising 368 B. napus cultivars and inbred lines was genotyped with a Brassica 60K Illumina Infinium SNP array. The results revealed that 75 single-nucleotide polymorphisms (SNPs distributed across 14 chromosomes were associated with four salt tolerance-related traits. These SNPs integrated into 25 QTLs that explained 4.21–9.23% of the phenotypic variation in the cultivars. Additionally, 38 possible candidate genes were identified in genomic regions associated with salt tolerance indices. These genes fell into several functional groups that are associated with plant salt tolerance, including transcription factors, aquaporins, transporters, and enzymes. Thus, salt tolerance in rapeseed involves complex molecula