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Sample records for rice cold tolerance

  1. Effect and Mechanism of Cold Tolerant Seed-Coating Agents on the Cold Tolerance of Early Indica Rice Seedlings

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hai-qing; ZOU Ying-bin; XIAO Guo-chao; XIONG Yuan-fu

    2007-01-01

    To better understand the effect and mechanism of cold tolerant seed-coating agents on the cold tolerance of rice seedlings,the physiological and biochemical effects of four cold tolerant seed-coating agents (HET, YKJ, YKZYJ, and the ABA seed coating agents) on two early indica rice varieties were studied under chilling stress. The results showed that the rice seedlings treated with cold tolerant seed-coating agents under chilling stress maintained dramatically higher root vigor,POD, CAT and SOD activities, and chlorophyll content, had lower MDA content and electrolyte leakage, and accumulated more soluble sugar and free proline, when compared with the control without the treatment, and finally showed lower plant injury rate. It was indicated that the cold tolerant seed coating agent improved the ability of rice seedlings in resisting to chilling stress. YKZYJ was ranked the first in terms of the efficiency in cold tolerance among the four cold tolerant seed-coating agents tested.

  2. Identification of Cold Tolerance of Rice Germplasm Resource at Germinating Stage in Cold Region

    Institute of Scientific and Technical Information of China (English)

    LIU Hualong; SUN Shiche; WANG Jingguo; ZOU Detang

    2008-01-01

    Total 75 rice varieties (lines) in Heilongiiang Province (or cold region) as germplasm resources were identified for cold tolerance at germinating stage by controlling temperature in artificial incubator. The results showed that the shooting seed rate at the germinating stage could be used as the evaluation index of cold tolerance. The cold tolerance was recorded on 1-9 scale and could be identified by the criteria of five indexes such as highly tolerant (HT), tolerant (T), moderately tolerant (MT), susceptible (S), highly susceptible (HS).

  3. Investigation on the cold tolerance of Dongxiang wild rice at seedling and heading stage

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    CHENDazhou; LUOLijun; XIAOYaqing; ZHAOShaxing; PIYonghua

    1997-01-01

    Dongxiang wild rice is an ecological type of wild rice that grows at 28°14′ N. To study its cold tolerance, Dongxiang wild rice (Shangtang 3) was compared with three cold tolerantlate season rice varieties, i.e. M112, IR24 (indica), and Jing0298 (japonica), and three cold sensitive indica varieties, i.e. 754, 6226, and D5035 in cold condition at seedling and heading stage.

  4. Differential Response of Grain Quality to Cold Water Irrigation in Cold Tolerant and Sensitive Lines of Rice

    Institute of Scientific and Technical Information of China (English)

    HAN Long-zhi; PIAO Zhong-ze; Koh Hee-jong

    2005-01-01

    Three rice varieties and several F3 lines with high and low cold tolerance, selected from F3 segregation lines of two crosses Milyang 23/Tong 88-7 and Milyang 23/TR22183 were used to analyze the effects of cold tolerance on the response of grain quality to cold water irrigation. The result showed that cold water irrigation led to the decrease of rice grain size. The length, length-width ratio and weight of brown rice grain were more sensitively affected by cold water irrigation than the width and thickness. The shape of brown rice grain was not significantly affected by the selection for cold tolerance at the seedling stage (CTS). The gel consistency, amylose content, peak viscosity, cool viscosity, breakdown viscosity and consistency viscosity were decreased, while alkali digestibility value and protein content were increased by cold water irrigation. Under normal irrigation condition the physicochemical properties of milled rice and viscogram components of milled rice flour were not significantly different between lines with high and low cold tolerance. Under cold water irrigation the amylose content, peak viscosity, hot viscosity, final viscosity of rice lines with high CTS or high cold tolerance at the booting stage (CTB) were higher, while the protein content, setback viscosity, breakdown ratio and setback ratio were lower, than those of rice lines with low cold tolerance. This implied that the cold water response of rice grain quality was less sensitive in the lines with high cold tolerance than in the lines with low cold tolerance, and the varietal improvement for cold tolerance would be important for grain quality improvement at the same time.

  5. Cold tolerance evaluation in Chilean rice genotypes at the germination stage

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    Gabriel Donoso Ñanculao

    2013-03-01

    Full Text Available Low temperature is the most important abiotic stress affecting rice (Oryza sativa L. yield in Chile. Rice in Chile is usually planted when the minimum air temperatures are below 12 °C. This temperature is lower than the optimum needed for normal rice germination. Therefore, the aim of this study was to evaluate cold tolerance in 20 experimental lines from the Rice Breeding Program of the Instituto de Investigaciones Agropecuarias (INIA, Chile, at the germination stage. Coleoptile length reduction (CRED, coleoptile length after cold treatment (CLEN, coleoptile length recovery (CREC, and coleoptile regrowth (CREG were evaluated at 13 °C for 4 d using 'Diamante-INIA' as the cold-tolerant control. To find genotypes with cold tolerance (low CRED value and high CLEN, CREC, and CREG values, genotypes were ranked, a biplot of principal components, and cluster analysis were performed. No differences were found among genotypes in the ranking based on CREC value so this trait was not considered. Analysis showed that only three experimental lines had cold tolerance similar to that of 'Diamante-INIA'; all other experimental lines exhibited intermediate to low cold tolerance. These results showed low cold tolerance of some Chilean genotypes at the germination stage, thus confirming the need to evaluate the rest of the germplasm from the Rice Breeding Program.

  6. Cold tolerance in rice germinating seeds revealed by deep RNAseq analysis of contrasting indica genotypes.

    Science.gov (United States)

    Dametto, Andressa; Sperotto, Raul A; Adamski, Janete M; Blasi, Édina A R; Cargnelutti, Denise; de Oliveira, Luiz F V; Ricachenevsky, Felipe K; Fregonezi, Jeferson N; Mariath, Jorge E A; da Cruz, Renata P; Margis, Rogério; Fett, Janette P

    2015-09-01

    Rice productivity is largely affected by low temperature, which can be harmful throughout plant development, from germination to grain filling. Germination of indica rice cultivars under cold is slow and not uniform, resulting in irregular emergence and small plant population. To identify and characterize novel genes involved in cold tolerance during the germination stage, two indica rice genotypes (sister lines previously identified as cold-tolerant and cold-sensitive) were used in parallel transcriptomic analysis (RNAseq) under cold treatment (seeds germinating at 13 °C for 7 days). We detected 1,361 differentially expressed transcripts. Differences in gene expression found by RNAseq were confirmed for 11 selected genes using RT-qPCR. Biological processes enhanced in the cold-tolerant seedlings include: cell division and expansion (confirmed by anatomical sections of germinating seeds), cell wall integrity and extensibility, water uptake and membrane transport capacity, sucrose synthesis, generation of simple sugars, unsaturation of membrane fatty acids, wax biosynthesis, antioxidant capacity (confirmed by histochemical staining of H2O2), and hormone and Ca(2+)-signaling. The cold-sensitive seedlings respond to low temperature stress increasing synthesis of HSPs and dehydrins, along with enhanced ubiquitin/proteasome protein degradation pathway and polyamine biosynthesis. Our findings can be useful in future biotechnological approaches aiming to cold tolerance in indica rice. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  7. Organic Molecules from Biochar Leacheates Have a Positive Effect on Rice Seedling Cold Tolerance.

    Science.gov (United States)

    Yuan, Jun; Meng, Jun; Liang, Xiao; E, Yang; Yang, Xu; Chen, Wenfu

    2017-01-01

    Biochar is known to have a number of positive effects on plant ecophysiology. However, limited research has been carried out to date on the effects and mechanisms of biochar on plant ecophysiology under abiotic stresses, especially responses to cold. In this study, we report on a series of experiments on rice seedlings treated with different concentrations of biochar leacheates (between 0 and 10% by weight) under cold stress (10°C). Quantitative real-time PCR (qRT-PCR) and cold-resistant physiological indicator analysis at low temperatures revealed that the cold tolerance of rice seedlings increased after treatment with high concentrations of biochar leacheates (between 3 and 10% by weight). Results also show that the organic molecules in biochar leacheates enhance the cold resistance of plants when other interference factors are excluded. We suggest that the positive influence of biochar on plant cold tolerance is because of surface organic molecules which likely function by entering a plant and interacting with stress-related proteins. Thus, to verify these mechanisms, this study used gas chromatography-mass spectrometry (GC-MS) techniques, identifying 20 organic molecules in biochar extracts using the National Institute of Standards and Technology (NIST) library. Further, to illustrate how these organic molecules work, we utilized the molecular docking software Autodock to show that the organic molecule 6-(Methylthio)hexa-1,5-dien-3-ol from biochar extracts can dock with the stress-related protein zinc-dependent activator protein (ZAP1). 6-(Methylthio)hexa-1,5-dien-3-ol has a similar binding mode with the ligand succinic acid of ZAP1. It can be inferred that the organic molecule identified in this study performs the same function as the ZAP1 ligand, stimulating ZAP1 driving cold-resistant functions, and enhancing plant cold tolerance. We conclude that biochar treatment enhances cold tolerance in rice seedlings via interactions between organic molecules and

  8. Genetic analysis of cold tolerance at the germination and booting stages in rice by association mapping.

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    Yinghua Pan

    Full Text Available Low temperature affects the rice plants at all stages of growth. It can cause severe seedling injury and male sterility resulting in severe yield losses. Using a mini core collection of 174 Chinese rice accessions and 273 SSR markers we investigated cold tolerance at the germination and booting stages, as well as the underlying genetic bases, by association mapping. Two distinct populations, corresponding to subspecies indica and japonica showed evident differences in cold tolerance and its genetic basis. Both subspecies were sensitive to cold stress at both growth stages. However, japonica was more tolerant than indica at all stages as measured by seedling survival and seed setting. There was a low correlation in cold tolerance between the germination and booting stages. Fifty one quantitative trait loci (QTLs for cold tolerance were dispersed across all 12 chromosomes; 22 detected at the germination stage and 33 at the booting stage. Eight QTLs were identified by at least two of four measures. About 46% of the QTLs represented new loci. The only QTL shared between indica and japonica for the same measure was qLTSSvR6-2 for SSvR. This implied a complicated mechanism of old tolerance between the two subspecies. According to the relative genotypic effect (RGE of each genotype for each QTL, we detected 18 positive genotypes and 21 negative genotypes in indica, and 19 positive genotypes and 24 negative genotypes in japonica. In general, the negative effects were much stronger than the positive effects in both subspecies. Markers for QTL with positive effects in one subspecies were shown to be effective for selection of cold tolerance in that subspecies, but not in the other subspecies. QTL with strong negative effects on cold tolerance should be avoided during MAS breeding so as to not cancel the effect of favorable QTL at other loci.

  9. Over-Expression of ICE1 Gene in Transgenic Rice Improves Cold Tolerance

    Institute of Scientific and Technical Information of China (English)

    XIANG Dian-jun; HU Xiang-yang; ZHANG Yu; YIN Kui-de

    2008-01-01

    ICE1, an Arabidopsis thaliana transcription factor gene, was cloned by RT-PCR and successfully transformed into rice variety Kenjiandao 10 by the Agrobacterium-mediated transformation method. PCR amplification and Southern blot analysis indicated that ICE1 had been integrated into rice genome. Compared with the non-transgenic plants, the transgenic plants exhibited high resistance to hygromycin B and were consistent with the Mendelian inheritance of a single copy of the transgenic ICE1. Under the low temperature stress, the transgenic plants showed the lower mortality rate and the increased proline content. These results suggest that the Arabidopsis ICE1 is functional in rice and the over-expression of ICE1 improves the tolerance to cold stress in rice.

  10. OsRAN2, essential for mitosis, enhances cold tolerance in rice by promoting export of intranuclear tubulin and maintaining cell division under cold stress.

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    Chen, Na; Xu, Yunyuan; Wang, Xin; DU, Cheng; DU, Jizhou; Yuan, Ming; Xu, Zhihong; Chong, Kang

    2011-01-01

    With global climate change, abnormally low temperatures have affected the world's rice production. Many genes have been shown to be essential for molecular improvement of rice cold-tolerance traits. However, less is known about the molecular cellular mechanism of their response to cold stress. Here, we investigated OsRAN2 involved in regulation of cell division during cold stress in rice. Expression of OsRAN2 was increased under cold treatment, but not during salt and drought stress. The mean root mitotic index was closely related to the expression level of OsRAN2. Knockdown transgenic rice lines showed an aberrant organization of spindles during mitosis and stunted growth during development. Overexpression of OsRAN2 enhanced cold tolerance in rice. The transgenic rice overexpressing OsRAN2 showed maintained cell division, decreased proportion of cells with intranuclear tubulin and formation of a normal nuclear envelope under the cold condition. Our study suggests a mechanism for OsRAN2 in regulating cold resistance in rice by maintaining cell division through promoting the normal export of intranuclear tubulin at the end of mitosis. This insight could help improve the cold-tolerance trait in rice.

  11. Glycine increases cold tolerance in rice via the regulation of N uptake, physiological characteristics, and photosynthesis.

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    Xiaochuang, Cao; Chu, Zhong; Lianfeng, Zhu; Junhua, Zhang; Hussain, Sajid; Lianghuan, Wu; Qianyu, Jin

    2017-03-01

    To investigate the response of rice growth and photosynthesis to different nitrogen (N) sources under cold stress, hydroponic cultivation of rice was done in greenhouse, with glycine, ammonium, and nitrate as the sole N sources. The results demonstrate that exposure to low temperature reduced the rice biomass and leaf chlorophyll content, but their values in the glycine-treated plants were significantly higher than in the ammonium- and nitrate-treated plants. This might be attributed to the higher N uptake rate and root area and activity in the glycine-treated plants. The glycine-treated plants also maintained high contents of soluble proteins, soluble sugars, and proline as well as enhanced antioxidant enzyme activities to protect themselves against chilling injury. Under cold stress, reduced stomatal conductance (gs) and effective quantum efficiency of PSII (ΦPSII) significantly inhibited the leaf photosynthesis; however, glycine treatment alleviated these effects compared to the ammonium and nitrate treatments. The high non-photochemical quenching (qN) and excess energy dissipative energy (Ex) in the glycine-treated plants were beneficial for the release of extra energy, thereby, strengthening their photochemical efficiency. We, therefore, conclude that the strengthened cold tolerance of glycine-treated rice plants was closely associated with the higher accumulation of dry matter and photosynthesis through the up-regulation of N-uptake, and increase in the content of osmoprotectants, activities of the antioxidant defense enzymes, and photochemical efficiency. The results of the present study provide new ideas for improving the plant tolerance to extreme temperatures by nutrient resource management in the cold regions. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  12. Identification and mapping of quantitative trait loci controlling cold-tolerance of Chinese common wild rice (O. rufipogon Griff.) at booting to flowering stages

    Institute of Scientific and Technical Information of China (English)

    LIU Fengxia; SUN Chuanqing; TAN Lubin; FU Yongcai; LI Dejun; WANG Xiangkun

    2003-01-01

    An advanced backcross population of rice was used to identify the quantitative trait locus (QTL) controlling the cold-tolerance at booting to flowering stages. The recipient, Guichao 2 (GC2), was a commercial Indica rice; the donor Dongxiang common wild rice, was an accession of common wild rice (DXCWR, Oryza rufipogon Griff.). Three QTLs for cold-tolerance were detected on chromosomes 1, 6and 11. Two of them coming from DXCWR could enhance the cold-tolerance of the backcross progenies. Moreover, one sterility QTL that could reduce the seed set rate of the backcross progenies by 78% was mapped on chromosome 5.

  13. Cold Tolerance of Core Collection at Booting Stage Associated with Eco-geographic Distribution in Yunnan Rice Landrace (Oryza sativa),China

    Institute of Scientific and Technical Information of China (English)

    LI Shen-chong; LIU Jia-fu; ZENG Ya-wen; WANG Lu-xiang; SHEN Shi-quan; PU Xiao-ying; LI Zi-chao; WANG Xiangkun; WEN Guo-song; YANG Zhong-yi

    2004-01-01

    Four hundred and seventy-seven accessions of the second core collection of rice landrace from five rice cropping regions (16 prefectures) of Yunnan Province, China, were evaluated for cold tolerance at booting stage. The results showed as follows: 1) there was a significant positive correlation (0.588**) between anther length and seed setting rate under natural low temperature conditions but was not significant in greenhouse (0.080). 2) there were significant differences in cold tolerance among cora collections from different cropping regions under natural low temperature conditions while a negligible cold damage in greenhouse (with a seed setting rate approaching or exceeding 70%) for cold tolerance evaluation. Cold tolerance of core collection from Northwest Yunnan cold highland japonica region was the strongest, and that from south marginal paddy-upland rice region was the most sensitive, suggesting that the breeding goals for cold tolerance should be different in various rice cropping regions. 3) there were remarkable differences in cold tolerance of core collections from different prefectures of Yunnan Province under natural low temperature conditions. Based on the reduction of seed setting rate and characteristics of natural climate, the 16prefectures could be divided into three categories, i.e. serious cold damage, cold damage and slight cold damage regions. 4)Difference of cold tolerance between different rice cropping regions and prefectures revealed further that temperature change caused by elevation and latitude was not only a dominant factor for differentiation of japonica and indica but also the basic reason that the genetic diversity and six ecological group of indica and japonica were being developed and, even the critical factor leading to the formation of the cold tolerance gene as well. The cold tolerance at booting stage could be believed to be resulted from the long term co-evolution between Yunnan rice landrce and cold stress in rice cropping

  14. QTLs conferring cold tolerance at the booting stage of rice using recombinant inbred lines from a japonica x indica cross.

    Science.gov (United States)

    Andaya, V C; Mackill, D J

    2003-04-01

    Low temperature stress is common for rice grown in temperate regions and at high elevations in the tropics. The most senstive stage to this stress is booting, about 11 days before heading. Japonica cultivars are known to be more tolerant than indicas. We constructed a genetic map using 191 recombinant inbred lines derived from a cross between a temperate japonica, M-202, and a tropical indica, IR50, in order to locate quantitative trait loci (QTLs) conferring cold tolerance. The map with a total length of 1,276.8 cM and an average density of one marker every 7.1 cM was developed from 181 loci produced by 175 microsatellite markers. Cold tolerance was measured as the degree of spikelet sterility of treated plants at a 12 degrees C temperature for 5 days in the growth chamber. QTLs on chromosomes 1, 2, 3, 5, 6, 7, 9 and 12 were identified to confer cold tolerance at the booting stage. The QTL contribution to the phenotypic variation ranged from 11 to 17%. The two QTLs with the highest contribution to variation, designated qCTB2a and qCTB3, were derived from the tolerant parent, M-202, each explaining approximately 17% of the phenotypic variance. Two of the eight QTLs for cold tolerance were contributed by IR50.

  15. QTLs Analysis of Cold Tolerance During Early Growth Period for Rice

    Institute of Scientific and Technical Information of China (English)

    HE Xiu-ying; HAN Long-zhi; XU Shi-ping; QIAO Yong-li; LIAO Yao-ping; CAO Gui-lan; MAO Xing-xue; ZHANG Yuan-yuan; WENG Ke-nan; AN Yong-ping; CHEN Zhao-ming; YE Jong-doo; CHEN Yue-han; KOH Hee-jong; XIAO Wan-sheng

    2004-01-01

    The quantitative trait loci (QTLs) for cold tolerance during early growth period were identified using a F2:3 population microsatellite markers. The cold tolerance at the seedling and tillering stages, and the growth ability of seedling under low temperature conditions were evaluated. All of the traits associated with cold tolerance at early growth stages appeared a continuous distribution near to normal in F3 lines, these were inherited as quantitative traits controlled by polygenes. Three QTLs on chromosomes 1, 5 and 9, which associated with cold tolerance at the seedling stage were detected. Among them, qCTS1accounted for 15.5% of observed phenotypic variation; Five QTLs on chromosomes 2, 3, 7, 9 and 11, associated with cold tolerance at the tillering stage were found, which explained lower percentage of observed phenotypic variation; Four QTLs on chromosomes 1,2, 11 and 12, which associated with the growth ability of seedling under low temperature conditions were found, among them,qGAS2 and qGAS12 explained 26.6 and 42.9% of observed phenotypic variation, respectively, which were major genes.

  16. Detection of QTL for Cold Tolerance at Bud Bursting Stage Using Chromosome Segment Substitution Lines in Rice (Oryza sativa)

    Institute of Scientific and Technical Information of China (English)

    LIN Jing; WANG Yan-ping; WANG Cai-lin; ZHU Wen-yin; ZHANG Ya-dong; ZHU Zhen; ZHAO Ling; CHEN Tao; ZHAO Qing-yong; ZHOU Li-hui; FANG Xian-wen

    2011-01-01

    The cold tolerance at the bud bursting stage (CTB) was evaluated at 5℃ by using a set of 95 chromosome segment substitution lines (CSSLs) derived from an indica rice 9311 and a japonica rice Nipponbare with a genetic background of 9311.The result showed that six CSSLs had slightly stronger effect on CTB than 9311.Total four quantitative trait loci (QTLs) for CTB were preliminary mapped on chromosomes 5 and 7 by substitution mapping.qCTB-5-1,qCTB-5-2 and qCTB-5-3 were mapped in the region of RM267-RM1237,RM2422-RM6054 and RM3321-RM1054,which were 21.3 cM,27.4 cM and 12.7 cM in genetic distance on rice chromosome 5,respectively.qCTB-7 was mapped in a 6.8-cM region of RM11-RM2752 on rice chromosome 7.

  17. Genetic architecture of cold tolerance in rice at the seedling stage and heading determined through genome-wide association studies

    Science.gov (United States)

    Cold stress at the seedling stage limits rice (Oryza sativa L.) production in temperate regions or at high elevations in the tropics due to poor plant stand establishment and delayed maturity. At the heading stage, cold temperature causes sterility, thus decreasing grain yield. Initially, the Rice D...

  18. Genetic Architecture of Cold Tolerance in Rice (Oryza sativa) Determined through High Resolution Genome-Wide Analysis

    Science.gov (United States)

    Cold temperature is an important abiotic stress which negatively affects morphological development and seed production in rice (Oryza sativa L.). At the seedling stage, cold stress causes poor germination, seedling injury and poor stand establishment; and at the reproductive stage cold decreases se...

  19. QTL analysis of the rice seedling cold tolerance in a double haploid population derived from anther culture of a hybrid between indica and japonica rice

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A doubled haploid population,derived from anther culture of Fl hybrid between a typical indica cv.and a japonica cv.has been used to investigate the seedling cold tolerance (SCT) in growth cabinet.By dynamically analyzing every day's survival percentages of the parents and DH lines under 7-d cold plus 9-d normal temperature condition,the quantitative trait loci (QTLs) for SCT have been mapped based on a molecular linkage map constructed from this population.The results show that two parents had significant differences in SCT and the segregation of SCT in DH lines was basically a continuous distribution with most serious injury on the 6th d of the cold treatment.A total of 4 QTLs for SCT have been identified on chromosomes 1,2,3 and 4 respectively.The additive effects of qSCT-1,qSCT-2 and qSCT-3 have been contributed by the japonica cv JX17,but that of qSCT-4 has been contributed by the indica cv ZYQ8.The mechanism of SCT seems complicated since the above 4 QTLs detected at different stages during the treatment.Further study on the genotypes for these SCT QTLs in the DH lines shows transgressive segregation.It is demonstrated that the lines with stronger SCT over JXl7 have 3-4 loci for SCT.Integration of these QTLs into an appropriate variety may lead to a successful rice breeding program for cold tolerance.

  20. Melhoramento genético para tolerância ao frio em arroz irrigado Breeding for cold tolerance in irrigated rice

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    Renata Pereira da Cruz

    2000-10-01

    Full Text Available O melhoramento genético para tolerância ao frio é apresentado como estratégia para enfrentar o problema de temperatura baixa no Rio Grande do Sul durante o período de cultivo do arroz irrigado. A ocorrência de temperaturas baixas em outros países é comparada com a situação no sul do Brasil. Os estádios de desenvolvimento da planta mais afetados pela temperatura baixa, as estratégias de seleção disponíveis sob condições controladas e os problemas encontrados para o melhoramento dessa característica são discutidos. Finalmente, estratégias de seleção promissoras baseadas em estudos de Fisiologia e Biotecnologia são apresentadas.Genetic breeding for cold tolerance is presented as a strategy to confront the problem of chilling temperature in Rio Grande do Sul during irrigated rice crop season. The occurence of chilling temperatures in other countries is compared to the situation in Southern Brazil. Plant developmental stages most affected by low temperatures, selection strategies available in controlled conditions and difficulties found for breeding this trait are discussed. Finally, promising selection strategies based on Physiology and Biotechnology studies are presented.

  1. 东北粳稻分蘖期耐冷性鉴定及SSR标记关联分析%Association Analysis of Rice Cold Tolerance at Tillering Stage with SSR Markers in japonica Cultivars in Northeast China

    Institute of Scientific and Technical Information of China (English)

    张艳梅; 邹德堂

    2012-01-01

    The cold tolerance of rice at the tillering stage was evaluated with 140 rice cultivars(lines) from Northeast China as materials and association analysis was conducted among 96 selected materials which differed in cold tolerance with 84 SSR markers. The experimental results showed: there were 20. 0% of rice materials with better cold tolerance,30. 71 % with intermediate cold tolerance and 49. 28% with worse cold tolerance! Correlation analysis showed that rice cold tolerance at the tillering stage was significantly positively correlated with seed setting rate and single panicle weight. Rice cold tolerance at the tillering stage and growth duration were significantly negatively correlated) Eighteen markers associated with rice cold tolerance were detected through the association analysis, markers like RM214,RM445,RM5O6,RM1O6,RM215,RM182,RM27O and RM229 were mutual authentication with family-based linkage mapping. These markers can be used for selection of rice cold tolerance resources in Northeast China. Finally, a serial of elite alleles, loci and their carrier materials were screened out by anglicizing these associated markers.%以140份东北粳稻品种(系)为材料进行分蘖期耐冷鉴定,用84个SSR标记对耐冷性差异较大的96份材料进行基于SSR标记的关联分析.结果表明,供试材料强耐冷品种(系)占20%,中间型(系)占30.71%,不耐冷品种(系)占49.28%;分蘖期耐冷性与结实率和单株穗重呈极显著正相关,与生育期呈极显著负相关;关联分析得到18个位点与分蘖期耐冷性关联,其中标记RM214,RM445,RM506,RM106.RM215,RM182,RM270和RM229与前人研究获得的水稻耐冷性QTL定位结果吻合.这些标记可作为东北粳稻耐冷性资源筛选重点选择的标记.还通过优异等位基因的挖掘,得到一系列的优异等位变异及载体材料.

  2. Identification of a QTL for cold tolerance at early seedling stage via RFLP markers in rice (O. Sativa L. )

    Institute of Scientific and Technical Information of China (English)

    YANChangjie; LIXin; YUHengriu; CHENGZhukuan; GUMinghang; ZHULihuang

    1998-01-01

    Recently,beneficial genes in japonica and indica varieties were widely used from each other to promote the yield and insect and disease resistance,etc.in rice.Most indica varieties are susceptible to low temperature,and cold injury will affect the rice yield at various growth stages.

  3. Effect of Rapid Cold Hardening on the Cold Tolerance of the Larvae of the Rice Stem Borer,Chilo suppressalis (Walker)

    Institute of Scientific and Technical Information of China (English)

    QIANG Cheng-kui; DU Yu-zhou; YU Ling-ya; CUI Ya-dong; ZHENG Fu-shan; LU Ming-xing

    2008-01-01

    The effects of rapid cold hardening(RCH)on the cold tolerance of the last instar larvae of Chilo suppressalis(Walker) were evaluated for the first time.The discriminating temperature,induction,detection,duration and extent of RCH of the larvae in the laboratory were tested,and the supercooling points(SCPs)and the contents of water and lipid of the larvae after RCH treatment were determined,respectively.The results showed that the discriminating temperature of the larvae was about-21℃.Mean survival rates of the larvae which exposed to either 0 or 5℃ for 2 and 4 h before exposure to the discriminating temperature for 2 h were significantly higher than those of the control groups(P<0.05).Moreover,the highest survival rate appeared in the larvae after 0℃ for 4 h treatment.The protection against low temperature gained by RCH at 0℃ for 4 h was rapidly lost on return to 28℃.Mean survival rates of RCH larvae were significantly higher than those of non-acclimated(NACC)larvae and acclimation(ACC)larvae when they were exposed to the discriminating temperature for 2 or 4 h(P<0.05).Moreover,the rates of NACC,ACC,RCH and ACC+RCH larvae from 2 to 6 h to the discriminating temperature resulted in a significant decline.The values of SCPs and the contents of lipid of the larvae which exposed tO either 0 or 5℃ for 2 and 4 h showed no significant difference at 0.05 level compared to those of the control groups.But the contents of water in the larvae were obviously decreased.Therefore,it could be concluded that RCH could enhance cold tolerance and affect partly physiological and biochemical components of the larvae of C.suppressalis,but the underlying mechanisms needs to be further explored.

  4. Effects of Chilling Stress on Photosynthetic Rate and Chlorophyll Fluorescence Parameter in Seedlings of Two Rice Cultivars Differing in Cold Tolerance

    Institute of Scientific and Technical Information of China (English)

    WANG Guo-li; GUO Zhen-fei

    2005-01-01

    A cold-tolerant cultivar, Xiangnuo 1, and a cold-sensitive cultivar, IR50, were used to study the influence of chilling on photosynthetic rate and chlorophyll fluorescence parameters in rice seedlings. The photosynthetic rates declined dramatically during chilling, and decreased by 48.7% and 67.5% in Xiangnuo 1 and IR50 seedlings, respectively, after being subjected to chilling treatment for two days. Chlorophyll fluorescence measurements showed that relatively higher qP and qNP in Xiangnuo 1 were maintained to dissipate the redundant excitation energy and protect the reaction centers from chill injury; accordingly, redundant excitation energy accumulated less in the reaction centers, and antenna systems were less injured by chilling in Xiangnuo 1. On the contrary, in IR50, qP and qNP declined rapidly while Ex increased, as the chilling persisted. This result indicated that the reaction centers and antenna systems in IR50 were damaged severely by chilling, which led to the lower photosynthetic rate.

  5. Rice's Salt Tolerance Gene Cloned

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ In cooperation with US colleagues, CAS researchers have made significant progress in their studies into functional genes for key agronomic traits by cloning SKC1, a salt-tolerant functional gene of rice and making clear its biological functions and mechanisms. This pioneering work,which was reported in the Oct. issue of Nature Genetics (37:1141-1146), is believed to hold promise to increase the output of the crop plant in this country.

  6. Cytological and SSR Analysis on Cold-tolerant Gene Introgression Lines from Dongxiang Wild Rice%东乡野生稻耐冷渐渗系的细胞学观察及SSR分析

    Institute of Scientific and Technical Information of China (English)

    曹娟芳; 罗向东; 邓晓娟; 戴亮芳; 胡标林; 张帆涛; 谢建坤

    2012-01-01

    Two previously identified strong cold-tolerant introgression lines of IL5243 and IL5335 from Dongxiang wild rice (Oryza rufipogon Griff. ) were used to investigate the meiosis behavior,chromosome recombination and the molecular evidence of alien genes introgression. The results showed that the rate of pollen mother cells (PMC) with normal meiotic behavior in the IL5243 and IL5335 was to 89. 93% and 90. 22% .respectively. And they finally formed the normal mature pollen;The rates of pollen germination in vitro were (83. 03±2. 82)% and (81. 96±1. 73)%,respectively. There were no significant differences between the cold-tolerant introgression lines and their parents. However,at meiosis I, the low frequency of abnormal chromosome behavior was observed in IL5243 and lL5335,such as univalent,8-shape bivalent, multivalent and some PMCs (3. 95%~5. 15%) exist lagging chromosomes at anaphase I and so on, which suggested that there were genetic exchange and recombination between cultivated rice and common wild rice. In addition, the high frequency of double nucleoli was observed at pachytene in the two cold tolerance introgression lines (IL5335 and IL5243 were 38. 9% and 27. 0% .respectively) .while their parents only had one nucleolus. Through SSR markers and structure analysis, we further confirmed that introgression of some Dongxiang wild rice DNA fragments in the strong cold resistance introgression lines through chromosome exchange and recombination between the cultivated rice and the wild rice. These results laid a foundation for further excavating and using this rice cold-tolerant gene in the future.%以前期鉴定筛选的2个东乡野生稻强耐冷渐渗系(IL5243和IL5335)为试材,研究其减数分裂时期的染色体行为特征及外源基因的渗入分子证据.结果表明:(1)IL5243和IL5335中正常减数分裂的花粉母细胞分别达89.93%和90.22%,最终形成正常的成熟花粉粒,花粉离体萌发率分别为(83.03±2.82)%和(81.96±1

  7. Tracking the evolution of a cold stress associated gene family in cold tolerant grasses

    DEFF Research Database (Denmark)

    Sandve, Simen R; Rudi, Heidi; Asp, Torben

    2008-01-01

    Background Grasses are adapted to a wide range of climatic conditions. Species of the subfamily Pooideae, which includes wheat, barley and important forage grasses, have evolved extreme frost tolerance. A class of ice binding proteins that inhibit ice re-crystallisation, specific to the Pooideae...... to the repeat motifs of the IRI-domain in cold tolerant grasses. Finally we show that the LRR-domain of carrot and grass IRI proteins both share homology to an Arabidopsis thaliana LRR-trans membrane protein kinase (LRR-TPK). Conclusion The diverse IRI-like genes identified in this study tell a tale...... of a complex evolutionary history including birth of an ice binding domain, a burst of gene duplication events after cold tolerant grasses radiated from rice, protein domain structure differentiation between paralogs, and sub- and/or neofunctionalisation of IRI-like proteins. From our sequence analysis we...

  8. Cold tolerance at the germination stage of rice: methods of evaluation and characterization of genotypes Tolerância ao frio no estádio de germinação em arroz: métodos de avaliação e caracterização de genótipos

    Directory of Open Access Journals (Sweden)

    Renata Pereira da Cruz

    2004-02-01

    Full Text Available Rice cold tolerance at the germination stage is important in Rio Grande do Sul (RS where temperatures below 15°C prevent or reduce germination and plant establishment in early sowings. The present study aimed at identifying an adequate method for cold tolerance evaluation of the rice germination stage and at verifying the variability among 24 rice genotypes of different origins. Cold tolerance was evaluated in experiment I, germination under two conditions: 13°C for 28 days and 28°C for seven days, and in experiment II, germination under 28°C for 72 hours, 13°C for 96 hours and again 28°C for 72 hours. In experiment I measured characteristics were germination index, percentage of seeds with coleoptile length superior to 5 mm and percentage of reduction in coleoptile length due to cold. In experiment II the measured characteristic was coleoptile regrowth after the cold period. Cold tolerance varied among genotypes studied in both experiments, but only the percentage of reduction in coleoptile length and coleoptile regrowth allowed a better distinction between the tolerant checks and the susceptible one. In general, genotypes belonging to the Japonica subspecies presented higher cold tolerance than Indica, but there was variability within subspecies. The most adequate method of evaluation of cold tolerance is through percentage of reduction in coleoptile length and coleoptile regrowth. Among Japonica genotypes, Quilla 64117 and Diamante presented the highest cold tolerance, and among Indica, cultivars BR-IRGA 410 and IRGA 416 were the most cold tolerant at the germination stage.A tolerância ao frio em arroz no estádio de germinação é importante no Rio Grande do Sul (RS onde temperaturas abaixo de 15°C impedem ou reduzem a germinação e o estabelecimento das plantas em semeaduras precoces. O presente trabalho teve por objetivos identificar uma metodologia adequada para avaliação da tolerância ao frio na germinação em arroz e

  9. Improving Drought Tolerance of Rice by Designed QTL Pyramiding

    Institute of Scientific and Technical Information of China (English)

    Z.K. Li; Y. Sun; L.H. Zhu; D. Dwivedi; Y.M. Gao; T.Q. Zheng; R. Lafitte; J.L. Xu; D. Mackill; B.Y. Fu; J.Domingo

    2007-01-01

    @@ Drought is the most important factor limiting rice yields in the rainfed areas of Asia. To overcome the problem, we developed a new strategy 'designed QTL pyramiding' to more efficiently develop drought tolerant (DT)rice cultivars.

  10. Cold Tolerance of Plants Used for Cold-Regions Revegetation

    Science.gov (United States)

    1990-10-01

    from tempted to transfer the rye cold-tolerance genome to increased concentrations of solutes in cells and extra- wheat in hybrids. While the gene...Journal, 76: 516-517. Tryon, E.H. and R.P. True (1952) Blister shake of Yelenosky, G. (1988) Capacity of citrus flowers to yellow poplar. Bulletin of the

  11. Mechanism of Salt Tolerance in Rice

    Institute of Scientific and Technical Information of China (English)

    N. HUSSAIN; A. ALI; G. SARWAR; F. MUJEEB; M. TAHIR

    2003-01-01

    Shaheen Basma ti was evolved as a salt tolerant fine rice va riety by the Soil Salinity Research Institute,Pindi Bhattian, Pakistan. Water culture studies were conducted to investigate the physiological mechanismexercised by this variety in particular and rice plant in general to face the saline environment. Performanceof this rice variety and the concentration and uptake of ions were studied under stress of three salinity levels(30, 60 and 90 mmol L-1) created with NaCl. Recorded data indicated that shoot dry matter was notsignificantly affected by all the three levels of salinity. However, NaCl levels of 60 and 90 mmol L-1 affectedthe root dry matter significantly. Sodium concentration and uptake was enhanced significantly in root andshoot at the first level of salinity (30 mmol L-1) but thereafter the differences were non-significant, indicatingthe preferential absorption of this cation. The K concentration decreased significantly in shoots at all thelevels. The impact was less pronounced in roots as far as K absorption was concerned. The effect on Ca andMg concentrations was not significant. The values of K:Na, Ca:Na and (Ca+Mg):Na ratios in shoot and rootwere comparatively low under stress conditions, indicating that selective ion absorption may be the principalsalt tolerance mechanism of variety Shaheen Basmati when grown in a saline medium.

  12. High resolution genotyping by restriction enzyme-phased sequencing of advanced backcross lines of rice exhibiting differential cold stress recovery

    Science.gov (United States)

    Advanced backcross rice lines MIb 4853-9 and 6885-2 harbor major seedling cold tolerance QTL qCTS4 and qCTS12 from the temperate japonica M202 in the genetic background of the indica IR50. Previous studies have shown that these lines exhibit the same tolerance, based on visual ratings, under constan...

  13. Supra-optimal expression of the cold-regulated OsMyb4 transcription factor in transgenic rice changes the complexity of transcriptional network with major effects on stress tolerance and panicle development

    KAUST Repository

    Park, Myoungryoul

    2010-09-28

    The R2R3-type OsMyb4 transcription factor of rice has been shown to play a role in the regulation of osmotic adjustment in heterologous overexpression studies. However, the exact composition and organization of its underlying transcriptional network has not been established to be a robust tool for stress tolerance enhancement by regulon engineering. OsMyb4 network was dissected based on commonalities between the global chilling stress transcriptome and the transcriptome configured by OsMyb4 overexpression. OsMyb4 controls a hierarchical network comprised of several regulatory sub-clusters associated with cellular defense and rescue, metabolism and development. It regulates target genes either directly or indirectly through intermediary MYB, ERF, bZIP, NAC, ARF and CCAAT-HAP transcription factors. Regulatory sub-clusters have different combinations of MYB-like, GCC-box-like, ERD1-box-like, ABRE-like, G-box-like, as1/ocs/TGA-like, AuxRE-like, gibberellic acid response element (GARE)-like and JAre-like cis-elements. Cold-dependent network activity enhanced cellular antioxidant capacity through radical scavenging mechanisms and increased activities of phenylpropanoid and isoprenoid metabolic processes involving various abscisic acid (ABA), jasmonic acid (JA), salicylic acid (SA), ethylene and reactive oxygen species (ROS) responsive genes. OsMyb4 network is independent of drought response element binding protein/C-repeat binding factor (DREB/CBF) and its sub-regulons operate with possible co-regulators including nuclear factor-Y. Because of its upstream position in the network hierarchy, OsMyb4 functions quantitatively and pleiotrophically. Supra-optimal expression causes misexpression of alternative targets with costly trade-offs to panicle development. © 2010 Blackwell Publishing Ltd.

  14. Supra-optimal expression of the cold-regulated OsMyb4 transcription factor in transgenic rice changes the complexity of transcriptional network with major effects on stress tolerance and panicle development.

    Science.gov (United States)

    Park, Myoung-Ryoul; Yun, Kil-Young; Mohanty, Bijayalaxmi; Herath, Venura; Xu, Fuyu; Wijaya, Edward; Bajic, Vladimir B; Yun, Song-Joong; De Los Reyes, Benildo G

    2010-12-01

    The R2R3-type OsMyb4 transcription factor of rice has been shown to play a role in the regulation of osmotic adjustment in heterologous overexpression studies. However, the exact composition and organization of its underlying transcriptional network has not been established to be a robust tool for stress tolerance enhancement by regulon engineering. OsMyb4 network was dissected based on commonalities between the global chilling stress transcriptome and the transcriptome configured by OsMyb4 overexpression. OsMyb4 controls a hierarchical network comprised of several regulatory sub-clusters associated with cellular defense and rescue, metabolism and development. It regulates target genes either directly or indirectly through intermediary MYB, ERF, bZIP, NAC, ARF and CCAAT-HAP transcription factors. Regulatory sub-clusters have different combinations of MYB-like, GCC-box-like, ERD1-box-like, ABRE-like, G-box-like, as1/ocs/TGA-like, AuxRE-like, gibberellic acid response element (GARE)-like and JAre-like cis-elements. Cold-dependent network activity enhanced cellular antioxidant capacity through radical scavenging mechanisms and increased activities of phenylpropanoid and isoprenoid metabolic processes involving various abscisic acid (ABA), jasmonic acid (JA), salicylic acid (SA), ethylene and reactive oxygen species (ROS) responsive genes. OsMyb4 network is independent of drought response element binding protein/C-repeat binding factor (DREB/CBF) and its sub-regulons operate with possible co-regulators including nuclear factor-Y. Because of its upstream position in the network hierarchy, OsMyb4 functions quantitatively and pleiotrophically. Supra-optimal expression causes misexpression of alternative targets with costly trade-offs to panicle development.

  15. 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.

  16. Tracking the evolution of a cold stress associated gene family in cold tolerant grasses

    DEFF Research Database (Denmark)

    Sandve, Simen R; Rudi, Heidi; Asp, Torben

    2008-01-01

    subfamily lineage, have been identified in perennial ryegrass and wheat, and these proteins are thought to have evolved from a leucine-rich repeat phytosulfokine receptor kinase (LRR-PSR)-like ancestor gene. Even though the ice re-crystallisation inhibition function of these proteins has been studied...... of a complex evolutionary history including birth of an ice binding domain, a burst of gene duplication events after cold tolerant grasses radiated from rice, protein domain structure differentiation between paralogs, and sub- and/or neofunctionalisation of IRI-like proteins. From our sequence analysis we......Background Grasses are adapted to a wide range of climatic conditions. Species of the subfamily Pooideae, which includes wheat, barley and important forage grasses, have evolved extreme frost tolerance. A class of ice binding proteins that inhibit ice re-crystallisation, specific to the Pooideae...

  17. Caracterização de famílias mutantes de arroz para tolerância ao frio nos períodos vegetativo e reprodutivo Characterization of rice families for cold tolerance in the vegetative and reproductive phases

    Directory of Open Access Journals (Sweden)

    Andreza Figueirola Martins

    2007-01-01

    Full Text Available As temperaturas baixas que ocorrem durante o cultivo do arroz na Região Sul do Brasil causam prejuízos ao rendimento e à qualidade dos grãos de arroz. Genótipos tolerantes a baixas temperaturas seriam uma alternativa para minimizar tais prejuízos. Desse modo, o presente trabalho teve como objetivo avaliar a tolerância ao frio em famílias mutantes de arroz (geração M4 nos períodos, vegetativo e reprodutivo, como forma de identificação de variabilidade genética para o caráter. Para a avaliação das famílias mutantes quanto à tolerância ao frio, no período vegetativo, foram utilizadas 10 sementes de cada família colocadas em bandejas celuladas, sendo as plântulas mantidas em casa de vegetação à temperatura de 13 ºC por 10 dias em sala climatizada, com fotoperíodo de 12 horas. A avaliação do período reprodutivo consistiu na aplicação de frio na antese, sendo caracterizada por um estresse de 15 ºC por sete dias. Pelos resultados verificou-se que no período vegetativo, seis famílias tiveram 0-20% de redução na estatura, com um elevado grau de tolerância. Para o período reprodutivo não foram encontradas famílias com tolerância superior à testemunha diamante.Low temperatures that occur during the cultivation of rice in the Southern region of Brazil cause reductions in to the yield and quality of the rice grain. Genotypes tolerant to low temperatures would be an alternative to minimize these problems. In the present work cold tolerance was evaluated in rice families (M4 generation in the vegetative and reproductive phases, in order to identify possible genetic variability. For the evaluation in the vegetative stage, 10 seeds from each family were placed in cell trays and kept at 13 ºC for 10 days in controlled chamber with 12 hour day light. The evaluation at the reproductive stage consisted of the application of low temperature at anthesis, by a stress of 15 ºC for 7 days. The results suggest that in the

  18. Molecular approaches to improve rice abiotic stress tolerance.

    Science.gov (United States)

    Mizoi, Junya; Yamaguchi-Shinozaki, Kazuko

    2013-01-01

    Abiotic stress is a major factor limiting productivity of rice crops in large areas of the world. Because plants cannot avoid abiotic stress by moving, they have acquired various mechanisms for stress tolerance in the course of their evolution. Enhancing or introducing such mechanisms in rice is one effective way to develop stress-tolerant cultivars. Based on physiological studies on stress responses, recent progress in plant molecular biology has enabled discovery of many genes involved in stress tolerance. These genes include regulatory genes, which regulate stress response (e.g., transcription factors and protein kinases), and functional genes, which protect the cell (e.g., enzymes for generating protective metabolites and proteins). Both kinds of genes are used to increase stress tolerance in rice. In addition, several quantitative trait loci (QTLs) associated with higher stress tolerance have been cloned, contributing to the discovery of significantly important genes for stress tolerance.

  19. Understanding Abiotic Stress Tolerance Mechanisms: Recent Studies on Stress Response in Rice

    Institute of Scientific and Technical Information of China (English)

    Ji-Ping Gao; Dai-Yin Chao; Hong-Xuan Lin

    2007-01-01

    Abiotic stress is the main factor negatively affecting crop growth and productivity worldwide. The advances in physiology, genetics, and molecular biology have greatly improved our understanding of plant responses to stresses. Rice plants are sensitive to various abiotic stresses. In this short review, we present recent progresses in adaptation of rice to salinity, water deficit and submergence. Many studies show that salt tolerance is tightly associated with the ability to maintain ion homeostasis under salinity. Na+ transporter SKC1 unloads NaMrom xylem, plasma membrane NaVHTantiporter SOS1 excludes sodium out of cytosol and tonoplast Na+/H+antiporter NHX1 sequesters Na+ into the vacuole. Silicon deposition in exodermis and endodermis of rice root reduces sodium transport through the apoplastic pathway. A number of transcription factors regulate stress-inducible gene expression that leads to initiating stress responses and establishing plant stress tolerance. Overexpression of some transcription factors, including DREB/CBF and MAC, enhances salt, drought, and cold tolerance in rice. A variant of one of ERF family genes, Sub1A-1, confers immersion tolerance to lowland rice. These findings and their exploitation will hold promise for engineering breeding to protect crop plants from certain abiotic stresses.

  20. Sustained low abscisic acid levels increase seedling vigor under cold stress in rice (Oryza sativa L.).

    Science.gov (United States)

    Mega, Ryosuke; Meguro-Maoka, Ayano; Endo, Akira; Shimosaka, Etsuo; Murayama, Seiji; Nambara, Eiji; Seo, Mitsunori; Kanno, Yuri; Abrams, Suzanne R; Sato, Yutaka

    2015-09-09

    Stress-induced abscisic acid (ABA) is mainly catabolized by ABA 8'-hydroxylase (ABA8ox), which also strictly regulates endogenous ABA levels. Although three members of the ABA8ox gene family are conserved in rice, it is not clear which stressors induce expression of these genes. Here, we found that OsABA8ox1 was induced by cold stress within 24 h and that OsABA8ox2 and OsABA8ox3 were not. In contrast, OsABA8ox2 and OsABA8ox3 were ABA-inducible, but OsABA8ox1 was not. OsABA8ox1, OsABA8ox2, and OsABA8ox3 restored germination of a cyp707a1/a2/a3 triple mutant of Arabidopsis to rates comparable to those of the wild type, indicating that OsABA8ox1, OsABA8ox2, and OsABA8ox3 function as ABA-catabolic genes in vivo. Transgenic rice lines overexpressing OsABA8ox1 showed decreased levels of ABA and increased seedling vigor at 15 °C. These results indicate that sustained low levels of ABA lead to increased seedling vigor during cold stress. On the other hand, excessively low endogenous ABA levels caused reduced drought and cold tolerance, although some of the transgenic rice lines expressing OsABA8ox1 at moderate levels did not show these harmful effects. Adequate regulation of endogenous ABA levels is thought to be crucial for maintaining seedling vigor under cold stress and for cold and drought tolerance in rice.

  1. Antioxidant Defense Mechanisms of Salinity Tolerance in Rice Genotypes

    Directory of Open Access Journals (Sweden)

    Mohammad Golam Kibria

    2017-05-01

    Full Text Available In order to elucidate the role of antioxidant responses in salinity tolerance in rice genotypes under salt stress, experiments were conducted using four rice varieties, including salt-sensitive BRRI dhan 28 and three salt-tolerant varieties BRRI dhan 47, BINA dhan 8 and BINA dhan 10. Thirty-day-old rice seedlings were transplanted into pots. At the active tillering stage (35 d after transplanting, plants were exposed to different salinity levels (0, 20, 40 and 60 mmol/L NaCl. Salt stress caused a significant reduction in growth for all the rice genotypes. Growth reduction was higher in the salt-sensitive genotype than in the salt-tolerant ones, and BINA dhan 10 showed higher salt tolerance in all measured physiological parameters. The reduction in shoot and root biomass was found to be minimal in BINA dhan 10. Chlorophyll content significantly decreased under salt stress except for BINA dhan 10. Proline content significantly increased in salt-tolerant rice genotypes with increased salt concentration, and the highest proline content was obtained from BINA dhan 10 under salt stress. Catalase and ascorbate peroxidase activities significantly decreased in salt-sensitive genotype whereas significantly increased in salt-tolerant ones with increasing salt concentration. However, salt stress significantly decreased guaiacol peroxidase activity in all the rice genotypes irrespective of salt tolerance. K+/Na+ ratio also significantly decreased in shoots and roots of all the rice genotypes. The salt-tolerant genotype BINA dhan 10 maintained higher levels of chlorophyll and proline contents as well as catalase and ascorbate peroxidase activities under salt stress, thus, this might be the underlying mechanism for salt tolerance.

  2. Transformation of japonica rice with RHL gene and salt tolerance of the transgenic rice plant

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Overexpression of the yeast HAL2 gene increases salt tolerance of yeast and plant. Rice HAL2-like (RHL) gene was introduced into a japonica rice cultivar HJ19 with Agrobacterium tumefaciens-mediated transformation. Transgenic plants in R0 generation were selected on the principle of GUS-positive, RHL gene PCR-positive and normal growth. Hygromycin-resistant plants of some transgenic lines in R1 generation increased salt tolerance during the seedling and booting stage, being less damaged in the cytomembrane and stronger in leaf tissue viability under salt stress during booting period. Southern analysis of transgenic lines tolerant to salt in R1 generation showed that the RHL gene expression cassette had been successfully integrated into rice genome. Moreover, gene engineering breeding methodology and really salt-tolerant rice cultivar were discussed.

  3. Inheritance and QTL Mapping of Salt Tolerance in Rice

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    An F2 population derived from the cross between Jiucaiqing (japonica) and IR36 (indica) was used to analyze the inheritance of salt tolerance in rice by genetic model of major-genes plus polygenes, and to map the corresponding QTLs by SSR molecular markers. Rice plants of P1, P2, F1 and F2 at 5- to 6- leaf stage were treated under 140 mmol/L NaCl for 10 days. Three indices representing the ability of salt tolerance of rice seedlings were measured, including salt tolerance rating (STR), Na+/K+ ratio in roots and dry matter weight of shoots (DWS). STR, Na+/K+ and DWS were all controlled by two major genes with modification by polygenes. Heritability of these traits from major genes was 17.8, 53.3 and 52.3%, respectively. The linkage map constructed by 62 SSR molecular markers covered a total length of about 1 142 cM. There were three QTLs detected for STR located on chromosome 1, 5 and 9, two QTLs for DWS on chromosomes 8 and 9, and two QTLs for Na+/K+ on chromosomes 2 and 6, one on each chromosome respectively. Single QTL accounted for 6.7 to 19.3% of phenotypic variation. Identification method of salt tolerance in rice and breeding of rice varieties with salt tolerance based on molecular markers assisted selection had been discussed.

  4. Overexpression of OsEm1 encoding a group I LEA protein confers enhanced drought tolerance in rice.

    Science.gov (United States)

    Yu, Jing; Lai, Yongmin; Wu, Xi; Wu, Gang; Guo, Changkui

    2016-09-16

    Drought is the greatest threat for crops, including rice. In an effort to identify rice genes responsible for drought tolerance, a drought-responsive gene OsEm1 encoding a group I LEA protein, was chosen for this study. OsEm1 was shown at vegetative stages to be responsive to various abiotic stresses, including drought, salt, cold and the hormone ABA. In this study, we generated OsEm1-overexpressing rice plants to explore the function of OsEm1 under drought conditions. Overexpression of OsEm1 increases ABA sensitivity and enhances osmotic tolerance in rice. Compared with wild type, the OsEm1-overexpressing rice plants showed enhanced plant survival ratio at the vegetative stage; moreover, over expression of OsEm1 in rice increased the expression of other LEA genes, including RAB16A, RAB16C, RAB21, and LEA3, likely protecting organ integrity against harsh environments. Interestingly, the elevated level of OsEm1 had no different phenotype compared with wild type under normal condition. Our findings suggest that OsEm1 is a positive regulator of drought tolerance and is potentially promising for engineering drought tolerance in rice.

  5. Cold stress alters transcription in meiotic anthers of cold tolerant chickpea (Cicer arietinum L.).

    Science.gov (United States)

    Sharma, Kamal Dev; Nayyar, Harsh

    2014-10-11

    Cold stress at reproductive phase in susceptible chickpea (Cicer arietinum L.) leads to pollen sterility induced flower abortion. The tolerant genotypes, on the other hand, produce viable pollen and set seed under cold stress. Genomic information on pollen development in cold-tolerant chickpea under cold stress is currently unavailable. DDRT-PCR analysis was carried out to identify anther genes involved in cold tolerance in chickpea genotype ICC16349 (cold-tolerant). A total of 9205 EST bands were analyzed. Cold stress altered expression of 127 ESTs (90 up-regulated, 37 down-regulated) in anthers, more than two third (92) of which were novel with unknown protein identity and function. Remaining about one third (35) belonged to several functional categories such as pollen development, signal transduction, ion transport, transcription, carbohydrate metabolism, translation, energy and cell division. The categories with more number of transcripts were carbohydrate/triacylglycerol metabolism, signal transduction, pollen development and transport. All but two transcripts in these categories were up-regulated under cold stress. To identify time of regulation after stress and organ specificity, expression levels of 25 differentially regulated transcripts were also studied in anthers at six time points and in four organs (anthers, gynoecium, leaves and roots) at four time points. Limited number of genes were involved in regulating cold tolerance in chickpea anthers. Moreover, the cold tolerance was manifested by up-regulation of majority of the differentially expressed transcripts. The anthers appeared to employ dual cold tolerance mechanism based on their protection from cold by enhancing triacylglycerol and carbohydrate metabolism; and maintenance of normal pollen development by regulating pollen development genes. Functional characterization of about two third of the novel genes is needed to have precise understanding of the cold tolerance mechanisms in chickpea anthers.

  6. Over-expression of OsDREB genes lead to enhanced drought tolerance in rice.

    Science.gov (United States)

    Chen, Jian-Qiang; Meng, Xiu-Ping; Zhang, Yun; Xia, Mian; Wang, Xi-Ping

    2008-12-01

    The DREB transcription factors, which specifically interact with C-repeat/DRE (A/GCCGAC), play an important role in plant abiotic stress tolerance by controlling the expression of many cold or/and drought-inducible genes in an ABA-independent pathway. We have isolated three novel rice DREB genes, OsDREB1E, OsDREB1G, and OsDREB2B, which are homologous to Arabidopsis DREB genes. The yeast one-hybrid assay indicated that OsDREB1E, OsDREB1G, and OsDREB2B can specifically bind to the C-repeat/DRE element. To elucidate the function of respective OsDREB genes, we have stably introduced these to rice by Agrobacterium-mediated transformation. Transgenic rice plants analysis revealed that over-expression of OsDREB1G and OsDREB2B in rice significantly improved their tolerance to water deficit stress, while over-expression of OsDREB1E could only slightly improved the tolerance to water deficit stress, suggesting that the OsDREBs might participate in the stress response pathway in different manners.

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

    Directory of Open Access Journals (Sweden)

    Tingzhang Hu

    2014-07-01

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

  8. Study of Chilling Tolerance in Rice Cultivars at Seedling Stage Using Morphological and Physiological Characteristics

    Directory of Open Access Journals (Sweden)

    T. Hedayatkhah

    2016-07-01

    Full Text Available Cold stress is one of the most important environmental stresses for rice especially in temperate and high elevation areas. In present study, the effect of different temperatures, as the main plot, including 25 (control, 10 and 5°C on 12 rice cultivars (including Champa Yasouj, Gerde, Lenjan Askari, Kaamfirouz, Kohsar, Shafagh, Domsiya Mamassani, Dular, Gharib, Hasan saraei, Mosa Tarom and 304 as the sub plot, was investigated using a split plot experiment based on a completely randomized design with 3 replications. According to the results of ANOVA, the effects of temperature, cultivar and their interaction were significant for all measured traits, indicating that there was high genetic diversity among the studied cultivars. Means of all studied morphological traits decreased in cold stress condition relative to non-stress condition. Genotypic and phenotypic correlation coefficients showed that shoot (seedling related traits such as shoot fresh and dry weights and shoot length could be used for indirect selection for chilling tolerance in cold stress conditions at seedling stage. Based on cultivar grouping using the 3-dimensional plot of STI, YS and YP, Gharib and Champa Yasouj cultivars were identified as the most suitable cultivars in both cold stress and non stress conditions. Most of the studied cultivars including Gerde, Lenjan Askari, Kaamfirouz, Kohsar, Domsiya Mamassani, 304, Mosa Tarom and Hasan Saraei were found to be chilling sensitive cultivars at the seedling stage. Therefore, crosses between chilling resistant (Gharib and Champa Yasouj and chilling sensitive cultivars will be useful for detecting transgressive segregation and improving cold stress tolerance in rice breeding programs.

  9. Rice Tolerance to Saflufenacil in Clomazone Weed Control Program

    Directory of Open Access Journals (Sweden)

    E. R. Camargo

    2011-01-01

    Full Text Available This research was conducted to evaluate (1 rice tolerance to saflufenacil applied preemergence (PRE and postemergence (POST and (2 the combination of saflufenacil and clomazone in light-textured soils. No injury from PRE application of saflufenacil was observed in 2009, and minimal injury for saflufenacil alone was observed in 2010. Injury as high as 68% was observed with combinations of 505 g ha−1 of clomazone applied PRE and 50 g ha−1 of saflufenacil applied POST in 2009 early evaluations. No interaction between clomazone and POST saflufenacil rates was observed in 2010. Rice injury intensified with increasing rates of saflufenacil applied POST. However, rice recovered with time for herbicide treatments applied PRE and POST in both years. Consequently, rice yield was not affected by any of the saflufenacil rates applied either PRE or POST in a clomazone weed control program.

  10. Heritability of cold tolerance in Nile tilapia, Oreochromis niloticus, juveniles

    NARCIS (Netherlands)

    Charo-Karisa, H.; Rezk, M.A.; Bovenhuis, H.; Komen, J.

    2005-01-01

    The inability of tilapia to tolerate low temperatures is of major economic concern as it reduces their growing season and leads to over winter mortality. In this study, cold tolerance of juvenile Nile tilapia, Oreochromis niloticus, was investigated and heritability estimates obtained. A total of 80

  11. Comparative transcriptomics of rice plants under cold, iron, and salt stresses.

    Science.gov (United States)

    do Amaral, Marcelo Nogueira; Arge, Luis Willian Pacheco; Benitez, Letícia Carvalho; Danielowski, Rodrigo; Silveira, Solange Ferreira da Silveira; Farias, Daniel da Rosa; de Oliveira, Antonio Costa; da Maia, Luciano Carlos; Braga, Eugenia Jacira Bolacel

    2016-09-01

    Abiotic stresses such as salinity, iron toxicity, and low temperatures are the main limiting factors of rice (Oryza sativa L.) yield. The elucidation of the genes involved in responses to these stresses is extremely important to understand the mechanisms that confer tolerance, as well as for the development of cultivars adapted to these conditions. In this study, the RNA-seq technique was used to compare the transcriptional profile of rice leaves (cv. BRS Querência) in stage V3, exposed to cold, iron, and salt stresses for 24 h. A range of 41 to 51 million reads was aligned, in which a total range of 88.47 to 89.21 % was mapped in the reference genome. For cold stress, 7905 differentially expressed genes (DEGs) were observed, 2092 for salt and 681 for iron stress; 370 of these were common to the three DEG stresses. Functional annotation by software MapMan demonstrated that cold stress usually promoted the greatest changes in the overall metabolism, and an enrichment analysis of overrepresented gene ontology (GO) terms showed that most of them are contained in plastids, ribosome, and chloroplasts. Saline stress induced a more complex interaction network of upregulated overrepresented GO terms with a relatively low number of genes compared with cold stress. Our study demonstrated a high number of differentially expressed genes under cold stress and a greater relationship between salt and iron stress levels. The physiological process most affected at the molecular level by the three stresses seems to be photosynthesis.

  12. Insect capa neuropeptides impact desiccation and cold tolerance.

    Science.gov (United States)

    Terhzaz, Selim; Teets, Nicholas M; Cabrero, Pablo; Henderson, Louise; Ritchie, Michael G; Nachman, Ronald J; Dow, Julian A T; Denlinger, David L; Davies, Shireen-A

    2015-03-03

    The success of insects is linked to their impressive tolerance to environmental stress, but little is known about how such responses are mediated by the neuroendocrine system. Here we show that the capability (capa) neuropeptide gene is a desiccation- and cold stress-responsive gene in diverse dipteran species. Using targeted in vivo gene silencing, physiological manipulations, stress-tolerance assays, and rationally designed neuropeptide analogs, we demonstrate that the Drosophila melanogaster capa neuropeptide gene and its encoded peptides alter desiccation and cold tolerance. Knockdown of the capa gene increases desiccation tolerance but lengthens chill coma recovery time, and injection of capa peptide analogs can reverse both phenotypes. Immunohistochemical staining suggests that capa accumulates in the capa-expressing Va neurons during desiccation and nonlethal cold stress but is not released until recovery from each stress. Our results also suggest that regulation of cellular ion and water homeostasis mediated by capa peptide signaling in the insect Malpighian (renal) tubules is a key physiological mechanism during recovery from desiccation and cold stress. This work augments our understanding of how stress tolerance is mediated by neuroendocrine signaling and illustrates the use of rationally designed peptide analogs as agents for disrupting protective stress tolerance.

  13. Insect capa neuropeptides impact desiccation and cold tolerance

    Science.gov (United States)

    Terhzaz, Selim; Teets, Nicholas M.; Cabrero, Pablo; Henderson, Louise; Ritchie, Michael G.; Nachman, Ronald J.; Dow, Julian A. T.; Denlinger, David L.; Davies, Shireen-A.

    2015-01-01

    The success of insects is linked to their impressive tolerance to environmental stress, but little is known about how such responses are mediated by the neuroendocrine system. Here we show that the capability (capa) neuropeptide gene is a desiccation- and cold stress-responsive gene in diverse dipteran species. Using targeted in vivo gene silencing, physiological manipulations, stress-tolerance assays, and rationally designed neuropeptide analogs, we demonstrate that the Drosophila melanogaster capa neuropeptide gene and its encoded peptides alter desiccation and cold tolerance. Knockdown of the capa gene increases desiccation tolerance but lengthens chill coma recovery time, and injection of capa peptide analogs can reverse both phenotypes. Immunohistochemical staining suggests that capa accumulates in the capa-expressing Va neurons during desiccation and nonlethal cold stress but is not released until recovery from each stress. Our results also suggest that regulation of cellular ion and water homeostasis mediated by capa peptide signaling in the insect Malpighian (renal) tubules is a key physiological mechanism during recovery from desiccation and cold stress. This work augments our understanding of how stress tolerance is mediated by neuroendocrine signaling and illustrates the use of rationally designed peptide analogs as agents for disrupting protective stress tolerance. PMID:25730885

  14. IMPROVING SUBMERGENCE TOLERANCE OF VIETNAMESE RICE CULTIVAR BY MOLECULAR BREEDING

    Directory of Open Access Journals (Sweden)

    Ta-Hong Linh

    2013-12-01

    Full Text Available Submergence stress has caused by climate change is the major hindrance to enhancing rice production of Vietnam. In this study, we have evaluated the levels of submergence tolerance ability of the imported rice cultivars under the 4 different field trials. Among these, IR64-Sub1 exhibits the highest submergence tolerance with stable and high yield, and was used as a donor plant, while Bacthom 7, an elite Vietnamese rice cultivar was used as the recipient plant. In molecular markers study, we have used closely linkage markers with Sub1, flanking markers Sub1, and unlinked marker to Sub1 for the foreground, recombinant and background selections in the backcrossing generations between the donor and the recipient plants. In BC3F1 generation, the individual plant number 116 has carried QTL/Sub1 and retained the highest genetic background of the recipient parent up to 98.6%. The newly improved rice line may be useful for growing in the flooding areas of Vietnam to cope with the climate change.

  15. Production and identification of salt_tolerant transgenic rice plants

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@To relieve the damage of salt to the cell, many plants accumulated some low_molecular weight organic compounds, which were called osmoprotectant, such as betaine, mannitol, and sorbitol. Therefore if the gene_encoding enzyme responsible for synthesizing the osmoprotectant was transformed into rice plants, the salt_tolerance capacity of the transgenic plants would be increased, and the enormous loss caused by salinization of soil would be reduced.

  16. Quantitative Trait Loci for Mercury Tolerance in Rice Seedlings

    Directory of Open Access Journals (Sweden)

    Chong-qing WANG

    2013-05-01

    Full Text Available Mercury (Hg is one of the most toxic heavy metals to living organisms and its conspicuous effect is the inhibition of root growth. However, little is known about the molecular genetic basis for root growth under excess Hg2+ stress. To map quantitative trait loci (QTLs in rice for Hg2+ tolerance, a population of 120 recombinant inbred lines derived from a cross between two japonica cultivars Yuefu and IRAT109 was grown in 0.5 mmol/L CaCl2 solution. Relative root length (RRL, percentage of the seminal root length in +HgCl2 to –HgCl2, was used for assessing Hg2+ tolerance. In a dose-response experiment, Yuefu had a higher RRL than IRAT109 and showed the most significant difference at the Hg2+ concentration of 1.5 μmol/L. Three putative QTLs for RRL were detected on chromosomes 1, 2 and 5, and totally explained about 35.7% of the phenotypic variance in Hg2+ tolerance. The identified QTLs for RRL might be useful for improving Hg2+ tolerance of rice by molecular marker-assisted selection.

  17. Quantitative Trait Loci for Mercury Tolerance in Rice Seedlings

    Institute of Scientific and Technical Information of China (English)

    WANG Chong-qing; WANG Tao; MU Ping; LI Zi-chao; YANG Ling

    2013-01-01

    Mercury (Hg) is one of the most toxic heavy metals to living organisms and its conspicuous effect is the inhibition of root growth.However,little is known about the molecular genetic basis for root growth under excess Hg2+ stress.To map quantitative trait loci (QTLs) in rice for Hg2+ tolerance,a population of 120 recombinant inbred lines derived from a cross between two japonica cultivars Yuefu and IRAT109 was grown in 0.5 mmol/L CaCl2 solution.Relative root length (RRL),percentage of the seminal root length in +HgCl2 to -HgCl2,was used for assessing Hg2+ tolerance.In a dose-response experiment,Yuefu had a higher RRL than IRAT109 and showed the most significant difference at the Hg2+ concentration of 1.5 μmol/L.Three putative QTLs for RRL were detected on chromosomes 1,2 and 5,and totally explained about 35.7% of the phenotypic variance in Hg2+ tolerance.The identified QTLs for RRL might be useful for improving Hg2+ tolerance of rice by molecular marker-assisted selection.

  18. Evaluation of Rice Seedling Tolerance to Constant and Intermittent Low Temperature Stress

    Institute of Scientific and Technical Information of China (English)

    Sang-Ic KIM; Dong-min KIM; Thomas H.TAI

    2012-01-01

    M202,IR50 and advanced backcross (BC4F6) lines carrying the cold tolerance QTLs qCTS4 and qCTS12 were evaluated using three low temperature stress assays (constant,intermittent and constant with recovery period).Under constant stress,two BC4F6 lines (MIb 4853-9 and MIb 6885-2) exhibited differences in seedling growth and accumulation of stress-related compounds although both carry the two QTLs in the IR50 background.Differences between these lines were also observed in the constant with recovery period assay,although both of them performed comparably under intermittent stress.MIb 6885-2 performed more similarly to M202 in the constant and constant with recovery period assays,suggesting that this line contains an introgressed region(s) not present in Mlb 4853-9.The three assays were also applied to assess variations in cold tolerance in a set of diverse germplasms.Performance metrics and visual ratings were comparable for evaluating tolerance to constant stress.However,differences in response to intermittent stress were more evident from growth and total chlorophyll measurements than from visual ratings.With regard to the constant with recovery period assay,about 15% of the germplasm accessions did not recover.However,some lines which exhibited chilling injuries of comparable severity were able to overcome them.This recovery phenotype may improve rice performance in the field and warrant further investigation.

  19. Down-Regulated Expression of RACK1 Gene by RNA Interference Enhances Drought Tolerance in Rice

    Institute of Scientific and Technical Information of China (English)

    LI Da-hong; LIU Hui; YANG Yan-li; ZHEN Ping-ping; LIANG Jian-sheng

    2009-01-01

    The receptor for activated C-kinase 1 (RACK1) is a highly conserved scaffold protein with versatile functions, and plays important roles in the regulation of plant growth and development. Transgenic rice plants, in which the expression of RACK1 gene was inhibited by RNA interference (RNAi), were studied to elucidate the possible functions of RACK1 in responses to drought stress in rice. Real-time PCR analysis showed that the expression of RACK1 in transgenic rice plants was inhibited by more than 50%. The tolerance to drought stress of the transgenic rice plants was higher as compared with the non-transgenic rice plants. The peroxidation of membrane and the production of malondialdehyde were significantly lower, and the superoxide dismutase activity in transgenic rice plants was significantly higher than those in non-trangenic rice plants. It is suggested that RACK1 negatively regulated the redox system-related tolerance to drought stress of rice plants.

  20. Anoxic stress and rapid cold hardening enhance cold tolerance of the migratory locust.

    Science.gov (United States)

    Cui, Feng; Wang, Hongsheng; Zhang, Hanying; Kang, Le

    2014-10-01

    Anoxia and rapid cold hardening (RCH) can increase the cold tolerance of many animals. However, mechanisms underlying these two kinds of stresses remain unclear. In this study, we aimed to explore the relationship of acclimation to cold stress with acclimation to anoxic stress in the migratory locust, Locusta migratoria. RCH at 0°C for 3h promoted the survival of cold stress-exposed locusts. Anoxic hypercapnia (CO2 anoxic treatment) for 40 min exerted an effect similar to that of RCH. Anoxic hypercapnia within 1h can all promote the cold hardiness of locusts. We investigated the transcript levels of six heat shock protein (Hsp) genes, namely, Hsp20.5, Hsp20.6, Hsp20.7, Hsp40, Hsp70, and Hsp90. Four genes, namely, Hsp90, Hsp40, Hsp20.5, and Hsp20.7, showed differential responses to RCH and anoxic hypercapnia treatments. Under cold stress, locusts exposed to the two regimens showed different responses for Hsp90, Hsp20.5, and Hsp20.7. However, the varied responses disappeared after recovery from cold stress. Compared with the control group, the transcript levels of six Hsp genes were generally downregulated in locusts subjected to anoxic hypercapnia or/and RCH. These results indicate that anoxic stress and RCH have different mechanisms of regulating the transcription of Hsp family members even if the two treatments exerted similar effects on cold tolerance of the migratory locust. However, Hsps may not play a major role in the promotion of cold hardiness by the two treatments.

  1. Low temperature tolerance and cold hardening of cacti

    Energy Technology Data Exchange (ETDEWEB)

    Nobel, P.S.

    1982-12-01

    Reduced uptake by the chlorenchyma cells of cacti of a stain (neutral red) was used as an indicator of low-temperature damage resulting from cooling stems in the laboratory. Necrosis set in a few degrees below the temperature at which the fraction of cells accumulating stain was reduced by 50%. Coryphantha vivipara, Opuntia polyacantha, and Pediocactus simpsonii, which range to over 3000 m altitude in southern Wyoming, were quite cold tolerant (50% inhibition of staining occurred from -17/sup 0/ to -20/sup 0/C), while O. bigelovii and O. ramosissima, which are restricted to much warmer habitats, were not very cold tolerant (50% inhibition from -4/sup 0/ to -7/sup 0/). Relationships among tissue cold sensitivity, morphological features which protect the stems from low temperatures, and the occurrence of species in progressively colder regions were investigated. Differences in tissue cold sensitivity accounted for the =600 m higher elevational limit of Coryphantha vivipara var. rosea compared to the morphologically similar var. deserti in southern Nevada. In contrast, morphological differences alone could adequately explain the relative northern limits of the columnar cacti Carnegiea gigantea vs. Stenocereus gummosus and the barrel cacti Ferocactus acanthodes vs. F. wislizenii in the southwestern United States, as previously indicated using a computer model. Differences in both morphology and tissue cold sensitivity apparently influenced the relative northern ranges of Lophocereus schottii with respect to the other columnar cacti and F. covillei with respect to the other barrel cacti, as well as the relative elevational range of Denmoza rhodacantha with respect to Trichocereus candicans in northcentral Argentina. Cold hardening in response to decreasing day/night air temperatures was observed for 10 species.

  2. Overexpression of Arabidopsis and rice stress genes' inducible transcription factor confers drought and salinity tolerance to rice.

    Science.gov (United States)

    Datta, Karabi; Baisakh, Niranjan; Ganguly, Moumita; Krishnan, Sellapan; Yamaguchi Shinozaki, Kazuko; Datta, Swapan K

    2012-06-01

    Rice yield is greatly affected by environmental stresses such as drought and salinity. In response to the challenge of producing rice plants tolerant to these stresses, we introduced cDNA encoding the transcription factors DREB1A and DREB1B under the control of the stress inducible rd29 promoter. Two different indica rice cultivars were used, BR29, an improved commercially cultivated variety from Bangladesh and IR68899B, an IRRI bred maintainer line for hybrid rice. Agrobacterium mediated transformation of BR29 was done independently with DREB1A isolated from rice and Arabidopsis and DREB1B isolated from rice, whereas biolistic transformation was done with rice- DREB1B in the case of IR68899B. Initial genetic integration was confirmed by PCR and Southern blot analysis. Salinity tolerance was assayed in very young seedlings. Drought stress tests were found to be more reliable when they were carried out at the pre-flowering booting stage. RNA gel blot analysis as well as quantitative PCR analysis was performed to estimate the transcription level under stressed and unstressed conditions. Agronomic performance studies were done with stressed and unstressed plants to compare the yield losses due to dehydration and salt loading stresses. Noticeably enhanced tolerance to dehydration was observed in the plants transformed with DREB1A isolated from Arabidopsis while DREB1B was found to be more effective for salt tolerance.

  3. An osmotin from the resurrection plant Tripogon loliiformis (TlOsm) confers tolerance to multiple abiotic stresses in transgenic rice.

    Science.gov (United States)

    Le, Trang T T; Williams, Brett; Mundree, Sagadevan G

    2017-05-03

    Osmotin is a key protein associated with abiotic and biotic stress response in plants. In this study, an osmotin from the resurrection plant Tripogon loliiformis (TlOsm) was characterized and functionally analyzed under abiotic stress conditions in T. loliiformis as well as in transgenic Nicotiana tabacum (tobacco) and Oryza sativa (rice) plants. Real-time PCR analysis on mixed elicitor cDNA libraries from T. loliiformis showed that TlOsm was upregulated a 1000-fold during the early stages of osmotic stresses (cold, drought, and salinity) in both shoots and roots but downregulated in shoots during heat stress. There was no change in TlOsm gene expression in roots of heat-stressed plants and during plant development. The plasma membrane localization of TlOsm was showed in fluorescent-tagged TlOsm tobacco plants using confocal laser scanning microscopic analysis. Transgenic rice plants expressing TlOsm were assessed for enhanced tolerance to salinity, drought and cold stresses. Constitutively expressed TlOsm in transgenic rice plants showed increased tolerance to cold, drought and salinity stress when compared with the wild-type and vector control counterparts. This was evidenced by maintained growth, retained higher water content and membrane integrity, and improved survival rate of TlOsm-expressing plants. The results thus indicate the involvement of TlOsm in plant response to multiple abiotic stresses, possibly through the signaling pathway, and highlight its potential applications for engineering crops with improved tolerance to cold, drought and salinity stress. © 2017 Scandinavian Plant Physiology Society.

  4. Development of Novel Glyphosate-Tolerant Japonica Rice Lines: A Step Toward Commercial Release

    Science.gov (United States)

    Cui, Ying; Huang, Shuqing; Liu, Ziduo; Yi, Shuyuan; Zhou, Fei; Chen, Hao; Lin, Yongjun

    2016-01-01

    Glyphosate is the most widely used herbicide for its low cost and high efficiency. However, it is rarely applied directly in rice field due to its toxicity to rice. Therefore, glyphosate-tolerant rice can greatly decrease the cost of rice production and provide a more effective weed management strategy. Although, several approaches to develop transgenic rice with glyphosate tolerance have been reported, the agronomic performances of these plants have not been well evaluated, and the feasibility of commercial production has not been confirmed yet. Here, a novel glyphosate-tolerant gene cloned from the bacterium Isoptericola variabilis was identified, codon optimized (designated as I. variabilis-EPSPS*), and transferred into Zhonghua11, a widely used japonica rice cultivar. After systematic analysis of the transgene integration via PCR, Southern blot and flanking sequence isolation, three transgenic lines with only one intact I. variabilis-EPSPS* expression cassette integrated into intergenic regions were identified. Seed test results showed that the glyphosate tolerance of the transgenic rice was about 240 times that of wild type on plant medium. The glyphosate tolerance of transgenic rice lines was further evaluated based on comprehensive agronomic performances in the field with T3 and T5generations in a 2-year assay, which showed that they were rarely affected by glyphosate even when the dosage was 8400 g ha−1. To our knowledge, this is the first demonstration of the development of glyphosate-tolerant rice lines based on a comprehensive analysis of agronomic performances in the field. Taken together, the results suggest that the selected glyphosate-tolerant rice lines are highly tolerant to glyphosate and have the possibility of commercial release. I. variabilis-EPSPS* also can be a promising candidate gene in other species for developing glyphosate-tolerant crops. PMID:27625652

  5. Development of Novel Glyphosate-Tolerant Japonica Rice Lines: A Step Toward Commercial Release.

    Science.gov (United States)

    Cui, Ying; Huang, Shuqing; Liu, Ziduo; Yi, Shuyuan; Zhou, Fei; Chen, Hao; Lin, Yongjun

    2016-01-01

    Glyphosate is the most widely used herbicide for its low cost and high efficiency. However, it is rarely applied directly in rice field due to its toxicity to rice. Therefore, glyphosate-tolerant rice can greatly decrease the cost of rice production and provide a more effective weed management strategy. Although, several approaches to develop transgenic rice with glyphosate tolerance have been reported, the agronomic performances of these plants have not been well evaluated, and the feasibility of commercial production has not been confirmed yet. Here, a novel glyphosate-tolerant gene cloned from the bacterium Isoptericola variabilis was identified, codon optimized (designated as I. variabilis-EPSPS (*)), and transferred into Zhonghua11, a widely used japonica rice cultivar. After systematic analysis of the transgene integration via PCR, Southern blot and flanking sequence isolation, three transgenic lines with only one intact I. variabilis-EPSPS (*) expression cassette integrated into intergenic regions were identified. Seed test results showed that the glyphosate tolerance of the transgenic rice was about 240 times that of wild type on plant medium. The glyphosate tolerance of transgenic rice lines was further evaluated based on comprehensive agronomic performances in the field with T3 and T5generations in a 2-year assay, which showed that they were rarely affected by glyphosate even when the dosage was 8400 g ha(-1). To our knowledge, this is the first demonstration of the development of glyphosate-tolerant rice lines based on a comprehensive analysis of agronomic performances in the field. Taken together, the results suggest that the selected glyphosate-tolerant rice lines are highly tolerant to glyphosate and have the possibility of commercial release. I. variabilis-EPSPS (*) also can be a promising candidate gene in other species for developing glyphosate-tolerant crops.

  6. In vitro screening for salt tolerance in Rice (Oryza sativa

    Directory of Open Access Journals (Sweden)

    P .Shanthi, S. Jebaraj and S. Geetha

    2010-07-01

    Full Text Available An experiment was conducted to study the performance of rice genotypes for salt tolerance under in vitro condition. Sevengenotypes include salt tolerant (Pokkali, CSR 10, TRY 1 and TRY2, moderately tolerant to salt (White Ponni and BPT5204 and susceptible (IR 29 were used for this study through embryo culture technique. Callus was initiated in MS medium+ 2 mgl-1 2,4D + 0.5 mgl-1 Kin and different concentration of Nacl viz., 50mM, 100mM and 150mM were added with themedium to create salt stress. Statistical analysis revealed that all the genotypes and treatments and their interaction effectwere significantly different from each other. Among the seven genotypes studied Pokkali was significantly superior for callusinduction with 62 % followed by CSR 10, TRY(R 2 and TRY1 with 58 %, 54.5 % and 53 % respectively. Pokkali registeredthe highest level of callus development (35% even at high level of Nacl stress (150mM followed by TRY 2 (25% and CSR10 (24%. When the callus for these genotypes were transferred to regeneration media in the same level of Nacl stress(50mm, 100mM and 150mM highest level of regeneration of green islets was realized in Pokkali (37.5 % followed by CSR10 (31 % and TRY (R2 (25 %. From these observation, it was concluded that somaclones obtained form the varieties ofPokkali, CSR 10 and TRY(R 2 could be evaluated further in the natural field condition to develop a high yielding salttolerant varieties or could be used as a donor for the development of salt tolerant varieties. This in vitro screening techniquewith different concentration of Nacl stress could also be used as a goof screening technique for salt tolerances rather than thefield screening because of less time, little space and less labour and the results also very accurate than the field screening.

  7. Low-temperature tolerance and cold hardening of cacti

    Energy Technology Data Exchange (ETDEWEB)

    Nobel, P.S.

    1982-12-01

    Reduced uptake by the chlorenchyma cells of cacti of a stain (neutral red) was used as an indicator of low-temperature damage resulting from cooling stems in the laboratory. Necrosis set in a few degrees below the temperature at which the fraction of cells accumulating stain was reduced by 50%. Coryphantha vivipara, Opuntia polyacantha, and Pediocactus simpsonii, which range to over 300 m altitude in southern Wyoming, were quite cold tolerant. Relationships among tissue cold sensitivity, morphological features which protect the stems from low temperatures, and the occurrence of species in progressively colder regions were investigated. Differences in tissue cold sensitivity accounted for the approx. = 600 m higher elevational limit of Coryphantha vivipara var. rosea compared to the morphologically similar var. deserti in southern Nevada. In contrast, morphological differences alone could adequately explain the relative northern limits of the columnar cacti Carnegiea gigantea vs Stenocereus gummosus and the barrel cacti Ferocactus acanthodes vs. F. wislizenii in the southwestern United States, as previously indicated using a computer model. Cold hardening in response to decreasing day/night air temperatures was observed for 10 species. A decrease from 50/sup 0//40/sup 0/ to 10/sup 0//0/sup 0/ lowered by 4/sup 0/ the temperature at which the fraction of the chlorenchyma cells taking up stain was reduced 50% for both D. rhodacantha and T. candicans, with a half-time for the shift of approx. = 3 d. The tolerance of subzero temperatures and the ability to cold harden allow cacti to range into regions with considerable wintertime freezing.

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

    Science.gov (United States)

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

    2017-01-01

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

  9. Comparative Transcriptome Analysis of Shoots and Roots of TNG67 and TCN1 Rice Seedlings under Cold Stress and Following Subsequent Recovery: Insights into Metabolic Pathways, Phytohormones, and Transcription Factors.

    Directory of Open Access Journals (Sweden)

    Yun-Wei Yang

    Full Text Available Cold stress affects rice growth, quality and yield. The investigation of genome-wide gene expression is important for understanding cold stress tolerance in rice. We performed comparative transcriptome analysis of the shoots and roots of 2 rice seedlings (TNG67, cold-tolerant; and TCN1, cold-sensitive in response to low temperatures and restoration of normal temperatures following cold exposure. TNG67 tolerated cold stress via rapid alterations in gene expression and the re-establishment of homeostasis, whereas the opposite was observed in TCN1, especially after subsequent recovery. Gene ontology and pathway analyses revealed that cold stress substantially regulated the expression of genes involved in protein metabolism, modification, translation, stress responses, and cell death. TNG67 takes advantage of energy-saving and recycling resources to more efficiently synthesize metabolites compared with TCN1 during adjustment to cold stress. During recovery, expression of OsRR4 type-A response regulators was upregulated in TNG67 shoots, whereas that of genes involved in oxidative stress, chemical stimuli and carbohydrate metabolic processes was downregulated in TCN1. Expression of genes related to protein metabolism, modification, folding and defense responses was upregulated in TNG67 but not in TCN1 roots. In addition, abscisic acid (ABA-, polyamine-, auxin- and jasmonic acid (JA-related genes were preferentially regulated in TNG67 shoots and roots and were closely associated with cold stress tolerance. The TFs AP2/ERF were predominantly expressed in the shoots and roots of both TNG67 and TCN1. The TNG67-preferred TFs which express in shoot or root, such as OsIAA23, SNAC2, OsWRKY1v2, 24, 53, 71, HMGB, OsbHLH and OsMyb, may be good candidates for cold stress tolerance-related genes in rice. Our findings highlight important alterations in the expression of cold-tolerant genes, metabolic pathways, and hormone-related and TF-encoding genes in TNG67 rice

  10. Arabidopsis enhanced drought tolerance1/HOMEODOMAIN GLABROUS11 confers drought tolerance in transgenic rice without yield penalty.

    Science.gov (United States)

    Yu, Linhui; Chen, Xi; Wang, Zhen; Wang, Shimei; Wang, Yuping; Zhu, Qisheng; Li, Shigui; Xiang, Chengbin

    2013-07-01

    Enhancing drought tolerance without yield decrease has been a great challenge in crop improvement. Here, we report the Arabidopsis (Arabidopsis thaliana) homodomain-leucine zipper transcription factor Enhanced Drought Tolerance/HOMEODOMAIN GLABROUS11 (EDT1/HDG11) was able to confer drought tolerance and increase grain yield in transgenic rice (Oryza sativa) plants. The improved drought tolerance was associated with a more extensive root system, reduced stomatal density, and higher water use efficiency. The transgenic rice plants also had higher levels of abscisic acid, proline, soluble sugar, and reactive oxygen species-scavenging enzyme activities during stress treatments. The increased grain yield of the transgenic rice was contributed by improved seed setting, larger panicle, and more tillers as well as increased photosynthetic capacity. Digital gene expression analysis indicated that AtEDT1/HDG11 had a significant influence on gene expression profile in rice, which was consistent with the observed phenotypes of transgenic rice plants. Our study shows that AtEDT1/HDG11 can improve both stress tolerance and grain yield in rice, demonstrating the efficacy of AtEDT1/HDG11 in crop improvement.

  11. 40 CFR 180.1291 - Cold pressed neem oil; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Cold pressed neem oil; exemption from... FOOD Exemptions From Tolerances § 180.1291 Cold pressed neem oil; exemption from the requirement of a tolerance. Residues of the biochemical pesticide cold pressed neem oil are exempt from the requirement of a...

  12. Cold tolerance and cold hardening strategy of the Japanese pine sawyer Monochamus alternatus (Coleoptera: Cerambycidae)

    Institute of Scientific and Technical Information of China (English)

    Jing Tian; Shu-Guang Hao; Wei-Na Kong; Rui-Yan Ma; Le Kang

    2008-01-01

    The Japanese pine sawyer, Monochamus alternatus, is an important pine forest pest and vector transmitting the pine wilt nematode that causes pine wilt disease. Low temperatures in autumn, winter and spring often differentially affect mortality of M.alternatus larvae. In this paper, we mainly compared the differences of mortality and cold hardening of larvae from different seasons, based on supercooling point (SCP) and cumulative probability of individuals freezing (CPIF). The cold hardening of the larvae from autumn, winter and spring seasons were largely different. Correlations between mortality and CPIF of autumn and spring larvae were highest on day 1/4, and gradually decreased with prolonged exposure duration. This beetle's death mainly resulted from freezing in short exposure duration. However, the correlation between mortality and CPIF of winter larvae increased gradually with the prolonged exposure duration. Death did not mainly result from freezing in long exposure duration. Autumn larvae are more susceptible and adaptable than winter and spring larvae. Winter larvae have a slight freeze-tolerance trend. Our research showed that M. alternatus came into complex cold-hardening strategies under natural selection. Freeze avoidance is the primary strategy; with prolonged exposure duration to above SCP or < 0℃, chill tolerance is more important; this is followed by freeze tolerance during harsh winters.

  13. Impact of Nitrogen, Phosphorus and Potassium on Brown Planthopper and Tolerance of Its Host Rice Plants

    Institute of Scientific and Technical Information of China (English)

    Md Mamunur RASHID; Mahbuba JAHAN; Khandakar Shariful ISLAM

    2016-01-01

    The brown planthopper (BPH),Nilaparvata lugens (Stål), appeared as a devastating pest of rice in Asia. Experiments were conducted to study the effects of three nutrients, nitrogen (N), phosphorus (P) and potassium (K), on BPH and its host rice plants. Biochemical constituents of BPH and rice plants with varying nutrient levels at different growth stages, and changes in relative water content (RWC) of rice plants were determined in the laboratory. Feeding of BPH and the tolerance of rice plants to BPH with different nutrient levels were determined in the nethouse. Concentrations of N and P were found much higher in the BPH body than in its host rice plants, and this elemental mismatch is an inherent constraint on meeting nutritional requirements of BPH. Nitrogen was found as a more limiting element for BPH than other nutrients in rice plants. Application of N fertilizers to the rice plants increased the N concentrations both in rice plants and BPH while application of P and K fertilizers increased their concentrations in plant tissues only but not in BPH. Nitrogen application also increased the level of soluble proteins and decreased silicon content in rice plants, which resulted in increased feeding of BPH with sharp reduction of RWC in rice plants ultimately caused susceptible to the pest. P fertilization increased the concentration of P in rice plant tissues but not changed N, K, Si, free sugar and soluble protein contents, which indicated little importance of P to the feeding of BPH and tolerance of plant against BPH. K fertilization increased K content but reduced N, Si, free sugar and soluble protein contents in the plant tissues which resulted in the minimum reduction of RWC in rice plants after BPH feeding, thereby contributed to higher tolerance of rice plants to brown planthopper.

  14. Impact of Nitrogen, Phosphorus and Potassium on Brown Planthopper and Tolerance of Its Host Rice Plants

    Directory of Open Access Journals (Sweden)

    Md Mamunur Rashid

    2016-05-01

    Full Text Available The brown planthopper (BPH, Nilaparvata lugens (Stål, appeared as a devastating pest of rice in Asia. Experiments were conducted to study the effects of three nutrients, nitrogen (N, phosphorus (P and potassium (K, on BPH and its host rice plants. Biochemical constituents of BPH and rice plants with varying nutrient levels at different growth stages, and changes in relative water content (RWC of rice plants were determined in the laboratory. Feeding of BPH and the tolerance of rice plants to BPH with different nutrient levels were determined in the nethouse. Concentrations of N and P were found much higher in the BPH body than in its host rice plants, and this elemental mismatch is an inherent constraint on meeting nutritional requirements of BPH. Nitrogen was found as a more limiting element for BPH than other nutrients in rice plants. Application of N fertilizers to the rice plants increased the N concentrations both in rice plants and BPH while application of P and K fertilizers increased their concentrations in plant tissues only but not in BPH. Nitrogen application also increased the level of soluble proteins and decreased silicon content in rice plants, which resulted in increased feeding of BPH with sharp reduction of RWC in rice plants ultimately caused susceptible to the pest. P fertilization increased the concentration of P in rice plant tissues but not changed N, K, Si, free sugar and soluble protein contents, which indicated little importance of P to the feeding of BPH and tolerance of plant against BPH. K fertilization increased K content but reduced N, Si, free sugar and soluble protein contents in the plant tissues which resulted in the minimum reduction of RWC in rice plants after BPH feeding, thereby contributed to higher tolerance of rice plants to brown planthopper.

  15. Differentially Methylated Epiloci Generated from Numerous Genotypes of Contrasting Tolerances Are Associated with Osmotic-Tolerance in Rice Seedlings

    Science.gov (United States)

    Xia, Hui; Huang, Weixia; Xiong, Jie; Yan, Shuaigang; Tao, Tao; Li, Jiajia; Wu, Jinhong; Luo, Lijun

    2017-01-01

    DNA methylation plays an essential role in plant responses to environmental stress. Since drought develops into a rising problem in rice cultivation, investigations on genome-wide DNA methylation in responses to drought stress and in-depth explorations of its association with drought-tolerance are required. For this study, 68 rice accessions were used for an evaluation of their osmotic-tolerance related to 20% PEG6000 simulated physiological traits. The tolerant group revealed significantly higher levels of total antioxidant capacity and higher contents of H2O2 in both normal and osmotic-stressed treatments, as well as higher survival ratios. We furthermore investigated the DNA methylation status in normal, osmotic-stressed, and re-watering treatments via the methylation-sensitive amplification polymorphism (MSAP). The averaged similarity between two rice accessions from tolerant and susceptible groups was approximately 50%, similar with that between two accessions within the tolerant/susceptible group. However, the proportion of overall tolerance-associated epiloci was only 5.2% of total epiloci. The drought-tolerant accessions revealed lower DNA methylation levels in the stressed condition and more de-methylation events when they encountered osmotic stress, compared to the susceptible group. During the recovery process, the drought-tolerant accessions possessed more re-methylation events. Fourteen differentially methylated epiloci (DME) were, respectively, generated in normal, osmotic-stressed, and re-watering treatments. Approximately, 35.7% DME were determined as tolerance-associated epiloci. Additionally, rice accessions with lower methylation degrees on DME in the stressed conditions had a higher survival ratio compared to these with higher methylation degrees. This result is consistent with the lower DNA methylation levels of tolerant accessions observed in the stressed treatment. Methylation degrees on a differentially methylated epilocus may further

  16. Rice calcium-dependent protein kinase OsCPK17 targets plasma membrane intrinsic protein and sucrose phosphate synthase and is required for a proper cold stress response

    KAUST Repository

    Almadanim, M. Cecília

    2017-01-19

    Calcium-dependent protein kinases (CDPKs) are involved in plant tolerance mechanisms to abiotic stresses. Although CDPKs are recognized as key messengers in signal transduction, the specific role of most members of this family remains unknown. Here we test the hypothesis that OsCPK17 plays a role in rice cold stress response by analyzing OsCPK17 knockout, silencing, and overexpressing rice lines under low temperature. Altered OsCPK17 gene expression compromises cold tolerance performance, without affecting the expression of key cold stress-inducible genes. A comparative phosphoproteomic approach led to the identification of six potential in vivo OsCPK17 targets, which are associated with sugar and nitrogen metabolism, and with osmotic regulation. To test direct interaction, in vitro kinase assays were performed, showing that the sucrose phosphate synthase OsSPS4, and the aquaporin OsPIP2;1/OsPIP2;6 are phosphorylated by OsCPK17 in a calcium-dependent manner. Altogether, our data indicates that OsCPK17 is required for a proper cold stress response in rice, likely affecting the activity of membrane channels and sugar metabolism.

  17. [Responses of Arma chinensis cold tolerance to rapid cold hardening and underlying physiological mechanisms].

    Science.gov (United States)

    Li, Xing-Peng; Song, Li-Wen; Zhang, Hong-Hao; Chen, Yue-Qu; Zuo, Tong-Tong; Wang, Jun; Sun, Wei

    2012-03-01

    Rapid cold hardening can enhance the cold tolerance of some insects. To explore the effects of different cold hardening induction temperature on the cold tolerance of Arma chinensis and related physiological mechanisms, the 3rd generation A. chinensis adults reared indoor were treated with cooling at 15, 10, and 4 degrees C for 4 h, respectively, or with gradual cooling from 15 degrees C for 4 h to 10 degrees C for 4 h, and finally to 4 degrees C for 4 h. The super-cooling point, water content, and the contents of low molecular carbohydrates, glycerol, and amino acids of the adults after cooling and the adults cold tolerance at 0, -5, and -10 degrees C were measured by thermocouple, high performance liquid chromatography, and other analytical techniques. When exposed at -10 degrees C after cooling, the survival rate of the adults treated with gradual cooling or treated with cooling at 4 degrees C for 4 h was averagely 58.3%, while that of the adults reared at room temperature (25 degrees C +/- 2 degrees C) or treated with cooling at 15 degrees C or 10 degrees C for 4 h decreased significantly, with an average of 8.9%. The super-cooling point of the adults treated with gradual cooling or with cooling at 4 degrees C for 4 h was -15.6 degrees C, which was averagely 1.3 degrees C lower than that of the other treatments. The water content of the adults had no significant difference among all treatments, with an average of 61.8%, but the glucose, sorbitolum, glycerol, Ala, and Glu contents in treatments gradual cooling and cooling at 4 degrees C for 4 h increased by 2.82-fold, 2.65-fold, 3.49-fold, 51.3%, and 80.2%, while the fucose, mannose, and Pro contents decreased by 68.4%, 52.2%, and 30.2%, respectively, as compared with the other treatments. The fructose content showed no significant difference among all treatments. It was suggested that rapid cool hardening had a critical temperature to induce the physiological metabolism process of adult A. chinensis, and

  18. Cold tolerance of potato plants transformed with yeast invertase gene

    Directory of Open Access Journals (Sweden)

    Alexander N. Deryaabin

    2013-12-01

    Full Text Available Our study was carried out with potato plants (Solanum tuberosun L.,cv. Désirée transformed with the yeast invertase gene under the control of the B33 class I patatin promoter and with the proteinase inhibitor II leader peptide sequence providing for the apoplastic enzyme localization (B33-inv plants and with the plants transformed with the reporter gene encoding bb-glucuronidase under the control of the 35S CaMV promoter (control plants. Exposure to 5°C during 6 days caused an increase in invertase activity and sugar content in B33-inv leaves in comparison with the control plants. Cell membranes of B33-inv plant cells showed greater cold tolerance under low temperature conditions than control plants that was recorded by electrolyte release. We supposed that higher cold tolerance of B33-inv plants was caused by stabilizing effect of sugar on the membranes, because B33-inv plants differ from the control plants in higher invertase activity, induced by expression of yeast invertase gene, and high content of sugars.

  19. The submergence tolerance regulator SUB1A mediates crosstalk between submergence and drought tolerance in rice.

    Science.gov (United States)

    Fukao, Takeshi; Yeung, Elaine; Bailey-Serres, Julia

    2011-01-01

    Submergence and drought are major constraints to rice (Oryza sativa) production in rain-fed farmlands, both of which can occur sequentially during a single crop cycle. SUB1A, an ERF transcription factor found in limited rice accessions, dampens ethylene production and gibberellic acid responsiveness during submergence, economizing carbohydrate reserves and significantly prolonging endurance. Here, we evaluated the functional role of SUB1A in acclimation to dehydration. Comparative analysis of genotypes with and without SUB1A revealed that SUB1A enhanced recovery from drought at the vegetative stage through reduction of leaf water loss and lipid peroxidation and increased expression of genes associated with acclimation to dehydration. Overexpression of SUB1A augmented ABA responsiveness, thereby activating stress-inducible gene expression. Paradoxically, vegetative tissue undergoes dehydration upon desubmergence even though the soil contains sufficient water, indicating that leaf desiccation occurs in the natural progression of a flooding event. Desubmergence caused the upregulation of gene transcripts associated with acclimation to dehydration, with higher induction in SUB1A genotypes. SUB1A also restrained accumulation of reactive oxygen species (ROS) in aerial tissue during drought and desubmergence. Consistently, SUB1A increased the abundance of transcripts encoding ROS scavenging enzymes, resulting in enhanced tolerance to oxidative stress. Therefore, in addition to providing robust submergence tolerance, SUB1A improves survival of rapid dehydration following desubmergence and water deficit during drought.

  20. Effects of Rice Yield and Quality Across Accumulated Temperature Zone Planting in Cold Area

    Institute of Scientific and Technical Information of China (English)

    Wang Qiu-ju; Liu Feng; Gao Pan; Gao Zhong-chao; Chang Ben-chao; Liu Yan-xia; Zhang Li-li

    2015-01-01

    Five rice varieties were planted to determine the variation of the yield and quality traits in five different regions in a cold area of China. The results showed that the number of the panicles, the number of grains per panicle and percentage of head-milled rice displayed quadratic curves against the accumulated temperature, and the sterile rate decreased with greater accumulated temperature. However, 1 000-grain weight had no correlation with the accumulated temperature and protein content, amylose content and taste also had no obvious relation with the accumulated temperature. The results from the accumulated temperature differed with rice variety, so the temperature insensitive type variety should be proposed for production.

  1. A novel gene OsAHL1 improves both drought avoidance and drought tolerance in rice

    OpenAIRE

    Liguo Zhou; Zaochang Liu; Yunhua Liu; Deyan Kong; Tianfei Li; Shunwu Yu; Hanwei Mei; Xiaoyan Xu; Hongyan Liu; Liang Chen; Lijun Luo

    2016-01-01

    A novel gene, OsAHL1, containing an AT-hook motif and a PPC domain was identified through genome-wide profiling and analysis of mRNAs by comparing the microarray of drought-challenged versus normally watered rice. The results indicated OsAHL1 has both drought avoidance and drought tolerance that could greatly improve drought resistance of the rice plant. Overexpression of OsAHL1 enhanced multiple stress tolerances in rice plants during both seedling and panicle development stages. Functional ...

  2. Identification for Heat Tolerance in Backcross Recombinant Lines and Screening of Backcross Introgression Lines with Heat Tolerance at Milky Stage in Rice

    Institute of Scientific and Technical Information of China (English)

    LIAO Jiang-lin; ZHANG Hong-yu; SHAO Xue-lian; ZHONG Ping-an; HUANG Ying-jin

    2011-01-01

    The present study aimed at breeding new rice germplasms with similar genome but significantly differed in heat tolerance during the grain filling stage.A total of 791 BC1F8 backcross recombinant lines,derived from the cross of Xieqingzao B / N22∥Xieqingzao B,were used as materials.Each rice line was separated evenly into two groups,and the heat tolerance of all rice lines were evaluated at natural high temperature in fields.The rice lines with heat tolerant index higher than 90% or lower than 40% were selected to compare the phenotypic characters and further identify heat tolerance at the early milky stage in a phytotron.Rice lines with similar phenotypic characters but significantly differed in heat tolerance at the milky stage were analyzed by 887 simple sequence repeat markers that were evenly distributed on the 12 rice chromosomes.In the result,12 (6 pairs) rice lines with similar phenotypic characters but significantly differed in heat tolerance at the milky stage were obtained.Molecular marker analysis indicated that the genomic polymorphism between 703T and 704S was the smallest in the 6 pairs of rice lines,with only 16 polymorphic sites,including 22 different alleles.The application of these two backcross introgression rice lines for future study on the mechanisms of heat tolerance in rice at the milky stage will be theoretically beneficial in reducing the interference caused by genetic differences from experimental materials.

  3. The effects of selection for cold tolerance on cross-tolerance to other environmental stressors in Drosophila melanogaster

    Institute of Scientific and Technical Information of China (English)

    Heath A.MacMillan; Jillian P.Walsh; Brent J.Sinclair

    2009-01-01

    Cross tolerance, whereby tolerance to one environmental stress is correlated with tolerance to other stressors, is thought to be widespread in insects. We used lines of Drosophila melanogaster Meigcn (Diptera: Drosophilidae) selected for survival at a 1-h exposure to -5°C to examine the extent to which this selection results in increased tolerance to other stresses, including high and low temperatures, desiccation and starvation. While selection improved tolerance to acute cold exposure and survival at -5℃, there was little effect of selection regime on tolerance to other stressors. There was no correlation between tolerances to any of the stressors, suggesting different mechanisms of tolerance. This supports arguments that correlations between stress tolerances during selection experiments with D. melanogaster may be coincidental. The magnitude of heat-hardening was apparently constrained by basal tolerance among lines, but the magnitude of the rapid cold-hardening response was not correlated with basal cold tolerance, implying that the relationship between inducible and basal tolerances differs at high and low temperatures.

  4. Analyzing cold tolerance mechanism in transgenic zebrafish (Danio rerio.

    Directory of Open Access Journals (Sweden)

    Qian Wang

    Full Text Available Low temperatures may cause severe growth inhibition and mortality in fish. In order to understand the mechanism of cold tolerance, a transgenic zebrafish Tg (smyd1:m3ck model was established to study the effect of energy homeostasis during cold stress. The muscle-specific promoter Smyd1 was used to express the carp muscle form III of creatine kinase (M3-CK, which maintained enzymatic activity at a relatively low temperature, in zebrafish skeletal muscle. In situ hybridization showed that M3-CK was expressed strongly in the skeletal muscle. When exposed to 13 °C, Tg (smyd1:m3ck fish maintained their swimming behavior, while the wild-type could not. Energy measurements showed that the concentration of ATP increased in Tg (smyd1:m3ck versus wild-type fish at 28 °C. After 2 h at 13 °C, ATP concentrations were 2.16-fold higher in Tg (smyd1:m3ck than in wild-type (P<0.05. At 13 °C, the ATP concentration in Tg (smyd1:m3ck fish and wild-type fish was 63.3% and 20.0%, respectively, of that in wild-type fish at 28 °C. Microarray analysis revealed differential expression of 1249 transcripts in Tg (smyd1:m3ck versus wild-type fish under cold stress. Biological processes that were significantly overrepresented in this group included circadian rhythm, energy metabolism, lipid transport, and metabolism. These results are clues to understanding the mechanisms underlying temperature acclimation in fish.

  5. Genetic diversity and association mapping for salinity tolerance in Bangladeshi rice landraces

    Institute of Scientific and Technical Information of China (English)

    Reza M Emon; Mirza M Islam; Jyotirmoy Halder; Yeyang Fan

    2015-01-01

    Breeding for salinity tolerance using Bangladeshi rice landraces and understand genetic diversity has been limited by the complex and polygenic nature of salt tolerance in rice genotypes. A genetic diversity and association mapping analysis was conducted using 96 germplasm accessions with variable response to salt stress at the seedling stage. These included 86 landraces and 10 indica varieties and lines including Nona Bokra, from southern Bangladesh. A total of 220 alleles were detected at 58 Simple Sequence Repeat (SSR) marker loci randomly distributed on all 12 rice chromosomes and 8 Sequence Tagged Site (STS) markers developed for genes SKC1, DST, and SalT. The average gene diversity was 0.5075 and polymorphism information content value was 0.4426, respectively. Cluster analysis revealed that 68 and 21 accessions were clustered into 2 distinct groups, possibly corresponding to indica and japonica groups, respectively and the remaining 7 landraces were classified as an admixed group. In addition to Wn11463, the STS marker for SKC1, RM22418 on Chr. 8 was significantly associated with salinity tolerance, at the location of a QTL detected in previous studies. Our findings of favorable alleles associated with salinity tolerance in Bangladeshi rice landraces, as well as the development of STS markers for salt tolerance genes, will be helpful in future efforts to breed salinity tolerance in rice.

  6. Genetic diversity and association mapping for salinity tolerance in Bangladeshi rice landraces

    Institute of Scientific and Technical Information of China (English)

    Reza; M.Emon; Mirza; M.Islam; Jyotirmoy; Halder; Yeyang; Fan

    2015-01-01

    Breeding for salinity tolerance using Bangladeshi rice landraces and understand genetic diversity has been limited by the complex and polygenic nature of salt tolerance in rice genotypes. A genetic diversity and association mapping analysis was conducted using 96 germplasm accessions with variable response to salt stress at the seedling stage. These included86 landraces and 10 indica varieties and lines including Nona Bokra, from southern Bangladesh. A total of 220 alleles were detected at 58 Simple Sequence Repeat(SSR) marker loci randomly distributed on all 12 rice chromosomes and 8 Sequence Tagged Site(STS) markers developed for genes SKC1, DST, and SalT. The average gene diversity was 0.5075 and polymorphism information content value was 0.4426, respectively. Cluster analysis revealed that 68 and 21 accessions were clustered into 2 distinct groups, possibly corresponding to indica and japonica groups, respectively and the remaining 7 landraces were classified as an admixed group. In addition to Wn11463, the STS marker for SKC1, RM22418 on Chr. 8 was significantly associated with salinity tolerance, at the location of a QTL detected in previous studies. Our findings of favorable alleles associated with salinity tolerance in Bangladeshi rice landraces, as well as the development of STS markers for salt tolerance genes, will be helpful in future efforts to breed salinity tolerance in rice.

  7. Effect of pullulan on the water distribution, microstructure and textural properties of rice starch gels during cold storage.

    Science.gov (United States)

    Chen, Long; Tian, Yaoqi; Tong, Qunyi; Zhang, Zipei; Jin, Zhengyu

    2017-01-01

    The effects of pullulan on the water distribution, microstructure and textural properties of rice starch gels during cold storage were investigated by low field-nuclear magnetic resonance (LF-NMR), scanning electron microscope (SEM), and texture profile analysis (TPA). The addition of pullulan reduced the transversal relaxation time of rice starch gels during cold storage. The microstructure of rice starch gel with 0.5% pullulan was denser and more uniform compared with that of rice starch without pullulan in each period of storage time. With regard to textural properties, 0.01% pullulan addition did not significantly change the texture of rice starch gels, while 0.5% pullulan addition appeared to reduce the hardness and retain the springiness of rice starch gels (P⩽0.05). The restriction effects of pullulan on water mobility and starch retrogradation were hypothesized to be mainly responsible for the water retention, gel structure maintenance, and modification of the textural attributes of rice starch gels.

  8. Hemolymph metabolites and osmolality are tightly linked to cold tolerance of Drosophila species

    DEFF Research Database (Denmark)

    Olsson, Trine; MacMillan, Heath A.; Nyberg, Nils

    2016-01-01

    Drosophila, like most insects, are susceptible to low temperatures, and will succumb to temperatures above the freezing point of their hemolymph. For these insects, cold exposure causes a loss of extracellular ion and water homeostasis, leading to chill injury and eventually death. Chill...... that the larger contribution of classical cryoprotectants in chill-tolerant Drosophila plays a non-colligative role for cold tolerance that contributes to osmotic and ion homeostasis during cold exposure and, in addition, we discuss how these comparative differences may represent an evolutionary pathway toward...... more extreme cold tolerance of insects....

  9. Identification of rice varieties tolerant to photooxidation and shading

    Institute of Scientific and Technical Information of China (English)

    JIAODemao; TONGHongyu; ZHANGTianxi

    1994-01-01

    Long time exposure of rice plants to strong light will cause leaves chlorosis due to photooxidation,while the long time exposure to weak light will do them shading. Six varieties-indica hybrid rice Shanyou 63 and its parents Minghui 63 and Zhenshan 97A, indica-japonica hybrid rice Yayou 2 and its parents 02428 and 3037-were identified for their sensibility to photooxidation and shading at the stem elongation stage.

  10. Male Parent Plays More Important Role in Heat Tolerance in Three-Line Hybrid Rice

    Directory of Open Access Journals (Sweden)

    Fu Guan-fu

    2015-05-01

    Full Text Available Ten F1 combinations with their male and female parents were employed to evaluate their heat tolerance during the flowering and early grain filling stages. The rice plants were subjected to heat stress (39 °C–43 °C for 1–15 d during flowering. Based on the heat stress index, heat tolerance was only observed in the F1 combinations H2 (K22A × R207, H3 (Bobai A × R207 and H4 (Bobai A × Minghui 63, whereas the others received above 0.5000 of heat stress index. Both parents of the tolerant combination (heat-tolerant × heat-tolerant possessed heat tolerance, whereas the susceptible combinations were crossed by heat-tolerant (sterile lines × heat-susceptible (restorer lines, heat-susceptible × heat-tolerant, or heat-susceptible × heat-susceptible parents. This result indicated that heat tolerance in rice was controlled by recessive genes. Thus, both parents should possess high temperature tolerance to develop heat-tolerant F1 combinations. Furthermore, the heat stress index of F1 combinations was significantly correlated with the heat stress index of restorer lines but not with the heat stress index of maintainer lines. This result suggested that male parents play a more important role in heat-tolerant combinations than female parents. Therefore, the heat susceptibility of the hybrid rice in China is mainly due to the wide application of low-heat-tolerant restorer lines with high yield in three-line hybrid rice breeding.

  11. Aluminium tolerance in rice is antagonistic with nitrate preference and synergistic with ammonium preference.

    Science.gov (United States)

    Zhao, Xue Qiang; Guo, Shi Wei; Shinmachi, Fumie; Sunairi, Michio; Noguchi, Akira; Hasegawa, Isao; Shen, Ren Fang

    2013-01-01

    Acidic soils are dominated chemically by more ammonium and more available, so more potentially toxic, aluminium compared with neutral to calcareous soils, which are characterized by more nitrate and less available, so less toxic, aluminium. However, it is not known whether aluminium tolerance and nitrogen source preference are linked in plants. This question was investigated by comparing the responses of 30 rice (Oryza sativa) varieties (15 subsp. japonica cultivars and 15 subsp. indica cultivars) to aluminium, various ammonium/nitrate ratios and their combinations under acidic solution conditions. indica rice plants were generally found to be aluminium-sensitive and nitrate-preferring, while japonica cultivars were aluminium-tolerant and relatively ammonium-preferring. Aluminium tolerance of different rice varieties was significantly negatively correlated with their nitrate preference. Furthermore, aluminium enhanced ammonium-fed rice growth but inhibited nitrate-fed rice growth. The results suggest that aluminium tolerance in rice is antagonistic with nitrate preference and synergistic with ammonium preference under acidic solution conditions. A schematic diagram summarizing the interactions of aluminium and nitrogen in soil-plant ecosystems is presented and provides a new basis for the integrated management of acidic soils.

  12. A novel gene OsAHL1 improves both drought avoidance and drought tolerance in rice

    Science.gov (United States)

    Zhou, Liguo; Liu, Zaochang; Liu, Yunhua; Kong, Deyan; Li, Tianfei; Yu, Shunwu; Mei, Hanwei; Xu, Xiaoyan; Liu, Hongyan; Chen, Liang; Luo, Lijun

    2016-01-01

    A novel gene, OsAHL1, containing an AT-hook motif and a PPC domain was identified through genome-wide profiling and analysis of mRNAs by comparing the microarray of drought-challenged versus normally watered rice. The results indicated OsAHL1 has both drought avoidance and drought tolerance that could greatly improve drought resistance of the rice plant. Overexpression of OsAHL1 enhanced multiple stress tolerances in rice plants during both seedling and panicle development stages. Functional studies revealed that OsAHL1 regulates root development under drought condition to enhance drought avoidance, participates in oxidative stress response and also regulates the content of chlorophyll in rice leaves. OsAHL1 specifically binds to the A/T rich sequence region of promoters or introns, and hence directly regulates the expression of many stress related downstream genes. PMID:27453463

  13. Tolerância ao frio do amendoim forrageiro Cold tolerance of forage peanut

    Directory of Open Access Journals (Sweden)

    Adriana Pires Soares Bresolin

    2008-08-01

    Full Text Available A produtividade de uma pastagem perene tropical, em regiões de clima temperado, é dependente de seu comportamento em relação às condições de temperatura. A avaliação da sensibilidade das plantas, através da sua exposição a temperaturas inferiores a 2°C em ambiente controlado, pode ser um procedimento bastante eficiente na predição de resistência, em função de assegurar uma homogeneidade dos níveis de frio. Considerando-se à reduzida disponibilidade de trabalhos científicos relacionados com a avaliação de leguminosas forrageiras tropicais quanto à tolerância ao frio, este experimento teve como objetivo avaliar o comportamento do amendoim forrageiro (cv. "Amarillo" sob temperaturas inferiores a 2°C. O delineamento experimental adotado foi completamente casualizado com 15 repetições e dois tratamentos, com exposição (CE e sem exposição ao frio (SE. Os caracteres mensurados foram: número de folhas por estolho, espessura do estolho e número de brotações novas. Os resultados indicaram que a exposição do amendoim forrageiro a um intervalo de temperatura de -1,0 a 1,3°C por um período de 3 horas é capaz de causar estresse de frio nas plantas, provocando uma redução no número de folhas e estimulando a formação de novas brotações, sem provocar a morte das plantas.The yield of tropical perennial forages in temperate climate areas depends on its cold tolerance. The exposure of genotypes to temperatures below 2oC, under controlled conditions is an efficient methodology to predict cold tolerance, since it maintains homogeneous levels of cold. Due to absence of information related to cold tolerance of tropical forages, this experiment was developed aiming to evaluate the behavior of forage peanut exposed to temperatures below 2oC. The design adopted was completely randomized with 15 replications and two treatments: exposed and not exposed to cold. The traits measured were: number of leaves per stolon; thickness

  14. Image-based phenotyping for non-destructive screening of different salinity tolerance traits in rice

    KAUST Repository

    Hairmansis, Aris

    2014-08-14

    Background Soil salinity is an abiotic stress wide spread in rice producing areas, limiting both plant growth and yield. The development of salt-tolerant rice requires efficient and high-throughput screening techniques to identify promising lines for salt affected areas. Advances made in image-based phenotyping techniques provide an opportunity to use non-destructive imaging to screen for salinity tolerance traits in a wide range of germplasm in a reliable, quantitative and efficient way. However, the application of image-based phenotyping in the development of salt-tolerant rice remains limited. Results A non-destructive image-based phenotyping protocol to assess salinity tolerance traits of two rice cultivars (IR64 and Fatmawati) has been established in this study. The response of rice to different levels of salt stress was quantified over time based on total shoot area and senescent shoot area, calculated from visible red-green-blue (RGB) and fluorescence images. The response of rice to salt stress (50, 75 and 100 mM NaCl) could be clearly distinguished from the control as indicated by the reduced increase of shoot area. The salt concentrations used had only a small effect on the growth of rice during the initial phase of stress, the shoot Na+ accumulation independent phase termed the ‘osmotic stress’ phase. However, after 20 d of treatment, the shoot area of salt stressed plants was reduced compared with non-stressed plants. This was accompanied by a significant increase in the concentration of Na+ in the shoot. Variation in the senescent area of the cultivars IR64 and Fatmawati in response to a high concentration of Na+ in the shoot indicates variation in tissue tolerance mechanisms between the cultivars. Conclusions Image analysis has the potential to be used for high-throughput screening procedures in the development of salt-tolerant rice. The ability of image analysis to discriminate between the different aspects of salt stress (shoot ion

  15. Cold tolerance of bed bugs and practical recommendations for control.

    Science.gov (United States)

    Olson, Joelle F; Eaton, Marc; Kells, Stephen A; Morin, Victor; Wang, Changlu

    2013-12-01

    Bed bugs were exposed to freezing temperatures for various exposure times to determine cold tolerance and mortality estimates for multiple life stages. The mean supercooling point for all bed bug life stages ranged from -21.3 degrees C to -30.3 degrees C, with the egg stage reporting the lowest value. A probit analysis provided a lower lethal temperature (LLT99) of -31.2 degrees C when estimates from all life stages were combined, demonstrating that all stages of bed bugs are not capable of surviving temperatures below body freezing and are therefore freeze intolerant. At conditions above the LLT99, bed bug mortality depended on temperature and exposure time at temperatures above LLT99. Based on our model estimates, survival was estimated for temperatures above -12 degrees C even after 1 wk of continuous exposure. However, exposure to temperatures below -13 degrees C will result in 100% mortality in d to ensure mortality of all life stages. Unfortunately, sublethal exposure to lower temperatures did not prevent subsequent feeding behavior in surviving stages. Practical recommendations for management of potentially infested items are discussed.

  16. An early response regulatory cluster induced by low temperature and hydrogen peroxide in seedlings of chilling-tolerant japonica rice

    Directory of Open Access Journals (Sweden)

    Jia Yulin

    2007-06-01

    Full Text Available Abstract Background Plants respond to low temperature through an intricately coordinated transcriptional network. The CBF/DREB-regulated network of genes has been shown to play a prominent role in freeze-tolerance of Arabidopsis through the process of cold acclimation (CA. Recent evidence also showed that the CBF/DREB regulon is not unique to CA but evolutionarily conserved between chilling-insensitive (temperate and chilling-sensitive (warm-season plants. In this study, the wide contrast in chilling sensitivity between indica and japonica rice was used as model to identify other regulatory clusters by integrative analysis of promoter architecture (ab initio and gene expression profiles. Results Transcriptome analysis in chilling tolerant japonica rice identified a subset of 121 'early response' genes that were upregulated during the initial 24 hours at 10°C. Among this group were four transcription factors including ROS-bZIP1 and another larger sub-group with a common feature of having as1/ocs-like elements in their promoters. Cold-induction of ROS-bZIP1 preceded the induction of as1/ocs-like element-containing genes and they were also induced by exogenous H2O2 at ambient temperature. Coordinated expression patterns and similar promoter architectures among the 'early response' genes suggest that they belong to a potential regulon (ROS-bZIP – as1/ocs regulatory module that responds to elevated levels of ROS during chilling stress. Cultivar-specific expression signatures of the candidate genes indicate a positive correlation between the activity of the putative regulon and genotypic variation in chilling tolerance. Conclusion A hypothetical model of an ROS-mediated regulon (ROS-bZIP – as1/ocs triggered by chilling stress was assembled in rice. Based on the current results, it appears that this regulon is independent of ABA and CBF/DREB, and that its activation has an important contribution in configuring the rapid responses of rice seedlings

  17. Marker Assisted Selection for Submergence Tolerance in Rice

    Institute of Scientific and Technical Information of China (English)

    D.J. Mackill; R. Maghirang-Rodriguez; S. Heuer; A.M. Ismail; E. Septiningsih; A.M. Pamplona; D. Sanchez; K. Iftekhar; A.S. Masudussaman; B.Collard; C. Neeraja; G. Vergara

    2007-01-01

    @@ Yields in the irrigated rice areas have improved remarkably over the last three decades. Farmers with access to assured water supply have adopted improved varieties, resulting in higher yields and improved income in rural areas.

  18. Mapping QTLs for submergence tolerance during germination in rice

    African Journals Online (AJOL)

    STORAGESEVER

    2008-08-04

    Aug 4, 2008 ... The study was conducted at NG-01 greenhouse, Genome and. Mapping (GML), the ..... International Rice Genome Sequencing Project (IRGSP) (2005). The ... A high-resolution recombination map of the human genome. Nat.

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

    Directory of Open Access Journals (Sweden)

    Shalini Tiwari

    2017-08-01

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

  20. Recent advances in the dissection of drought-stress regulatory networks and strategies for development of drought-tolerant transgenic rice plants

    OpenAIRE

    Todaka, Daisuke; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

    2015-01-01

    Advances have been made in the development of drought-tolerant transgenic plants, including cereals. Rice, one of the most important cereals, is considered to be a critical target for improving drought tolerance, as present-day rice cultivation requires large quantities of water and as drought-tolerant rice plants should be able to grow in small amounts of water. Numerous transgenic rice plants showing enhanced drought tolerance have been developed to date. Such genetically engineered plants ...

  1. Over-expression of PsGPD, a mushroom glyceraldehyde-3-phosphate dehydrogenase gene, enhances salt tolerance in rice plants.

    Science.gov (United States)

    Cho, Jung-Il; Lim, Hye-Min; Siddiqui, Zamin Shaheed; Park, Sung-Han; Kim, A-Ram; Kwon, Taek-Ryoun; Lee, Seong-Kon; Park, Soo-Chul; Jeong, Mi-Jeong; Lee, Gang-Seob

    2014-08-01

    Transgenic potatoes expressing glyceraldehyde-3-phosphate dehydrogenase (GPD), isolated from the oyster mushroom, Pleurotus sajor-caju, had increased tolerance to salt stress (Jeong et al. Biochem Biophys Res Commun 278:192-196, 2000). To examine the physiological mechanisms enhancing salt tolerance in GPD-transgenic rice plants, the salt tolerance of five GPD transgenic rice lines (T1-T5) derived from Dongjin rice cultivar were evaluated in a fixed 150 mM saline environment in comparison to two known wild-type rice cultivars, Dongjin (salt sensitive) and Pokali (salt tolerant). Transgenic lines, T2, T3, and T5, had a substantial increase in biomass and relative water content compared to Dongjin. Stomatal conductance and osmotic potential were higher in the GPD transgenic lines and were similar to those in Pokali. The results are discussed based on the comparative physiological response of GPD transgenic lines with those of the salt-sensitive and salt-tolerant rice cultivars.

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

    Science.gov (United States)

    Chen, Shuang; Xu, Yan

    2014-08-01

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

  3. Physiological and biochemical mechanisms of seed priming-induced chilling tolerance in rice cultivars

    Directory of Open Access Journals (Sweden)

    Saddam eHussain

    2016-02-01

    Full Text Available Rice belongs to tropical and subtropical environments and is extremely sensitive to chilling stress particularly during emergence and early stages of seedling development. Seed priming can be a good approach to enhance rice germination and stand establishment under chilling stress. The present study examined the role of different seed priming techniques viz., hydropriming, osmopriming, redox priming, chemical priming, and hormonal priming, in enhancing the chilling tolerance in rice. The most effective reagents and their pre-optimized concentrations based on preliminary experiments were used in this study. Two different rice cultivars were sown under chilling stress (18˚C and normal temperatures (28˚C in separate growth chambers. A non-primed control treatment was also maintained for comparison. Chilling stress caused erratic and delayed germination, poor seedling growth, reduced starch metabolism and lower respiration rate, while higher lipid peroxidation and hydrogen peroxide accumulation in rice seedlings of both cultivars. Nevertheless, all the seed priming treatments effectively alleviated the negative effects of chilling stress. In addition, seed priming treatments triggered the activities of superoxide dismutase, peroxidase, and catalase, and enhanced the accumulations of glutathione and free proline in rice seedlings, which suggests that these measures help prevent the rice seedlings from chilling induced oxidative stress. Chemical priming with selenium and hormonal priming with salicylic acid remained more effective treatments for both rice cultivars under chilling stress than all other priming treatments. The better performance and greater tolerance of primed rice seedlings was associated with enhanced starch metabolism, high respiration rate, lower lipid peroxidation, and strong antioxidative defense system under chilling stress.

  4. Effect of Nitrogen on Water Content, Sap Flow, and Tolerance of Rice Plants to Brown Planthopper, Nilaparvata lugens

    Institute of Scientific and Technical Information of China (English)

    LU Zhong-xian; S. VILLAREAL; YU Xiao-ping; K. L. HEONG; HU Cui

    2004-01-01

    Water content (WC) and sap flow from leaf sheath of rice plants with varying nitrogen levels at different growth stages,and fluctuations in relative water content (RWC) of rice plants being damaged by brown planthopper (BPH), Nilaparvata lugens were determined in the laboratory, and the tolerance of rice plants to BPH at different nitrogen regimes was evaluated in the greenhouse at International Rice Research Institute (IRRI), the Philippines. The results indicated that both WC and RWC were increased significantly, as the amount of sap flow from rice plants was reduced statistically, with the increase of nitrogen content in rice plants. RWC in rice plants applied with high nitrogen fertilizer decreased drastically by the injury of BPH nymphs, while the reduced survival duration of rice plants with the increase of nitrogen content was recorded. These may be considered to be one of the important factors in increasing the susceptibility to BPH damage on rice plants applied with nitrogen fertilizer.

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

    OpenAIRE

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

    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...

  6. Germplasm Innovation of Heat Tolerance in Rice for Irrigated Lowland Conditions in the Philippines

    Institute of Scientific and Technical Information of China (English)

    Norvie L.MANIGBAS; Leslie Angela F.LAMBIO; Luvina B.MADRID; Corazon C.CARDENAS

    2014-01-01

    Heat-tolerant varieties, such as N22 and Dular, which were used in this study, usually have low yield potential and undesirable plant characteristics but combining them with high yielding and improved rice varieties, new heat-tolerant rice genotypes with high yield potential can be achieved. In this study, phenotyping and selecting desirable materials from various crosses were performed under high temperature conditions during the reproductive stage. Screening was performed in the field and glasshouse to select individuals with heat tolerance and high yield potential. Several advanced breeding lines from Gayabyeo/N22 cross produced desirable individuals with heat tolerance, resistance to pests and diseases, and high yield potential. The genetic variation in percent sterility among the selected backcross populations grown in high temperature environments showed that large number of plants can be identified and selected with lower percent sterility.

  7. Transcriptome Profiling of the Pineapple under Low Temperature to Facilitate Its Breeding for Cold Tolerance

    Science.gov (United States)

    Chen, Chengjie; Zhang, Yafeng; Xu, Zhiqiang; Luan, Aiping; Mao, Qi; Feng, Junting; Xie, Tao; Gong, Xue; Wang, Xiaoshuang; Chen, Hao; He, Yehua

    2016-01-01

    The pineapple (Ananas comosus) is cold sensitive. Most cultivars are injured during winter periods, especially in sub-tropical regions. There is a lack of molecular information on the pineapple’s response to cold stress. In this study, high-throughput transcriptome sequencing and gene expression analysis were performed on plantlets of a cold-tolerant genotype of the pineapple cultivar ‘Shenwan’ before and after cold treatment. A total of 1,186 candidate cold responsive genes were identified, and their credibility was confirmed by RT-qPCR. Gene set functional enrichment analysis indicated that genes related to cell wall properties, stomatal closure and ABA and ROS signal transduction play important roles in pineapple cold tolerance. In addition, a protein association network of CORs (cold responsive genes) was predicted, which could serve as an entry point to dissect the complex cold response network. Our study found a series of candidate genes and their association network, which will be helpful to cold stress response studies and pineapple breeding for cold tolerance. PMID:27656892

  8. A novel Azotobacter vinellandii (SRIAz3) functions in salinity stress tolerance in rice.

    Science.gov (United States)

    Sahoo, Ranjan Kumar; Ansari, Mohammad Wahid; Pradhan, Madhusmita; Dangar, Tushar K; Mohanty, Santanu; Tuteja, Narendra

    2014-01-01

    The plant growth promoting rhizobacteria (PGPRs) as a biofertilizer provide agricultural benefits to advance various crops productivity. Recently, we discovered a novel Azotobacter vinellandii (SRIAz3) from rice rhizosphere, which is well competent to improve rice productivity. In this study, we investigated a role of A. vinellandii to confer salinity tolerance in rice (var. IR64). A. vinellandii inoculated rice plants showed higher proline and malondialdehyde content under 200 mM NaCl stress as compared with uninoculated one. The endogenous level of plant hormones viz., indole-3 acetic acid (IAA), gibberellins (GA3), zeatint (Zt) was higher in A. vinellandii inoculated plants under high salinity. The fresh biomass of root and shoot were relatively elevated in A. vinellandii inoculated rice. Further, the macronutrient profile was superior in A. vinellandii inoculated plants under salinity as compared with non-inoculated plants. The present findings further suggest that A. vinellandii, a potent biofertilzer, potentially confer salinity stress tolerance in rice via sustaining growth and improving compatible solutes and nutrients profile and thereby crop improvement.

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

    DEFF Research Database (Denmark)

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

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

  10. Assessment of salinity tolerance in rice using seedling based morpho-physiological indices

    Directory of Open Access Journals (Sweden)

    Syed Adeel Zafar

    2015-08-01

    Full Text Available Background: Salinity is among the most damaging abiotic stresses for rice production which limits its growing area. The present research was conducted to evaluate five rice varieties for salinity tolerance at seedling stage. Methods: Experiment was conducted in triplicate and in two sets. One set was grown as a control (non-stress and other as salt stressed. Salt stress of 15 dS/m was applied to one set of rice seedlings under controlled conditions. Data for different growth related morpho-physiological traits, i.e. germination percentage, root and shoot length, seedling fresh and dry weight, Na+ and K+ uptake were recorded after 15 days of seedling emergence under control as well as salinity condition. Results: Significant differences were observed among the genotypes under both the treatments and interaction of the evaluated traits suggested a significant variability among the rice genotypes under salt stress. NIAB-IRRI-9, Basmati-198 and KSK-133 were proved to be relatively salt tolerant varieties as they showed good performance for the recorded parameters. However, Basmati-385 was observed a salt sensitive variety due to highest reduction in seedling fresh and dry weight along with the maximum Na+ uptake. Conclusion: Based on obtained results, it was concluded that the evaluated morpho-physiological traits were useful to screen rice cultivars for salinity stress. In addition, NIAB-IRRI-9, Basmati-198 and KSK-133 can be used in breeding programs as tolerant check and Basmati-385 can be used as sensitive check.

  11. Enhanced drought tolerance of transgenic rice plants expressing a pea manganese superoxide dismutase.

    Science.gov (United States)

    Wang, Fang-Zheng; Wang, Qing-Bin; Kwon, Suk-Yoon; Kwak, Sang-Soo; Su, Wei-Ai

    2005-04-01

    We investigated the role that manganese superoxide dismutase (MnSOD), an important antioxidant enzyme, may play in the drought tolerance of rice. MnSOD from pea (Pisum sativum) under the control of an oxidative stress-inducible SWPA2 promoter was introduced into chloroplasts of rice (Oryza sativa) by Agrobacterium-mediated transformation to develop drought-tolerant rice plants. Functional expression of the pea MnSOD in transgenic rice plants (T1) was revealed under drought stress induced by polyethylene glycol (PEG) 6000. After PEG treatment the transgenic leaf slices showed reduced electrolyte leakage compared to wild type (WT) leaf slices, whether they were exposed to methyl viologen (MV) or not, suggesting that transgenic plants were more resistant to MV- or PEG-induced oxidative stress. Transgenic plants also exhibited less injury, measured by net photosynthetic rate, when treated with PEG. Our data suggest that SOD is a critical component of the ROS scavenging system in plant chloroplasts and that the expression of MnSOD can improve drought tolerance in rice.

  12. Esterase as molecular marker for salt tolerance in regenerated plants of rice, Oryza sativa L.

    Science.gov (United States)

    Swapna, T S

    2002-09-01

    Esterase variation was studied in plants regenerated from callus cultures of four rice (Oryza sativa) varieties, viz. pokkali, which is a moderately salt tolerant variety and three salt sensitive varieties MI 48, annapoorna and jyothi. Variation was studied at tillering stage of plants regenerated from callus culture and germinated from seeds. Somaclonal variants for salt tolerance could be detected using variation in esterase banding pattern and activity.

  13. Variation of photosynthetic tolerance of rice cultivars (Oryza sativa L ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-03-01

    Mar 1, 2010 ... Institute of Food Crops, Jiangsu High Quality Rice R and D Center, ... temperature in the light at bud, seedling and booting stages and divided into three basic types; cultivars .... saturating photon pulse (4000 mol/m2 s).

  14. 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.

  15. Rice-arsenate interactions in hydroponics: a three-gene model for tolerance.

    Science.gov (United States)

    Norton, Gareth J; Nigar, Meher; Williams, Paul N; Dasgupta, Tapash; Meharg, Andrew A; Price, Adam H

    2008-01-01

    In this study, the genetic mapping of the tolerance of root growth to 13.3 muM arsenate [As(V)] using the BalaxAzucena population is improved, and candidate genes for further study are identified. A remarkable three-gene model of tolerance is advanced, which appears to involve epistatic interaction between three major genes, two on chromosome 6 and one on chromosome 10. Any combination of two of these genes inherited from the tolerant parent leads to the plant having tolerance. Lists of potential positional candidate genes are presented. These are then refined using whole genome transcriptomics data and bioinformatics. Physiological evidence is also provided that genes related to phosphate transport are unlikely to be behind the genetic loci conferring tolerance. These results offer testable hypotheses for genes related to As(V) tolerance that might offer strategies for mitigating arsenic (As) accumulation in consumed rice.

  16. Ectopic expression of Arabidopsis RCI2A gene contributes to cold tolerance in tomato.

    Science.gov (United States)

    Sivankalyani, Velu; Geetha, Mahalingam; Subramanyam, Kondeti; Girija, Shanmugam

    2015-04-01

    Cold is a major stress that limits the quality and productivity of economically important crops such as tomato (Solanum lycopersicum L.). Generating a cold-stress-tolerant tomato by expressing cold-inducible genes would increase agricultural strategies. Rare cold-inducible 2a (RCI2A) is expressed in Arabidopsis, but its molecular function during cold stress is not fully understood. Here we ectopically expressed Arabidopsis RCI2A in transgenic tomato to evaluate tolerance to cold stress without altering agronomic traits. Biochemical and physiological study demonstrated that expression of RCI2A in transgenic tomato enhanced the activity of peroxidase and ascorbate peroxidase (APX) and reduced the accumulation of H2O2, alleviated lipid peroxidation, increased the accumulation of chlorophyll, reduced chilling-induced membrane damage, retained relative water content and enhanced cold tolerance. A motif search revealed that the motifs of photosystem II (PSII) phosphoproteins PsbJ and PsbH and reaction-center proteins PsbL and PsbK were common to cold-inducible RCI2A and peroxidase proteins RCI3A, tomato peroxidase (TPX1), TPX2, tomato ascorbate peroxidase (APX1), and horseradish peroxidase (HRP-c). In addition to membrane protection, RCI2A may cross talk with PSII-associated proteins or peroxidase family enzymes in response to cold stress. Our findings may strengthen the understanding of the molecular function of RCI2A in cold-stress tolerance. RCI2A could be used to improve abiotic stress tolerance in agronomic crops.

  17. A Transgenic approach to understanding cold tolerance in blueberry cultivars

    Science.gov (United States)

    Cold hardiness is an important trait in highbush blueberry. Cold hardiness is induced in the fall and helps prevent freezing damage to buds and other plant parts. Plant damage not only directly reduces yield potential, but provides ‘wounds’ that act as an entry point for some pathogens such as stem ...

  18. Effect of Nitrogen on Water Content, Sap Flow, and Tolerance of Rice Plants to Brown Planthopper, Nilaparvata lugens

    Institute of Scientific and Technical Information of China (English)

    LuZhong-xian; S.VILLAREAL; YuXiao-ping; K.L.HEONG; HuCui

    2004-01-01

    Water content (WC) and sap flow from leaf sheath of rice plants with varying nitrogen levels at different growth stages and fluctuations in relative water content (RWC) of rice plants being damaged by brown planthopper (BPH), Nilaparvata lugens were determincd in the laboratory, and the tolerance of rice plants to BPH at different nitrogen regimes was evaluated in the greenhouse at International Rice Research institute (1RRI), the Philippines. The results indicated that both WC and RWC were increased significantly, as the amount of sap flow from rice plants was reduced statistically, with the in crease of nitrogen content inrice plants. RWC in rice plants applied with high nitrogen fertilizer decreased drastically by the injury, of BPH nymphs, while the reduced survival duration of rice plants with the increase of nitrogen content was recorded. These may be considered to be one of the important factors in increasing the susceptibility' to BPH damage on rice plants applied with nitrogen fertilizer

  19. Site Suitability Analysis for Dissemination of Salt-tolerant Rice Varieties in Southern Bangladesh

    Science.gov (United States)

    Sinha, D. D.; Singh, A. N.; Singh, U. S.

    2014-11-01

    Bangladesh is a country of 14.4 million ha geographical area and has a population density of more than 1100 persons per sq. km. Rice is the staple food crop, growing on about 72 % of the total cultivated land and continues to be the most important crop for food security of the country. A project "Sustainable Rice Seed Production and Delivery Systems for Southern Bangladesh" has been executed by the International Rice Research Institute (IRRI) in twenty southern districts of Bangladesh. These districts grow rice in about 2.9 million ha out of the country's total rice area of 11.3 million ha. The project aims at contributing to the Government of Bangladesh's efforts in improving national and household food security through enhanced and sustained productivity by using salinity-, submergence- and drought- tolerant and high yielding rice varieties. Out of the 20 project districts, 12 coastal districts are affected by the problem of soil salinity. The salt-affected area in Bangladesh has increased from about 0.83 million ha in 1973 to 1.02 million ha in 2000, and 1.05 million ha in 2009 due to the influence of cyclonic storms like "Sidr", "Laila" and others, leading to salt water intrusion in croplands. Three salinity-tolerant rice varieties have recently been bred by IRRI and field tested and released by the Bangladesh Rice Research Institute (BRRI) and Bangladesh Institute of Nuclear Agriculture (BINA). These varieties are BRRI dhan- 47 and Bina dhan-8 and - 10. However, they can tolerate soil salinity level up to EC 8-10 dSm-1, whereas the EC of soils in several areas are much higher. Therefore, a large scale dissemination of these varieties can be done only when a site suitability analysis of the area is carried out. The present study was taken up with the objective of preparing the site suitability of the salt-tolerant varieties for the salinity-affected districts of southern Bangladesh. Soil salinity map prepared by Soil Resources Development Institute of

  20. Calcium effect on the process of cold-hardening of rice seedlings

    Institute of Scientific and Technical Information of China (English)

    LIMeiru; LIUHongxian; WANGYirou; ZENGShaoxi

    1997-01-01

    Low temperature is an important environmental factor that limits the productivity and distribution of plant . The ability to cold acclimation is a common adaptive response in plants natiye in temperate regions and results in enhancing tolerance to chílling stress.

  1. Assessing foliar ascorbate content in the rice diversity panel 1

    Science.gov (United States)

    Early spring plantings of rice can have poor stands due to cold temperatures. Our previous studies have shown that high vitamin C (ascorbate AsA) Arabidopsis lines are tolerant to cold stress. The rice diversity panel 1 (RDP1) represents the genetic diversity of Oryza sativa and has been extensively...

  2. Phosphate acquisition efficiency and phosphate starvation tolerance locus (PSTOL1) in rice

    Indian Academy of Sciences (India)

    Arijit Mukherjee; Sutanu Sarkar; Amrita Sankar Chakraborty; Roshan Yelne; Vinay Kavishetty; Tirthankar Biswas; N. Mandal; Somnath Bhattacharyya

    2014-12-01

    Phosphate availability is a major factor limiting tillering, grain filling vis-à-vis productivity of rice. Rice is often cultivated in soil like red and lateritic or acid, with low soluble phosphate content. To identify the best genotype suitable for these types of soils, P acquisition efficiency was estimated from 108 genotypes. Gobindabhog, Tulaipanji, Radhunipagal and Raghusail accumulated almost equal amounts of phosphate even when they were grown on P-sufficient soil. Here, we have reported the presence as well as the expression of a previously characterized rice gene, phosphate starvation tolerance locus (PSTOL1) in a set of selected genotypes. Two of four genotypes did not show any detectable expression but carried the gene. One mega cultivar, Swarna did not possess this gene but showed high P-deficiency tolerance ability. Increase of root biomass, not length, in P-limiting situations might be considered as one of the selecting criteria at the seedling stage. Neither the presence of PSTOL1 gene nor its closely-linked SSR RM1261, showed any association with P-deficiency tolerance among the 108 genotypes. Not only this, but the presence of PSTOL1 in recombinant inbred line (RIL) developed from a cross between Gobindabhog and Satabdi, also did not show any linkage with P-deficiency tolerance ability. Thus, before considering PSTOL1 gene in MAB, its expression and role in P-deficiency tolerance in the donor parent must be ascertained.

  3. Physiological and biochemical parameters for evaluation and clustering of rice cultivars differing in salt tolerance at seedling stage

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    Sumitahnun Chunthaburee

    2016-07-01

    Full Text Available Salinity tolerance levels and physiological changes were evaluated for twelve rice cultivars, including four white rice and eight black glutinous rice cultivars, during their seedling stage in response to salinity stress at 100 mM NaCl. All the rice cultivars evaluated showed an apparent decrease in growth characteristics and chlorophyll accumulation under salinity stress. By contrast an increase in proline, hydrogen peroxide, peroxidase (POX activity and anthocyanins were observed for all cultivars. The K+/Na+ ratios evaluated for all rice cultivars were noted to be highly correlated with the salinity scores thus indicating that the K+/Na+ ratio serves as a reliable indicator of salt stress tolerance in rice. Principal component analysis (PCA based on physiological salt tolerance indexes could clearly distinguish rice cultivars into 4 salt tolerance clusters. Noteworthy, in comparison to the salt-sensitive ones, rice cultivars that possessed higher degrees of salt tolerance displayed more enhanced activity of catalase (CAT, a smaller increase in anthocyanin, hydrogen peroxide and proline content but a smaller drop in the K+/Na+ ratio and chlorophyll accumulation.

  4. A Mixed-Methods Study on Acceptability, Tolerability, and Substitution of Brown Rice for White Rice to Lower Blood Glucose Levels among Nigerian Adults

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    Sally N. Adebamowo

    2017-07-01

    Full Text Available BackgroundWhole-grain products such as brown rice have been associated with lower risk of metabolic disorders including diabetes. We examined the acceptability and tolerability of substituting brown rice for white rice and the feasibility of introducing brown rice into the diet through a long-term trial to lower the risk of type 2 diabetes.MethodsFifty-one adults residing in Abuja, Nigeria, participated in this study. Using purposeful sampling for focus group discussions (FGDs, participants were enrolled based on their age (19–25 vs. 40–60 years and body mass index (BMI (normal weight vs. overweight/obese. Participants tasted four meals with different constitution of brown and white rice (25:75%, 50:50%, 75:25%, and 100% brown rice. Twelve FGDs were conducted, six before and six after the food tasting. Two-hour postprandial blood glucose was measured after consumption of each rice meal.ResultsThe mean age of the participants was 39 (±14 years, their mean BMI was 25.6 (±5.2 and about half of them were male. Most of the participants (61% reported that rice was their main source of carbohydrate and 67% consumed rice at least five times/week. Before the food tasting, participants considered white polished rice superior to brown rice with regard to quality, taste, and nutritional value. After the food tasting, most of the participants (49% indicated a preference for the 100% brown rice, 19% preferred the 25% brown rice, 18% preferred the 50% brown rice, and 7% preferred the 75% brown rice meals. Factors that may affect the acceptability of brown rice include its appearance, longer cooking time, cost, limited availability, and poor appreciation of its nutritional value. In general, 2-h postprandial glucose levels were lower, after consumption of meals with higher proportion of brown rice.ConclusionThis study provides valuable insight into the acceptability of brown rice as a substitute for white rice in Nigeria. If confirmed in larger studies

  5. Rice Yellow Mottle Virus stress responsive genes from susceptible and tolerant rice genotypes

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    Siré Christelle

    2008-03-01

    Full Text Available Abstract Background The effects of viral infection involve concomitant plant gene variations and cellular changes. A simple system is required to assess the complexity of host responses to viral infection. The genome of the Rice yellow mottle virus (RYMV is a single-stranded RNA with a simple organisation. It is the most well-known monocotyledon virus model. Several studies on its biology, structure and phylogeography have provided a suitable background for further genetic studies. 12 rice chromosome sequences are now available and provide strong support for genomic studies, particularly physical mapping and gene identification. Results The present data, obtained through the cDNA-AFLP technique, demonstrate differential responses to RYMV of two different rice cultivars, i.e. susceptible IR64 (Oryza sativa indica, and partially resistant Azucena (O. s. japonica. This RNA profiling provides a new original dataset that will enable us to gain greater insight into the RYMV/rice interaction and the specificity of the host response. Using the SIM4 subroutine, we took the intron/exon structure of the gene into account and mapped 281 RYMV stress responsive (RSR transcripts on 12 rice chromosomes corresponding to 234 RSR genes. We also mapped previously identified deregulated proteins and genes involved in partial resistance and thus constructed the first global physical map of the RYMV/rice interaction. RSR transcripts on rice chromosomes 4 and 10 were found to be not randomly distributed. Seven genes were identified in the susceptible and partially resistant cultivars, and transcripts were colocalized for these seven genes in both cultivars. During virus infection, many concomitant plant gene expression changes may be associated with host changes caused by the infection process, general stress or defence responses. We noted that some genes (e.g. ABC transporters were regulated throughout the kinetics of infection and differentiated susceptible and

  6. ABA Inducible Rice Protein Phosphatase 2C Confers ABA Insensitivity and Abiotic Stress Tolerance in Arabidopsis

    Science.gov (United States)

    Singh, Amarjeet; Jha, Saroj K.; Bagri, Jayram; Pandey, Girdhar K.

    2015-01-01

    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. PMID:25886365

  7. Tolerance of upland rice cultivars to aluminum and acidic pH

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    Lucas B. de Freitas

    Full Text Available ABSTRACT Although the upland rice has been known by its moderate tolerance to aluminum, the presence of exchangeable aluminum in acidic soils may inhibit and compromise the adequate plant growth. However, there are few reports detailing modern cultivars used by Brazilian farmers with respect to their susceptibility to aluminum toxicity. This study aimed to characterize the cultivars currently used in the upland rice production with respect to their tolerance to aluminum and their growth under low pH conditions without aluminum. The treatments were arranged in a randomized block design, in a 2 x 9 factorial scheme: presence and absence of aluminum in the nutrient solution and nine upland rice cultivars (BRS Monarca, BRS Pepita, BRS Bonança, BRS Primavera, BRS Sertaneja, Maravilha, IAC 202, ANCambará and ANa7007, with four replicates. Based on the distribution of upland rice cultivars in quartiles, they were divided into two groups; aluminum-tolerant group: BRS Pepita, BRS Primavera and ANa7007; and aluminum-susceptible group: BRS Monarca, BRS Bonança, BRS Sertaneja, Maravilha, IAC 202 and ANCambará.

  8. Proteomic study of low-temperature responses in strawberry cultivars (Fragaria x ananassa) that differ in cold tolerance.

    Science.gov (United States)

    Koehler, Gage; Wilson, Robert C; Goodpaster, John V; Sønsteby, Anita; Lai, Xianyin; Witzmann, Frank A; You, Jin-Sam; Rohloff, Jens; Randall, Stephen K; Alsheikh, Muath

    2012-08-01

    To gain insight into the molecular basis contributing to overwintering hardiness, a comprehensive proteomic analysis comparing crowns of octoploid strawberry (Fragaria × ananassa) cultivars that differ in freezing tolerance was conducted. Four cultivars were examined for freeze tolerance and the most cold-tolerant cultivar ('Jonsok') and least-tolerant cultivar ('Frida') were compared with a goal to reveal how freezing tolerance is achieved in this distinctive overwintering structure and to identify potential cold-tolerance-associated biomarkers. Supported by univariate and multivariate analysis, a total of 63 spots from two-dimensional electrophoresis analysis and 135 proteins from label-free quantitative proteomics were identified as significantly differentially expressed in crown tissue from the two strawberry cultivars exposed to 0-, 2-, and 42-d cold treatment. Proteins identified as cold-tolerance-associated included molecular chaperones, antioxidants/detoxifying enzymes, metabolic enzymes, pathogenesis-related proteins, and flavonoid pathway proteins. A number of proteins were newly identified as associated with cold tolerance. Distinctive mechanisms for cold tolerance were characterized for two cultivars. In particular, the 'Frida' cold response emphasized proteins specific to flavonoid biosynthesis, while the more freezing-tolerant 'Jonsok' had a more comprehensive suite of known stress-responsive proteins including those involved in antioxidation, detoxification, and disease resistance. The molecular basis for 'Jonsok'-enhanced cold tolerance can be explained by the constitutive level of a number of proteins that provide a physiological stress-tolerant poise.

  9. Effects of diapause and cold-acclimation on the avoidance of freezing injury in fat body tissue of the rice stem borer, Chilo suppressalis Walker.

    Science.gov (United States)

    Izumi, Yohei; Sonoda, Shoji; Tsumuki, Hisaaki

    2007-07-01

    Overwintering freeze-tolerant larvae of Chilo suppressalis can survive at -25 degrees C, but non-diapausing larvae cannot. We reported earlier that to prevent intracellular freezing, which causes death in overwintering larvae of the Saigoku ecotype distributed in southwestern Japan, water leaves and glycerol enters fat body cells through water channels during freezing. However, it is still unclear how diapause and low-temperature exposure are related to the acquisition of freeze tolerance. We compared the extent of tissue damage, accumulation of glycerol, and transport of glycerol and water in fat body tissues between cold-acclimated and non-acclimated non-diapausing and diapausing larvae. The tissue from cold-acclimated diapausing larvae could survive only when frozen in Grace's insect medium with 0.25 M glycerol at -20 degrees C. The protection provided by glycerol was offset by mercuric chloride, which is a water-channel inhibitor. Fat body tissue isolated from non-acclimated diapausing larvae was injured by freezing even though glycerol was added to the medium, but the level of freezing injury was significantly lower than in non-diapausing larvae. Radiotracer assays in cold-acclimated diapausing larvae showed that during freezing, water left the cells into the medium and glycerol entered the cells from the medium at the same time. Therefore, in Saigoku ecotype larvae of the rice stem borer, both diapause and cold-acclimation are essential to accumulate glycerol and activate aquaporin for the avoidance of freezing injury.

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

    Science.gov (United States)

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

    2001-02-01

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

  11. TrustRank: a Cold-Start tolerant recommender system

    Science.gov (United States)

    Zou, Haitao; Gong, Zhiguo; Zhang, Nan; Zhao, Wei; Guo, Jingzhi

    2015-02-01

    The explosive growth of the World Wide Web leads to the fast advancing development of e-commerce techniques. Recommender systems, which use personalised information filtering techniques to generate a set of items suitable to a given user, have received considerable attention. User- and item-based algorithms are two popular techniques for the design of recommender systems. These two algorithms are known to have Cold-Start problems, i.e., they are unable to effectively handle Cold-Start users who have an extremely limited number of purchase records. In this paper, we develop TrustRank, a novel recommender system which handles the Cold-Start problem by leveraging the user-trust networks which are commonly available for e-commerce applications. A user-trust network is formed by friendships or trust relationships that users specify among them. While it is straightforward to conjecture that a user-trust network is helpful for improving the accuracy of recommendations, a key challenge for using user-trust network to facilitate Cold-Start users is that these users also tend to have a very limited number of trust relationships. To address this challenge, we propose a pre-processing propagation of the Cold-Start users' trust network. In particular, by applying the personalised PageRank algorithm, we expand the friends of a given user to include others with similar purchase records to his/her original friends. To make this propagation algorithm scalable to a large amount of users, as required by real-world recommender systems, we devise an iterative computation algorithm of the original personalised TrustRank which can incrementally compute trust vectors for Cold-Start users. We conduct extensive experiments to demonstrate the consistently improvement provided by our proposed algorithm over the existing recommender algorithms on the accuracy of recommendations for Cold-Start users.

  12. Tolerance to multiple climate stressors: A case study of Douglas-fir drought and cold hardiness

    Science.gov (United States)

    Bansal, Sheel; Harrington, Constance A; St. Clair, John Bradley

    2016-01-01

    Summary: 1. Drought and freeze events are two of the most common forms of climate extremes which result in tree damage or death, and the frequency and intensity of both stressors may increase with climate change. Few studies have examined natural covariation in stress tolerance traits to cope with multiple stressors among wild plant populations. 2. We assessed the capacity of coastal Douglas-fir (Pseudotsuga menziesii var. menziesii), an ecologically and economically important species in the northwestern USA, to tolerate both drought and cold stress on 35 populations grown in common gardens. We used principal components analysis to combine drought and cold hardiness trait data into generalized stress hardiness traits to model geographic variation in hardiness as a function of climate across the Douglas-fir range. 3. Drought and cold hardiness converged among populations along winter temperature gradients and diverged along summer precipitation gradients. Populations originating in regions with cold winters had relatively high tolerance to both drought and cold stress, which is likely due to overlapping adaptations for coping with winter desiccation. Populations from regions with dry summers had increased drought hardiness but reduced cold hardiness, suggesting a trade-off in tolerance mechanisms. 4. Our findings highlight the necessity to look beyond bivariate trait–climate relationships and instead consider multiple traits and climate variables to effectively model and manage for the impacts of climate change on widespread species.

  13. SSR Mapping of QTLs Conferring Cold Tolerance in an Interspecific Cross of Tomato

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    Yang Liu

    2016-01-01

    Full Text Available A population of 146 RILs (Recombinant Inbred Line was derived from the cross between a cold-sensitive cultivated Solanum lycopersicum L. XF98-7 and a cold-tolerant wild Solanum pimpinellifolium LA2184. Relative germination ratio (RGR and chilling index (CI were used to evaluate the cold tolerance of the parental lines and RILs. It was found that the RGR and CI were significantly different between S. lycopersicum XF98-7 and S. pimpinellifolium LA2184 under cold treatment, indicating that wild species was more adapted to chilling temperature. The continuous and normal distribution of RGR and CI in RIL population suggested that the trait of cold tolerance was a typically quantitative trait controlled by multigenes. The molecular linkage map was constructed by using 120 simple-sequence repeat (SSR markers, resulting in 15 linkage groups, with a total distance of 256.8 cM and average interval of 2.14 cM. Five QTLs controlling RGR and four QTLs for CI were detected with genetic contribution ranging from 0.95% to 19.55%. Thus, the nine QTLs will provide references for further fine position mapping for cold tolerance. The polymorphic markers could be used as a way of indirectly selecting the plant trait of interest and would promote developing new tomato variety by marker-assisted selection.

  14. Mapping QTLs for Drought Tolerance at Seedling Stage in Rice Using Doubled Haploid Population

    Institute of Scientific and Technical Information of China (English)

    Xu Qun; YUAN Xiao-ping; Yu Han-yong; WANG Yi-ping; TANG Sheng-xiang; WEI Xing-hua

    2011-01-01

    QTLs for drought tolerance at the rice seedling stage were analyzed using a doubled haploid (DH) population consisted of 251 lines from the cross between a japonica parent Maybelle and an indica parent Baiyeqiu.A genetic linkage map with 226 SSR marker loci was constructed.Single-locus analysis following composite interval mapping (CIM) detected a total of five QTLs located on five different chromosomes of rice.Four QTLs were also detected following two-locus analysis,resolving two pairs of epistatic QTLs (E-QTLs) with positive and additive genetic effects.The results indicated that the alleles from the parent Baiyeqiu contributed DH population to improve drought tolerance at the seedling stage.

  15. RNAi-mediated disruption of squalene synthase improves drought tolerance and yield in rice.

    Science.gov (United States)

    Manavalan, Lakshmi P; Chen, Xi; Clarke, Joseph; Salmeron, John; Nguyen, Henry T

    2012-01-01

    About one-third of the world's rice area is in rain-fed lowlands and most are prone to water shortage. The identification of genes imparting tolerance to drought in the model cereal plant, rice, is an attractive strategy to engineer improved drought tolerance not only rice but other cereals as well. It is demonstrated that RNAi-mediated disruption of a rice farnesyltransferase/squalene synthase (SQS) by maize squalene synthase improves drought tolerance at both the vegetative and reproductive stages. Twenty-day-old seedlings of wild type (Nipponbare) and seven independent events of transgenic RNAi lines showed no difference in morphology. When subjected to water stress for a period of 32 d under growth chamber conditions, transgenic positives showed delayed wilting, conserved more soil water, and improved recovery. When five independent events along with wild-type plants were subjected to drought at the reproductive stage under greenhouse conditions, the transgenic plants lost water more slowly compared with the wild type, through reduced stomatal conductance and the retention of high leaf relative water content (RWC). After 28 d of slow progressive soil drying, transgenic plants recovered better and flowered earlier than wild-type plants. The yield of water-stressed transgenic positive plants ranged from 14-39% higher than wild-type plants. When grown in plates with Yoshida's nutrient solution with 1.2% agar, transgenic positives from three independent events showed increased root length and an enhanced number of lateral roots. The RNAi-mediated inactivation produced reduced stomatal conductance and subsequent drought tolerance.

  16. The enhanced drought tolerance of rice plants under ammonium is related to aquaporin (AQP).

    Science.gov (United States)

    Ding, Lei; Gao, Cuimin; Li, Yingrui; Li, Yong; Zhu, Yiyong; Xu, Guohua; Shen, Qirong; Kaldenhoff, Ralf; Kai, Lei; Guo, Shiwei

    2015-05-01

    Previously, we demonstrated that drought resistance in rice seedlings was increased by ammonium (NH4(+)) treatment, but not by nitrate (NO3(-)) treatment, and that the change was associated with root development. To study the effects of different forms of nitrogen on water uptake and root growth under drought conditions, we subjected two rice cultivars (cv. 'Shanyou 63' hybrid indica and cv. 'Yangdao 6' indica, China) to polyethylene glycol-induced drought stress in a glasshouse using hydroponic culture. Under drought conditions, NH4(+) significantly stimulated root growth compared to NO3(-), as indicated by the root length, surface area, volume, and numbers of lateral roots and root tips. Drought stress decreased the root elongation rate in both cultivars when they were supplied with NO3(-), while the rate was unaffected in the presence of NH4(+). Drought stress significantly increased root protoplast water permeability, root hydraulic conductivity, and the expression of root aquaporin (AQP) plasma intrinsic protein (PIP) genes in rice plants supplied with NH4(+); these changes were not observed in plants supplied with NO3(-). Additionally, ethylene, which is involved in the regulation of root growth, accumulated in rice roots supplied with NO3(-) under conditions of drought stress. We conclude that the increase in AQP expression and/or activity enhanced the root water uptake ability and the drought tolerance of rice plants supplied with NH4(+).

  17. Drought-tolerant rice germplasm developed from an Oryza officinalis transformation-competent artificial chromosome clone.

    Science.gov (United States)

    Liu, R; Zhang, H H; Chen, Z X; Shahid, M Q; Fu, X L; Liu, X D

    2015-10-29

    Oryza officinalis has proven to be a natural gene reservoir for the improvement of domesticated rice as it carries many desirable traits; however, the transfer of elite genes to cultivated rice by conventional hybridization has been a challenge for rice breeders. In this study, the conserved sequence of plant stress-related NAC transcription factors was selected as a probe to screen the O. officinalis genomic transformation-competent artificial chromosome library by Southern blot; 11 positive transformation-competent artificial chromosome clones were subsequently detected. By Agrobacterium-mediated transformation, an indica rice variety, Huajingxian 74 (HJX74), was transformed with a TAC clone harboring a NAC gene-positive genomic fragment from O. officinalis. Molecular analysis revealed that the O. officinalis genomic fragment was integrated into the genome of HJX74. The transgenic lines exhibited high tolerance to drought stress. Our results demonstrate that the introduction of stress-related transformation-competent artificial chromosome clones, coupled with a transgenic validation approach, is an effective method of transferring agronomically important genes from O. officinalis to cultivated rice.

  18. Comparative Analysis of Anther Transcriptome Profiles of Two Different Rice Male Sterile Lines Genotypes under Cold Stress

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    Bin Bai

    2015-05-01

    Full Text Available Rice is highly sensitive to cold stress during reproductive developmental stages, and little is known about the mechanisms of cold responses in rice anther. Using the HiSeq™ 2000 sequencing platform, the anther transcriptome of photo thermo sensitive genic male sterile lines (PTGMS rice Y58S and P64S (Pei’ai64S were analyzed at the fertility sensitive stage under cold stress. Approximately 243 million clean reads were obtained from four libraries and aligned against the oryza indica genome and 1497 and 5652 differentially expressed genes (DEGs were identified in P64S and Y58S, respectively. Both gene ontology (GO and Kyoto Encyclopedia of Genes and Genomes (KEGG analyses were conducted for these DEGs. Functional classification of DEGs was also carried out. The DEGs common to both genotypes were mainly involved in signal transduction, metabolism, transport, and transcriptional regulation. Most of the DEGs were unique for each comparison group. We observed that there were more differentially expressed MYB (Myeloblastosis and zinc finger family transcription factors and signal transduction components such as calmodulin/calcium dependent protein kinases in the Y58S comparison group. It was also found that ribosome-related DEGs may play key roles in cold stress signal transduction. These results presented here would be particularly useful for further studies on investigating the molecular mechanisms of rice responses to cold stress.

  19. Interpopulational variation in the cold tolerance of a broadly distributed marine copepod.

    Science.gov (United States)

    Wallace, Gemma T; Kim, Tiffany L; Neufeld, Christopher J

    2014-01-01

    Latitudinal trends in cold tolerance have been observed in many terrestrial ectotherms, but few studies have investigated interpopulational variation in the cold physiology of marine invertebrates. Here, the intertidal copepod Tigriopus californicus was used as a model system to study how local adaptation influences the cold tolerance of a broadly distributed marine crustacean. Among five populations spanning 18° in latitude, the following three metrics were used to compare cold tolerance: the temperature of chill-coma onset, the chill-coma recovery time and post-freezing recovery. In comparison to copepods from warmer southern latitudes, animals from northern populations exhibited lower chill-coma onset temperatures, shorter chill-coma recovery times and faster post-freezing recovery rates. Importantly, all three metrics showed a consistent latitudinal trend, suggesting that any single metric could be used equivalently in future studies investigating latitudinal variation in cold tolerance. Our results agree with previous studies showing that populations within a single species can display strong local adaptation to spatially varying climatic conditions. Thus, accounting for local adaptation in bioclimate models will be useful for understanding how broadly distributed species like T. californicus will respond to anthropogenic climate change.

  20. More grain per drop of water: Screening rice genotype for physiological parameters of drought tolerance

    Science.gov (United States)

    Massanelli, J.; Meadows-McDonnell, M.; Konzelman, C.; Moon, J. B.; Kumar, A.; Thomas, J.; Pereira, A.; Naithani, K. J.

    2016-12-01

    Meeting agricultural water demands is becoming progressively difficult due to population growth and changes in climate. Breeding stress-resilient crops is a viable solution, as information about genetic variation and their role in stress tolerance is becoming available due to advancement in technology. In this study we screened eight diverse rice genotypes for photosynthetic capacity under greenhouse conditions. These include the Asian rice (Oryza sativa) genotypes, drought sensitive Nipponbare, and a transgenic line overexpressing the HYR gene in Nipponbare; six genotypes (Vandana, Bengal, Nagina-22, Glaberrima, Kaybonnet, Ai Chueh Ta Pai Ku) and an African rice O. glaberrima, all selected for varying levels of drought tolerance. We collected CO2 and light response curve data under well-watered and simulated drought conditions in greenhouse. From these curves we estimated photosynthesis model parameters, such as the maximum carboxylation rate (Vcmax), the maximum electron transport rate (Jmax), the maximum gross photosynthesis rate, daytime respiration (Rd), and quantum yield (f). Our results suggest that O. glaberrima and Nipponbare were the most sensitive to drought because Vcmax and Pgmax declined under drought conditions; other drought tolerant genotypes did not show significant changes in these model parameters. Our integrated approach, combining genetic information and photosynthesis modeling, shows promise to quantify drought response parameters and improve crop yield under drought stress conditions.

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

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    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.

  2. Salt tolerant SUV3 overexpressing transgenic rice plants conserve physicochemical properties and microbial communities of rhizosphere.

    Science.gov (United States)

    Sahoo, Ranjan K; Ansari, Mohammad W; Tuteja, Renu; Tuteja, Narendra

    2015-01-01

    Key concerns in the ecological evaluation of GM crops are undesirably spread, gene flow, other environmental impacts, and consequences on soil microorganism's biodiversity. Numerous reports have highlighted the effects of transgenic plants on the physiology of non-targeted rhizospheric microbes and the food chain via causing adverse effects. Therefore, there is an urgent need to develop transgenics with insignificant toxic on environmental health. In the present study, SUV3 overexpressing salt tolerant transgenic rice evaluated in New Delhi and Cuttack soil conditions for their effects on physicochemical and biological properties of rhizosphere. Its cultivation does not affect soil properties viz., pH, Eh, organic C, P, K, N, Ca, Mg, S, Na and Fe(2+). Additionally, SUV3 rice plants do not cause any change in the phenotype, species characteristics and antibiotic sensitivity of rhizospheric bacteria. The population and/or number of soil organisms such as bacteria, fungi and nematodes were unchanged in the soil. Also, the activity of bacterial enzymes viz., dehydrogenase, invertase, phenol oxidases, acid phosphatases, ureases and proteases was not significantly affected. Further, plant growth promotion (PGP) functions of bacteria such as siderophore, HCN, salicylic acid, IAA, GA, zeatin, ABA, NH3, phosphorus metabolism, ACC deaminase and iron tolerance were, considerably, not influenced. The present findings suggest ecologically pertinent of salt tolerant SUV3 rice to sustain the health and usual functions of the rhizospheric organisms.

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

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    Amrit Kaur eNanda

    2016-03-01

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

  4. ICE1 Ser403 is necessary for protein stabilization and regulation of cold signaling and tolerance

    OpenAIRE

    Miura, Kenji; Ohta, Masaru; Nakazawa, Machiko; Ono, Michiyuki; Hasegawa, Paul M.

    2011-01-01

    ICE1, a MYC-type transcription factor, has an important role in the induction of CBF3/DREB1A for regulation of cold signaling and tolerance. Here we reveal that serine 403 of ICE1 is involved in regulating the transactivation and stability of the ICE1 protein. Substitution of serine 403 by alanine enhanced the transactivational activity of ICE1 in Arabidopsis protoplasts. Over-expression of ICE1(S403A) conferred more freezing tolerance than ICE1(WT) in Arabidopsis, and the expression of cold-...

  5. Cold Tolerance of the Mediterranean Fruit Fly in Date and Mandarin.

    Science.gov (United States)

    Gazit, Yoav; Akiva, Ruti; Gavriel, Sagi

    2014-10-01

    The Mediterranean fruit fly, Ceratitis capitata (Wiedemann), is an endemic pest in Israel and there can be low levels of infestation of dates (Phoenix dactylifera L.). Because C. capitata is considered a quarantine pest by several major importing countries, the export of fresh dates requires the elimination of this pest. For mandarin, cold storage at 1.11°C for 15 d is considered to be an effective treatment for the elimination of C. capitata. In this study, we compared the cold tolerance of C. capitata in "Barhi" dates to that of C. capitata in mandarins (Citrus unshiu Marcovitch, "Satsuma"). In Barhi dates, we found the third instars to be the most cold-tolerant as compared with other life stages. Ceratitis capitata in date fruits were significantly less cold-tolerant than C. capitata in Satsuma mandarins. The last viable larvae in dates and mandarins were found after 8 and 13 d of treatment, respectively, and the calculated mortality curves in the two crops were significantly different. These results demonstrate that C. capitata is more sensitive to cold treatment when in date fruits than in mandarins. Therefore, the quarantine cold treatments used to eliminate C. capitata from mandarins should be sufficiently effective if applied to fresh date fruits.

  6. Genetic parameters for cold tolerance and body weight of Chinese fleshy prawn,Fenneropenaeus chinensis

    Institute of Scientific and Technical Information of China (English)

    LI Wenjia; LUAN Sheng; LUO Kun; SUI Juan; LU Xia; WANG Qingyin; KONG Jie

    2016-01-01

    The inability ofFenneropenaeus chinensis to tolerate low temperatures is of major economic concern in temperate climates, as it reduces their growing season and leads to over-winter mortality. In this study, the heritability of body weight under low grow-out temperature and cold tolerance inF. chinensis were first investigated and estimated using 88 ful-sib families, which might provide crucial information in Chinese fleshy prawn breeding programs. The heritability for body weight under suitable and low temperature ofF. chinensis were both moderate (0.158 0±0.307 5 and 0.132 0±0.026 9 respectively); the large coefficient of variation (approximately 21%) and moderate estimate of heritability for body weight indicated substantial potential for selective breeding. The heritability estimate for cold tolerance was low (0.019 2±0.023 5), and showed no significant differences from zero (P>0.05). A weak genetic correlation between cold tolerance and body weight was also estimated in the present study, also showing no significant differences from zero (P>0.05). Thus, more research needs to be conducted on the more accurate heritability estimate of cold tolerance and genetic correlations between traits inF. chinensis to further improve the achievement of breeding goals.

  7. Tolerance and compensatory response of rice to sugarcane borer (Lepidoptera: Crambidae) injury.

    Science.gov (United States)

    Lv, J; Wilson, L T; Longnecker, M T

    2008-06-01

    A 3-yr field experiment was conducted to evaluate the tolerance and compensatory response of rice (Oryza sativa L.) to injury caused by sugarcane borer, Diatraea saccharalis (F.), as affected by cultivar (Cocodrie, Francis, and Jefferson), stage of crop growth during which the injury occurred (third tiller stage, panicle differentiation stage, and heading stage), and sugarcane borer density. The proportion of rice tillers with sugarcane borer injury (leaf and leaf sheath injury and/or stem injury) was lower when injury occurred at the third tiller stage (0.05) than at panicle differentiation (0.19) and heading (0.18). When injury occurred at the two latter stages, both the proportion of tillers with injury and the proportion of tillers with stem injury were negatively correlated with rainfall. Rainfall resulted in dislodgement and mortality of sugarcane borer eggs and larvae before the larvae entered the stems. Rice plant density in this study (111.1 plants/m2) was higher than recorded for previous research on rice compensation using potted rice or conducted in low-density hill production systems (26.7-51.3 plants/m2). Two mechanisms of within-plant tolerance/compensation were observed. Stem injured plants produced approximately 0.69 more tillers than uninjured plants, whereas tillers with leaf and leaf sheath injury produced larger panicles, up to 39.5 and 21.0% heavier than uninjured tillers, when injury occurred at third tiller stage and at panicle differentiation, respectively. Rice yield was not reduced with up to 23% injured tiller and up to 10% injured stems at the third tiller stage, 42% injured tillers and 17% injured stems at panicle differentiation, and 28% injured tillers and 14% injured stems at heading. Significant between-plant compensation was not detected, suggesting competition between adjacent plants is not significantly reduced by injury. Our results suggest that rice can tolerate and/or compensate for a level of stem borer injury previously

  8. 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.

  9. Enhanced tolerance to drought in transgenic rice plants overexpressing C4 photosynthesis enzymes

    Directory of Open Access Journals (Sweden)

    Jun-Fei Gu

    2013-12-01

    Full Text Available Maize-specific pyruvate orthophosphate dikinase (PPDK was overexpressed in rice independently or in combination with the maize C4-specific phosphoenolpyruvate carboxylase (PCK. The wild-type (WT cultivar Kitaake and transgenic plants were evaluated in independent field and tank experiments. Three soil moisture treatments, well-watered (WW, moderate drought (MD and severe drought (SD, were imposed from 9 d post-anthesis till maturity. Leaf physiological and biochemical traits, root activities, biomass, grain yield, and yield components in the untransformed WT and two transgenic rice lines (PPDK and PCK were systematically studied. Compared with the WT, both transgenic rice lines showed increased leaf photosynthetic rate: by 20%–40% under WW, by 45%–60% under MD, and by 80%–120% under SD. The transgenic plants produced 16.1%, 20.2% and 20.0% higher grain yields than WT under the WW, MD and SD treatments, respectively. Under the same soil moisture treatments, activities of phosphoenolpyruvate carboxylase (PEPC and carbonic anhydrase (CA in transgenic plants were 3–5-fold higher than those in WT plants. Compared with ribulose-1,5-bisphosphate carboxylase, activities of PEPC and CA were less reduced under both MD and SD treatments. The transgenic plants also showed higher leaf water content, stomatal conductance, transpiration efficiency, and root oxidation activity and a stronger active oxygen scavenging system than the WT under all soil moisture treatments, especially MD and SD. The results suggest that drought tolerance is greatly enhanced in transgenic rice plants overexpressing C4 photosynthesis enzymes. This study was performed under natural conditions and normal planting density to evaluate yield advantages on a field basis. It may open a new avenue to drought-tolerance breeding via overexpression of C4 enzymes in rice.

  10. Identification of Upregulated Genes under Cold Stress in Cold-Tolerant Chickpea Using the cDNA-AFLP Approach

    Science.gov (United States)

    Dinari, Ali; Niazi, Ali; Afsharifar, Ali Reza; Ramezani, Amin

    2013-01-01

    Low temperature injury is one of the most significant causes of crop damage worldwide. Cold acclimatization processes improve the freezing tolerance of plants. To identify genes of potential importance for acclimatzation to the cold and to elucidate the pathways that regulate this process, global transcriptome expression of the chickpea (Cicer arietinum L), a species of legume, was analyzed using the cDNA-AFLP technique. In total, we generated 4800 transcript-derived fragments (TDFs) using cDNA-AFLP in conjunction with 256 primer combinations. We only considered those cDNA fragments that seemed to be up-regulated during cold acclimatization. Of these, 102 TDFs with differential expression patterns were excised from gels and re-amplified by PCR. Fifty-four fragments were then cloned and sequenced. BLAST search of the GenBank non-redundant (nr) sequence database demonstrated that 77 percent of the TDFs belonged to known sequences with putative functions related to metabolism (31), transport (10), signal transduction pathways (15) and transcription factors (21). The last group of expressed transcripts showed homology to genes of unknown function (22). To further analyze and validate our cDNA-AFLP experiments, the expression of 9 TDFs during cold acclimatzatiion was confirmed using real time RT-PCR. The results of this research show that cDNA-AFLP is a powerful technique for investigating the expression pattern of chickpea genes under low-temperature stress. Moreover, our findings will help both to elucidate the molecular basis of low-temperature effects on the chickpea genome and to identify those genes that could increase the cold tolerance of the chickpea plant. PMID:23341906

  11. Internal Zn allocation influences Zn deficiency tolerance and grain Zn loading in rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Impa Muthappa Somayanda

    2013-12-01

    Full Text Available One of the important factors that influences Zn deficiency tolerance and grain Zn loading in crops is the within-plant allocation of Zn. Three independent experiments were carried out to understand the internal Zn distribution patterns in rice genotypes grown in Zn-sufficient and Zn-deficient agar nutrient solution (ANS. In one of the experiments, two rice genotypes (IR55179 and KP contrasting in Zn deficiency tolerance were leaf-labeled with 65Zn. In the other two experiments, two Zn biofortification breeding lines (IR69428 and SWHOO were either root- or leaf-labeled with 65Zn. Rice genotype IR55179 showed significantly higher Zn deficiency tolerance than KP at 21 and 42 days after planting. When KP was Zn-deficient, it failed to translocate 65Zn from the labeled leaf to newly emerging leaves. Similarly, the root-to-shoot translocation of unlabeled Zn was lower in KP than in IR55179. These results suggest that some Zn-efficient rice genotypes have greater ability to translocate Zn from older to actively growing tissues than genotypes sensitive to Zn deficiency. Among the two Zn biofortication breeding lines that were leaf-labeled with 65Zn at 10 days before panicle initiation stage, 65Zn distribution in the grains at maturity was similar between both genotypes in Zn-sufficient conditions. However, under Zn-deficient conditions, SWHOO accumulated significantly higher 65Zn in grains than IR69428, indicating that SWHOO is a better remobilizer than IR69428. When the roots of these two Zn biofortication breeding lines were exposed to 65Zn solution at 10 days after flowering, IR69428 showed higher root uptake of 65Zn than SWHOO in Zn-sufficient conditions, but 65Zn allocation in the aerial parts of the plant was similar between both genotypes.

  12. Quantitative analysis of γ-oryzanol content in cold pressed rice bran oil by TLC-image analysis method.

    Science.gov (United States)

    Sakunpak, Apirak; Suksaeree, Jirapornchai; Monton, Chaowalit; Pathompak, Pathamaporn; Kraisintu, Krisana

    2014-02-01

    To develop and validate an image analysis method for quantitative analysis of γ-oryzanol in cold pressed rice bran oil. TLC-densitometric and TLC-image analysis methods were developed, validated, and used for quantitative analysis of γ-oryzanol in cold pressed rice bran oil. The results obtained by these two different quantification methods were compared by paired t-test. Both assays provided good linearity, accuracy, reproducibility and selectivity for determination of γ-oryzanol. The TLC-densitometric and TLC-image analysis methods provided a similar reproducibility, accuracy and selectivity for the quantitative determination of γ-oryzanol in cold pressed rice bran oil. A statistical comparison of the quantitative determinations of γ-oryzanol in samples did not show any statistically significant difference between TLC-densitometric and TLC-image analysis methods. As both methods were found to be equal, they therefore can be used for the determination of γ-oryzanol in cold pressed rice bran oil.

  13. Quantitative analysis of γ-oryzanol content in cold pressed rice bran oil by TLC-image analysis method

    Institute of Scientific and Technical Information of China (English)

    Apirak Sakunpak; Jirapornchai Suksaeree; Chaowalit Monton; Pathamaporn Pathompak; Krisana Kraisintu

    2014-01-01

    Objective: To develop and validate an image analysis method for quantitative analysis ofγ-oryzanol in cold pressed rice bran oil.Methods:TLC-densitometric and TLC-image analysis methods were developed, validated, and used for quantitative analysis of γ-oryzanol in cold pressed rice bran oil. The results obtained by these two different quantification methods were compared by paired t-test.Results:Both assays provided good linearity, accuracy, reproducibility and selectivity for determination of γ-oryzanol. Conclusions: The TLC-densitometric and TLC-image analysis methods provided a similar reproducibility, accuracy and selectivity for the quantitative determination of γ-oryzanol in cold pressed rice bran oil. A statistical comparison of the quantitative determinations of γ-oryzanol in samples did not show any statistically significant difference between TLC-densitometric and TLC-image analysis methods. As both methods were found to be equal, they therefore can be used for the determination of γ-oryzanol in cold pressed rice bran oil.

  14. Effect of soil salinity on cold tolerance of mangrove Kandelia candel

    Institute of Scientific and Technical Information of China (English)

    YANG Shengchang; LI Yunbo; LIN Peng

    2005-01-01

    Analysis of cold tolerance on mangrove Kandelia candel leaf growing in different soil salinity along Jiulong River Estuary in South China showed that the cold tolerance decreased as the increase of soil salinity. The lethal temperatures of K. candel leaf were -10.4, -9.9 and -8.6 ℃ in Liaodong, Baijiao and Aotou, respectively. Under 1-2℃ cold stress treatment on detached leaves ofK. candel, their caloric value gradually decreased, while electrolyte leakage gradually increased. The leaf's caloric value and electrolyte leakage in Aotou with higher soil salinity varied more largely than those in Liaodong with lower soil salinity. In K. candel leaf, total water content lowered a little, bound water content rose significantly and free water content dropped significantly with duration of cold stress. At the same time, reduction sugar, soluble sugar and starch content gradually decreased and sucrose content gradually increased. Bound water, free water and sucrose content in K. candel leaf from Aotou with higher soil salinity changed more slowly than those from Liaodong with lower soil salinity, but reduction sugar, soluble sugar and starch content in K. candel leaf from Aotou had faster variations than those from Liaodong. These data indicated that soil salinity can reduce cold tolerance of K.candel leaf by increasing negative effect of salt ions in cell membrane, inhibiting variations of water content, and aggravating consumption of material and energy.

  15. Effect of soil salinity on cold tolerance of mangrove Kandelia candel

    Science.gov (United States)

    Yang, Shengchang; Li, Yunbo; Lin, Peng

    2005-03-01

    Analysis of cold tolerance on mangrove Kandelia candel leaf growing in different soil salinity along Jiulong River Estuary in South China showed that the cold tolerance decreased as the increase of soil salinity. The lethal temperatures of K. candel leaf were -10.4, -9.9 and -8.6 °C in Liaodong, Baijiao and Aotou, respectively. Under 1 2°C cold stress treatment on detached leaves of K. candel, their caloric value gradually decreased, while electrolyte leakage gradually increased. The leaf's caloric value and electrolyte leakage in Aotou with higher soil salinity varied more largely than those in Liaodong with lower soil salinity. In K. candel leaf, total water content lowered a little, bound water content rose significantly and free water content dropped significantly with duration of cold stress. At the same time, reduction sugar, soluble sugar and starch content gradually decreased and sucrose content gradually increased. Bound water, free water and sucrose content in K. candel leaf from Aotou with higher soil salinity changed more slowly than those from Liaodong with lower soil salinity, but reduction sugar, soluble sugar and starch content in K. candel leaf from Aotou had faster variations than those from Liaodong. These data indicated that soil salinity can reduce cold tolerance of K. candel leaf by increasing negative effect of salt ions in cell membrane, inhibiting variations of water content, and aggravating consumption of material and energy.

  16. Overexpression of a blueberry-derived CBF enhances cold tolerance in a southern highbush blueberry cultivar

    Science.gov (United States)

    Blueberry cultivars are subject to freezing damage in the winter and early spring. C-repeat binding factor (CBF) genes are transcription factors known to induce the expression of genes associated with cold acclimation and freezing tolerance. A CBF-encoding gene (BB-CBF) was isolated from the northe...

  17. Using ORYZA2000 to model cold rice yield response to climate change in the Heilongjiang province, China

    Institute of Scientific and Technical Information of China (English)

    Jingting; Zhang; Liping; Feng; Haiping; Zou; De; Li; Liu

    2015-01-01

    Rice(Oryza sativa L.) is one of the most important staple crops in China. Increasing atmospheric greenhouse gas concentrations and associated climate change may greatly affect rice production. We assessed the potential impacts of climate change on cold rice production in the Heilongjiang province, one of China’s most important rice production regions. Data for a baseline period(1961–1990) and the period 2010–2050 in A2 and B2 scenarios were used as input to drive the rice model ORYZA2000 with and without accounting for the effects of increasing atmospheric CO2 concentration. The results indicate that mean,maximum, and minimum temperature during the rice growing season, in the future period considered, would increase by 1.8 °C under the A2 scenario and by 2.2 °C under the B2 scenario compared with those in the baseline. The rate of change in average maximum and minimum temperatures would increase by 0.6 °C per 10-year period under the A2 scenario and by 0.4 °C per 10-year period under the B2 scenario. Precipitation would increase slightly in the rice growing season over the next 40 years. The rice growing season would be shortened and the yield would increase in most areas in the Heilongjiang province. Without accounting for CO2 effect, the rice growing season in the period 2010–2050 would be shortened by 4.7 and 5.8 days,and rice yields would increase by 11.9% and 7.9%, under the A2 and B2 scenarios, respectively.Areas with simulated rice yield increases greater than 30.0% were in the Xiaoxing’an Mountain region. The simulation indicated a decrease in yield of less than 15% in the southwestern Songnen Plain. The rate of change in simulated rice yield was 5.0% and 2.5% per 10 years under the A2 and B2 scenarios, respectively. When CO2 effect was accounted for, rice yield increased by 44.5% and 31.3% under the A2 and B2 scenarios, respectively. The areas of increasing yield were sharply expanded. The area of decreasing yield in the western region of

  18. Using ORYZA2000 to model cold rice yield response to climate change in the Heilongjiang province, China

    Institute of Scientific and Technical Information of China (English)

    Jingting Zhang; Liping Feng; Haiping Zou; De Li Liu

    2015-01-01

    Rice (Oryza sativa L.) is one of the most important staple crops in China. Increasing atmospheric greenhouse gas concentrations and associated climate change may greatly affect rice production. We assessed the potential impacts of climate change on cold rice production in the Heilongjiang province, one of China's most important rice production regions. Data for a baseline period (1961–1990) and the period 2010–2050 in A2 and B2 scenarios were used as input to drive the rice model ORYZA2000 with and without accounting for the effects of increasing atmospheric CO2 concentration. The results indicate that mean, maximum, and minimum temperature during the rice growing season, in the future period considered, would increase by 1.8 °C under the A2 scenario and by 2.2 °C under the B2 scenario compared with those in the baseline. The rate of change in average maximum and minimum temperatures would increase by 0.6 °C per 10-year period under the A2 scenario and by 0.4 °C per 10-year period under the B2 scenario. Precipitation would increase slightly in the rice growing season over the next 40 years. The rice growing season would be shortened and the yield would increase in most areas in the Heilongjiang province. Without accounting for CO2 effect, the rice growing season in the period 2010–2050 would be shortened by 4.7 and 5.8 days, and rice yields would increase by 11.9%and 7.9%, under the A2 and B2 scenarios, respectively. Areas with simulated rice yield increases greater than 30.0%were in the Xiaoxing'an Mountain region. The simulation indicated a decrease in yield of less than 15% in the southwestern Songnen Plain. The rate of change in simulated rice yield was 5.0%and 2.5%per 10 years under the A2 and B2 scenarios, respectively. When CO2 effect was accounted for, rice yield increased by 44.5%and 31.3%under the A2 and B2 scenarios, respectively. The areas of increasing yield were sharply expanded. The area of decreasing yield in the western region of Songnen

  19. Expression Profiling of Abiotic Stress-Inducible Genes in response to Multiple Stresses in Rice (Oryza sativa L. Varieties with Contrasting Level of Stress Tolerance

    Directory of Open Access Journals (Sweden)

    Supratim Basu

    2014-01-01

    Full Text Available The present study considered transcriptional profiles and protein expression analyses from shoot and/or root tissues under three abiotic stress conditions, namely, salinity, dehydration, and cold, as well as following exogenous abscisic acid treatment, at different time points of stress exposure in three indica rice varieties, IR-29 (salt sensitive, Pokkali, and Nonabokra (both salt tolerant. The candidate genes chosen for expression studies were HKT-1, SOS-3, NHX-1, SAPK5, SAPK7, NAC-1, Rab16A, OSBZ8, DREBP2, CRT/DREBP, WRKY24, and WRKY71, along with the candidate proteins OSBZ8, SAMDC, and GST. Gene expression profile revealed considerable differences between the salt-sensitive and salt-tolerant rice varieties, as the expression in the latter was higher even at the constitutive level, whereas it was inducible only by corresponding stress signals in IR-29. Whether in roots or shoots, the transcriptional responses to different stressors peaked following 24 h of stress/ABA exposure, and the transcript levels enhanced gradually with the period of exposure. The generality of stress responses at the transcriptional level was therefore time dependent. Heat map data also showed differential transcript abundance in the three varieties, correlating the observation with transcript profiling. In silico analysis of the upstream regions of all the genes represented the existence of conserved sequence motifs in single or multiple copies that are indispensable to abiotic stress response. Overall, the transcriptome and proteome analysis undertaken in the present study indicated that genes/proteins conferring tolerance, belonging to different functional classes, were overrepresented, thus providing novel insight into the functional basis of multiple stress tolerance in indica rice varieties. The present work will pave the way in future to select gene(s for overexpression, so as to generate broad spectrum resistance to multiple stresses simultaneously.

  20. Arsenite tolerance is related to proportional thiolic metabolite synthesis in rice (Oryza sativa L.).

    Science.gov (United States)

    Dave, Richa; Singh, Pradyumna Kumar; Tripathi, Preeti; Shri, Manju; Dixit, Garima; Dwivedi, Sanjay; Chakrabarty, Debasis; Trivedi, Prabodh Kumar; Sharma, Yogesh Kumar; Dhankher, Om Prakash; Corpas, Francisco Javier; Barroso, Juan B; Tripathi, Rudra Deo

    2013-02-01

    Thiol metabolism is the primary detoxification strategy by which rice plants tolerate arsenic (As) stress. In light of this, it is important to understand the importance of harmonised thiol metabolism with As accumulation and tolerance in rice plant. For this aim, tolerant (T) and sensitive (S) genotypes were screened from 303 rice (Oryza sativa) genotypes on exposure to 10 and 25 μM arsenite (As(III)) in hydroponic culture. On further As accumulation estimation, contrasting (13-fold difference) T (IC-340072) and S (IC-115730) genotypes were selected. This difference was further evaluated using biochemical and molecular approaches to understand involvement of thiolic metabolism vis-a-vis As accumulation in these two genotypes. Various phytochelatin (PC) species (PC(2), PC(3) and PC(4)) were detected in both the genotypes with a dominance of PC(3). However, PC concentrations were greater in the S genotype, and it was noticed that the total PC (PC(2) + PC(3 )+ PC(4))-to-As(III) molar ratio (PC-SH:As(III)) was greater in T (2.35 and 1.36 in shoots and roots, respectively) than in the S genotype (0.90 and 0.15 in shoots and roots, respectively). Expression analysis of several metal(loid) stress-related genes showed significant upregulation of glutaredoxin, sulphate transporter, and ascorbate peroxidase in the S genotype. Furthermore, enzyme activity of phytochelatin synthase and cysteine synthase was greater on As accumulation in the S compared with the T genotype. It was concluded that the T genotype synthesizes adequate thiols to detoxify metalloid load, whereas the S genotype synthesizes greater but inadequate levels of thiols to tolerate an exceedingly greater load of metalloids, as evidenced by thiol-to-metalloid molar ratios, and therefore shows a phytotoxicity response.

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

    Science.gov (United States)

    Wu, Xi; Liang, Chanjuan

    2016-12-16

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

  2. Differences between Rice Cultivars in Iron Plaque Formation on Roots and Plant Lead Tolerance

    Directory of Open Access Journals (Sweden)

    Xinmei Ma

    2013-02-01

    Full Text Available The aim of this study was to understand some mechanisms on the variations between rice cultivars in lead (Pb tolerance. Pot soil experiments were conducted with two rice cultivars under different soil Pb levels and the relationships between Pb phytotoxicity, uptake and iron plaque formation on roots were investigated. The results showed that the rice cultivar with indica consanguinity (Shanyou 63 were more sensitive to soil Pb stress than the cultivar with japonica consanguinity (Wuyunjing 7, particularly for the roots. Pb concentrations and distribution ratios in root tissues were higher for Shan you 63 than for Wuyunjing 7, but those in the plaques showed a reverse order. Fe distribution ratios in plaques were also larger for Wuyunjing 7 than for Shanyou 63, but the ratios in root tissues showed a reverse order. The results indicate that iron plaque formation on rice roots can provide a barrier to soil Pb stress in Pb-contaminated soils. The plaque will increase the sequestration of Pb on root surface, providing a means of external exclusion of soil Pb. But the function of the plaque is limited, only effective in relatively lower or moderate levels of soil Pb contamination.

  3. Virtual-reality distraction and cold-pressor pain tolerance: does avatar point of view matter?

    Science.gov (United States)

    Dahlquist, Lynnda M; Herbert, Linda J; Weiss, Karen E; Jimeno, Monica

    2010-10-01

    This study tested the effects of distraction using virtual-reality (VR) technology on acute pain tolerance in young adults. Forty-one undergraduate students, aged 18-23 years, used a VR head-mounted display helmet, steering wheel, and foot pedal to play an auto racing video game while undergoing exposure to very cold water (cold pressor set at 1 °C). Two different game views were tested that were hypothesized to affect the degree to which participants felt "present" in the virtual environment: a first-person view, in which the participant saw the virtual environment through the eyes of the game character being manipulated; and a third-person view, in which the participant viewed the game character from a distance. The length of time participants tolerated the cold-water exposure (pain tolerance) under each distraction condition was compared to a baseline (no distraction) trial. Subjects also rated the degree to which they felt "present" in the virtual environment after each distraction trial. Results demonstrated that participants had significantly higher pain tolerance during both VR-distraction conditions relative to baseline (no distraction) trials. Although participants reported a greater sense of presence during the first-person condition than the third-person condition, pain-tolerance scores associated with the two distraction conditions did not differ. The types of VR applications in which presence may be more or less important are discussed.

  4. Identification of cold tolerance genes from leaves of mangrove plant Kandelia obovata by suppression subtractive hybridization.

    Science.gov (United States)

    Fei, Jiao; Wang, You-Shao; Jiang, Zhao-Yu; Cheng, Hao; Zhang, Jian-Dong

    2015-10-01

    Low temperature is a major abiotic stress that seriously limits mangrove productivity and distribution, the molecular mechanisms of cold tolerance involved in mangroves are still poorly understood at present. It was used to identify the potential cold-related genes in Kandelia obovata (K. obovata) by suppression subtractive hybridization. 334 cold-related expressed sequence tags (ESTs) out of 670 clones were isolated and sequenced. Among these ESTs, 143 unique cDNAs were identified and classified into ten groups, such as metabolism, energy, cell rescue and defense, transcription and photosynthesis according to NCBI blast. Based on bioinformatics analysis, these ESTs were mainly related to response to stimulus and metabolic process, and were included to 72 KEGG pathways. Two selected genes (e.g., aquaporin gene and zinc family protein gene) from the library were further analyzed by quantitative real-time PCR analysis. Both the two genes were found to be transcriptionally up-regulated under cold stress, which partly approve the construction of the subtractive cDNA library. The diversity of the putative functions of these genes indicated that cold stress resulted in a complex response in K. obovata. Further investigation on the functions and potential pathways of these genes will facilitate the understanding of the molecular adaptations to cold tolerance in mangrove plants.

  5. Snow white and the seven dwarfs: a multivariate approach to classification of cold tolerance.

    Science.gov (United States)

    Nedved, O

    2000-01-01

    Two main cold hardiness strategies of insects - freeze tolerance in some species, and overwintering in a supercooled state without tolerance of freezing in many others - were recently reclassified. However, I present several problems with the current systems. My suggested classification is based on clearer definitions of the causes of cold injury. I recognize three main mortality factors: freezing of body liquids, cold shock, and cumulative chill injury. Presence or absence of each of these factors produce eight combinations. I have named the eight classes after Snow White and the Seven Dwarfs to avoid nomenclatural confusion. Some of these classes are probably not used as tactics against cold injury by any insect species. Other classes contain so many species that they might be reclassified in more detail, using values of supercooling point and other quantitative parameters. However, widely comparable parameters, like the upper limit of cold injury zone and the sum of injurious temperatures are still rarely published, thus we still lack comprehensive data for multivariate analyses. Every cold hardiness strategy should be characterized by a meaningful class or subclass together with the physiological, biochemical, and behavioural mechanisms employed by the insects. I also point out the existence of strategies that combine two tactics - either a switching strategy (during preparation for winter, population "chooses" which tactic will be used), or a dual strategy (individuals are ready to use one of the tactics depending on the prevailing environmental conditions).

  6. Effects of cold-hardening on compatible solutes and antioxidant enzyme activities related to freezing tolerance in Ammopiptanthus mongolicus seedlings

    Institute of Scientific and Technical Information of China (English)

    WANG Wei-juan; CHEN Yu-zhen; LIU Mei-qin; LU Cun-fu

    2008-01-01

    Cold acclimation is associated with many metabolic changes that lead to an increase of freezing tolerance. In order to investigate the biochemical process of cold acclimation in Ammopiptanthus mongolicus, seedlings were acclimated at 2℃ under 16-h photoperiod (150 μmol·m-2·s-1 photosynthetically active radiation) for 14 d. Freezing tolerance in seedlings increased after 14 d of cold-hardening. Contents of protein, proline and solute carbohydrate in cotyledon increased after cold acclimation. Patterns of isozymes of superoxide dismutase (SOD), peroxidase, catalase and polyphenol oxidase (PPO) were investigated. The activities of SOD, peroxidase and PPO in cold acclimated plants were increased during cold-hardening. We deduced that compatible solutes and antioxidant enzymes play important roles in development of freezing tolerance during cold acclimation in this evergreen woody plant.

  7. The embryo rescue derived intergeneric hybrid between chrysanthemum and Ajania przewalskii shows enhanced cold tolerance.

    Science.gov (United States)

    Deng, Yanming; Chen, Sumei; Chen, Fadi; Cheng, Xi; Zhang, Fei

    2011-12-01

    Five intergeneric hybrids between the chrysanthemum cultivar 'Zhongshanjingui' (as female) and Ajania przewalskii (as male) were obtained with the help of embryo culture. While 'Zhongshanjingui' bears a standard anemone type flower and A. przewalskii a non-anemone type one, the inflorescence type of the hybrids varied. The diameter of the hybrids' flowers was intermediate between those of the parents. The chromosome number of the hybrids was 2n = 45, of which GISH analysis was able to establish that 27 were inherited from 'Zhongshanjingui' and the other 18 from A. przewalskii. A combination of various assays was used to show that the cold tolerance of the hybrids was equivalent to that of the highly tolerant A. przewalskii parent. Enhanced cold tolerance was correlated with an increase in free proline and a decrease in malondialdehyde content.

  8. Proteomic Analysis of the Response of Liangyoupeijiu (Super High-Yield Hybrid Rice) Seedlings to Cold Stress

    Institute of Scientific and Technical Information of China (English)

    Ping-Fang Yang; Xiao-Juan Li; Yu Liang; Yu-Xiang Jing; Shi-Hua Shen; Ting-Yun Kuang

    2006-01-01

    Liangyoupeijiu is a super high-yield hybrid rice. Despite its advantages with respect to yield and grain quality, it is sensitive to cold, which keeps it from being widely cultivated. We subjected Liangyoupeijiu seedlings to 4 ℃ cold treatment, then extracted the leaf proteins. After 2-D gel electrophoresis separation and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis, a series of differentially displayed proteins were identified. Some metabolism-associated proteins were found among the downregulated proteins, such as carbamoyl phosphate synthetase, transketolase 1, dihydrolipoamide dehydrogenase and glyceraldehyde 3-phosphate dehydrogenase. The upregulated proteins included both stress-resistance proteins such as nucleoside diphosphate kinase Ⅰ and proteins that are negative for rice growth, such as FtsH-like protein, plastid fusion and/or translocation factor (Pftf) and actin. Our results indicate that cold may inhibit Liangyoupeijiu growth through decreasing metabolic activity and damaging cell structure.

  9. Expression of betaine aldehyde dehydrogenase gene and salinity tolerance in rice transgenic plants

    Institute of Scientific and Technical Information of China (English)

    郭岩; 张莉; 肖岗; 曹守云; 谷冬梅; 田文忠; 陈受宜

    1997-01-01

    Betaine as one of osmolytes plays an important role in osmoregulation of most high plants. Betaine aldehyde dehydrogenase C BADH) is the second enzyme involved in betaine biosynthesis. The BADH gene from a halophite, Atriplex hortensis, was transformed into rice cultivars by bombarment method. Totally 192 transgenic rice plants were obtained and most of them had higher salt tolerance than controls. Among transgenic plants transplanted in the saline pool containing 0.5% NaCl in a greenhouse, 22 survived, 13 of which set seeds, and the frequency of seed setting was very low, only 10% . But the controls could not grow under the same condition. The results of BADH ac-tivity assay and Northern blot showed that the BADH gene was integrated into chromosomes of transgenic plants and expressed.

  10. Determination of mercury in rice by cold vapor atomic fluorescence spectrometry after microwave-assisted digestion

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Maria Jose da [Department of Analytical Chemistry, Edificio de Investigacion, University of Valencia, 50 Dr. Moliner Street, E-46100 Burjassot, Valencia (Spain); Departamento de Quimica Fundamental, Universidade Federal de Pernambuco, Cidade Universitaria, 50740-550 Recife, PE (Brazil); Paim, Ana Paula S. [Departamento de Quimica Fundamental, Universidade Federal de Pernambuco, Cidade Universitaria, 50740-550 Recife, PE (Brazil); Pimentel, Maria Fernanda [Departamento de Engenharia Quimica, Universidade Federal de Pernambuco, Recife, PE (Brazil); Cervera, M. Luisa, E-mail: m.luisa.cervera@uv.es [Department of Analytical Chemistry, Edificio de Investigacion, University of Valencia, 50 Dr. Moliner Street, E-46100 Burjassot, Valencia (Spain); Guardia, Miguel de la [Department of Analytical Chemistry, Edificio de Investigacion, University of Valencia, 50 Dr. Moliner Street, E-46100 Burjassot, Valencia (Spain)

    2010-05-14

    A cold vapor atomic fluorescence spectrometry method (CV-AFS) has been developed for the determination of Hg in rice samples at a few ng g{sup -1} concentration level. The method is based on the previous digestion of samples in a microwave oven with HNO{sub 3} and H{sub 2}O{sub 2} followed by dilution with water containing KBr/KBrO{sub 3} and hydroxylamine and reduction with SnCl{sub 2} in HCl using external calibration. The matrix interferences and the effect of nitrogen oxide vapors have been evaluated and the method validated using a certified reference material. The limit of detection of the method was 0.9 ng g{sup -1} with a recovery percentage of 95 {+-} 4% at an added concentration of 5 ng g{sup -1}. The concentration level of Hg found in 24 natural rice samples from different origin ranged between 1.3 and 7.8 ng g{sup -1}.

  11. Low cadmium (LCD), a novel gene related to cadmium tolerance and accumulation in rice.

    Science.gov (United States)

    Shimo, Hugo; Ishimaru, Yasuhiro; An, Gynheung; Yamakawa, Takashi; Nakanishi, Hiromi; Nishizawa, Naoko K

    2011-11-01

    The contamination of food crops by cadmium (Cd) is a major concern in food production because it can reduce crop yields and threaten human health. In this study, knockout rice plants (Oryza sativa) tagged with the gene trap vector pGA2707 were screened for Cd tolerance, and the tolerant line lcd was obtained. The lcd mutant showed tolerance to Cd on agar plates and in hydroponic culture during early plant development. Metal concentration measurements in hydroponically grown plants revealed significantly less Cd in the shoots of lcd plants compared with wild-type (WT) shoots. When cultured in the field in soil artificially contaminated with low levels of Cd, lcd showed no significant difference in the Cd content of its leaf blades; however, the Cd concentration in the grains was 55% lower in 2009 and 43% lower in 2010. There were no significant differences in plant dry weight or seed yield between lcd and wild-type plants. LCD, a novel gene, is not homologous to any other known gene. LCD localized to the cytoplasm and nucleus, and was expressed mainly in the vascular tissues in the roots and phloem companion cells in the leaves. These data indicate that lcd may be useful for understanding Cd transport mechanisms and is a promising candidate rice line for use in combating the threat of Cd to human health.

  12. Selection of Rice Genotypes for Salinity Tolerance Through Morpho-Biochemical Assessment

    Institute of Scientific and Technical Information of China (English)

    Md Nasim ALI; Bhaswati GHOSH; Saikat GANTAIT; SomsubhraCHAKRABORTY

    2014-01-01

    The present study reported the morpho-biochemical evaluation of 15 selected rice genotypes for salt tolerance at the seedling stage. Growth parameters including shoot length, root length, plant biomass, plant turgid weight, plant dry weight along with relative water content were measured after exposure to saline solution (with electrical conductivity value of 12 dS/m). Genotypes, showing significant differential responses towards salinity in the fields, were assessed through 14 salinity-linked morpho-biochemical attributes, measured at 14 d after exposure of seedling in saline nutrient solution. Relative water content, chlorophyll a/b, peroxidase activity and plant biomass were identified as potential indicators of salt tolerance. Principal component analysis and successive Hierarchical clustering using Euclidean distance revealed that Talmugur, Gheus, Ghunsi, Langalmura, Sabitapalui, and Sholerpona were promising genotypes for further breeding programmes in rice. The maximum Euclidean distance was plotted between Thavallakanan and Talmugur (7.49), followed by Thavallakanan and Langalmura (6.82), indicating these combinations may be exploited as parental lines in hybridization programmes to develop salinity tolerant variety.

  13. Selection of Rice Genotypes for Salinity Tolerance Through Morpho-Biochemical Assessment

    Directory of Open Access Journals (Sweden)

    Md. Nasim ALI

    2014-09-01

    Full Text Available The present study reported the morpho-biochemical evaluation of 15 selected rice genotypes for salt tolerance at the seedling stage. Growth parameters including shoot length, root length, plant biomass, plant turgid weight, plant dry weight along with relative water content were measured after exposure to saline solution (with electrical conductivity value of 12 dS/m. Genotypes, showing significant differential responses towards salinity in the fields, were assessed through 14 salinity-linked morpho-biochemical attributes, measured at 14 d after exposure of seedling in saline nutrient solution. Relative water content, chlorophyll a/b, peroxidase activity and plant biomass were identified as potential indicators of salt tolerance. Principal component analysis and successive Hierarchical clustering using Euclidean distance revealed that Talmugur, Gheus, Ghunsi, Langalmura, Sabitapalui, and Sholerpona were promising genotypes for further breeding programmes in rice. The maximum Euclidean distance was plotted between Thavallakanan and Talmugur (7.49, followed by Thavallakanan and Langalmura (6.82, indicating these combinations may be exploited as parental lines in hybridization programmes to develop salinity tolerant variety.

  14. In-vitro screening and field validation of rice (Oryza sativa L. genotypes for drought tolerance

    Directory of Open Access Journals (Sweden)

    S. Utharasu1* and C. R. Anandakumar1

    2014-03-01

    Full Text Available In vitro screening using polyethylene glycol (PEG was performed with matured seed-derived callus from six elite rice varieties and eight advanced cultures to understand the response to drought stress. Murashige and Skoog medium supplemented with 2 mg l-1 of 1-napthaleneacetic acid and 5, 10, 15 and 20 g l-1 of PEG 6000 were used to induce drought stress in callus. Significant differences were observed among the genotypes, treatments and their interactions for callus morphology and fresh weight. The genotypes PMK3, RMD(R1, ARB6 , ARB7 and ARB8 were identified as the most tolerant to drought stress using principal component analysis (PCA. A total of 48 crosses made from these genotypes showed significant yield increase over their respective parents. The hybrids RMD(R1/ARB7, PMK3/ARB7 and PMK3/ARB8 were identified as drought tolerant using PCA analysis. From the study it is proved that in vitro screening method can be used to identify drought tolerant rice genotypes.

  15. Enhanced tolerance to drought in transgenic rice plants overexpressing C4 photosynthesis enzymes

    Institute of Scientific and Technical Information of China (English)

    Jun-Fei; Gu; Ming; Qiu; Jian-Chang; Yang

    2013-01-01

    Maize-specific pyruvate orthophosphate dikinase(PPDK) was overexpressed in rice independently or in combination with the maize C4-specific phosphoenolpyruvate carboxylase(PCK). The wild-type(WT) cultivar Kitaake and transgenic plants were evaluated in independent field and tank experiments. Three soil moisture treatments,well-watered(WW), moderate drought(MD) and severe drought(SD), were imposed from 9d post-anthesis till maturity. Leaf physiological and biochemical traits, root activities,biomass, grain yield, and yield components in the untransformed WT and two transgenic rice lines(PPDK and PCK) were systematically studied. Compared with the WT, both transgenic rice lines showed increased leaf photosynthetic rate: by 20%–40% under WW, by45%–60% under MD, and by 80%–120% under SD. The transgenic plants produced 16.1%,20.2% and 20.0% higher grain yields than WT under the WW, MD and SD treatments,respectively. Under the same soil moisture treatments, activities of phosphoenolpyruvate carboxylase(PEPC) and carbonic anhydrase(CA) in transgenic plants were 3–5-fold higher than those in WT plants. Compared with ribulose-1,5-bisphosphate carboxylase, activities of PEPC and CA were less reduced under both MD and SD treatments. The transgenic plants also showed higher leaf water content, stomatal conductance, transpiration efficiency, and root oxidation activity and a stronger active oxygen scavenging system than the WT under all soil moisture treatments, especially MD and SD. The results suggest that drought tolerance is greatly enhanced in transgenic rice plants overexpressing C4photosynthesis enzymes. This study was performed under natural conditions and normal planting density to evaluate yield advantages on a field basis. It may open a new avenue to droughttolerance breeding via overexpression of C4enzymes in rice.

  16. Cold tolerance abilities of two entomopathogenic nematodes, Steinernema feltiae and Heterorhabditis bacteriophora.

    Science.gov (United States)

    Ali, Farman; Wharton, David A

    2013-02-01

    Entomopathogenic nematodes are effective biological control agents against insect pests but their commercial application is restricted by their limited shelf life. This study applies our knowledge of the cold tolerance of nematodes to this problem and investigates further the cold tolerance mechanisms of Steinernema feltiae and Heterorhabditis bacteriophora infective juveniles. When frozen using a fast freezing regime these nematodes are moderately freezing tolerant, with a lower lethal temperature of -5°C. Survival is significantly enhanced by slow freezing overnight (at -1°C), with a decrease in the lower lethal temperature to -14°C. This may indicate that these nematodes are capable of cryoprotective dehydration. Acclimation at 5°C further enhanced freezing survival in S. feltiae but only by a small amount. Nematodes that had survived freezing to -13°C retained their pathogenicity to an insect host. Rapid cold hardening or exposure to a cold shock had no significant effect on freezing survival. The further development of methods based on cryoprotective dehydration may result in a method for the commercial storage of these nematodes.

  17. Cold tolerance is unaffected by oxygen availability despite changes in anaerobic metabolism

    Science.gov (United States)

    Boardman, Leigh; Sørensen, Jesper G.; Koštál, Vladimír; Šimek, Petr; Terblanche, John S.

    2016-09-01

    Insect cold tolerance depends on their ability to withstand or repair perturbations in cellular homeostasis caused by low temperature stress. Decreased oxygen availability (hypoxia) can interact with low temperature tolerance, often improving insect survival. One mechanism proposed for such responses is that whole-animal cold tolerance is set by a transition to anaerobic metabolism. Here, we provide a test of this hypothesis in an insect model system (Thaumatotibia leucotreta) by experimental manipulation of oxygen availability while measuring metabolic rate, critical thermal minimum (CTmin), supercooling point and changes in 43 metabolites in moth larvae at three key timepoints (before, during and after chill coma). Furthermore, we determined the critical oxygen partial pressure below which metabolic rate was suppressed (c. 4.5 kPa). Results showed that altering oxygen availability did not affect (non-lethal) CTmin nor (lethal) supercooling point. Metabolomic profiling revealed the upregulation of anaerobic metabolites and alterations in concentrations of citric acid cycle intermediates during and after chill coma exposure. Hypoxia exacerbated the anaerobic metabolite responses induced by low temperatures. These results suggest that cold tolerance of T. leucotreta larvae is not set by oxygen limitation, and that anaerobic metabolism in these larvae may contribute to their ability to survive in necrotic fruit.

  18. Cold tolerance is unaffected by oxygen availability despite changes in anaerobic metabolism

    Science.gov (United States)

    Boardman, Leigh; Sørensen, Jesper G.; Koštál, Vladimír; Šimek, Petr; Terblanche, John S.

    2016-01-01

    Insect cold tolerance depends on their ability to withstand or repair perturbations in cellular homeostasis caused by low temperature stress. Decreased oxygen availability (hypoxia) can interact with low temperature tolerance, often improving insect survival. One mechanism proposed for such responses is that whole-animal cold tolerance is set by a transition to anaerobic metabolism. Here, we provide a test of this hypothesis in an insect model system (Thaumatotibia leucotreta) by experimental manipulation of oxygen availability while measuring metabolic rate, critical thermal minimum (CTmin), supercooling point and changes in 43 metabolites in moth larvae at three key timepoints (before, during and after chill coma). Furthermore, we determined the critical oxygen partial pressure below which metabolic rate was suppressed (c. 4.5 kPa). Results showed that altering oxygen availability did not affect (non-lethal) CTmin nor (lethal) supercooling point. Metabolomic profiling revealed the upregulation of anaerobic metabolites and alterations in concentrations of citric acid cycle intermediates during and after chill coma exposure. Hypoxia exacerbated the anaerobic metabolite responses induced by low temperatures. These results suggest that cold tolerance of T. leucotreta larvae is not set by oxygen limitation, and that anaerobic metabolism in these larvae may contribute to their ability to survive in necrotic fruit. PMID:27619175

  19. Cold acclimation induced accumulation of phenolic compounds and freezing tolerance in Ammopiptanthus mongolicus

    Institute of Scientific and Technical Information of China (English)

    Liu Mei-qin; Chen Yi-yin; Lu Cun-fu; Zhang Hui; Yin Wei-lun

    2007-01-01

    Ammopiptanthus mongolicus, the only freezing tolerant evergreen broad-leaved shrub, local species of the Alashan desert,northwest sand area of China, can survive -30℃ or even lower temperature in winter. In the present study, the secondary products phenolics in A. mongolicus cotyledons were determined to study the effects ofphenolics on cold tolerance. Cytochemical localization of phenolics in cotyledon cells was observed by electron microscopy and the content of phenolic compounds was assayed by spectrophotometric measurement. The results showed that the freezing tolerance of A. mongolicus seedlings increased after acclimation at 2-6℃ for 14 days, which accompanied the increase of the content of phenolic compounds in cotyledons. Cytochemical observation showed that phenolic deposits were mainly localized in vacuoles and in close proximity to tonoplast, and also in the cytoplasm. The amount and the size of phenolics droplets increased obviously in cytoplasm and vacuoles after cold acclimation, predominantly aggregated along membranes of vacuoles and tonoplast. No phenolic deposits were found in cell walls. As hydrogen- or electron-donating agents, phenolics may protect plant cells against reactive oxygen species formed during chilling or freezing stress and improve the freezing tolerance of cold-acclimated A. mongolicus seedlings.

  20. A Casparian strip domain-like gene, CASPL, negatively alters growth and cold tolerance.

    Science.gov (United States)

    Yang, Jinghua; Ding, Changqing; Xu, Baochen; Chen, Cuiting; Narsai, Reena; Whelan, Jim; Hu, Zhongyuan; Zhang, Mingfang

    2015-09-24

    A cold-induced transcript encoding a Casparian strip membrane domain (CASP)-like protein (ClCASPL) was identified in watermelon (Citrullus lanatus). Fluorescence microscopy analysis showed that ClCASPL-GFP is localized in the plasma membrane. The orthologous gene in Arabidopsis thaliana (AtCASPL4C1) was also found to play an important role in cold tolerance. Expression analysis using a β-glucuronidase (GUS) reporter reveals that AtCASPL4C1 is widely expressed in a variety of organs and is cold inducible. Analysis of AtCASPL4C1 T-DNA knock-out plants showed altered growth dynamics, faster growth, increased biomass (dry weight) and earlier flowering compared to wild type (Col-0) and ClCASPL overexpressing plants. AtCASPL4C1 knock-out plants showed elevated tolerance to cold stress, while overexpressing CICASPL resulted in increased sensitivity to cold stress in Arabidopsis. Interestingly, AtCASPL4C1 knock-out plants did not display significant alterations in the Casparian strip formation in roots. Thus, the combination of these results suggests a role for CICASPL and AtCASPL4C1 beyond Casparian strip formation in roots, possibly indicating a more fundamental role in vascular tissue.

  1. Anthocyanin biosynthesis for cold and freezing stress tolerance and desirable color in Brassica rapa.

    Science.gov (United States)

    Ahmed, Nasar Uddin; Park, Jong-In; Jung, Hee-Jeong; Hur, Yoonkang; Nou, Ill-Sup

    2015-07-01

    Flavonoids are divided into several structural classes, including anthocyanins, which provide flower and leaf colors and other derivatives that play diverse roles in plant development and interactions with the environment. This study characterized four anthocyanidin synthase (ANS) genes of Brassica rapa, a structural gene of the anthocyanin biosynthetic pathway, and investigated their association with pigment formation, cold and freezing tolerance in B. rapa. Sequences of these genes were analyzed and compared with similar gene sequences from other species, and a high degree of homology with their respective functions was found. Organ-specific expression analysis revealed that these genes were only expressed in the colored portion of leaves of different lines of B. rapa. Conversely, B. rapa anthocyanidin synthase (BrANS) genes also showed responses to cold and freezing stress treatment in B. rapa. BrANSs were also shown to be regulated by two transcription factors, BrMYB2-2 and BrTT8, contrasting with anthocyanin accumulation and cold stress. Thus, the above results suggest the association of these genes with anthocyanin biosynthesis and cold and freezing stress tolerance and might be useful resources for development of cold-resistant Brassica crops with desirable colors as well.

  2. Differential response of oxidative stress and thiol metabolism in contrasting rice genotypes for arsenic tolerance.

    Science.gov (United States)

    Tripathi, Preeti; Mishra, Aradhana; Dwivedi, Sanjay; Chakrabarty, Debasis; Trivedi, Prabodh K; Singh, Rana Pratap; Tripathi, Rudra Deo

    2012-05-01

    The mechanism of arsenic (As) tolerance was investigated on two contrasting rice (Oryza sativa L.) genotypes, selected for As tolerance and accumulation. One tolerant (Triguna) and one sensitive (IET-4786) variety were exposed to various arsenate (0-50 μM) levels for 7 d for biochemical analyses. Arsenic induced oxidative stress was more pronounced in IET-4786 than Triguna especially in terms of reactive oxygen species, lipid peroxidation, EC and pro-oxidant enzymes (NADPH oxidase and ascorbate oxidase). However, Triguna tolerated As stress through the enhanced enzymes activities particularly pertaining to thiol metabolism such as serine acetyl transferase (SAT), cysteine synthase (CS), γ-glutamyl cysteine synthase (γ-ECS), γ-glutamyl transpeptidase (γ-GT), and glutathione-S-transferase (GST) as well as arsenate reductase (AR). Besides maintaining the ratio of redox couples GSH/GSSG and ASC/DHA, the level of phytochelatins (PCs) and phytochelatin synthase (PCS) activity were more pronounced in Triguna, in which harmonized responses of thiol metabolism was responsible for As tolerance in contrast to IET-4786 showing its susceptible nature towards As exposure.

  3. Impact of bacterial priming on some stress tolerance mechanisms and growth of cold stressed wheat seedlings

    Directory of Open Access Journals (Sweden)

    Mohammed E.H. Osman

    2014-01-01

    Full Text Available The potential to enhance growth of cold stressed wheat by seed treatment (priming with the beneficial bacteria Bacillus amyloliquefaciens 5113 and Azospirillum brasilense NO40 were tested. Results showed an improved ability of bacteria-treated seedlings to survive at −5°C up to 12 h. Cold stress increased transcript levels of three stress marker genes and increased activity for the ascorbate-glutathione redox enzymes. However, primed and stressed seedlings generally showed smaller effects on the stress markers correlating with better growth and improved stress tolerance. Bacterial priming to improve crop plant performance at low temperature seems a useful strategy to explore further.

  4. Salt tolerance of transgenic rice (Oryza sativa L.) with mtlD gene and gutD gene

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Southern blot analysis indicated that mtlD gene (encoding mannitol-1-phosphate dehydrogenase) and gutD gene (encoding glucitol-6-phosphate dehydrogenase) had been integrated into the rice genome mediated by Agrobacterium tumefaciens LBA4404(pBIGM). The expression of the above two genes in transgenic rice plants was demonstrated by Northern blot analysis and enzymatic activity assay. Analysis of sugar alcohol showed that transgenic rice plants could produce and accumulate mannitol and sorbitol. The salt tolerance of transgenic plants was much higher than that of their controls.

  5. Mapping regulatory genes as candidates for cold and drought stress tolerance in barley.

    Science.gov (United States)

    Tondelli, A; Francia, E; Barabaschi, D; Aprile, A; Skinner, J S; Stockinger, E J; Stanca, A M; Pecchioni, N

    2006-02-01

    Cereal crop yield is greatly affected in many growing areas by abiotic stresses, mainly low temperature and drought. In order to find candidates for the tolerance genes for these stresses, 13 genes encoding for transcription factors and upstream regulators were screened by amplification and SSCP on six parental genotypes of three barley mapping populations ('Nure' x 'Tremois', 'Proctor' x 'Nudinka', and 'Steptoe' x 'Morex'), and mapped as newly developed STS, SNP, and SSCP markers. A new consensus function map was then drawn using the three maps above, including 16 regulatory candidate genes (CGs). The positions of barley cold and drought tolerance quantitative trait loci (QTLs) presently described in the literature were added to the consensus map to find positional candidates from among the mapped genes. A cluster of six HvCBF genes co-mapped with the Fr-H2 cold tolerance QTL, while no QTLs for the same trait were positioned on chromosome 7H, where two putative barley regulators of CBF expression, ICE1 and FRY1, found by homology search, were mapped in this work. These observations suggest that CBF gene(s) themselves, rather than their two regulators, are at present the best candidates for cold tolerance. Four out of 12 drought tolerance QTLs of the consensus map are associated with regulatory CGs, on chromosomes 2H, 5H, and 7H, and two QTLs with effector genes, on chromosomes 5H and 6H. The results obtained could be used to guide MAS applications, allowing introduction into an ideal genotype of favourable alleles of tolerance QTLs.

  6. Drough tolerance estimation of several rainfed rice (Oryza sativa L. of lokal veriety using polyethilene glycol (PEG

    Directory of Open Access Journals (Sweden)

    Diana Susanti

    2017-01-01

    Full Text Available The yield of rice crop was highly affected by water availability and drought condition . The effort was done to seek local varieties of rainfed rice which tend to be tolerance to drought condition. This research objective was to seek some local varieties of rainfed rice that tolerance to several drought conditions. This research was conducted at Farm Exprimentation Site of Agrotechnology Study Program, Baturaja University from November 2015 to April 2016. Exprimental design used in this research was Split Plot Design with three replications. The main plot was variety treatments (varieties of Henik, Henik Pisang, Serenik, Remaja, Semester, Selanggar, Duku, Serendah Putih, Agai and Tinta, whereas the subplot was Polyethilene glycol (PEG treatments (concentrations of 0%, 20%, 25% dan 30%. The results showed that varieties of Henik, Henik Pisang, Serenik, Semester, Duku, Serendah Putih and Tinta had produced high yield at drought condition. Rainfed rice could produced high yield at treatments of 20% and 25% PEG, respectively. Treatment combination of Duku variety and 30% PEG had produced the highest weight of unhulled rice/clump and fully unhulled rice/clump, respectively. The highest weight of unhulled rice per 1000 grains was found on treatment combination of Duku variety and 25% PEG.

  7. Cold-tolerant crop species have greater temperature homeostasis of leaf respiration and photosynthesis than cold-sensitive species.

    Science.gov (United States)

    Yamori, Wataru; Noguchi, Ko; Hikosaka, Kouki; Terashima, Ichiro

    2009-02-01

    Some plant species show constant rates of respiration and photosynthesis measured at their respective growth temperatures (temperature homeostasis), whereas others do not. However, it is unclear what species show such temperature homeostasis and what factors affect the temperature homeostasis. To analyze the inherent ability of plants to acclimate respiration and photosynthesis to different growth temperatures, we examined 11 herbace-ous crops with different cold tolerance. Leaf respiration (R(area)) and photosynthetic rate (P(area)) under high light at 360 microl l(-1) CO(2) concentrations were measured in plants grown at 15 and 30 degrees C. Cold-tolerant species showed a greater extent of temperature homeostasis of both R(area) and P(area) than cold-sensitive species. The underlying mechanisms which caused differences in the extent of temperature homeostasis were examined. The extent of temperature homeostasis of P(area) was not determined by differences in leaf mass and nitrogen content per leaf area, but by differences in photosynthetic nitrogen use efficiency (PNUE). Moreover, differences in PNUE were due to differences in the maximum catalytic rate of Rubisco, Rubisco contents and amounts of nitrogen invested in Rubisco. These findings indicated that the temperature homeostasis of photosynthesis was regulated by various parameters. On the other hand, the extent of temperature homeostasis of R(area) was unrelated to the maximum activity of the respiratory enzyme (NAD-malic enzyme). The R(area)/P(area) ratio was maintained irrespective of the growth temperatures in all the species, suggesting that the extent of temperature homeostasis of R(area) interacted with the photosynthetic rate and/or the homeostasis of photosynthesis.

  8. OsSGL, a Novel DUF1645 Domain-Containing Protein, Confers Enhanced Drought Tolerance in Transgenic Rice and Arabidopsis.

    Science.gov (United States)

    Cui, Yanchun; Wang, Manling; Zhou, Huina; Li, Mingjuan; Huang, Lifang; Yin, Xuming; Zhao, Guoqiang; Lin, Fucheng; Xia, Xinjie; Xu, Guoyun

    2016-01-01

    Drought is a major environmental factor that limits plant growth and crop productivity. Genetic engineering is an effective approach to improve drought tolerance in various crops, including rice (Oryza sativa). Functional characterization of relevant genes is a prerequisite when identifying candidates for such improvements. We investigated OsSGL (Oryza sativa Stress tolerance and Grain Length), a novel DUF1645 domain-containing protein from rice. OsSGL was up-regulated by multiple stresses and localized to the nucleus. Transgenic plants over-expressing or hetero-expressing OsSGL conferred significantly improved drought tolerance in transgenic rice and Arabidopsis thaliana, respectively. The overexpressing plants accumulated higher levels of proline and soluble sugars but lower malondialdehyde (MDA) contents under osmotic stress. Our RNA-sequencing data demonstrated that several stress-responsive genes were significantly altered in transgenic rice plants. We unexpectedly observed that those overexpressing rice plants also had extensive root systems, perhaps due to the altered transcript levels of auxin- and cytokinin-associated genes. These results suggest that the mechanism by which OsSGL confers enhanced drought tolerance is due to the modulated expression of stress-responsive genes, higher accumulations of osmolytes, and enlarged root systems.

  9. Genetic variation and host-parasite specificity of Striga resistance and tolerance in rice: the need for predictive breeding.

    Science.gov (United States)

    Rodenburg, Jonne; Cissoko, Mamadou; Kayongo, Nicholas; Dieng, Ibnou; Bisikwa, Jenipher; Irakiza, Runyambo; Masoka, Isaac; Midega, Charles A O; Scholes, Julie D

    2017-02-13

    The parasitic weeds Striga asiatica and Striga hermonthica cause devastating yield losses to upland rice in Africa. Little is known about genetic variation in host resistance and tolerance across rice genotypes, in relation to virulence differences across Striga species and ecotypes. Diverse rice genotypes were phenotyped for the above traits in S. asiatica- (Tanzania) and S. hermonthica-infested fields (Kenya and Uganda) and under controlled conditions. New rice genotypes with either ecotype-specific or broad-spectrum resistance were identified. Resistance identified in the field was confirmed under controlled conditions, providing evidence that resistance was largely genetically determined. Striga-resistant genotypes contributed to yield security under Striga-infested conditions, although grain yield was also determined by the genotype-specific yield potential and tolerance. Tolerance, the physiological mechanism mitigating Striga effects on host growth and physiology, was unrelated to resistance, implying that any combination of high, medium or low levels of these traits can be found across rice genotypes. Striga virulence varies across species and ecotypes. The extent of Striga-induced host damage results from the interaction between parasite virulence and genetically determined levels of host-plant resistance and tolerance. These novel findings support the need for predictive breeding strategies based on knowledge of host resistance and parasite virulence.

  10. RNAi-directed downregulation of betaine aldehyde dehydrogenase 1 (OsBADH1) results in decreased stress tolerance and increased oxidative markers without affecting glycine betaine biosynthesis in rice (Oryza sativa).

    Science.gov (United States)

    Tang, Wei; Sun, Jiaqi; Liu, Jia; Liu, Fangfang; Yan, Jun; Gou, Xiaojun; Lu, Bao-Rong; Liu, Yongsheng

    2014-11-01

    As an important osmoprotectant, glycine betaine (GB) plays an essential role in resistance to abiotic stress in a variety of organisms, including rice (Oryza sativa L.). However, GB content is too low to be detectable in rice, although rice genome possesses several orthologs coding for betaine aldehyde dehydrogenase (BADH) involved in plant GB biosynthesis. Rice BADH1 (OsBADH1) has been shown to be targeted to peroxisome and its overexpression resulted in increased GB biosynthesis and tolerance to abiotic stress. In this study, we demonstrated a pivotal role of OsBADH1 in stress tolerance without altering GB biosynthesis capacity, using the RNA interference (RNAi) technique. OsBADH1 was ubiquitously expressed in different organs, including roots, stems, leaves and flowers. Transgenic rice lines downregulating OsBADH1 exhibited remarkably reduced tolerance to NaCl, drought and cold stresses. The decrease of stress tolerance occurring in the OsBADH1-RNAi repression lines was associated with an elevated level of malondialdehyde content and hydrogen peroxidation. No GB accumulation was detected in transgene-positive and transgene-negative lines derived from heterozygous transgenic T0 plants. Moreover, transgenic OsBADH1-RNAi repression lines showed significantly reduced seed set and yield. In conclusion, the downregulation of OsBADH1, even though not causing any change of GB content, was accounted for the reduction of ability to dehydrogenate the accumulating metabolism-derived aldehydes and subsequently resulted in decreased stress tolerance and crop productivity. These results suggest that OsBADH1 possesses an enzyme activity to catalyze other aldehydes in addition to betaine aldehyde (the precursor of GB) and thus alleviate their toxic effects under abiotic stresses.

  11. Harnessing the hidden genetic diversity for improving multiple abiotic stress tolerance in rice (Oryza sativa L.)

    Science.gov (United States)

    Gao, Yong-Ming; Ma, Xiu-Fang; Meng, Li-Jun; Wang, Ying; Pang, Yun-Long; Guan, Yong-Sheng; Xu, Mei-Rong; Revilleza, Jastin E.; Franje, Neil J.; Zhou, Shao-Chuan; Li, Zhi-Kang

    2017-01-01

    To develop superior rice varieties with improved yield in most rainfed areas of Asia/Africa, we started an introgression-breeding program for simultaneously improving yield and tolerances of multiple abiotic stresses. Using eight BC1 populations derived from a widely adaptable recipient and eight donors plus three rounds of phenotypic selection, we developed 496 introgression lines (ILs) with significantly higher yield under drought, salt and/or non-stress conditions in 5 years. Six new varieties were released in the Philippines and Pakistan and many more are being evaluated in multi-location yield trials for releasing in several countries. Marker-facilitated genetic characterization revealed three interesting aspects of the breeding procedure: (1) the donor introgression pattern in specific BC populations was characteristic; (2) introgression frequency in different genomic regions varied considerably, resulting primarily from strong selection for the target traits; and (3) significantly lower heterozygosity was observed in BC progenies selected for drought and salinity tolerance. Applying strong phenotypic selection under abiotic stresses in early segregating generations has major advantages for not only improving multiple abiotic stress tolerance but also achieving quicker homozygosity in early generations. This breeding procedure can be easily adopted by small breeding programs in developing countries to develop high-yielding varieties tolerant of abiotic stresses. The large set of trait-specific ILs can be used for genetic mapping of genes/QTL that affect target and non-target traits and for efficient varietal development by designed QTL pyramiding and genomics-based recurrent selection in our Green Super Rice breeding technology. PMID:28278154

  12. Differential activation of genes related to aluminium tolerance in two contrasting rice cultivars.

    Science.gov (United States)

    Roselló, Maite; Poschenrieder, Charlotte; Gunsé, Benet; Barceló, Juan; Llugany, Mercè

    2015-11-01

    Rice (Oryza sativa) is a highly Al-tolerant crop. Among other mechanisms, a higher expression of STAR1/STAR2 (sensitive to Al rhizotoxicity1/2) genes and of Nrat1 (NRAMP Aluminium Transporter 1), and ALS1 (Aluminium sensitive 1) can at least in part be responsible for the inducible Al tolerance in this species. Here we analysed the responses to Al in two contrasting rice varieties. All analysed toxicity/tolerance markers (root elongation, Evans blue, morin and haematoxylin staining) indicated higher Al-tolerance in variety Nipponbare, than in variety Modan. Nipponbare accumulated much less Al in the roots than Modan. Aluminium supply caused stronger expression of STAR1 in Nipponbare than in Modan. A distinctively higher increase of Al-induced abscisic acid (ABA) accumulation was found in the roots of Nipponbare than in Modan. Highest ABA levels were observed in Nipponbare after 48 h exposure to Al. This ABA peak was coincident in time with the highest expression level of STAR1. It is proposed that ABA may be required for cell wall remodulation facilitated by the enhanced UDP-glucose transport to the walls through STAR1/STAR2. Contrastingly, in the roots of Modan the expression of both Nrat1 coding for a plasma membrane Al-transporter and of ALS1 coding for a tonoplast-localized Al transporter was considerably enhanced. Moreover, Modan had a higher Al-induced expression of ASR1 a gene that has been proposed to code for a reactive oxygen scavenging protein. In conclusion, the Al-exclusion strategy of Nipponbare, at least in part mediated by STAR1 and probably regulated by ABA, provided better protection against Al toxicity than the accumulation and internal detoxification strategy of Modan mediated by Nrat1, ALS1 and ARS1. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Responsiveness of cold tolerant chickpea characteristics in fall and spring planting: II. yield and yield components

    Directory of Open Access Journals (Sweden)

    ahmad nezami

    2009-06-01

    Full Text Available Previous research in Mashhad collection chickpeas (MCC has shown that there are some cold tolerant genotypes for fall planting in the highlands. To obtain more detailed information about the reaction of these genotypes to fall and spring planting, the yield and yield component responses of 33 chickpea genotypes (32 cold tolerant genotypes and one susceptible genotypes to four planting dates (28 Sep., 16 Oct., 2 Nov., and 7 Mar. were evaluated in 2000-2001 growing season. The experiment was conducted at the experimental field of college of agriculture, Ferdowsi University of Mashhad as a split plot design with two replications. The planting dates were imposed as main plot and chickpea genotypes as subplot. Effects of planting date and genotype on percent of plant survival (PPS after winter, number. of pod per plant, 100 seed weight, yield and Harvest Index (HI were significant (p

  14. Cold tolerance and freeze-induced glucose accumulation in three terrestrial slugs

    DEFF Research Database (Denmark)

    Slotsbo, Stine; Hansen, Lars Monrad; Jordaens, Kurt;

    2012-01-01

    in their habitat. Slugs spontaneously froze at about -4 °C when cooled under dry conditions, but freezing of body fluids was readily induced at -1 °C when in contact with external ice crystals. All three species survived freezing for 2 days at -1 °C, and some A. rufus and A. lusitanicus also survived freezing......Cold tolerance and metabolic responses to freezing of three slug species common in Scandinavia (Arion ater, Arion rufus and Arion lusitanicus) are reported. Autumn collected slugs were cold acclimated in the laboratory and subjected to freezing conditions simulating likely winter temperatures....... Glucose increased from about 6 to 22 µg/mg dry tissue upon freezing in A. rufus, but less so in A. ater and A. lusitanicus. Glucose may thus act as a cryoprotectant in these slugs, although the concentrations are not as high as reported for other freeze tolerant invertebrates....

  15. Lipophilic Contaminants Influence Cold Tolerance of Invertebrates through Changes in Cell Membrane Fluidity

    DEFF Research Database (Denmark)

    Holmstrup, Martin; Bouvrais, Hélène; Westh, Peter

    2014-01-01

    temperatures of organisms that cannot regulate their body temperature (ectotherms) depends on their ability to increase the fluidity of their cellular membranes at low temperatures. Our study shows that contaminants accumulating in lipids of organisms alter the physical state of their membranes simply by being...... present. Contaminants of varying chemical structures can alter the membrane fluidity in either direction and correspondingly modulate the cold tolerance of intact animals....

  16. Improvement Of Salt Tolerance In Some Varieties Of Rice By Ascorbic Acid Application

    Directory of Open Access Journals (Sweden)

    Wan Arfiani Barus

    2015-05-01

    Full Text Available ABSTRACT Salinity stress is one of the serious abiotic stress and lead to reduced productivity and plant growth. The effect of salinity stress and its interaction with ascorbic acid was investigated on some morphological traits. Ascorbate is a strong antioxidant which has remarkable biological effects on plants growth including an improvement in plants tolerance under salinity stress conditions. The purpose of this study was to determine the effect of ascorbic acid application to improve salt tolerance of rice on saline soil. This research was down as a factorial based on randomized block design with 3 replications. In this research were tested eight varieties of Rice Ciherang V1 IR 64 V2 Lambur V4 Batanghari V5 Banyuasin V6 IR 42 V8 Inpara 10 V9 and Margasari V10 and Ascorbic Acid is applied at concentrations of 0 A0 500 ppm A1 1000 ppm A2 and 1500 ppm A3. Ascorbic acid is applied in 4 times with at the age of 15 35 55 and 75 days after sowing. All concentrations of ascorbic acid generally has a positive effect on morphological characters. However the best response was found at 1500 ppm A3 concentration of ascorbic acid on Banyuasin variety.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Local melatonin application induces cold tolerance in distant organs of Citrullus lanatus L. via long distance transport.

    Science.gov (United States)

    Li, Hao; Chang, Jingjing; Zheng, Junxian; Dong, Yuchuan; Liu, Qiyan; Yang, Xiaozhen; Wei, Chunhua; Zhang, Yong; Ma, Jianxiang; Zhang, Xian

    2017-01-19

    Melatonin is a ubiquitous chemical substance that regulates plant growth and responses to stress. Several recent studies show that exogenous melatonin confers cold tolerance to plants; however, the underlying mechanisms remain largely unknown. Here, we report that melatonin application at optimal dose, either on the leaves or the roots, not only induced cold stress tolerance in the site of application, but also systemically induced cold tolerance in untreated distant parts. Foliar or rhizospheric treatment with melatonin increased the melatonin levels in untreated roots or leaves, respectively, under both normal and cold stress conditions, whereas rhizospheric melatonin treatment increased the melatonin exudation rates from the xylem. An increased accumulation of melatonin accompanied with an induction in antioxidant enzyme activity in distant untreated tissues alleviated cold-induced oxidative stress. In addition, RNA-seq analysis revealed that an abundance of cold defense-related genes involved in signal sensing and transduction, transcriptional regulation, protection and detoxification, and hormone signaling might mediate melatonin-induced cold tolerance. Taken together, our results suggest that melatonin can induce cold tolerance via long distance signaling, and such induction is associated with an enhanced antioxidant capacity and optimized defense gene expression. Such a mechanism can be greatly exploited to benefit the agricultural production.

  19. Inhibition of Aspergillus flavus on agar media and brown rice cereal bars using cold atmospheric plasma treatment.

    Science.gov (United States)

    Suhem, Kitiya; Matan, Narumol; Nisoa, Mudtorlep; Matan, Nirundorn

    2013-02-01

    This study aimed to optimize the operating parameters of cold atmospheric plasma treatment to inhibit the growth of Aspergillus flavus on agar media and brown rice cereal bars. The effects of argon plasma jet treatment on the growth of A. flavus on malt extract agar (MEA) at powers of 20 W and 40 W with exposure times at 5, 15 and 25 min were studied using response surface methodology (RSM) with a central composite face-centered (CCF) design. Multiple regression analysis indicated that plasma treatment at 40 W for 25 min is most effective for inhibiting growth of A. flavus on the agar medium. On brown rice cereal bars, plasma powered at 40 W for 20 min was capable of giving protection against A. flavus growth for up to 20 days under storage conditions of 25°C and 100% RH. These results demonstrated the potential of cold atmospheric plasma jet treatment to control mold growth on various food products.

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Association Mapping for Drought Tolerance of Rice (Oryza sativa L.) at Vegetative Stage

    Institute of Scientific and Technical Information of China (English)

    Yulong XIAO; Chuanyuan YU; Jianguo LEI; Quirino D; DELA CRUZ; Jonalyn M.YABES; Dindo A.TABANAo

    2012-01-01

    [Objective] This study aimed to identify possible quantitative trait loci (QTL) for vegetative drought tolerance traits of rice (Oryza sativa L.). [Method] A total of 184 rice genotypes were field screened and 156 SSR markers randomly distributed at each 3 Mb bin were used through genome-wide scanning method and association analysis to detect QTLs for vegetative drought tolerance traits leaf rolling (LER), leaf drying (LED) and drought recovery rate (DRR). [Result] The experimental rice geno- types showed varied response under vegetative drought, LER, LED and DRR were highly correlated. Population structure was detected at K=3 and K=7, certain extent of admixture existed in the experimental rice genotypes, relative kinship of the rice genotypes ranged from 0 to 0.924 5. Significant linkage disequilibrium among SSR markers was detected. Sixteen SSR markers have been detected to be associated with vegetative drought tolerance traits, four for LER, eight for LED and four for DDR. Most of the markers were associated with more than one trait, indicating a single mechanism might involve in expression of several related traits, i.e. osmotic adjustment. RM107 (Chr.9) was associated with all the three traits and fell exactly within or closely nearby to previous reported regions, was a major QTL for vegeta- tive drought tolerance, RM477 (Chr.8) was significantly associated with DRR and ex- tremely significantly associated with LER was probably another major QTL for vege- tative drought tolerance. [Conclusion] Association mapping is a very effective method for describing complex traits like drought tolerance.

  2. Over-expression of OsHsfA7 enhanced salt and drought tolerance in transgenic rice

    Directory of Open Access Journals (Sweden)

    Ai-Ling Liu

    2013-01-01

    Full Text Available Heat shock proteins play an important role in plant stresstolerance and are mainly regulated by heat shock transcriptionfactors (Hsfs. In this study, we generated transgenic riceover-expressing OsHsfA7 and carried out morphologicalobservation and stress tolerance assays. Transgenic plantsexhibited less, shorter lateral roots and root hair. Under salttreatment, over-expressing OsHsfA7 rice showed alleviativeappearance of damage symptoms and higher survival rate, leafelectrical conductivity and malondialdehyde content of transgenicplants were lower than those of wild type plants. Meanwhile,transgenic rice seedlings restored normal growth but wild typeplants could not be rescued after drought and re-wateringtreatment. These findings indicate that over-expression ofOsHsfA7 gene can increase tolerance to salt and drought stressesin rice seedlings. [BMB Reports 2013; 46(1: 31-36

  3. Cold tolerance in juvenile sorghum is associated with root traits and is influenced by accumulation of soluble sugars

    Science.gov (United States)

    Cold tolerance at seedling/juvenile stage is an important and desirable trait in sorghum cultivars grown in northern latitudes. To address the need for this favorable trait, analysis of the important metabolites during cold stress treatment using a sorghum diversity panel was conducted and results ...

  4. An S-domain receptor-like kinase, OsSIK2, confers abiotic stress tolerance and delays dark-induced leaf senescence in rice.

    Science.gov (United States)

    Chen, Li-Juan; Wuriyanghan, Hada; Zhang, Yu-Qin; Duan, Kai-Xuan; Chen, Hao-Wei; Li, Qing-Tian; Lu, Xiang; He, Si-Jie; Ma, Biao; Zhang, Wan-Ke; Lin, Qing; Chen, Shou-Yi; Zhang, Jin-Song

    2013-12-01

    Receptor-like kinases play important roles in plant development and defense responses; however, their functions in other processes remain unclear. Here, we report that OsSIK2, an S-domain receptor-like kinase from rice (Oryza sativa), is involved in abiotic stress and the senescence process. OsSIK2 is a plasma membrane-localized protein with kinase activity in the presence of Mn(2+). OsSIK2 is expressed mainly in rice leaf and sheath and can be induced by NaCl, drought, cold, dark, and abscisic acid treatment. Transgenic plants overexpressing OsSIK2 and mutant sik2 exhibit enhanced and reduced tolerance to salt and drought stress, respectively, compared with the controls. Interestingly, a truncated version of OsSIK2 without most of the extracellular region confers higher salt tolerance than the full-length OsSIK2, likely through the activation of different sets of downstream genes. Moreover, seedlings of OsSIK2-overexpressing transgenic plants exhibit early leaf development and a delayed dark-induced senescence phenotype, while mutant sik2 shows the opposite phenotype. The downstream PR-related genes specifically up-regulated by full-length OsSIK2 or the DREB-like genes solely enhanced by truncated OsSIK2 are all induced by salt, drought, and dark treatments. These results indicate that OsSIK2 may integrate stress signals into a developmental program for better adaptive growth under unfavorable conditions. Manipulation of OsSIK2 should facilitate the improvement of production in rice and other crops.

  5. Overwintering strategy and mechanisms of cold tolerance in the codling moth (Cydia pomonella.

    Directory of Open Access Journals (Sweden)

    Jan Rozsypal

    Full Text Available BACKGROUND: The codling moth (Cydia pomonella is a major insect pest of apples worldwide. Fully grown last instar larvae overwinter in diapause state. Their overwintering strategies and physiological principles of cold tolerance have been insufficiently studied. No elaborate analysis of overwintering physiology is available for European populations. PRINCIPAL FINDINGS: We observed that codling moth larvae of a Central European population prefer to overwinter in the microhabitat of litter layer near the base of trees. Reliance on extensive supercooling, or freeze-avoidance, appears as their major strategy for survival of the winter cold. The supercooling point decreases from approximately -15.3 °C during summer to -26.3 °C during winter. Seasonal extension of supercooling capacity is assisted by partial dehydration, increasing osmolality of body fluids, and the accumulation of a complex mixture of winter specific metabolites. Glycogen and glutamine reserves are depleted, while fructose, alanine and some other sugars, polyols and free amino acids are accumulated during winter. The concentrations of trehalose and proline remain high and relatively constant throughout the season, and may contribute to the stabilization of proteins and membranes at subzero temperatures. In addition to supercooling, overwintering larvae acquire considerable capacity to survive at subzero temperatures, down to -15 °C, even in partially frozen state. CONCLUSION: Our detailed laboratory analysis of cold tolerance, and whole-winter survival assays in semi-natural conditions, suggest that the average winter cold does not represent a major threat for codling moth populations. More than 83% of larvae survived over winter in the field and pupated in spring irrespective of the overwintering microhabitat (cold-exposed tree trunk or temperature-buffered litter layer.

  6. 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.

  7. Members of rice plasma membrane intrinsic proteins subfamily are involved in arsenite permeability and tolerance in plants.

    Science.gov (United States)

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

    2012-12-01

    Rice accumulates high level of arsenic (As) in its edible parts and thus plays an important role in the transfer of As into the food chain. However, the mechanisms of As uptake and its detoxification in rice are not well understood. Recently, members of the Nodulin 26-like intrinsic protein (NIP) subfamily of plant aquaporins were shown to transport arsenite in rice and Arabidopsis. Here we report that members of the rice plasma membrane intrinsic protein (PIP) subfamily are also involved in As tolerance and transport. Based on the homology search with the mammalian AQP9 and yeast Fps1 arsenite transporters, we identified and cloned five rice PIP gene subfamily members. qRT-PCR analysis of PIPs in rice root and shoot tissues revealed a significant down regulation of transcripts encoding OsPIP1;2, OsPIP1;3, OsPIP2;4, OsPIP2;6, and OsPIP2;7 in response to arsenite treatment. Heterologous expression of OsPIP2;4, OsPIP2;6, and OsPIP2;7 in Xenopus laevis oocytes significantly increased the uptake of arsenite. Overexpression of OsPIP2;4, OsPIP2;6, and OsPIP2;7 in Arabidopsis yielded enhanced arsenite tolerance and higher biomass accumulation. Further, these transgenic plants showed no significant accumulation of As in shoot and root tissues in long term uptake assays. Whereas, short duration exposure to arsenite caused both active influx and efflux of As in the roots. The data suggests a bidirectional arsenite permeability of rice PIPs in plants. These rice PIPs genes will be highly useful for engineering important food and biofuel crops for enhanced crop productivity on contaminated soils without increasing the accumulation of toxic As in the biomass or edible tissues.

  8. Water-deficit tolerant classification in mutant lines of indica rice

    Directory of Open Access Journals (Sweden)

    Suriyan Cha-um

    2012-04-01

    Full Text Available Water shortage is a major abiotic stress for crop production worldwide, limiting the productivity of crop species, especially in dry-land agricultural areas. This investigation aimed to classify the water-deficit tolerance in mutant rice (Oryza sativa L. spp. indica genotypes during the reproductive stage. Proline content in the flag leaf of mutant lines increased when plants were subjected to water deficit. Relative water content (RWC in the flag leaf of different mutant lines dropped in relation to water deficit stress. A decrease RWC was positively related to chlorophyll a degradation. Chlorophyll a , chlorophyll b , total chlorophyll , total carotenoids , maximum quantum yield of PSII , stomatal conductance , transpiration rate and water use efficiency in mutant lines grown under water deficit conditions declined in comparison to the well-watered, leading to a reduction in net-photosynthetic rate. In addition, when exposed to water deficit, panicle traits, including panicle length and fertile grains were dropped. The biochemical and physiological data were subjected to classify the water deficit tolerance. NSG19 (positive control and DD14 were identified as water deficit tolerant, and AA11, AA12, AA16, BB13, BB16, CC12, CC15, EE12, FF15, FF17, G11 and IR20 (negative control as water deficit sensitive, using Ward's method.

  9. Comparative physiological and transcriptomic analyses provide integrated insight into osmotic, cold, and salt stress tolerance mechanisms in banana

    Science.gov (United States)

    Hu, Wei; Ding, Zehong; Tie, Weiwei; Yan, Yan; Liu, Yang; Wu, Chunlai; Liu, Juhua; Wang, Jiashui; Peng, Ming; Xu, Biyu; Jin, Zhiqiang

    2017-01-01

    The growth, development, and production of banana plants are constrained by multiple abiotic stressors. However, it remains elusive for the tolerance mechanisms of banana responding to multiple abiotic stresses. In this study, we found that Fen Jiao (FJ) was more tolerant to osmotic, cold, and salt stresses than BaXi Jiao (BX) by phenotypic and physiological analyses. Comparative transcriptomic analyses highlighted stress tolerance genes that either specifically regulated in FJ or changed more than twofold in FJ relative to BX after treatments. In total, 933, 1644, and 133 stress tolerance genes were identified after osmotic, cold, and salt treatments, respectively. Further integrated analyses found that 30 tolerance genes, including transcription factor, heat shock protein, and E3 ubiquitin protein ligase, could be commonly regulated by osmotic, cold, and salt stresses. Finally, ABA and ROS signaling networks were found to be more active in FJ than in BX under osmotic, cold, and salt treatments, which may contribute to the strong stress tolerances of FJ. Together, this study provides new insights into the tolerance mechanism of banana responding to multiple stresses, thus leading to potential applications in the genetic improvement of multiple abiotic stress tolerances in banana. PMID:28223714

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

    Science.gov (United States)

    Dou, Mingzhu; Fan, Sanhong; Yang, Suxin; Huang, Rongfeng; Yu, Huiyun; Feng, Xianzhong

    2016-01-01

    Ectopic expression of the MYB transcription factor of AmROSEA1 from Antirrhinum majus has been reported to change anthocyanin and other metabolites in several species. In this study, we found that overexpression of AmRosea1 significantly improved the tolerance of transgenic rice to drought and salinity stresses. Transcriptome analysis revealed that a considerable number of stress-related genes were affected by exogenous AmRosea1 during both drought and salinity stress treatments. These affected genes are involved in stress signal transduction, the hormone signal pathway, ion homeostasis and the enzymes that remove peroxides. This work suggests that the AmRosea1 gene is a potential candidate for genetic engineering of crops. PMID:28025485

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

    Directory of Open Access Journals (Sweden)

    Mingzhu Dou

    2016-12-01

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

  12. Rice ONAC106 Inhibits Leaf Senescence and Increases Salt Tolerance and Tiller Angle.

    Science.gov (United States)

    Sakuraba, Yasuhito; Piao, Weilan; Lim, Jung-Hyun; Han, Su-Hyun; Kim, Ye-Sol; An, Gynheung; Paek, Nam-Chon

    2015-12-01

    NAM/ATAF1/ATAF2/CUC2 (NAC) is a plant-specific transcription factor (TF) family, and NACs participate in many diverse processes during the plant life cycle. Several Arabidopsis thaliana NACs have important roles in positively or negatively regulating leaf senescence, but in other plant species, including rice, the senescence-associated NACs (senNACs) remain largely unknown. Here we show that the rice senNAC TF ONAC106 negatively regulates leaf senescence. Leaves of onac106-1D (insertion of the 35S enhancer in the promoter region of the ONAC106 gene) mutants retained their green color under natural senescence and dark-induced senescence conditions. Genome-wide transcriptome analysis revealed that key senescence-associated genes (SGR, NYC1, OsNAC5, OsNAP, OsEIN3 and OsS3H) were differentially expressed in onac106-1D during dark-induced senescence. In addition to delayed senescence, onac106-1D also showed a salt stress-tolerant phenotype; key genes that down-regulate salt response signaling (OsNAC5, OsDREB2A, OsLEA3 and OsbZIP23) were rapidly up-regulated in onac106-1D under salt stress. Interestingly, onac106-1D also exhibited a wide tiller angle phenotype throughout development, and the tiller angle-related gene LPA1 was down-regulated in onac106-1D. Using yeast one-hybrid assays, we found that ONAC106 binds to the promoter regions of SGR, NYC1, OsNAC5 and LPA1. Taking these results together, we propose that ONAC106 functions in leaf senescence, salt stress tolerance and plant architecture by modulating the expression of its target genes that function in each signaling pathway.

  13. Marker traits association of agronomical traits correlated with stagnant flooding tolerance in rice

    Science.gov (United States)

    Sitaresmi, T.; Utami, D. W.; Suwarno, W. B.; Ardie, S. W.; Susanto, U.; Aswidinnoor, H.

    2017-05-01

    In deep-water areas, the water depth increases gradually throughout the year and maintains up to more than 50 cm of deep of water for long period. In these situations, elongation ability is necessary to allow the plants to keep up with rising floodwater. The elongation of internode during submergence is regulated by environmental and hormonal factors. The objective of this study was aimed to identify the SNP markers on 384 SNPs linked with agronomical and morphological traits related to stagnant flooding tolerance. The research were conducted at Indonesian Center for Rice Research and Indonesian Centre for Agricultural Biotechnology and Genetic Resources Research and Development. The phenotypical data was collected from F2 from bi-parental crossing of IR 42 and IRRI 119. IR 42 was sensitive parent, and IRRI 119 was tolerant. DNA extraction for rice was using a modified version of Murray and Thompson method using cetyl tri-methyl-ammonium bromide (CTAB). The genotyping was carried out using 384 SNPs Golden Gate Illumina assay. Association analysis between SNP markers and phenotypical data was performed using General Linear Model in Tassel versus 5.0 software program. Based on GLM analysis, the significant marker for plant height with P value < 0.05 are TBGI275345, TBGI275367, and TBGI424383. The significant marker for number of tiller are TBGI000722, TBGI258600, TBGI270843, TBGI271066, TBGI271076, TBGI272122, TBGI272241, and TBGI327790. Two of them, TBGI424383 and TBGI271066 were expected associated with family of protein kinase which play role in plant stress signalling.

  14. Identification of quantitative trait loci for salinity tolerance in rice (Oryza sativa L.) using IR29/Hasawi mapping population

    Indian Academy of Sciences (India)

    J. B. BIZIMANA; A. LUZI-KIHUPI; ROSEMARY W. MURORI; R. K. SINGH

    2017-09-01

    Salinity is the second most important abiotic stress after drought that hampers rice production, especially in south and Southeast Asia. Breeding approach supplemented with molecular markers-assisted selection is the most promising approach in terms of efficiency to increase the productivity under salt-affected soils. Thirty-day-old rice seedlings of 300 F5:6 recombinant-inbred lines derived from a cross between the salt sensitive, IR29 (indica), and a salt tolerant, Hasawi (aus), were used to identify quantitative trait loci (QTLs) linked to salinity tolerance. One hundred and ninety four polymorphic SNP markers were used to construct a genetic linkage map involving 142 selected RILs that covered 1441.96 cM genome with an average distance of 7.88 cM between loci. Twentynew QTLs (LOD > 3) were identified on chromosomes 1, 2, 4, 6, 8, 9 and 12 using composite interval mapping with R2 as high as >20% with LODvalue of 7.21. Many earlier studies reported big qSaltol for seedling stage salinity tolerance in rice is on short arm of chromosome 1 but none of the QTL in our study was on qSaltol or nearby position, therefore, Hasawi conferred salinity tolerance in RILs due to novel QTLs. It is suggested to fine map the novel QTLs so that the level of salinity tolerance could be further enhanced by pyramiding of the different QTLs in one genetic background through marker-assisted selection.

  15. Comparative mapping of QTLs for AI tolerance in rice and identification of positional Al-induced genes

    Institute of Scientific and Technical Information of China (English)

    毛传澡; 杨玲; 郑炳松; 吴运荣; 刘非燕; 易可可; 吴平

    2004-01-01

    Aluminum (A1) toxicity is the major factor limiting crop productivity in acid soils. In this study, a recombinant inbreed line (RIL) population derived from a cross between an A1 sensitive lowland indica rice variety IR1552 and an A1 tolerant upland japonica rice variety Azucena, was used for mapping quantitative trait loci (QTLs) for A1 tolerance. Three QTLs for relative root length (RRL) were detected on chromosome 1,9, 12, respectively, and 1 QTL for root length under A1 stress is identical on chromosome 1 after one week and two weeks stress. Comparison of QTLs on chromosome 1 from different studies indicated an identical interval between C86 and RZ801 with gene(s) for A1 tolerance. This interval provides an important start point for isolating genes responsible for A1 tolerance and understanding the genetic nature of Al tolerance in rice. Four A1 induced ESTs located in this interval were screened by reverse Northern analysis and confirmed by Northern analysis. They would be candidate genes for the QTL.

  16. Comparative mapping of QTLs for Al tolerance in rice and identification of positional Al-induced genes

    Institute of Scientific and Technical Information of China (English)

    毛传澡; 杨玲; 郑炳松; 吴运荣; 刘非燕; 易可可; 吴平

    2004-01-01

    Aluminum (Al) toxicity is the major factor limiting crop productivity in acid soils. In this study, a recombinant inbreed line (RIL) population derived from a cross between an A1 sensitive lowland indica rice variety IR1552 and an Al tolerant upland japonica rice variety Azucena, was used for mapping quantitative trait loci (QTLs) for A1 tolerance. Three QTLs for relative root length (RRL) were detected on chromosome 1, 9, 12, respectively, and I QTL for root length under Al stress is identical on chromosome I after one week and two weeks stress. Comparison of QTLs on chromosome 1 from different studies indicated an identical interval between C86 and RZ801 with gene(s) for Al tolerance. This interval provides an important start point for isolating genes responsible for A1 tolerance and understanding the genetic nature of Al tolerance in rice. Four Al induced ESTs located in this interval were screened by reverse Northern analysis and confirmed by Northern analysis. They would be candidate genes for the QTL.

  17. Cross-tolerance and cross-talk in the cold: relating low temperatures to desiccation and immune stress in insects.

    Science.gov (United States)

    Sinclair, Brent J; Ferguson, Laura V; Salehipour-shirazi, Golnaz; MacMillan, Heath A

    2013-10-01

    Multiple stressors, both abiotic and biotic, often are experienced simultaneously by organisms in nature. Responses to these stressors may share signaling pathways ("cross-talk") or protective mechanisms ("cross-tolerance"). Temperate and polar insects that must survive the winter experience low temperatures accompanied by additional abiotic stressors, such as low availability of water. Cold and desiccation have many similar effects at a cellular level, and we present evidence that the cellular mechanisms that protect against cold stress also protect against desiccation, and that the responses to cold and dehydration likely evolved as cross-tolerance. By contrast, there are several lines of evidence suggesting that low temperature stress elicits an upregulation of immune responses in insects (and vice versa). Because there is little mechanistic overlap between cold stress and immune stress at the cellular level, we suggest that this is cross-talk. Both cross-talk and cross-tolerance may be adaptive and likely evolved in response to synchronous stressors; however, we suggest that cross-talk and cross-tolerance may lead to different responses to changes in the timing and severity of multiple stress interactions in a changing world. We present a framework describing the potentially different responses of cross-tolerance and cross-talk to a changing environment and describe the nature of these impacts using interaction of cold-desiccation and cold-immunity in overwintering insects as an example.

  18. Cold tolerance and disinfestation of Bactrocera invadens (Diptera: Tephritidae) in 'Hass' avocado.

    Science.gov (United States)

    Ware, A B; Du Toit, C L N; Mohamed, S A; Nderitu, P W; Ekasi, S

    2012-12-01

    Bactrocera invadens (Diptera: Tephritidae) has spread rapidly across Africa and currently poses a phytosanitary threat to the fruit industry of South Africa. In reaction a cold mitigating treatment to provide phytosanitary security to importing countries was developed in Nairobi, Kenya. Using laboratory reared fruit flies, the rate of development in 'Hass' avocado (Persea americana Miller) was determined at 28 degrees C. Fruit ripeness or softness was found to be a factor improving larval fruit fly survival. Using this information the egg and larval developmental stages were subjected to 2 degrees C cold treatment and it was found that the third instars were the most cold tolerant life stage and that it was expected that between 16 and 17 d treatment would provide phytosanitary security. There were no survivors in the treatment of an estimated 153,001 individuals in four replicates at an average fruit pulp temperature of 2 degrees C satisfying the Probit 9 level of efficiency at a confidence of >95%. These data provide evidence that a continuous cold treatment of 1.5 degrees C or lower for 18 d would provide phytosanitary security in that any consignment entering an importing country poses no risk of accidental importation of B. invadens.

  19. Biochemical and molecular responses underlying differential arsenic tolerance in rice (Oryza sativa L.).

    Science.gov (United States)

    Begum, Most Champa; Islam, Mohammad Saiful; Islam, Monirul; Amin, Ruhul; Parvez, Mohammad Sarwar; Kabir, Ahmad Humayan

    2016-07-01

    The arsenic (As) is a toxic element causing major health concern worldwide. Arsenate stress caused no significant reduction in growth parameters and shoot electrolyte leakage but showed increased root arsenate reductase activity along with relatively lower root As content and shoot translocation rate in As-tolerant BRRI 33 than in As-sensitive BRRI 51. It indicates that As inhibition and tolerance mechanisms are driven by root responses. Interestingly, As stress showed consistent decrease in phosphate content and expression of phosphate transporters (OsPT8, OsPT4, OsPHO1;2) under both high and low phosphate conditions in roots of BRRI 33, suggesting that limiting phosphate transport mainly mediated by OsPHO1;2 directs less As accumulation in BRRI 33. Further, BRRI 33 showed simultaneous increase in OsPCS1 (phytochelatin synthase) expression and phytochelatins (PCs) content in roots under As exposure supporting the hypothesis that root As sequestration acts as 'firewall system' in limiting As translocation in shoots. Furthermore, increased CAT, POD, SOD, GR, along with elevated glutathione, methionine, cysteine and proline suggests that strong antioxidant defense plays integral part to As tolerance in BRRI 33. Again, BRRI 33 self-grafts and plants having BRRI 33 rootstock combined with BRRI 51 scion had no adverse effect on morphological parameters but showed reduced As translocation rate, increased root arsenate reductase activity, shoot PC synthesis and root OsPHO1;2 expression due to As stress. It confirms that signal driving As tolerance mechanisms is generated in the roots. These findings can be implemented for As detoxification and As-free transgenic rice production for health safety.

  20. 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.

  1. Effects of feeding beef females supplemental fat during gestation on cold tolerance in newborn calves.

    Science.gov (United States)

    Lammoglia, M A; Bellows, R A; Grings, E E; Bergman, J W; Short, R E; MacNeil, M D

    1999-04-01

    Effects of prepartum fat supplementation of the dam on cold tolerance of calves were determined in two studies. In Exp. 1, 22 F1, crossbred heifers gestating F2 calves received diets containing either 1.7 or 4.7% dietary fat starting at d 230+/-2d of gestation. Safflower seeds (Carthamus tinctorius) containing 37% oil with 79% linoleic acid were the supplemental fat source in isocaloric-isonitrogenous diets. Calves were separated from their dams at birth, fed pooled dairy-cow colostrum, muzzled to prevent sucking, and returned to their dams in a heated (22 degrees C) barn for 3.5 h. At 4 h of age, a jugular catheter was inserted. At 5 h of age, calves were placed in a 0 degrees C room for 140 min and rectal temperatures and blood samples were obtained at 10- and 20-min intervals. Blood was assayed for glucose, cortisol, and cholesterol. In Exp. 2, 18 multiparous, crossbred beef cows bred to Murray Grey sires were randomly assigned to receive diets containing either 1.7 or 3.1% dietary fat starting at 235+/-2 d gestation. Safflower seeds were used as the supplemental fat source in isocaloric-isonitrogenous diets. At d 260 of gestation, premature parturition was induced in one-half of the cows from each diet group by feeding Ponderosa pine (Pinus ponderosa) needles. Experimental protocols were the same as in Exp. 1, except that cold exposure was at 9 degrees C for 200 min. Rectal temperatures were affected in Exp. 1 by time and diet x time (both P stressed newborns. This increase in substrate availability suggests a potential positive effect on heat generation in newborns during sustained periods of cold stress. In Exp. 2, premature calves had compromised cold tolerance possibly due to impaired shivering or brown adipose tissue thermogenesis.

  2. The functions of an apple cytosolic malate dehydrogenase gene in growth and tolerance to cold and salt stresses.

    Science.gov (United States)

    Yao, Yu-Xin; Dong, Qing-Long; Zhai, Heng; You, Chun-Xiang; Hao, Yu-Jin

    2011-03-01

    It is well-known that cytosolic NAD-dependent malate dehydrogenase (cyMDH; l-malate:NAD-oxidoreductase; EC 1.1.1.37) is an enzyme crucial for malic acid synthesis in the cytosol. Nothing is known about cyMDH in growth and stress tolerance. Here we characterised the role of the apple cyMDH gene (MdcyMDH, GenBank ID: DQ221207) in growth and tolerance to cold and salt stresses. MdcyMDH transcripts were highly accumulated in vigorously growing apple tissues, organs and suspension cells. In addition, MdcyMDH was sensitive to cold and salt stresses. MdcyMDH overexpression favourably contributed to cell and plant growth and conferred stress tolerance both in the apple callus and tomato. Taken together, our results indicated that MdcyMDH is involved in plant and cell growth as well as the tolerance to cold and salt stresses.

  3. Biological activities of thermo-tolerant microbes from fermented rice bran as an alternative microbial feed additive.

    Science.gov (United States)

    Koh, J H; Suh, H J

    2009-06-01

    To evaluate the commercial potential of new microbial feed additive, Issatchenkia orientalis Y266 and Bacillus subtilis B266 from commercial fermented rice bran were tested for their tolerance or resistance to pH, bile, oxgall, and temperature. It was found that the strains grew very well up to pH 3.0 and resistant to relatively high concentrations of bile salt and oxgall. I. orientalis and B. subtilis are extremely tolerant in range of 70-90 degrees C in solid medium. B. subtilis B266 also has excellent tolerant property up to 90 degrees C in liquid medium. The health indexes (the microflora in the small intestines and the antibody titer to Newcastle disease virus) of chicks were significantly improved in the fermented rice bran with these strains (0.25% addition to diet) in comparison with the Avilamycin (20 mg/kg diet)-fed group (p fermented rice bran-fed group showed a better microbial flora in the small intestines. Accordingly, it would appear that the fermented rice bran with these strains may be a potential candidate for an alternative microbial feed additive.

  4. Bulked Segregant Analysis to Detect QTL Related to Heat Tolerance in Rice(Oryza sativa L.)Using SSR Markers

    Institute of Scientific and Technical Information of China (English)

    ZHANG Gui-lian; CHEN Li-yun; XIAO Guo-ying; XIAO Ying-hui; CHEN Xin-bo; ZHANG Shun-tang

    2009-01-01

    The study was undertaken to assess the genetic effect of quantitative trait loci(QTLs)conferring heat tolerance at flowering stage in rice.A population consisting of 279 F2 individuals from the cross between 996,a heat tolerant cultivar and 4628,a heat-sensitive cultivar,was analyzed for their segregation pattern of the difference of seed set rate under optimal temperature condition and high temperature condition.The difference of seed set rate under optimal temperature condition and high temperature condition showed normal distribution,indicating the polygenic control over the trait.To identify main effect of QTL for heat tolerance,the parents were surveyed with 200 primer pairs of simple sequence repeats(SSR).The parental survey revealed 30% polymorphism between parents.In order to detect the main QTL association with heat tolerance,a strategy of combining the DNA pooling from selected segregants and genotyping was adopted.The association of putative markers identified based on DNA pooling from selected segregants was established by single marker analysis(SMA).The results of SMA revealed that SSR markers,RM3735 on chromosome 4 and RM3586 on chromosome 3 showed significant association with heat tolerance respectively.accounted for 17 and 3% of the total variation respectively.The heat tolerance during flowering stage in rice was controlled by multiple gene.The SSR markers,RM3735 on chromosome 4 and RM3586 on chromosome 3 showed significant association with heat tolerance respectively,accounted for 17 and 3% of the total variation respectively.The two genetic loci,especially for RM3735 on chromosome 4,can be used in marker-assistant-selected method in heat tolerance breeding in rice.

  5. Over-expression of an Arabidopsis δ-OAT gene enhances salt and drought tolerance in transgenic rice

    Institute of Scientific and Technical Information of China (English)

    WU Liangqi; FAN Zhanmin; GUO Lei; LI Yongqing; ZHANG Wenjing; QU Li-Jia; CHEN Zhangliang

    2003-01-01

    δ-OAT, ornithine-δ-aminotransferase, is the key enzyme involved in proline biosynthesis. In this study the Arabidopsisδ-OAT gene was transferred into rice (Oryza sativa L. ssp japonica cv. Zhongzuo 321), whose successful integration was demonstrated by PCR and Southern blot analysis. The over-expression of the gene in transgenic rice was also confirmed. Biochemical analysis showed that, under salt or drought stress conditions, proline contents in the leaves and roots in transgenic rice plants were 5- to 15-fold of those in non-transgenic controls. Under stress conditions, germinating rate of transgenic lines is higher than that of controls. Although the growth of rice plants tested were more and more retarded with the increasing of NaCl concentration, the transgenic plants grow faster compared to the controls under the same stress condition. Meanwhile, the resistance to KCl and MgSO4 stresses was also found enhanced in transgenic rice. Furthermore, the over-expression ofδ-OAT also improved the yield of transgenic plants under stress conditions. The average yield per plant of transgenic lines increases about 12%-41% more than that of control lines under 0.1 mol/L NaCl stress. These data indicated that the over-expression of δ-OAT, with the accumulation of proline, resulted in the enhancement of salt and drought tolerance and an increase of rice yield, which is of significance in agriculture.

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

    Science.gov (United States)

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

    2015-01-01

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

  7. Mn tolerance in rice is mediated by MTP8.1, a member of the cation diffusion facilitator family

    Science.gov (United States)

    Ueno, Daisei

    2013-01-01

    Manganese (Mn) is an essential micronutrient for plants, but is toxic when present in excess. The rice plant (Oryza sativa L.) accumulates high concentrations of Mn in the aerial parts; however, the molecular basis for Mn tolerance is poorly understood. In the present study, genes encoding Mn tolerance were screened for by expressing cDNAs of genes from rice shoots in Saccharomyces cerevisiae. A gene encoding a cation diffusion facilitator (CDF) family member, OsMTP8.1, was isolated, and its expression was found to enhance Mn accumulation and tolerance in S. cerevisiae. In plants, OsMTP8.1 and its transcript were mainly detected in shoots. High or low supply of Mn moderately induced an increase or decrease in the accumulation of OsMTP8.1, respectively. OsMTP8.1 was detected in all cells of leaf blades through immunohistochemistry. OsMTP8.1 fused to green fluorescent protein was localized to the tonoplast. Disruption of OsMTP8.1 resulted in decreased chlorophyll levels, growth inhibition in the presence of high concentrations of Mn, and decreased accumulation of Mn in shoots and roots. However, there was no difference in the accumulation of other metals, including Zn, Cu, Fe, Mg, Ca, and K. These results suggest that OsMTP8.1 is an Mn-specific transporter that sequesters Mn into vacuoles in rice and is required for Mn tolerance in shoots. PMID:23963678

  8. Antibacterial and anticancerous biocompatible silver nanoparticles synthesised from the cold-tolerant strain of Spirulina platensis

    Directory of Open Access Journals (Sweden)

    Selvaraj Karthick Raja Namasivayam

    2015-04-01

    Full Text Available Objective: To synthesize silver nanoparticles from the biomass of cold tolerant strain of Spirulina platensis and evalute the synthesized nanoparticles against antibacterial and anticancer activity. Methods: Silver nanoparticles were synthesized by the algal culture and characterized by UV-vis spectroscopy, Fourier transform infrared spectroscopy, field emission scanning electron microscopy and X ray diffraction studies. Antibacterial activity has been studied with free nanoparticles adopting agar diffusion assay, biofilm inhibition assay and nanoparticles fabricated wound dressing against representative Gram-negative organism Pseudomonas aeruginosa and Gram-positive organism Staphylococcus aureus respectively. The in vitro anticancer activity of silver nanoparticles were screened against human Hep2 cell lines by means of MTT assay. Results: Reduction of silver ions by the algal culture was observed during 72 h of incubation and the synthesized nanoparticles were further characterized. Antibacterial study reveals both the strains were susceptible to free nanoparticles and fabricated wound dressing treatment. The in vitro anticancer activity of silver nanoparticles were screened against human Hep 2 cell lines by means of MTT assay which reveals that cell viability has been reduced as dose dependent manner. Conclusions: The observed results imply that silver nanoparticles synthesized from Spirulina platensis cold tolerant strain can be used as potential antibacterial and anticancerous agent.

  9. Antibacterial and anticancerous biocompatible silver nanoparticles synthesised from the cold-tolerant strain of Spirulina platensis

    Institute of Scientific and Technical Information of China (English)

    Duraisamy Jayakumar; Ramesh Kumar; Rajan SowriArvind Bharani

    2015-01-01

    Objective: To synthesize silver nanoparticles from the biomass of cold tolerant strain of Spirulina platensis and evalute the synthesized nanoparticles against antibacterial and anticancer activity. Methods: Silver nanoparticles were synthesized by the algal culture and characterized by UV-vis spectroscopy, Fourier transform infrared spectroscopy, field emission scanning electron microscopy and X ray diffraction studies. Antibacterial activity has been studied with free nanoparticles adopting agar diffusion assay, biofilm inhibition assay and nanoparticles fabricated wound dressing against representative Gram-negative organism Pseudomonas aeruginosa and Gram-positive organism Staphylococcus aureus respectively. The in vitro anticancer activity of silver nanoparticles were screened against human Hep2 cell lines by means of MTT assay. Results: Reduction of silver ions by the algal culture was observed during 72 h of incubation and the synthesized nanoparticles were further characterized. Antibacterial study reveals both the strains were susceptible to free nanoparticles and fabricated wound dressing treatment. The in vitro anticancer activity of silver nanoparticles were screened against human Hep 2 cell lines by means of MTT assay which reveals that cell viability has been reduced as dose dependent manner. Conclusions: The observed results imply that silver nanoparticles synthesized from Spirulina platensis cold tolerant strain can be used as potential antibacterial and anticancerous agent.

  10. Importance of freeze-thaw events in low temperature ecotoxicology of cold tolerant enchytraeids.

    Science.gov (United States)

    Silva, Ana L Patrício; Enggrob, Kirsten; Slotsbo, Stine; Amorim, Mónica J B; Holmstrup, Martin

    2014-08-19

    Due to global warming it is predicted that freeze-thaw cycles will increase in Arctic and cold temperate regions. The effects of this variation becomes of particular ecological importance to freeze-tolerant species when it is combined with chemical pollutants. We compared the effect of control temperature (2 °C), daily freeze-thaw cycles (2 to -4 °C) and constant freezing (-2 °C) temperatures on the cold-tolerance of oligochaete worms (Enchytraeus albidus) and tested how survival was influenced by pre-exposure to 4-nonylphenol (4-NP), a common nonionic detergent found in sewage sludge amended soils. Results showed that combined effect of 4-NP and daily freeze-thaw cycles can cause higher mortality to worms as compared with sustained freezing or control temperature. Exposure to 4-NP caused a substantial depletion of glycogen reserves which is catabolized during freezing to produce cryoprotective concentrations of free glucose. Further, exposure to freeze-thaw cycles resulted in higher concentrations of 4-NP in worm tissues as compared to constant freezing or control temperature (2 °C). Thus, worms exposed to combined effect of freeze-thaw cycles and 4-NP suffer higher consequences, with the toxic effect of the chemical potentiating the deleterious effects of freezing and thawing.

  11. Characterization of Metarhizium species and varieties based on molecular analysis, heat tolerance and cold activity

    Science.gov (United States)

    Fernandes, E.K.K.; Keyser, C.A.; Chong, J.P.; Rangel, D.E.N.; Miller, M.P.; Roberts, D.W.

    2010-01-01

    Aims: The genetic relationships and conidial tolerances to high and low temperatures were determined for isolates of several Metarhizium species and varieties. Methods and Results: Molecular-based techniques [AFLP and rDNA (ITS1, ITS2 and 5??8S) gene sequencing] were used to characterize morphologically identified Metarhizium spp. isolates from a wide range of sources. Conidial suspensions of isolates were exposed to wet heat (45 ?? 0??2??C) and plated on potato dextrose agar plus yeast extract (PDAY) medium. After 8-h exposure, the isolates divided clearly into two groups: (i) all isolates of Metarhizium anisopliae var. anisopliae (Ma-an) and Metarhizium from the flavoviride complex (Mf) had virtually zero conidial relative germination (RG), (ii) Metarhizium anisopliae var. acridum (Ma-ac) isolates demonstrated high heat tolerance (c. 70-100% RG). Conidial suspensions also were plated on PDAY and incubated at 5??C for 15 days, during which time RGs for Ma-an and Ma-ac isolates were virtually zero, whereas the two Mf were highly cold active (100% RG). Conclusions: Heat and cold exposures can be used as rapid tools to tentatively identify some important Metarhizium species and varieties. Significance and Impact of the Study: Identification of Metarhizium spp. currently relies primarily on DNA-based methods; we suggest a simple temperature-based screen to quickly obtain tentative identification of isolates as to species or species complexes. ?? 2009 The Society for Applied Microbiology.

  12. Physiological basis and transcriptional profiling of three salt-tolerant mutant lines of rice

    Directory of Open Access Journals (Sweden)

    Concha Domingo

    2016-09-01

    Full Text Available Salinity is a complex trait that affects growth and productivity in many crops, including rice. Mutation induction, a useful tool to generate salt tolerant plants, enables the analysis of plants with similar genetic background, facilitating the understanding of the salt tolerance mechanisms. In this work, we generated three salt tolerant mutant lines by irradiation of a salt-sensitive cultivar plants and screened M2 plants at seedling stage in the presence of high salinity. These three lines, SaT20, SaS62 and SaT58, showed different responses to salinity, but exhibited similar phenotype to wild type plants, except SaT20 that displayed shorter height when grown in the absence of salt. Under salt conditions, all three mutants and the parental line showed similar reduction in yield, although relevant differences in other physiological parameters, such as Na+ accumulation in healthy leaves of SaT20, were registered. Microarray analyses of gene expression profiles in roots revealed the occurrence of common and specific responses in the mutants. The three mutants showed up-regulation of responsive genes, the activation of oxido-reduction process and the inhibition of ion transport. The participation of jasmonate in the plant response to salt was evident by down-regulation of a gene coding for a jasmonate O-methyltransferase. Genes dealing with lipid transport and metabolism were, in general, up-regulated except in SaS62, that also exhibited down-regulation of genes involved in ion transport and Ca2+ signal transduction. The two most tolerant varieties, SaS62 and SaT20, displayed lower levels of transcripts involved in K+ uptake. The physiological study and the description of the expression analysis evidenced that the three lines showed different responses to salt: SaT20 showed a high Na+ content in leaves, SaS62 presented an inhibition of lipid metabolism and ion transport and SaT58 differs in both features in the response to salinity. The analysis of

  13. Physiological Basis and Transcriptional Profiling of Three Salt-Tolerant Mutant Lines of Rice

    Science.gov (United States)

    Domingo, Concha; Lalanne, Eric; Catalá, María M.; Pla, Eva; Reig-Valiente, Juan L.; Talón, Manuel

    2016-01-01

    Salinity is a complex trait that affects growth and productivity in many crops, including rice. Mutation induction, a useful tool to generate salt tolerant plants, enables the analysis of plants with similar genetic background, facilitating the understanding of the salt tolerance mechanisms. In this work, we generated three salt tolerant mutant lines by irradiation of a salt-sensitive cultivar plants and screened M2 plants at seedling stage in the presence of high salinity. These three lines, SaT20, SaS62, and SaT58, showed different responses to salinity, but exhibited similar phenotype to wild type plants, except SaT20 that displayed shorter height when grown in the absence of salt. Under salt conditions, all three mutants and the parental line showed similar reduction in yield, although relevant differences in other physiological parameters, such as Na+ accumulation in healthy leaves of SaT20, were registered. Microarray analyses of gene expression profiles in roots revealed the occurrence of common and specific responses in the mutants. The three mutants showed up-regulation of responsive genes, the activation of oxido-reduction process and the inhibition of ion transport. The participation of jasmonate in the plant response to salt was evident by down-regulation of a gene coding for a jasmonate O-methyltransferase. Genes dealing with lipid transport and metabolism were, in general, up-regulated except in SaS62, that also exhibited down-regulation of genes involved in ion transport and Ca2+ signal transduction. The two most tolerant varieties, SaS62 and SaT20, displayed lower levels of transcripts involved in K+ uptake. The physiological study and the description of the expression analysis evidenced that the three lines showed different responses to salt: SaT20 showed a high Na+ content in leaves, SaS62 presented an inhibition of lipid metabolism and ion transport and SaT58 differs in both features in the response to salinity. The analysis of these salt

  14. Regulatory role of DREB transcription factors in plant drought, salt and cold tolerance

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    rd29A gene of Arabidopsis encodes a LEA-like hydrophilic protein, its expression is induced by drought, high-salt and cold stress. In the promoter region of rd29A gene, there are 2 DRE cis-acting elements involved in responses to these environmental stresses. 5 cDNAs (DREB1A~C and DREB2A~B) encoding DREB transcription factors, which specifically bind to DRE element and control the expression of reporter gene under drought, high-salt and stress, have been isolated by One-Hybrid screening method and with DRE element of rd29A promoter. DREB transcription factors and DRE element function in signal transduction of drought, high-salt and cold stress. One DREB transcription factor can control the expression of several target functional genes involved in plant tolerance to drought, high-salt and cold stress. Thus, it may be an effective strategy to achieve ideal, multiple and fundamental effect for improving plant stress-resistance by DREB gene transfer.

  15. Aerobic rice genotypes displayed greater adaptation to water-limited cultivation and tolerance to polyethyleneglycol-6000 induced stress.

    Science.gov (United States)

    Sandhu, Nitika; Jain, Sunita; Battan, K R; Jain, R K

    2012-01-01

    Water scarcity and drought have seriously threatened traditional rice cultivation practices in several parts of the world including India. In the present investigation, experiments were conducted to see if the water-efficient aerobic rice genotypes developed at UAS, Bangalore (MAS25, MAS26 and MAS109) and IRRI, Philippines (MASARB25 and MASARB868), are endowed with drought tolerance or not. A set of these aerobic and five lowland high-yielding (HKR47 and PAU201, Taraori Basmati, Pusa1121 and Pusa1460) indica rice genotypes were evaluated for: (i) yield and yield components under submerged and aerobic conditions in field, (ii) root morphology and biomass under aerobic conditions in pots in the nethouse, (iii) PEG-6000 (0, -1, -2 and -3 bar) induced drought stress at vegetative stage using a hydroponic culture system and (iv) polymorphism for three SSR markers associated with drought resistance traits. Under submerged conditions, the yield of aerobic rice genotypes declined by 13.4-20.1 % whereas under aerobic conditions the yield of lowland indica/Basmati rice varieties declined by 23-27 %. Under water-limited conditions in pots, aerobic rice genotypes had 54-73.8 % greater root length and 18-60 % higher fresh root biomass compared to lowland indica rice varieties. Notably, root length of MASARB25 was 35 % shorter than MAS25 whereas fresh and dry root biomass of MASARB25 was 10 % and 64 % greater than MAS25. The lowland indica were more sensitive to PEG-stress with a score of 5.9-7.6 for Basmati and 6.1-6.7 for non-aromatic indica rice varieties, than the aerobic rice genotypes (score 2.7-3.3). A set of three microsatellite DNA markers (RM212, RM302 and RM3825) located on chromosome 1 which has been shown to be associated with drought resistance was investigated in the present study. Two of these markers (RM212 and RM302) amplified a specific allele in all the aerobic rice genotypes which were absent in lowland indica rice genotypes.

  16. Root ABA Accumulation Enhances Rice Seedling Drought Tolerance under Ammonium Supply: Interaction with Aquaporins

    Science.gov (United States)

    Ding, Lei; Li, Yingrui; Wang, Ying; Gao, Limin; Wang, Min; Chaumont, François; Shen, Qirong; Guo, Shiwei

    2016-01-01

    In previous studies, we demonstrated that ammonium nutrition enhances the drought tolerance of rice seedlings compared to nitrate nutrition and contributes to a higher root water uptake ability. It remains unclear why rice seedlings maintain a higher water uptake ability when supplied with ammonium under drought stress. Here, we focused on the effects of nitrogen form and drought stress on root abscisic acid (ABA) concentration and aquaporin expression using hydroponics experiments and stimulating drought stress with 10% PEG6000. Drought stress decreased the leaf photosynthetic rate and stomatal conductivity and increased the leaf temperature of plants supplied with either ammonium or nitrate, but especially under nitrate supply. After 4 h of PEG treatment, the root protoplast water permeability and the expression of root PIP and TIP genes decreased in plants supplied with ammonium or nitrate. After 24 h of PEG treatment, the root hydraulic conductivity, the protoplast water permeability, and the expression of some aquaporin genes increased in plants supplied with ammonium compared to those under non-PEG treatment. Root ABA accumulation was induced by 24 h of PEG treatment, especially in plants supplied with ammonium. The addition of exogenous ABA decreased the expression of PIP and TIP genes under non-PEG treatment but increased the expression of some of them under PEG treatment. We concluded that drought stress induced a down-regulation of aquaporin expression, which appeared earlier than did root ABA accumulation. With continued drought stress, aquaporin expression and activity increased due to root ABA accumulation in plants supplied with ammonium. PMID:27559341

  17. Cold tolerance of the Antarctic nematodes Plectus murrayi and Scottnema lindsayae.

    Science.gov (United States)

    Wharton, David A; Raymond, Mélianie R

    2015-04-01

    The cold tolerance of the Antarctic nematodes Scottnema lindsayae and Plectus murrayi was determined using material freshly isolated from the field. Both species could survive low temperatures but the survival of S. lindsayae was greater than that of P. murrayi. Field soil temperatures in late spring-early summer indicated a minimum temperature of -19.5 °C and a maximum cooling rate of 0.71 °C min(-1). In P. murrayi grown in culture, there was no significant effect of acclimation, nor of the two culture media used, on survival after freezing but survival was greater if freezing was seeded at -1 °C than at lower temperatures. The freezing survival ability of P. murrayi is much less than that of Panagrolaimus davidi CB1, another Antarctic nematode. Cryomicroscopy indicates that P. murrayi can survive low temperatures by either cryoprotective dehydration or freezing tolerance, but that freezing tolerance is the dominant strategy. Measurable thermal hysteresis was detected only in highly concentrated extracts of the nematodes, indicating the presence of an antifreeze protein, but at the concentrations likely to be found in vivo, the major function of the ice active protein involved is probably recrystallization inhibition.

  18. ISSR markers based on GA and AG repeats reveal genetic relationship among rice varieties tolerant to drought,flood,or salinity

    Institute of Scientific and Technical Information of China (English)

    Ch Surendhar REDDY; A.Prasad BABU; B.P.Mallikarjuna SWAMY; K.KALADHAR; N.SARLA

    2009-01-01

    Drought,flood,salinity,or a combination of these limits rice production.Several rice varieties are well known for their tolerance to specific abiotic stresses.We determined genetic relationship among 12 rice varieties including 9 tolerant to drought,flood,or salinity using inter-simple sequence repeat (ISSR) markers.Based on all markers,the nine tolerant varieties formed one cluster distinct from the cluster of three control varieties.The salt-tolerant varieties were closest to two flood-tolerant varieties,and together they were distinct from the drought-tolerant varieties.(GA)8 YG was the most informative primer,showing the highest polymorphic information content (PIC) and resolving power (Rp).The drought-,flood-,and salt-tolerant varieties grouped in three distinct clusters within the group of tolerant varieties,when (GA)8 YG was used.Sabita was the only exception.The two aus varieties,Nagina22 and FR13A,were separated and grouped with the drought-and flood-tolerant varieties,respectively,but they were together in dendrograms based on other primers.The results show that ISSR markers associated with (GA)8 YG delineated the three groups of stress-tolerant varieties from each other and can be used to identify genes/new alleles associated with the three abiotic stresses in rice germplasm.

  19. Can arbuscular mycorrhizal fungi improve grain yield, As uptake and tolerance of rice grown under aerobic conditions?

    Energy Technology Data Exchange (ETDEWEB)

    Li, H. [Croucher Institute for Environmental Sciences, Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong (Hong Kong); Ye, Z.H. [State Key Laboratory for Bio-control, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006 (China); Chan, W.F.; Chen, X.W.; Wu, F.Y. [Croucher Institute for Environmental Sciences, Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong (Hong Kong); Wu, S.C. [Croucher Institute for Environmental Sciences, Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong (Hong Kong); School of Environment and Natural Resources, Zhejiang Agriculture and Forestry University, Lin' an, Zhejiang 311300 (China); Wong, M.H., E-mail: mhwong@hkbu.edu.hk [Croucher Institute for Environmental Sciences, Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong (Hong Kong); School of Environment and Natural Resources, Zhejiang Agriculture and Forestry University, Lin' an, Zhejiang 311300 (China)

    2011-10-15

    The effects of arbuscular mycorrhizal fungi (AMF) -Glomus intraradices and G. geosporum on arsenic (As) and phosphorus (P) uptake by lowland (Guangyinzhan) and upland rice (Handao 502) were investigated in soil, spiked with and without 60 mg As kg{sup -1}. In As-contaminated soil, Guangyinzhan inoculated with G. intraradices or Handao 502 inoculated with G. geosporum enhanced As tolerance, grain P content, grain yield. However, Guangyinzhan inoculated with G. geosporum or Handao 502 inoculated with G. intraradices decreased grain P content, grain yield and the molar ratio of grain P/As content, and increased the As concentration and the ratio of grain/straw As concentration. These results show that rice/AMF combinations had significant (p < 0.05) effects on grain As concentration, grain yield and grain P uptake. The variation in the transfer and uptake of As and P reflected strong functional diversity in AM (arbuscular mycorrhizal) symbioses. - Highlights: > Rice/AMF combinations had significant effects on grain As concentration, grain yield and grain P uptake. > Rice colonized with suitable AMF can increase grain yield. > The variation in the transfer and uptake of As and P reflected strong functional diversity in AM symbioses. - Different rice/AMF combinations had very different effects on arsenic and phosphorus uptake.

  20. Transcriptomic and Metabolomic Studies Disclose Key Metabolism Pathways Contributing to Well-maintained Photosynthesis under the Drought and the Consequent Drought-Tolerance in Rice

    OpenAIRE

    Ma, Xiaosong; Xia, Hui; Liu, Yunhua; Wei, Haibin; Zheng, Xiaoguo; Song, Congzhi; Chen, Liang; Liu, Hongyan; Luo, Lijun

    2016-01-01

    In contrast to wild species, drought-tolerance in crops requires a fully functional metabolism during drought (particularly photosynthetic processes). However, the link between drought-tolerance, photosynthetic regulation during drought, and the associated transcript and metabolic foundation, remains largely unknown. For this study, we used two rice cultivars with contrasting drought-tolerance (the drought-intolerant cultivar IRAT109 and the drought-tolerant cultivar IAC1246) to explore trans...

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

    Science.gov (United States)

    Cui, Long-Gang; Shan, Jun-Xiang; Shi, Min; Gao, Ji-Ping; Lin, Hong-Xuan

    2015-10-01

    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.

  2. 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.

  3. Functional validation of a novel isoform of Na+/H+ antiporter from Pennisetum glaucum for enhancing salinity tolerance in rice

    Indian Academy of Sciences (India)

    Dheeraj Verma; Sneh L Singla-Pareek; Divya Rajagopal; M K Reddy; S K Sopory

    2007-04-01

    Salt stress is an environmental factor that severely impairs plant growth and productivity. We have cloned a novel isoform of a vacuolar Na+/H+ antiporter from Pennisetum glaucum (PgNHX1) that contains 5 transmembrane domains in contrast to AtNHX1 and OsNHX1 which have 9 transmembrane domains. Recently we have shown that PgNHX1 could confer high level of salinity tolerance when overexpressed in Brassica juncea. Here, we report the functional validation of this antiporter in crop plant rice. Overexpression of PgNHX1 conferred high level of salinity tolerance in rice. Transgenic rice plants overexpressing PgNHX1 developed more extensive root system and completed their life cycle by setting flowers and seeds in the presence of 150 mM NaCl. Our data demonstrate the potential of PgNHX1 for imparting enhanced salt tolerance capabilities to salt-sensitive crop plants for growing in high saline areas.

  4. Quantitative proteomic analysis reveals that antioxidation mechanisms contribute to cold tolerance in plantain (Musa paradisiaca L.; ABB Group) seedlings.

    Science.gov (United States)

    Yang, Qiao-Song; Wu, Jun-Hua; Li, Chun-Yu; Wei, Yue-Rong; Sheng, Ou; Hu, Chun-Hua; Kuang, Rui-Bin; Huang, Yong-Hong; Peng, Xin-Xiang; McCardle, James A; Chen, Wei; Yang, Yong; Rose, Jocelyn K C; Zhang, Sheng; Yi, Gan-Jun

    2012-12-01

    Banana and its close relative, plantain are globally important crops and there is considerable interest in optimizing their cultivation. Plantain has superior cold tolerance compared with banana and a thorough understanding of the molecular mechanisms and responses of plantain to cold stress has great potential value for developing cold tolerant banana cultivars. In this study, we used iTRAQ-based comparative proteomic analysis to investigate the temporal responses of plantain to cold stress. Plantain seedlings were exposed for 0, 6, and 24 h of cold stress at 8 °C and subsequently allowed to recover for 24 h at 28 °C. A total of 3477 plantain proteins were identified, of which 809 showed differential expression from the three treatments. The majority of differentially expressed proteins were predicted to be involved in oxidation-reduction, including oxylipin biosynthesis, whereas others were associated with photosynthesis, photorespiration, and several primary metabolic processes, such as carbohydrate metabolic process and fatty acid beta-oxidation. Western blot analysis and enzyme activity assays were performed on seven differentially expressed, cold-response candidate plantain proteins to validate the proteomics data. Similar analyses of the seven candidate proteins were performed in cold-sensitive banana to examine possible functional conservation, and to compare the results to equivalent responses between the two species. Consistent results were achieved by Western blot and enzyme activity assays, demonstrating that the quantitative proteomics data collected in this study are reliable. Our results suggest that an increase of antioxidant capacity through adapted ROS scavenging capability, reduced production of ROS, and decreased lipid peroxidation contribute to molecular mechanisms for the increased cold tolerance in plantain. To the best of our knowledge, this is the first report of a global investigation on molecular responses of plantain to cold stress by

  5. Quantitative Proteomic Analysis Reveals that Antioxidation Mechanisms Contribute to Cold Tolerance in Plantain (Musa paradisiaca L.;ABB Group) Seedlings

    Institute of Scientific and Technical Information of China (English)

    Qiaosong Yang; Junhua Wu; Chunyu Li; Yuerong Wei; Ou Sheng; Chunhua Hu; Ruibin Kuang

    2012-01-01

    Banana and its close relative,plantain are globally important crops and there is of considerable interest in optimizing their cultivation.Plantain has superior cold tolerance compared to banana and a thorough understanding of the molecular mechanisms and responses of plantain to cold stress has great potential value for developing cold tolerant banana cultivars.In this study,we used iTRAQ-based comparative proteomic analysis to investigate the temporal responses of plantain to cold stress.Plantain seedlings were exposed for 0,6 and 24 h of cold stress at 8℃ and subsequently allowed to recover for 24 h at 28℃.A total of 3,477 plantain proteins were identified,of which 809 showed differential expression from the three treatments.The majority of differentially expressed proteins were predicted to be involved in oxidation-reduction,including oxylipin biosynthesis,while others were associated with photosynthesis,photorespiration and several primary metabolic processes,such as carbohydrate metabolic process and fatty acid beta-oxidation.Western blot analysis and enzyme activity assays were performed on 7 differentially expressed,cold-response candidate plantain proteins in order to validate the proteomics data.Similar analyses of the 7 candidate proteins were performed in cold-sensitive banana to examine possible functional conservation and to compare the results to equivalent responses between the two species.Consistent results were achieved by Western blot and enzyme activity assays,demonstrating that the quantitative proteomics data collected in this study are reliable.Our results suggest that an increase of antioxidant capacity through adapted ROS scavenging capability,reduced production of ROS and decreased lipid peroxidation contribute to molecular mechanisms for the higher cold tolerance in plantain.To the best of our knowledge,this is the first report of a global investigation on molecular responses of plantain to cold stress by proteomic analysis.

  6. A built-in mechanism to mitigate the spread of insect-resistance and herbicide-tolerance transgenes into weedy rice populations.

    Directory of Open Access Journals (Sweden)

    Chengyi Liu

    Full Text Available BACKGROUND: The major challenge of cultivating genetically modified (GM rice (Oryza sativa at the commercial scale is to prevent the spread of transgenes from GM cultivated rice to its coexisting weedy rice (O. sativa f. spontanea. The strategic development of GM rice with a built-in control mechanism can mitigate transgene spread in weedy rice populations. METHODOLOGY/PRINCIPAL FINDINGS: An RNAi cassette suppressing the expression of the bentazon detoxifying enzyme CYP81A6 was constructed into the T-DNA which contained two tightly linked transgenes expressing the Bt insecticidal protein Cry1Ab and the glyphosate tolerant 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS, respectively. GM rice plants developed from this T-DNA were resistant to lepidopteran pests and tolerant to glyphosate, but sensitive to bentazon. The application of bentazon of 2000 mg/L at the rate of 40 mL/m(2, which is approximately the recommended dose for the field application to control common rice weeds, killed all F(2 plants containing the transgenes generated from the Crop-weed hybrids between a GM rice line (CGH-13 and two weedy rice strains (PI-63 and PI-1401. CONCLUSIONS/SIGNIFICANCE: Weedy rice plants containing transgenes from GM rice through gene flow can be selectively killed by the spray of bentazon when a non-GM rice variety is cultivated alternately in a few-year interval. The built-in control mechanism in combination of cropping management is likely to mitigate the spread of transgenes into weedy rice populations.

  7. Differential molecular responses of rice and wheat coleoptiles to anoxia reveal novel metabolic adaptations in amino acid metabolism for tissue tolerance.

    Science.gov (United States)

    Shingaki-Wells, Rachel N; Huang, Shaobai; Taylor, Nicolas L; Carroll, Adam J; Zhou, Wenxu; Millar, A Harvey

    2011-08-01

    Rice (Oryza sativa) and wheat (Triticum aestivum) are the most important starch crops in world agriculture. While both germinate with an anatomically similar coleoptile, this tissue defines the early anoxia tolerance of rice and the anoxia intolerance of wheat seedlings. We combined protein and metabolite profiling analysis to compare the differences in response to anoxia between the rice and wheat coleoptiles. Rice coleoptiles responded to anoxia dramatically, not only at the level of protein synthesis but also at the level of altered metabolite pools, while the wheat response to anoxia was slight in comparison. We found significant increases in the abundance of proteins in rice coleoptiles related to protein translation and antioxidant defense and an accumulation of a set of enzymes involved in serine, glycine, and alanine biosynthesis from glyceraldehyde-3-phosphate or pyruvate, which correlates with an observed accumulation of these amino acids in anoxic rice. We show a positive effect on wheat root anoxia tolerance by exogenous addition of these amino acids, indicating that their synthesis could be linked to rice anoxia tolerance. The potential role of amino acid biosynthesis contributing to anoxia tolerance in cells is discussed.

  8. Differential gene expression in salt-tolerant rice mutant and its parental variety

    Institute of Scientific and Technical Information of China (English)

    张劲松; 周骏马; 张驰; 陈受宜

    1996-01-01

    The differential expressions of three genes rbcL, salT and rab!6 in response to ABA, NaCl, PEG and heat shock were investigated in seedlings of a salt-tolerant rice mutant 20 (mutant 20) and its parental variety Oryza sativa var. japonica 77-170(170). By Northern blot analysis it was found that ABA induced the expression of all three genes of rbcL, salT and rab16 in shoots and roots of both 170 and mutant 20 with the exceptions of rab16 in shoots of mutant 20 and rbcL in roots of 170. Lower concentrations of NaCl induced rbcL expression in shoots of mutant 20 but not 170. Higher concentrations of NaCl decreased rbcL expression but induced expressions of salT and rab16 in shoots of both 170 and mutant 20. PEG(15%) and 37℃ heat shock showed almost no effects on the expression of the three genes in mutant 20. However, they caused a decrease in rbcL expression and slight induction of the rab16 gene in 170, with salT expression unaffected. These results indicated that mutant 20 was relatively less responsiv

  9. Drought stress-induced compositional changes in tolerant transgenic rice and its wild type.

    Science.gov (United States)

    Nam, Kyong-Hee; Kim, Do-Young; Shin, Hee Jae; Nam, Ki Jung; An, Joo Hee; Pack, In-Soon; Park, Jung-Ho; Jeong, Soon-Chun; Kim, Ho Bang; Kim, Chang-Gi

    2014-06-15

    Comparing well-watered versus deficit conditions, we evaluated the chemical composition of grains harvested from wild-type (WT) and drought-tolerant, transgenic rice (Oryza sativa L.). The latter had been developed by inserting AtCYP78A7, which encodes a cytochrome P450 protein. Two transgenic Lines, '10B-5' and '18A-4', and the 'Hwayoung' WT were grown under a rainout shelter. After the harvested grains were polished, their levels of key components, including proximates, amino acids, fatty acids, minerals and vitamins were analysed to determine the effect of watering system and genotype. Drought treatment significantly influenced the levels of some nutritional components in both transgenic and WT grains. In particular, the amounts of lignoceric acid and copper in the WT decreased by 12.6% and 39.5%, respectively, by drought stress, whereas those of copper and potassium in the transgenics rose by 88.1-113.3% and 10.4-11.9%, respectively, under water-deficit conditions.

  10. Identification of quantitative trait loci affecting tolerance to low phosphorus in rice (Oryza Sativa L.)

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Phosphorus (P)-deficiency in rice (Oryza.Sativa.L) may cause yield reductions.This research has been conducted to map quantitative trait loci (QTLs) for tolerance to low phosphorus stress in a doubled haploid (DH) population.By using the linkage map of this population,the QTLs for relative dry weight,relative P content and relative P utilization efficiency have been located.The results indicate that one RFLP marker located on chromosome 6 is closely associated with relative root dry weight,relative shoot dry weight and relative total dry weight,which explain 24.9%,20.5% and 25.2% of the total phenotypic variations,respectively.Two QTLs affect relative P uptake content,which account for 20.7% of the total phenotypic variations.One micro-effect QTL has been found to be associated with relative P utilization efficiency.It is suggested that the P uptake efficiency is more associated with P efficiency.Among the secondary physiological indices of P uptake efficiency,the root dry weight is more important than others.

  11. Development of cold and drought tolerant short-season maize germplasm for fuel and feed utilization

    Directory of Open Access Journals (Sweden)

    Marcelo J Carena

    2013-04-01

    Full Text Available Maize has become a profitable alternative for North Dakota (ND farmers and ranchers. However, U.S. northern industry hybrids still lack cold and drought stress tolerance as well as adequate grain quality for ethanol and feedstock products. Moreover, there is a need to increase the value of feedstock operations before and after ethanol utilization. The ND maize breeding program initiated the development of hybrids with high quality protein content through the Early Quality Protein Maize for Feedstock (EarlyQPMF project. The North Dakota State University (NDSU maize breeding program acts as a genetic provider to foundation seed companies, retailer seed companies, processing industry, and breeders nationally and internationally. In the past 10 years, NDSU was awarded 9 PVP maize certificates and released 38 maize products. Within those, 13 inbred lines were exclusively released to a foundation seed company for commercial purposes. In addition, 2 hybrids were identified for commercial production in central and western ND.

  12. From QTL to variety-harnessing the benefits of QTLs for drought, flood and salt tolerance in mega rice varieties of India through a multi-institutional network.

    Science.gov (United States)

    Singh, Renu; Singh, Yashi; Xalaxo, Suchit; Verulkar, S; Yadav, Neera; Singh, Shweta; Singh, Nisha; Prasad, K S N; Kondayya, K; Rao, P V Ramana; Rani, M Girija; Anuradha, T; Suraynarayana, Y; Sharma, P C; Krishnamurthy, S L; Sharma, S K; Dwivedi, J L; Singh, A K; Singh, P K; Nilanjay; Singh, N K; Kumar, Rajesh; Chetia, S K; Ahmad, T; Rai, M; Perraju, P; Pande, Anita; Singh, D N; Mandal, N P; Reddy, J N; Singh, O N; Katara, J L; Marandi, B; Swain, P; Sarkar, R K; Singh, D P; Mohapatra, T; Padmawathi, G; Ram, T; Kathiresan, R M; Paramsivam, K; Nadarajan, S; Thirumeni, S; Nagarajan, M; Singh, A K; Vikram, Prashant; Kumar, Arvind; Septiningshih, E; Singh, U S; Ismail, A M; Mackill, D; Singh, Nagendra K

    2016-01-01

    Rice is a staple cereal of India cultivated in about 43.5Mha area but with relatively low average productivity. Abiotic factors like drought, flood and salinity affect rice production adversely in more than 50% of this area. Breeding rice varieties with inbuilt tolerance to these stresses offers an economically viable and sustainable option to improve rice productivity. Availability of high quality reference genome sequence of rice, knowledge of exact position of genes/QTLs governing tolerance to abiotic stresses and availability of DNA markers linked to these traits has opened up opportunities for breeders to transfer the favorable alleles into widely grown rice varieties through marker-assisted backcross breeding (MABB). A large multi-institutional project, "From QTL to variety: marker-assisted breeding of abiotic stress tolerant rice varieties with major QTLs for drought, submergence and salt tolerance" was initiated in 2010 with funding support from Department of Biotechnology, Government of India, in collaboration with International Rice Research Institute, Philippines. The main focus of this project is to improve rice productivity in the fragile ecosystems of eastern, northeastern and southern part of the country, which bear the brunt of one or the other abiotic stresses frequently. Seven consistent QTLs for grain yield under drought, namely, qDTY1.1, qDTY2.1, qDTY2.2, qDTY3.1, qDTY3.2, qDTY9.1 and qDTY12.1 are being transferred into submergence tolerant versions of three high yielding mega rice varieties, Swarna-Sub1, Samba Mahsuri-Sub1 and IR 64-Sub1. To address the problem of complete submergence due to flash floods in the major river basins, the Sub1 gene is being transferred into ten highly popular locally adapted rice varieties namely, ADT 39, ADT 46, Bahadur, HUR 105, MTU 1075, Pooja, Pratikshya, Rajendra Mahsuri, Ranjit, and Sarjoo 52. Further, to address the problem of soil salinity, Saltol, a major QTL for salt tolerance is being transferred into

  13. Role of ferritin in the rice tolerance to iron overload Papel da ferritina na tolerância de arroz ao excesso de ferro

    Directory of Open Access Journals (Sweden)

    Vivian Chagas da Silveira

    2009-08-01

    Full Text Available Plants ordinarily face iron (Fe deficiency, since this mineral is poorly available in soils under aerobic conditions. Nonetheless, wetland and irrigated rice plants can be exposed to excess, highly toxic Fe. Ferritin is a ubiquitous Fe-storage protein, important for iron homeostasis. Increased ferritin accumulation resulting from higher Fe availability was shown in some plant species. However, the role of ferritin in tolerance mechanisms to Fe overload in rice is yet to be established. In this study, recombinant rice ferritin was expressed in Escherichia coli, producing an anti-rice ferritin polyclonal antibody which was used to evaluate ferritin accumulation in two rice (Oryza sativa L. cultivars, either susceptible (BR-IRGA 409 or tolerant (EPAGRI 108 to Fe toxicity. Increased ferritin mRNA and protein levels resulting from excess Fe treatment were detected in both cultivars, with higher ferritin protein accumulation in EPAGRI 108 plants, which also reached lower shoot Fe concentrations when submitted to iron overload. The tolerance mechanism to excess Fe in EPAGRI 108 seems to include both restricted Fe translocation and increased ferritin accumulation. This is the first work that shows higher accumulation of the ferritin protein in an iron-excess tolerant Oryza sativa cultivar, providing evidence of a possible role of this protein in iron tolerance mechanisms.Deficiência de ferro (Fe ocorre freqüentemente em plantas, uma vez que este mineral é pouco disponível em condições aeróbicas. Plantas de arroz cultivadas sob alagamento, no entanto, estão sujeitas ao excesso de Fe, que pode ser extremamente tóxico. Alguns cultivares de arroz são resistentes a altas concentrações de ferro, mas os mecanismos fisiológicos responsáveis por essa resistência são pouco conhecidos. A ferritina é uma proteína de ampla distribuição e capaz de armazenar ferro, sendo considerada importante para a homeostase deste metal. Acúmulo de ferritina em

  14. Effect of cold stratification treatments on germination of drought tolerant shrubs seeds.

    Science.gov (United States)

    Olmez, Zafer; Temel, Fatih; Gokturk, Askin; Yahyaoglu, Zeki

    2007-04-01

    This study was carried out to determine effects of different durations (20, 40, 60 days and control) of cold stratification treatments on seed germination and to overcome dormancy in seeds of twelve different drought tolerant plants. The species used in this study were Arbutus andrachne L., Cistus creticus L., Colutea armena Bois. Huet., Cotinus coggygria Scop., Cotoneaster numullaria Fisch. and Mey, Elaeagnus angustifolia L., Jasminum fruticans L., Paliurus spina-christii Mill., Punica granatum L., Pyracantha coccinea Roem., Rhus coriaria L., and Ziziphus jujuba Mill. The seeds were sown in polyethylene pots under greenhouse and on seedbeds under open field conditions. Statistical design was a randomized complete block design with three replications. Germinated seeds were counted and observed periodically for 90 days after sowing to determine germination percentages (GP) and germination rates (GR). While the highest GP were determined according to duration of cold stratification under greenhouse conditions for each species were 44.2% for 60 days, 2.5% for 20 days, 85.6% for 60 days, 13.5% for 20 and 60 days, 64.3% for 20 days, 11.2% for 60 days, 8.2% for 20 days and 14.1% for 20 days for Cotinus coggygria, Cotoneaster numullaria, Jasminum fruticans, Paliurus spina-christii, Pyracantha coccinea, Punica granatum, Rhus coriaria and Ziziphus jujuba respectively The highest GP were 16.5% forArbutus andrachne and 91.3% for Colutea armena for 20 days cold stratified seeds and sown under open field conditions. Furthermore, the highest GP were obtained from seeds of Cistus creticus (27.5%) and Elaeagnus angustifolia (56.2%) in control sowing.

  15. Does morphological and anatomical plasticity during the vegetative stage make wheat more tolerant of water deficit stress than rice?

    Science.gov (United States)

    Kadam, Niteen N; Yin, Xinyou; Bindraban, Prem S; Struik, Paul C; Jagadish, Krishna S V

    2015-04-01

    Water scarcity and the increasing severity of water deficit stress are major challenges to sustaining irrigated rice (Oryza sativa) production. Despite the technologies developed to reduce the water requirement, rice growth is seriously constrained under water deficit stress compared with other dryland cereals such as wheat (Triticum aestivum). We exposed rice cultivars with contrasting responses to water deficit stress and wheat cultivars well adapted to water-limited conditions to the same moisture stress during vegetative growth to unravel the whole-plant (shoot and root morphology) and organ/tissue (root anatomy) responses. Wheat cultivars followed a water-conserving strategy by reducing specific leaf area and developing thicker roots and moderate tillering. In contrast, rice 'IR64' and 'Apo' adopted a rapid water acquisition strategy through thinner roots under water deficit stress. Root diameter, stele and xylem diameter, and xylem number were more responsive and varied with different positions along the nodal root under water deficit stress in wheat, whereas they were relatively conserved in rice cultivars. Increased metaxylem diameter and lower metaxylem number near the root tips and exactly the opposite phenomena at the root-shoot junction facilitated the efficient use of available soil moisture in wheat. Tolerant rice 'Nagina 22' had an advantage in root morphological and anatomical attributes over cultivars IR64 and Apo but lacked plasticity, unlike wheat cultivars exposed to water deficit stress. The key traits determining the adaptation of wheat to dryland conditions have been summarized and discussed. © 2015 American Society of Plant Biologists. All Rights Reserved.

  16. A cold-induced phytosulfokine peptide is related to the improvement of loquat fruit chilling tolerance.

    Science.gov (United States)

    Song, Huwei; Wang, Xinfeng; Hu, Weicheng; Yang, Xianghui; Diao, Enjie; Shen, Ting; Qiang, Qian

    2017-10-01

    A novel peptidomics approach was used to discover cold-induced peptides in loquat fruit. Twenty unique peptides derived from 18 proproteins were identified, and they were involved in sugar signalling, protein metabolism and stress response. The quantitative analysis revealed 7 peptides with more than 2-fold upregulation, especially a 4.96-fold increase detected in the phytosulfokine (PSK) peptide. To further evaluate effects of PSK1 on fruit chilling tolerance, weight loss, firmness and internal browning were investigated in PSK1-treated loquat fruit at 0°C. By contrast, these chilling injury symptoms were effectively reduced by PSK1. PSK1 markedly delayed decreases of ATP content and energy charge. The PSK1-treated fruit exhibited significantly lower activities of cell-wall degrading enzymes and transcripts of genes related to lignin synthesis. Our results demonstrated that PSK1 improves chilling tolerance of loquat fruit by maintaining high energy status and cell integrity. Peptidomics analysis provides a promising tool to discover some key peptides. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Effects of starvation on body composition and cold tolerance in the collembolan Orchesella cincta and the isopod Porcellio scaber.

    Science.gov (United States)

    Verhoef, H A.; Nedved, O; Lavy, D

    1997-10-01

    The effects of long-term starvation on the body composition of the isopod Porcellio scaber (Latreille) and the collembolan Orchesella cincta (L.) were studied, by determining the body composition in starved and fed animals. A period under summer conditions (19 degrees C, 75% RH and L/D 16/8 photoperiod), was followed by a period under winter conditions (5 degrees C, 75% RH and LD 6/18 photoperiod). O. cincta was held under summer conditions for 3weeks, during which its protein and lipid content decreased, while its water content increased. In P. scaber, the same occurred during the 6weeks they were kept under summer conditions. During subsequent weeks under winter conditions, changes in cold tolerance of the animals were investigated. Cold tolerance and haemolymph osmolality were measured once a week. Starved animals had lower cold tolerance than fed ones. For P. scaber a decreased haemolymph osmolality was found in starved animals compared to fed ones. This is assumed to be caused by a combination of the consumption of carbohydrates out of the haemolymph and of protein reserves and the accumulation of body water. O. cincta appeared to be capable of osmoregulation, as haemolymph osmolality did not differ between starved and fed animals, despite differences in body water content. Decreased cold tolerance in starved animals of both species may be caused by increased water content or, more probably, by the decrease in reserves needed to produce cryoprotective substances.

  18. Salicylic acid and methyl jasmonate improve chilling tolerance in cold-stored lemon fruit (Citrus limon).

    Science.gov (United States)

    Siboza, Xolani Irvin; Bertling, Isa; Odindo, Alfred Oduor

    2014-11-15

    Chilling injury (CI) is associated with the degradation of membrane integrity which can be aligned to phenolic oxidation activated by polyphenol oxidase (PPO) and peroxidase (POD), enzymes responsible for tissue browning. Phenylalanine ammonia-lyase (PAL) is a further enzyme prominent in the phenolic metabolism that is involved in acclimation against chilling stress. It was hypothesized that treatment with methyl jasmonate (MJ) and salicylic acid (SA) may enhance chilling tolerance in lemon fruit by increasing the synthesis of total phenolics and PAL by activating the key enzyme regulating the shikimic acid pathway whilst inhibiting the activity of POD and PPO. Lemon fruit were treated with 10μM MJ, 2mM SA or 10μM MJ plus 2mM SA, waxed, stored at -0.5, 2 or 4.5°C for up to 28 days plus 7 days at 23°C. Membrane integrity was studied by investigating membrane permeability and the degree of membrane lipid peroxidation in lemon flavedo following cold storage. The 10μM MJ plus 2mM SA treatment was most effective in enhancing chilling tolerance of lemon fruit, significantly reducing chilling-induced membrane permeability and membrane lipid peroxidation of lemon flavedo tissue. This treatment also increased total phenolics and PAL activity in such tissue while inhibiting POD activity, the latter possibly contributing to the delay of CI manifestation. PPO activity was found to be a poor biochemical marker of CI. Treatment with 10μM MJ plus 2mM SA resulted in an alteration of the phenolic metabolism, enhancing chilling tolerance, possibly through increased production of total phenolics and the activation of PAL and inhibition of POD.

  19. Exogenous Abscisic Acid Mimics Cold Acclimation for Cacti Differing in Freezing Tolerance.

    Science.gov (United States)

    Loik, M. E.; Nobel, P. S.

    1993-11-01

    The responses to low temperature were determined for two species of cacti sensitive to freezing, Ferocactus viridescens and Opuntia ficus-indica, and a cold hardy species, Opuntia fragilis. Fourteen days after shifting the plants from day/night air temperatures of 30/20[deg]C to 10/0[deg]C, the chlorenchyma water content decreased only for O. fragilis. This temperature shift caused the freezing tolerance (measured by vital stain uptake) of chlorenchyma cells to be enhanced only by about 2.0[deg]C for F. viridescens and O. ficus-indica but by 14.6[deg]C for O. fragilis. Also, maintenance of high water content by injection of water into plants at 10/0[deg]C reversed the acclimation. The endogenous abscisic acid (ABA) concentration was below 0.4 pmol g-1 fresh weight at 30/20[deg]C, but after 14 d at 10/0[deg]C it increased to 84 pmol g-1 fresh weight for O. ficus-indica and to 49 pmol g-1 fresh weight for O. fragilis. Four days after plants were sprayed with 7.5 x 10-5 M ABA at 30/20[deg]C, freezing tolerance was enhanced by 0.5[deg]C for F. viridescens, 4.1[deg]C for O. ficus-indica, and 23.4[deg]C for O. fragilis. Moreover, the time course for the change in freezing tolerance over 14 d was similar for plants shifted to low temperatures as for plants treated with exogenous ABA at moderate temperatures. Decreases in plant water content and increases in ABA concentration may be important for low-temperature acclimation by cacti, especially O. fragilis, which is widely distributed in Canada and the United States.

  20. 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...

  1. Root transcriptomes of two acidic soil adapted Indica rice genotypes suggest diverse and complex mechanism of low phosphorus tolerance.

    Science.gov (United States)

    Tyagi, Wricha; Rai, Mayank

    2017-03-01

    Low phosphorus (P) tolerance in rice is a biologically and agronomically important character. Low P tolerant Indica-type rice genotypes, Sahbhagi Dhan (SD) and Chakhao Poreiton (CP), are adapted to acidic soils and show variable response to low P levels. Using RNAseq approach, transcriptome data was generated from roots of SD and CP after 15 days of low P treatment to understand differences and similarities at molecular level. In response to low P, number of genes up-regulated (1318) was more when compared with down-regulated genes (761). Eight hundred twenty-one genes found to be significantly regulated between SD and CP in response to low P. De novo assembly using plant database led to further identification of 1535 novel transcripts. Functional annotation of significantly expressed genes suggests two distinct methods of low P tolerance. While root system architecture in SD works through serine-threonine kinase PSTOL1, suberin-mediated cell wall modification seems to be key in CP. The transcription data indicated that CP relies more on releasing its internally bound Pi and coping with low P levels by transcriptional and translational modifications and using dehydration response-based signals. Role of P transporters seems to be vital in response to low P in CP while sugar- and auxin-mediated pathway seems to be preferred in SD. At least six small RNA clusters overlap with transcripts highly expressed under low P, suggesting role of RNA super clusters in nutrient response in plants. These results help us to understand and thereby devise better strategy to enhance low P tolerance in Indica-type rice.

  2. Selection efficiencies for improving drought/salt tolerances and yield using introgression breeding in rice(Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    Ying; Wang; Lubiao; Zhang; Afif; Nafisah; Linghua; Zhu; Jianlong; Xu; Zhikang; Li

    2013-01-01

    The backcross(BC) breeding strategy has been increasingly used for developing high yielding varieties with improved abiotic stress tolerances in rice. In this study, 189Huang-Hua-Zhan(HHZ) introgression lines(ILs) developed from three different selection schemes were evaluated for yield related traits under drought stress and non-stress conditions in the target and off-season winter nursery environments to assess the selection efficiency of BC breeding for improving different complex traits, and led us to five important results. The first result indicated that the primary target traits should be selected first in the target environments(TEs) in order to achieve the maximum genetic gain. Secondly, BC breeding for drought tolerance(DT) in rice was almost equally effective by strong phenotypic selection in the main target environments and in the winter-season of Hainan.Thirdly, exploiting genetic diversity in the subspecific gene pools is of great importance for future genetic improvement of complex traits in rice. Fourthly, considerable genetic gain can be effectively achieved by selection for secondary target traits among the ILs with the primary traits. Finally, the developed ILs provide useful materials for future genetic/genomic dissection and molecular breeding of complex traits.

  3. Zinc up-regulated the expression of the rice metallonthionein gene family and enhanced the zinc tolerance of yeast cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Northern blot and functional complementation assay were employed to analyze the effects of zinc on expression of ten rice metallothionein genes (OsMT-Is) in rice seedlings and the growth of yeast cells transformed with OsMT-Is. Northern blot revealed that in shoots of the rice seedlings treated with different Zn2+ concentrations, expression of most members of OsMT-I family was increased, except the type 4 OsMT-Is (OsMT-I-4a, 4b and 4c). In roots, Zn2+ significantly increased the transcription of OsMT-I-1b and OsMT-I-2c, but reduced the trascription of OsMT-I-1a and OsMT-I-3a. When these ten cDNAs were heterologously expressed in zinc sensitive yeast mutant, all transgenic yeasts showed increased tolerance to Zn2+, and zinc accumulation in these yeast cells also increased.These indicated that OsMT-I family members might respond to extra Zn2+, and they could enhance Zn2+ tolerance of cells by direct binding Zn2+.

  4. The Effect of Spermidine on Cold Tolerance Induction in Cucumber Seedlings ‘Cv. Super-Dominus’

    Directory of Open Access Journals (Sweden)

    Golnar GhazianTafrishi

    2017-02-01

    Full Text Available Introduction: Plants native to tropical and subtropical climates which grown in the temperate climate zone, suffer chilling injury when exposed to non-freezing temperatures for a certain period of time. The optimum growth temperature for cucumber (a tropical plant is 20 to 25°C. Cucumber is sensitive to temperatures lower than 10 °C. Cucumber area of production exposes to late spring and early autumn cold weather in Khorasan-e-Razavai, Iran. Studies showed that chilling leads to an alteration in fatty acid composition of membrane lipids and its permeability, changes in photosynthetic pigments content and decrease in photosynthesis. Many researchers pointed to a possible role of polyamine compounds in plant defense against environmental stresses. Exog enous application Spd could prevent the electrolyte and amino acid leakage or recovering the plasma membrane damage in rice and cucumber in response to salinity, chilling and water stressed conditions. Materials and methods: A factorial experiment, based on completely randomized design was conducted to investigate the effect of short-term chilling on cucumber plantlets which was earlier treated with spermidine. Factors were included two levels of temperature (6 and 12°C and four levels of spermidine (0, 0.25, 0.5 and .0.75 mg/L. The studied cultivar was ‘Super-Dominus’. In order to determine the extent of chilling injury, plants of each treatment were rated based on visual symptoms. By assigning values of 1, 2, 3, 4, and 5 while 1: no visible symptoms 2:5% of leaf area necrotic, 3: 5-25% of leaf area necrotic, 4: 26-50% of leaf area necrotic but plant still alive, 5: lost, entire plant necrotic and collapsed. Measured traits were root and shoot length, root and shoot dry weight, root and leaf electrical leakage, and leaf chlorophyll content. Results and discussion: Plants which exposed to low temperature showed chilling injury symptoms (5-25% leaf area necrotic. The symptoms reduced (less

  5. Variation in tolerance of rice to long-term stagnant flooding that submerges most of the shoot will aid in breeding tolerant cultivars.

    Science.gov (United States)

    Vergara, Georgina V; Nugraha, Yudhistira; Esguerra, Manuel Q; Mackill, David J; Ismail, Abdelbagi M

    2014-09-08

    Stagnant flooding (SF) is a major problem in rainfed lowlands where floodwater of 25-50 cm stagnates in the field for most of the season. We aimed to establish a system for phenotyping SF tolerance and identifying tolerant germplasm through screening of landraces. A total of 626 rice accessions were evaluated over 3 years under control conditions and two levels of SF. Floodwater was raised to 20 cm at 25 or 30 days after transplanting (DAT). In one trial, the depth was increased subsequently by 5 cm a week and in another (severe stress), it was increased to 40 cm at 37 DAT and to 50 cm at 42 DAT. In both trials, water depth was maintained at 50-60 cm until maturity. In all cases, no plant was completely submerged. Plant height, elongation rate and yield were measured at maturity. Genotypes best suited to SF showed moderate elongation of 1.3-2.3 cm day(-1) under SF. In contrast, semi-dwarf and fast-elongating types performed poorly. Subsequent trials using 18 genotypes, including six pairs of near isogenic lines (NILs) with or without SUB1 showed that all SUB1 NILs were sensitive to SF. Five of the other six genotypes contained SUB1 and were SF tolerant, suggesting the possibility of combining tolerances to complete submergence (SUB1) and SF. Stem starch and soluble sugar concentrations were similar under control conditions among the 18 genotypes, but starch was depleted by 37 % under SF, with less depletion in tolerant genotypes. SUB1 NILs contained similar concentrations of starch and sugars under SF. We conclude that survival and yield under SF are dependent on moderate elongation, high tillering, lesser carbohydrate depletion and higher fertility. The tolerant genotypes identified here performed strongly in both wet and dry seasons and will be used to identify tolerance mechanisms and alleles for use in marker-assisted breeding.

  6. [Influence of paddy rice-upland crop rotation of cold-waterlogged paddy field on crops produc- tion and soil characteristics].

    Science.gov (United States)

    Wang, Fei; Li, Qing-hua; Lin, Cheng; He, Chun-mei; Zhong, Shao-jie; Li, Yu; Lin, Xin-jian; Huang, Jian-cheng

    2015-05-01

    Two consecutive years (4-crop) experiments were conducted to study the influence of different paddy rice-upland crop rotation in cold-waterlogged paddy field on the growth of crops and soil characteristics. The result showed that compared with the rice-winter fallow (CK) pattern, the two-year average yield of paddy rice under four rotation modes, including rape-rice (R-R), spring corn-rice (C-R), Chinese milk vetch-rice (M-R) and bean-rice (B-R), were increased by 5.3%-26.7%, with significant difference observed in C-R and R-R patterns. Except for M-R pattern, the annual average total economic benefits were improved by 79.0%-392.4% in all rotation pattern compared with the CK, and the ration of output/input was enhanced by 0.06-0.72 unit, with the most significant effect found in the C-R pattern. Likewise, compared with the CK, the contents of chlorophyll and carotenoid, and net photosynthetic rate (Pn) of rice plant were all increased during the full-tillering stage of rice in all rotation patterns. The rusty lines and rusty spots of soils were more obvious compared with the CK during the rice harvest, particularly in R-R, C-R and B-R patterns. The ratio of water-stable soil macro aggregates of plough layer of soil (> 2 mm) decreased at different levels in all rotation patterns while the ratios of middle aggregate (0.25-2 mm, expect for M-R) and micro aggregate of soil (benefits, and soil physical and chemical properties were improved.

  7. Degradation of transgene DNA in genetically modified herbicide-tolerant rice during food processing.

    Science.gov (United States)

    Song, Shangxin; Zhou, Guanghong; Gao, Feng; Zhang, Wei; Qiu, Liangyan; Dai, Sifa; Xu, Xinglian; Xiao, Hongmei

    2011-12-01

    In order to assess the effect of food processing on the degradation of exogenous DNA components in sweet rice wine and rice crackers made from genetically modified (GM) rice (Oryza sativa L.), we developed genomic DNA extraction methods and compared the effect of different food processing procedures on DNA degradation. It was found that the purity, quantity and quality of DNA by alkaline lysis method were higher than by CTAB (cetyltrimethylammonium bromide) method. For sweet rice wine, CAMV35S (cauliflower mosaic virus 35S) promoter and NOS (nopaline synthase) terminator were degraded by the third day, whereas the exogenous gene Bar (bialaphos resistance) remained unaffected. For rice crackers, boiling, drying and microwaving contributed to the initial degradations of DNA. Baking resulted in further degradations, and frying led to the most severe changes. These results indicated that the stability of DNA in GM rice was different under different processing conditions. For sweet rice wine, Bar was most stable, followed by NOS, CAMV35S, and SPS. For rice crackers, CAMV35S was most stable, followed by SPS, NOS, and Bar.

  8. Leaf gas films contribute to rice (Oryza sativa) submergence tolerance during saline floods

    DEFF Research Database (Denmark)

    Herzog, Max; Konnerup, Dennis; Pedersen, Ole

    2017-01-01

    Floods and salinization of agricultural land adversely impact global rice production. We investigated whether gas films on leaves of submerged rice delay salt entry during saline submergence. Two-week-old plants with leaf gas films (+GF) or with gas films experimentally removed (-GF) were submerged...

  9. Elicitor-Induced Biochemical and Molecular Manifestations to Improve Drought Tolerance in Rice (Oryza sativa L.) through Seed-Priming

    Science.gov (United States)

    Samota, Mahesh K.; Sasi, Minnu; Awana, Monika; Yadav, Om P.; Amitha Mithra, S. V.; Tyagi, Aruna; Kumar, Suresh; Singh, Archana

    2017-01-01

    Rice (Oryza sativa L.) is one of the major grain cereals of the Indian subcontinent which face water-deficit stress for their cultivation. Seed-priming has been reported to be a useful approach to complement stress responses in plants. In the present study, seed-priming with hormonal or chemical elicitor [viz. methyl jasmonate (MJ), salicylic acid (SA), paclobutrazol (PB)] showed significant increase in total phenolic content, antioxidant activity and expression of Rice Drought-responsive (RD1 and RD2) genes (of AP2/ERF family) in contrasting rice genotypes (Nagina-22, drought-tolerant and Pusa Sugandh-5, drought-sensitive) under drought stress. However, decrease in lipid peroxidation and protein oxidation was observed not only under the stress but also under control condition in the plants raised from primed seeds. Expression analyses of RD1 and RD2 genes showed upregulated expression in the plants raised from primed seeds under drought stress. Moreover, the RD2 gene and the drought-sensitive genotype showed better response than that of the RD1 gene and the drought-tolerant genotype in combating the effects of drought stress. Among the elicitors, MJ was found to be the most effective for seed-priming, followed by PB and SA. Growth and development of the plants raised from primed seeds were found to be better under control and drought stress conditions compared to that of the plants raised from unprimed seeds under the stress. The present study suggests that seed-priming could be one of the useful approaches to be explored toward the development of simple, cost-effective and farmer-friendly technology to enhance rice yield in rainfed areas. PMID:28634483

  10. Development of herbicide-tolerant irrigated rice cultivars Desenvolvimento de cultivares de arroz irrigado tolerantes a herbicida

    Directory of Open Access Journals (Sweden)

    Paulo Hideo Nakano Rangel

    2010-07-01

    Full Text Available The objective of this work was to develop new irrigated rice lines tolerant to imidazolinone herbicides. The backcross breeding procedure was used to transfer the imidazolinone tolerance allele from mutant 93AS3510 to the recurrent parents 'BRS 7 Taim' and 'BRS Pelota'. Individual herbicide-tolerant plants were selected in each generation, for three backcrossings (RC1 to RC3, followed by three selfing generations (RC3F1 to RC3F3. The best four RC3F3 lines for agronomic traits were genotyped with 44 microsatellite markers. The observed conversion index of the new imidazolinone-tolerant lines varied from 91.86 to 97.67%. Pairwise genetic distance analysis between these lines and 22 accessions from the Embrapa's Rice Germplasm Bank clustered the new lines with their respective recurrent parents, but not with 'IRGA 417', which was originally used as recurrent parent to derive IRGA 422 CL, the only imidazolinone-tolerant irrigated rice cultivar recommended for cultivation in Brazil. Therefore, these lines represent new options of genetically diverse imidazolinone-tolerant rice accessions. Lines CNA10756 ('BRS Sinuelo CL' and CNA10757 will be released for cultivation in the Clearfield irrigated rice production system in Rio Grande do Sul, Brazil.O objetivo deste trabalho foi desenvolver novas linhagens de arroz irrigado tolerantes ao herbicida imidazolinona. O método de retrocruzamento foi usado para transferir o alelo de tolerância à imidazolinona do mutante 93AS3510 para os genitores recorrentes 'BRS 7 Taim' e 'BRS Pelota'. Indivíduos tolerantes ao herbicida foram selecionados em cada geração, por três gerações de retrocruzamento (RC1 a RC3, seguidas por três gerações de autofecundação (RC3F1 a RC3F3. As quatro melhores linhagens RC3F3 quanto às características agronômicas foram genotipadas com 44 marcadores microssatélites. O índice de conversão observado nas novas linhagens tolerantes à imidazolinona variou de 91,86 a 97

  11. GID1 modulates stomatal response and submergence tolerance involving abscisic acid and gibberellic acid signaling in rice.

    Science.gov (United States)

    Du, Hao; Chang, Yu; Huang, Fei; Xiong, Lizhong

    2015-11-01

    Plant responses to abiotic stresses are coordinated by arrays of growth and developmental programs. Gibberellic acid (GA) and abscisic acid (ABA) play critical roles in the developmental programs and environmental responses, respectively, through complex signaling and metabolism networks. However, crosstalk between the two phytohormones in stress responses remains largely unknown. In this study, we report that GIBBERELLIN-INSENSITIVE DWARF 1 (GID1), a soluble receptor for GA, regulates stomatal development and patterning in rice (Oryza sativa L.). The gid1 mutant showed impaired biosynthesis of endogenous ABA under drought stress conditions, but it exhibited enhanced sensitivity to exogenous ABA. Scanning electron microscope and infrared thermal image analysis indicated an increase in the stomatal conductance in the gid1 mutant under drought conditions. Interestingly, the gid1 mutant had increased levels of chlorophyll and carbohydrates under submergence conditions, and showed enhanced reactive oxygen species (ROS)-scavenging ability and submergence tolerance compared with the wild-type. Further analyses suggested that the function of GID1 in submergence responses is partially dependent on ABA, and GA signaling by GID1 is involved in submergence tolerance by modulating carbohydrate consumption. Taken together, these findings suggest GID1 plays distinct roles in stomatal response and submergence tolerance through both the ABA and GA signaling pathways in rice.

  12. Arsenite tolerance in rice (Oryza sativa L.) involves coordinated role of metabolic pathways of thiols and amino acids.

    Science.gov (United States)

    Tripathi, Preeti; Tripathi, Rudra Deo; Singh, Rana Pratap; Dwivedi, Sanjay; Chakrabarty, Debasis; Trivedi, Prabodh K; Adhikari, Bijan

    2013-02-01

    Thiolic ligands and several amino acids (AAs) are known to build up in plants against heavy metal stress. In the present study, alteration of various AAs in rice and its synchronized role with thiolic ligand was explored for arsenic (As) tolerance and detoxification. To understand the mechanism of As tolerance and stress response, rice seedlings of one tolerant (Triguna) and one sensitive (IET-4786) cultivar were exposed to arsenite (0-25 μM) for 7 days for various biochemical analyses using spectrophotometer, HPLC and ICPMS. Tolerant and sensitive cultivars respond differentially in terms of thiol metabolism, essential amino acids (EEAs) and nonessential amino acids (NEEAs) vis-á-vis As accumulation. Thiol biosynthesis-related enzymes were positively correlated to As accumulation in Triguna. Conversely, these enzymes, cysteine content and GSH/GSSG ratio declined significantly in IET-4786 upon As exposure. The level of identified phytochelatin (PC) species (PC(2), PC(3) and PC(4)) and phytochelatin synthase activity were also more pronounced in Triguna than IET-4786. Nearly all EAAs were negatively affected by As-induced oxidative stress (except phenylalanine in Triguna), but more significantly in IET-4786 than Triguna. However, most of the stress-responsive NEAAs like glutamic acid, histidine, alanine, glycine, tyrosine, cysteine and proline were enhanced more prominently in Triguna than IET-4786 upon As exposure. The study suggests that IET-4786 appears sensitive to As due to reduction of AAs and thiol metabolic pathway. However, a coordinated response of thiolic ligands and stress-responsive AAs seems to play role for As tolerance in Triguna to achieve the effective complexation of As by PCs.

  13. Orthologs of the class A4 heat shock transcription factor HsfA4a confer cadmium tolerance in wheat and rice.

    Science.gov (United States)

    Shim, Donghwan; Hwang, Jae-Ung; Lee, Joohyun; Lee, Sichul; Choi, Yunjung; An, Gynheung; Martinoia, Enrico; Lee, Youngsook

    2009-12-01

    Cadmium (Cd) is a widespread soil pollutant; thus, the underlying molecular controls of plant Cd tolerance are of substantial interest. A screen for wheat (Triticum aestivum) genes that confer Cd tolerance to a Cd hypersensitive yeast strain identified Heat shock transcription factor A4a (HsfA4a). Ta HsfA4a is most similar to the class A4 Hsfs from monocots. The most closely related rice (Oryza sativa) homolog, Os HsfA4a, conferred Cd tolerance in yeast, as did Ta HsfA4a, but the second most closely related rice homolog, Os HsfA4d, did not. Cd tolerance was enhanced in rice plants expressing Ta HsfA4a and decreased in rice plants with knocked-down expression of Os HsfA4a. An analysis of the functional domain using chimeric proteins constructed from Ta HsfA4a and Os HsfA4d revealed that the DNA binding domain (DBD) of HsfA4a is critical for Cd tolerance, and within the DBD, Ala-31 and Leu-42 are important for Cd tolerance. Moreover, Ta HsfA4a-mediated Cd resistance in yeast requires metallothionein (MT). In the roots of wheat and rice, Cd stress caused increases in HsfA4a expression, together the MT genes. Our findings thus suggest that HsfA4a of wheat and rice confers Cd tolerance by upregulating MT gene expression in planta.

  14. Contribution of seedling vigour and anoxia/hypoxia-responsive genes to submergence tolerance in Vietnamese lowland rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Hien Thi Thu Vu

    2016-09-01

    Full Text Available A direct-seeded rice cultivation system has been widely adopted in Asian countries. Optimum germination and vigorous seedling growth under submergence are key traits for the practice of direct seeding. We studied the post-germination seedling vigour in Vietnamese lowland rice accessions based on three bio-parameters, shoot elongation growth under five-day submergence in water-filled test-tubes, seedling recovery rate five days after transferring submerged seedlings to pots with soil and seedling survival rate 21 days after sowing seeds in nursery beds and immediate incubation under submergence. A large diversity was found in seedling vigour thus estimated among the accessions. Significantly high correlations were observed among all three bio-parameters, verifying the contribution of seedling vigour to the manifestation of submergence tolerance at this critical stage of rice development. To examine the roles of anoxia/hypoxia-responsive genes, the expression of 17 candidate genes was studied by reverse transcription polymerase chain reaction (RT-PCR and compared between selected vigorous and non-vigorous groups of accessions. Transcripts of all but two genes showed marked accumulation in submerged seedlings. No differences, however, were found between the two contrasting groups. The observed common and coordinate expression of anoxia/hypoxia-induced genes suggests that they might assume roles in attaining baseline tolerance against submergence stress. It was also suggested that some unknown genetic factors are operating in determining cultivar/genotype-specific levels of submergence tolerance as assessed by post-germination seedling vigour.

  15. Agro-Morphological Evaluation of Rice (Oryza sativa L. for Seasonal Adaptation in the Sahelian Environment

    Directory of Open Access Journals (Sweden)

    Daba Ndour

    2016-02-01

    Full Text Available In the Sahel zone of West Africa that extends from Senegal to Chad, temperatures can vary from less than 15 °C to 25 °C from November to February. These low temperatures affect the growth, development and yield of rice plants, and therefore constitute a major constraint to rice production in the Sahel. In order to identify rice varieties tolerant to cold stress at different developmental stages, a diverse set of 224 rice germplasm was evaluated for yield and yield-related traits in Ndiaye, Senegal, using three different sowing dates. The first sowing date (October 2010, was chosen so as to expose the rice plants to cold stress at the reproductive stage while the rice crop planted at the second sowing date (January 2011 experienced cold stress at the vegetative stage. The third sowing date (July 2011 was the normal planting date for irrigated rice in the Sahel and it served as the control date when the crop does not experience any cold stress throughout its growth cycle. Among the data collected, significant genetic variation was detected and genotype-by-environment interaction was also significant for the traits. At the vegetative stage, cold stress reduced tillering and plant vigor and delayed flowering but increased yield, whereas at the reproductive stage, aside from delaying flowering, cold stress also inhibited panicle exsertion and reduced panicle length, spikelet fertility, grain filling and strongly reduced yields. Principal Component Analysis and correlation analysis using agro-morphological traits helped to identify genotypes that were tolerant to cold stress at either the vegetative or the reproductive stage and the traits associated with high yield under cold stress at each of these stages. Our results can be used to develop cold tolerant rice varieties adapted to double cropping in the Sahelian zone of West Africa.

  16. Detection on Cold Tolerance and Analysis on Polymorphic SSR in Oryza rufipogon Griff.Indigenous to Gaozhou, Guangdong%高州普通野生稻苗期耐寒性鉴定及其SSR多态标记分析

    Institute of Scientific and Technical Information of China (English)

    王兰; 蔡东长

    2011-01-01

    Cold damage at seedling stage is one of the major factors for reducing the rice products. Gaozhou wild rice (Oryza rufipogon Griff) possesses abundant genetic diversity, and perhaps which carries some strong cold-tolerant genes. In this study,cold-tolerant ability was detected at seedling stage in Gaozhou wild rice,and of which two numbers( GZW5 and GZW18)was identified to have strong cold-tolerant ability. Then the polymorphism markers were screened between Gaozhou wild rice with strong cold resistance and its control Sanbaili with cold sensitive by using 225 simple sequence repeat( SSR) markers even distributing on 12 pairs of chromosomes in rice. A total of 83 pairs of SSR markers were identified to have polymorphism, and the polymorphic ratio was 36. 9 percent. These polymorphic markers distributed equally on the chromosomes in rice except the chromosome 5,10 and 12,which only of 4,3 and 4 polymorphic markers,respectively. The hybrid F1 was constructed between Gaozhou wild rice and Sanbaili , and the genotype of its F2 individuals was investigated using some of the polymorphism markers, and in F2 groups these markers generated obviously separation, so we predicted these markers may be linkage with some cold tolerant genes. Our results will provide a basis for mapping the cold-tolerant genes at seedling stage in Gaozhou wild rice and researching further the molecular mechanism of their actions.%水稻苗期寒害是引起水稻产量下降的主要因素之一.高州普通野生稻具有丰富的遗传多样性,可能蕴含苗期强耐寒基因.本研究通过苗期耐寒性鉴定,初步鉴定出2个编号(GZW5、GZW18)的高州普通野生稻具有苗期强耐寒性.利用平均分布于水稻12条染色体的225对SSR标记,对耐寒的高州普通野生稻与对照水稻不耐寒品种三百粒之间进行多态性筛选,共筛出83对引物具有SSR标记的多态性,多态率为36.9%.这些多态标记在第5,10,12号染色体上

  17. A previously unknown zinc finger protein, DST, regulates drought and salt tolerance in rice via stomatal aperture control.

    Science.gov (United States)

    Huang, Xin-Yuan; Chao, Dai-Yin; Gao, Ji-Ping; Zhu, Mei-Zhen; Shi, Min; Lin, Hong-Xuan

    2009-08-01

    Abiotic stresses, such as drought and salinity, lead to crop growth damage and a decrease in crop yields. Stomata control CO(2) uptake and optimize water use efficiency, thereby playing crucial roles in abiotic stress tolerance. Hydrogen peroxide (H(2)O(2)) is an important signal molecule that induces stomatal closure. However, the molecular pathway that regulates the H(2)O(2) level in guard cells remains largely unknown. Here, we clone and characterize DST (drought and salt tolerance)-a previously unknown zinc finger transcription factor that negatively regulates stomatal closure by direct modulation of genes related to H(2)O(2) homeostasis-and identify a novel pathway for the signal transduction of DST-mediated H(2)O(2)-induced stomatal closure. Loss of DST function increases stomatal closure and reduces stomatal density, consequently resulting in enhanced drought and salt tolerance in rice. These findings provide an interesting insight into the mechanism of stomata-regulated abiotic stress tolerance, and an important genetic engineering approach for improving abiotic stress tolerance in crops.

  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 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 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

  19. UV and cold tolerance of a pigment-producing Antarctic Janthinobacterium sp. Ant5-2

    KAUST Repository

    Mojib, Nazia

    2013-03-20

    In this paper, we describe the UV and cold tolerance of a purple violet pigment (PVP)-producing Antarctic bacterium, Janthinobacterium sp. Ant5-2 (PVP+) and compared its physiological adaptations with a pigmentless mutant strain (PVP-). A spontaneous deletion of vioA that codes for tryptophan monooxygenase, the first gene involved in the biosynthesis of PVP was found in PVP- strain. The PVP- culture exhibited significantly reduced survival during exponential and stationary growth phase following exposure to UVB (320 nm) and UVC (254 nm) (dose range: 0-300 J/m2) when compared to wild-type (PVP+) cultures. In addition, upon biochemical inhibition of pigment synthesis by 2(5H)-furanone, wild-type PVP+ cultures exhibited approximately 50-fold growth reduction at a higher dose (300 J/m2) of UV. Increased resistance to UV was observed upon inducing starvation state in both PVP+ and PVP- cultures. There was 80 % (SD = ±8) reduction in extrapolymeric substance (EPS) production in the PVP- cultures along with a compromised survival to freeze-thaw cycles when compared to the PVP+ cultures. Perhaps synthesis of PVP and EPS are among the key adaptive features that define the survival of this bacterium in Antarctic extreme conditions, especially during austral summer months. © 2013 Springer Japan.

  20. High thermal tolerance of two Mediterranean cold-water coral species maintained in aquaria

    Science.gov (United States)

    Naumann, M. S.; Orejas, C.; Ferrier-Pagès, C.

    2013-09-01

    In the Mediterranean deep-sea, scleractinian cold-water corals (CWC) are observed to survive at the uppermost end of their presumed thermal distribution range (4-13 °C). Here, we show that 2 common CWC species (i.e. Dendrophyllia cornigera and Desmophyllum dianthus) maintained in aquaria can indeed tolerate considerably elevated seawater temperatures (17.5 ± 0.1 °C), while growing at similar ( D. dianthus) or significantly higher ( D. cornigera) rates than conspecifics cultured in parallel for 87 days at ambient Mediterranean deep-sea temperature (12.5 ± 0.1 °C). Neither differences in coral appearance nor mortality were evident for both species at either temperature. D. dianthus grew significantly faster (0.23 ± 0.08 % day-1) than D. cornigera (0.05 ± 0.01 % day-1) under ambient thermal conditions. Growth of D. cornigera increased significantly (0.14 ± 0.07 % day-1) at elevated temperature, while Desmophyllum dianthus growth showed no significant difference under both conditions. These findings suggest that D. dianthus and D. cornigera may be capable of surviving in warmer environments than previously reported, and thus challenge temperature as the paramount limiting environmental factor for the occurrence of some CWC species.

  1. Generation of insect-resistant and glyphosate-tolerant rice by introduction of a T-DNA containing two Bt insecticidal genes and an EPSPS gene.

    Science.gov (United States)

    Zhao, Qi-chao; Liu, Ming-hong; Zhang, Xian-wen; Lin, Chao-yang; Zhang, Qing; Shen, Zhi-cheng

    2015-10-01

    Insect resistance and glyphosate tolerance have been two of the most important traits in the genetic improvement of various crops. In this study, two Bacillus thuringiensis (Bt) insecticidal genes, Cry1Ac and Cry1Ig, and a modified glyphosate-tolerant 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene (G10) were combined into a single transferred DNA (T-DNA) fragment and introduced into rice by Agrobacterium-mediated transformation. A transgenic line with single-copy T-DNA insertion named GAI-14 was found to be highly resistant to striped stem borer and rice leaf roller, and tolerant to glyphosate. Analysis of T-DNA border sequence suggested that the transgenes were inserted at the chromosome 3 and appeared to have not interrupted any known or putative genes. A field trial observed no significant difference in the basic agronomic traits between GAI-14 and the recipient rice.

  2. Expression of OsDREB2A transcription factor confers enhanced dehydration and salt stress tolerance in rice (Oryza sativa L.).

    Science.gov (United States)

    Mallikarjuna, Garladinne; Mallikarjuna, Kokkanti; Reddy, M K; Kaul, Tanushri

    2011-08-01

    Stress responsive transcriptional regulation is an adaptive strategy of plants that alleviates the adverse effects of environmental stresses. The ectopic overexpression of Dehydration-Responsive Element Binding transcription factors (DREBs) either in homologous or in heterologous plants improved stress tolerance indicating the DRE/DREB regulon is conserved across plants. We developed 30 transgenic T(0) rice plants overexpressing OsDREB2A which were devoid of any growth penalty or phenotypic abnormalities during stressed or non-stressed conditions. Integration of T-DNA in the rice genome and stress inducible overexpression of OsDREB2A had occurred in these transgenic lines. Functional analyses of T(1)-3 and T(1)-10 lines revealed significant tolerance to osmotic, salt and dehydration stresses during simulated stress conditions with enhanced growth performance as compared to wild type. OsDREB2A, thus, confers stress tolerance in homologous rice system that failed in the heterologous Arabidopsis system earlier.

  3. Identification of candidate genes for drought stress tolerance in rice by the integration of a genetic (QTL) map with the rice genome physical map

    Institute of Scientific and Technical Information of China (English)

    WANG Xu-sheng; ZHU Jun; MANSUETO Locedie; BRUSKIEWICH Richard

    2005-01-01

    Genetic improvement for drought stress tolerance in rice involves the quantitative nature of the trait, which reflects the additive effects of several genetic loci throughout the genome. Yield components and related traits under stressed and well-water conditions were assayed in mapping populations derived from crosses of Azucena×IR64 and Azucena×Bala. To find the candidate rice genes underlying Quantitative Trait Loci (QTL) in these populations, we conducted in silico analysis of a candidate region flanked by the genetic markers RM212 and RM319on chromosome 1, proximal to the semi-dwarf (sd1) locus. A total of 175annotated genes were identified from this region. These included 48 genes annotated by functional homology to known genes, 23pseudogenes, 24 ab initio predicted genes supported by an alignment match to an EST (Expressed sequence tag) of unknown function, and 80 hypothetical genes predicted solely by ab initio means. Among these, 16 candidate genes could potentially be involved in drought stress response.

  4. Rice cyclophilin OsCYP18-2 is translocated to the nucleus by an interaction with SKIP and enhances drought tolerance in rice and Arabidopsis.

    Science.gov (United States)

    Lee, Sang Sook; Park, Hyun Ji; Yoon, Dae Hwa; Kim, Beom-Gi; Ahn, Jun Cheul; Luan, Sheng; Cho, Hye Sun

    2015-10-01

    Cyclophilin 18-2 (CYP18-2) genes, homologues of human peptidyl-prolyl isomerase-like 1 (PPiL1), are conserved across multicellular organisms and Schizosaccharomyces pombe. Although PPiL1 is known to interact with ski-interacting protein (SKIP), a transcriptional co-regulator and spliceosomal component, there have been no functional analyses of PPiL1 homologues in plants. Rice cyclophilin 18-2 (OsCYP18-2) bound directly to amino acids 56-95 of OsSKIP and its binding was independent of cyclosporin A, a cyclophilin-binding drug. Moreover, OsCYP18-2 exhibited PPIase activity regardless of its interaction with OsSKIP. Therefore, the binding site for OsCYP18-2's interaction with SKIP was distinct from the PPIase active site. OsCYP18-2's interaction with SKIP full-length protein enabled OsCYP18-2's translocation from the cytoplasm into the nucleus and AtSKIP interacted in planta with both AtCYP18-2 and OsCYP18-2. Drought and salt stress induced similar expression of OsCYP18-2 and OsSKIP. Overexpression of OsCYP18-2 in transgenic rice and Arabidopsis thaliana plants enhanced drought tolerance and altered expression and pre-mRNA splicing patterns of stress-related genes in Arabidopsis under drought conditions. Furthermore, OsCYP18-2 caused transcriptional activation with/without OsSKIP in the GAL4 system of yeast; thus the OsSKIP-OsCYP18-2 interaction has an important role in the transcriptional and post-transcriptional regulation of stress-related genes and increases tolerance to drought stress.

  5. Salinity tolerance loci revealed in rice using high-throughput non-invasive phenotyping

    KAUST Repository

    Al-Tamimi, Nadia

    2016-11-17

    High-throughput phenotyping produces multiple measurements over time, which require new methods of analyses that are flexible in their quantification of plant growth and transpiration, yet are computationally economic. Here we develop such analyses and apply this to a rice population genotyped with a 700k SNP high-density array. Two rice diversity panels, indica and aus, containing a total of 553 genotypes, are phenotyped in waterlogged conditions. Using cubic smoothing splines to estimate plant growth and transpiration, we identify four time intervals that characterize the early responses of rice to salinity. Relative growth rate, transpiration rate and transpiration use efficiency (TUE) are analysed using a new association model that takes into account the interaction between treatment (control and salt) and genetic marker. This model allows the identification of previously undetected loci affecting TUE on chromosome 11, providing insights into the early responses of rice to salinity, in particular into the effects of salinity on plant growth and transpiration.

  6. Recent advances in the dissection of drought-stress regulatory networks and strategies for development of drought-tolerant transgenic rice plants.

    Science.gov (United States)

    Todaka, Daisuke; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

    2015-01-01

    Advances have been made in the development of drought-tolerant transgenic plants, including cereals. Rice, one of the most important cereals, is considered to be a critical target for improving drought tolerance, as present-day rice cultivation requires large quantities of water and as drought-tolerant rice plants should be able to grow in small amounts of water. Numerous transgenic rice plants showing enhanced drought tolerance have been developed to date. Such genetically engineered plants have generally been developed using genes encoding proteins that control drought regulatory networks. These proteins include transcription factors, protein kinases, receptor-like kinases, enzymes related to osmoprotectant or plant hormone synthesis, and other regulatory or functional proteins. Of the drought-tolerant transgenic rice plants described in this review, approximately one-third show decreased plant height under non-stressed conditions or in response to abscisic acid treatment. In cereal crops, plant height is a very important agronomic trait directly affecting yield, although the improvement of lodging resistance should also be taken into consideration. Understanding the regulatory mechanisms of plant growth reduction under drought stress conditions holds promise for developing transgenic plants that produce high yields under drought stress conditions. Plant growth rates are reduced more rapidly than photosynthetic activity under drought conditions, implying that plants actively reduce growth in response to drought stress. In this review, we summarize studies on molecular regulatory networks involved in response to drought stress. In a separate section, we highlight progress in the development of transgenic drought-tolerant rice plants, with special attention paid to field trial investigations.

  7. Recent advances in the dissection of drought-stress regulatory networks and strategies for development of drought-tolerant transgenic rice plants

    Directory of Open Access Journals (Sweden)

    Daisuke eTodaka

    2015-02-01

    Full Text Available Advances have been made in the development of drought-tolerant transgenic plants, including cereals. Rice, one of the most important cereals, is considered to be a critical target for improving drought tolerance, as present-day rice cultivation requires large quantities of water and as drought-tolerant rice plants should be able to grow in small amounts of water. Numerous transgenic rice plants showing enhanced drought tolerance have been developed to date. Such genetically engineered plants have generally been developed using genes encoding proteins that control drought regulatory networks. These proteins include transcription factors, protein kinases, receptor-like kinases, enzymes related to osmoprotectant or plant hormone synthesis, and other regulatory or functional proteins. Of the drought-tolerant transgenic rice plants described in this review, approximately one-third show decreased plant height under non-stressed conditions or in response to abscisic acid treatment. In cereal crops, plant height is a very important agronomic trait directly affecting yield, although the improvement of lodging resistance should also be taken into consideration. Understanding the regulatory mechanisms of plant growth reduction under drought stress conditions holds promise for developing transgenic plants that produce high yields under drought stress conditions. Plant growth rates are reduced more rapidly than photosynthetic activity under drought conditions, implying that plants actively reduce growth in response to drought stress. In this review, we summarize studies on molecular regulatory networks involved in response to drought stress. In a separate section, we highlight progress in the development of transgenic drought-tolerant rice plants, with special attention paid to field trial investigations.

  8. Effect of salinity tolerant PDH45 transgenic rice on physicochemical properties, enzymatic activities and microbial communities of rhizosphere soils.

    Science.gov (United States)

    Sahoo, Ranjan Kumar; Tuteja, Narendra

    2013-08-01

    The effect of genetically modified (GM) plants on environment is now major concern worldwide. The plant roots of rhizosphere soil interact with variety of bacteria which could be influenced by the transgene in GM plants. The antibiotic resistance genes in GM plants may be transferred to soil microbes. In this study we have examined the effect of overexpression of salinity tolerant pea DNA helicase 45 (PDH45) gene on microbes and enzymatic activities in the rhizosphere soil of transgenic rice IR64 in presence and absence of salt stress in two different rhizospheric soils (New Delhi and Odisha, India). The diversity of the microbial community and soil enzymes viz., dehydrogenase, alkaline phosphatase, urease and nitrate reductase was assessed. The results revealed that there was no significant effect of transgene expression on rhizosphere soil of the rice plants. The isolated bacteria were phenotyped both in absence and presence of salt and no significant changes were found in their phenotypic characters as well as in their population. Overall, the overexpression of PDH45 in rice did not cause detectable changes in the microbial population, soil enzymatic activities and functional diversity of the rhizosphere soil microbial community.

  9. Cold urticaria patients exhibit normal skin levels of functional mast cells and histamine after tolerance induction

    DEFF Research Database (Denmark)

    Kring Tannert, Line; Stahl Skov, Per; Bjerremann Jensen, Louise

    2012-01-01

    Cold urticaria is a skin condition characterized by rapid appearance of itchy wheals and occasionally angioedema in response to cold stimulation. Antihistamines do not sufficiently protect all patients from symptoms, even when used in higher than standard doses. In these patients, desensitization...... to cold can be beneficial. The aim was to investigate whether desensitization can lower temperature thresholds and reduce release of histamine in the skin. Cold urticaria patients were subjected to desensitization and assessed for skin responses to cold stimulation and codeine before and after. Histamine...... levels mediated by cold and codeine were determined by cutaneous microdialysis before and after desensitization in patients and healthy controls. Desensitization to cold resulted in protection from cold-induced symptoms and lower temperature thresholds in six out of nine patients. Desensitization also...

  10. Transcriptome sequencing and identification of cold tolerance genes in hardy Corylus species (C. heterophylla Fisch floral buds.

    Directory of Open Access Journals (Sweden)

    Xin Chen

    Full Text Available BACKGROUND: The genus Corylus is an important woody species in Northeast China. Its products, hazelnuts, constitute one of the most important raw materials for the pastry and chocolate industry. However, limited genetic research has focused on Corylus because of the lack of genomic resources. The advent of high-throughput sequencing technologies provides a turning point for Corylus research. In the present study, we performed de novo transcriptome sequencing for the first time to produce a comprehensive database for the Corylus heterophylla Fisch floral buds. RESULTS: The C. heterophylla Fisch floral buds transcriptome was sequenced using the Illumina paired-end sequencing technology. We produced 28,930,890 raw reads and assembled them into 82,684 contigs. A total of 40,941 unigenes were identified, among which 30,549 were annotated in the NCBI Non-redundant (Nr protein database and 18,581 were annotated in the Swiss-Prot database. Of these annotated unigenes, 25,311 and 10,514 unigenes were assigned to gene ontology (GO categories and clusters of orthologous groups (COG, respectively. We could map 17,207 unigenes onto 128 pathways using the Kyoto Encyclopedia of Genes and Genomes Pathway (KEGG database. Additionally, based on the transcriptome, we constructed a candidate cold tolerance gene set of C. heterophylla Fisch floral buds. The expression patterns of selected genes during four stages of cold acclimation suggested that these genes might be involved in different cold responsive stages in C. heterophylla Fisch floral buds. CONCLUSION: The transcriptome of C. heterophylla Fisch floral buds was deep sequenced, de novo assembled, and annotated, providing abundant data to better understand the C. heterophylla Fisch floral buds transcriptome. Candidate genes potentially involved in cold tolerance were identified, providing a material basis for future molecular mechanism analysis of C. heterophylla Fisch floral buds tolerant to cold stress.

  11. Conserved synteny at the protein family level reveals genes underlying Shewanella species cold tolerance and predicts their novel phenotypes

    Energy Technology Data Exchange (ETDEWEB)

    Karpinets, Tatiana V.; Obraztsova, Anna; Wang, Yanbing; Schmoyer, Denise D.; Kora, Guruprasad; Park, Byung H.; Serres, Margrethe H.; Romine, Margaret F.; Land, Miriam L.; Kothe, Terence B.; Fredrickson, Jim K.; Nealson, Kenneth H.; Uberbacher, Edward

    2010-03-01

    Bacteria of the genus Shewanella can thrive in different environments and demonstrate significant variability in their metabolic and ecophysiological capabilities including cold and salt tolerance. Genomic characteristics underlying this variability across species are largely unknown. In this study we address the problem by a comparison of the physiological, metabolic and genomic characteristics of 19 sequenced Shewanella species. We have employed two novel approaches based on association of a phenotypic trait with the number of the trait-specific protein families (Pfam domains) and on the conservation of synteny (order in the genome) of the trait-related genes. Our first approach is top-down and involves experimental evaluation and quantification of the species’ cold tolerance followed by identification of the correlated Pfam domains and genes with a conserved synteny. The second, a bottom-up approach, predicts novel phenotypes of the species by calculating profiles of each Pfam domain among their genomes and following pair-wise correlation of the profiles and their network clustering. Using the first approach we find a link between cold and salt tolerance of the species and the presence in the genome of a Na+/H+ antiporter gene cluster. Other cold tolerance related genes includes peptidases, chemotaxis sensory transducer proteins, a cysteine exporter, and helicases. Using the bottom-up approach we found several novel phenotypes in the newly sequenced Shewanella species, including degradation of aromatic compounds by an aerobic hybrid pathway in S. woodyi, degradation of ethanolamine by S. benthica, and propanediol degradation by S. putrefaciens CN32 and S. sp. W3-18-1.

  12. A high-resolution linkage map of the vicinity of the rice submergence tolerance locus Sub1.

    Science.gov (United States)

    Xu, K; Xu, X; Ronald, P C; Mackill, D J

    2000-05-01

    Resistance to submergence stress is an important breeding objective in areas where rice cultivars are subjected to complete inundation for a week or more. The present study was conducted to develop a high-resolution map of the region surrounding the submergence tolerance gene Sub1 in rice, which derives from the Indian cultivar FR13A. Submergence screening of 8-day-old plants of F3 families kept for 14 days submerged in 60 cm of water allowed an accurate classification of Sub1 phenotypes. Bulked segregant analysis was used to identify AFLP markers linked to Sub1. A population of 2950 F2 plants segregating for Sub1 was screened with two RFLP markers flanking the Sub1 locus, 2.4 and 4.9 cM away. Submergence tolerance was measured in the recombinant plants, and AFLP markers closely linked to Sub1 were mapped. Two AFLP markers cosegregated with Sub1 in this large population, and other markers were localized within 0.2 cM of Sub1. The high-resolution map should serve as the basis for map-based cloning of this important locus, as it will permit the identification of BAC clones spanning the region.

  13. OsPOP5, A Prolyl Oligopeptidase Family Gene from Rice Confers Abiotic Stress Tolerance in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Ping-Rong Wang

    2013-10-01

    Full Text Available The prolyl oligopeptidase family, which is a group of serine peptidases, can hydrolyze peptides smaller than 30 residues. The prolyl oligopeptidase family in plants includes four members, which are prolyl oligopeptidase (POP, EC3.4.21.26, dipeptidyl peptidase IV (DPPIV, EC3.4.14.5, oligopeptidase B (OPB, EC3.4.21.83, and acylaminoacyl peptidase (ACPH, EC3.4.19.1. POP is found in human and rat, and plays important roles in multiple biological processes, such as protein secretion, maturation and degradation of peptide hormones, and neuropathies, signal transduction and memory and learning. However, the function of POP is unclear in plants. In order to study POP function in plants, we cloned the cDNA of the OsPOP5 gene from rice by nested-PCR. Sequence analysis showed that the cDNA encodes a protein of 596 amino acid residues with Mw ≈ 67.29 kD. In order to analyze the protein function under different abiotic stresses, OsPOP5 was expressed in Escherichia coli. OsPOP5 protein enhanced the tolerance of E. coli to high salinity, high temperature and simulated drought. The results indicate that OsPOP5 is a stress-related gene in rice and it may play an important role in plant tolerance to abiotic stress.

  14. Study of phenological and morphological characteristics of chickpea (Cicer arietinum L. cold tolerant genotypes in fall planting

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    samane najib niya

    2009-06-01

    Full Text Available In order to evaluate phenological and morphological characteristics of chickpea (Cicer arietinum L. cold tolerant genotypes, a field trial carried out on 2004-2005 at the experimental field of College of Agriculture, Ferdowsi University of Mashhad. In this study 152 cold tolerant accessions with 4 checks (Karaj12-60-31, ILC482, ILC3279 and FLIP84-48C were evaluated in the Augmented preliminarily design in fall planting (9 October. There were considerable variations among genotypes with each other and with checks about phonological stages (days from sowing to emergence, emergence to flowering and flowering to ripening and morphological characteristics (plant height, number of branches and their length per plant. The differences in all cases were significant (p≤0.05. Vegetative growth period was more than 165 days in 84% of accessions and reproductive growth period was more than 29 days in 87% of them. The height of plant in 86% of accessions was more than 30cm, and total branch length per plant was more than 300cm in 82% of accessions. According to the results and regarding to the remarkable yield of some accessions, there is a suitable possibility for selecting genotypes with suitable agronomical characteristics in order to continue cold tolerance trials in replicated experiments.

  15. Anatomical Structure Comparison Between Leaves of Two Winter Wheat Cultivars with Different Cold/Freezing Tolerance Under Low Temperature Stress

    Institute of Scientific and Technical Information of China (English)

    YU Jing; CANG Jing; ZHOU Zishan; LIU Lijie

    2011-01-01

    Winter wheat (Triticum aestivum) cultivars Dongnongdongmai 1 with strong cold/freezing tolerance and Jimai 22 with weak cold/freezing tolerance were used for investigating the difference of microstructure and ultrastructure between leaves of two cultivars under low temperature stress (5℃ and -15 ℃) using optical and electron microscope. The results showed that there was no obvious difference between leaves of Dongnongdongmai 1 and Jimai 22 in microstructure. However, the difference between those leaves was distinct in ultrastructure. The grana lamella and stroma lamella were stacked regularly and arranged parallelly along the long axis of chloroplasts in cv. Dongnongdongmai 1, while the arrangement directions of thylakoids in Jimai 22's leaves were so irregular as to form various angles with the long axis of chloroplasts. At -15℃, the mitochondrias were swelled to be round and the structure of cristaes became blurry in both cultivars' leaves, while some cristaes of Jimai 22 disappeared. These results would provide theoretical evidence for selecting cold/freezing tolerant winter wheat germplasm resources

  16. Thermal tolerance and survival responses to scenarios of experimental climatic change: changing thermal variability reduces the heat and cold tolerance in a fly.

    Science.gov (United States)

    Bozinovic, Francisco; Medina, Nadia R; Alruiz, José M; Cavieres, Grisel; Sabat, Pablo

    2016-07-01

    Climate change poses one of the greatest threats to biodiversity. Most analyses of the impacts have focused on changes in mean temperature, but increasing variance will also impact organisms and populations. We assessed the combined effects of the mean and the variance of temperature on thermal tolerances-i.e., critical thermal maxima, critical thermal minima, scope of thermal tolerance, and survival in Drosophila melanogaster. Our six experimental climatic scenarios were: constant mean with zero variance or constant variance or increasing variance; changing mean with zero variance or constant variance or increasing variance. Our key result was that environments with changing thermal variance reduce the scope of thermal tolerance and survival. Heat tolerance seems to be conserved, but cold tolerance decreases significantly with mean low as well as changing environmental temperatures. Flies acclimated to scenarios of changing variance-with either constant or changing mean temperatures-exhibited significantly lower survival rate. Our results imply that changing and constant variances would be just as important in future scenarios of climate change under greenhouse warming as increases in mean annual temperature. To develop more realistic predictions about the biological impacts of climate change, such interactions between the mean and variance of environmental temperature should be considered.

  17. Futile Na+ cycling at the root plasma membrane in rice (Oryza sativa L.): kinetics, energetics, and relationship to salinity tolerance

    Science.gov (United States)

    Malagoli, Philippe; Britto, Dev T.; Schulze, Lasse M.; Kronzucker, Herbert J.

    2008-01-01

    Globally, over one-third of irrigated land is affected by salinity, including much of the land under lowland rice cultivation in the tropics, seriously compromising yields of this most important of crop species. However, there remains an insufficient understanding of the cellular basis of salt tolerance in rice. Here, three methods of 24Na+ tracer analysis were used to investigate primary Na+ transport at the root plasma membrane in a salt-tolerant rice cultivar (Pokkali) and a salt-sensitive cultivar (IR29). Futile cycling of Na+ at the plasma membrane of intact roots occurred at both low and elevated levels of steady-state Na+ supply ([Na+]ext=1 mM and 25 mM) in both cultivars. At 25 mM [Na+]ext, a toxic condition for IR29, unidirectional influx and efflux of Na+ in this cultivar, but not in Pokkali, became very high [>100 μmol g (root FW)−1 h−1], demonstrating an inability to restrict sodium fluxes. Current models of sodium transport energetics across the plasma membrane in root cells predict that, if the sodium efflux were mediated by Na+/H+ antiport, this toxic scenario would impose a substantial respiratory cost in IR29. This cost is calculated here, and compared with root respiration, which, however, comprised only ∼50% of what would be required to sustain efflux by the antiporter. This suggests that either the conventional ‘leak-pump’ model of Na+ transport or the energetic model of proton-linked Na+ transport may require some revision. In addition, the lack of suppression of Na+ influx by both K+ and Ca2+, and by the application of the channel inhibitors Cs+, TEA+, and Ba2+, questions the participation of potassium channels and non-selective cation channels in the observed Na+ fluxes. PMID:18854575

  18. Screening and selection of most potent diazotrophic cyanobacterial isolate exhibiting natural tolerance to rice field herbicides for exploitation as biofertilizer.

    Science.gov (United States)

    Singh, Surendra; Datta, Pallavi

    2006-01-01

    Periodic applications of heavy dosages of herbicides in modern rice-agriculture are a necessary evil for obtaining high crop productivity. Such herbicides are not only detrimental to weeds but biofertilizer strains of diazotrophic cyanobacteria also. It is therefore, essential to screen and select such biofertilizer strains of diazotrophic cyanobacteria exhibiting natural tolerance to common rice-field herbicides that can be further improved by mutational techniques to make biofertilizer technology a viable one. Therefore, efforts have been made to screen five dominant diazotrophic cyanobacterial forms e.g. filamentous heterocystous Nostoc punctiforme , Nostoc calcicola , Anabaena variabilis and unicellular Gloeocapsa sp. and Aphanocapsa sp. along with standard laboratory strain Nostoc muscorum ISU against increasing concentrations (0-100 mg l(-1) of four commercial grade common rice-field herbicides i.e. Arozin, Butachlor, Alachlor and 2,4-D under diazotrophic growth conditions. The lethal and IGC(50) concentrations for all four herbicides tested were found highest for A. variabilis as compared to other test cyanobacteria. The lowest reduction in chlorophyll a content, photosynthetic oxygen evolution, and N(2)-fixation was found in A. variabilis as compared to other rice field isolates and standard laboratory strain N. muscorum ISU. On the basis of prolong survival potential and lowest reductions in vital metabolic activities tested at IGC(50) concentration of four herbicides, it is concluded that A. variabilis is the most potent and promising cyanobacterial isolate as compared with other forms. This could be further improved by mutational techniques for exploitation as most potential and viable biofertilizer strain.

  19. Rice genotype differences in tolerance of zinc-deficient soils: evidence for the importance of root-induced changes in the rhizosphere

    Directory of Open Access Journals (Sweden)

    Asako eMori

    2016-01-01

    Full Text Available Zinc (Zn deficiency is a major constraint to rice production and Zn is also often deficient in humans with rice-based diets. Efforts to breed more Zn-efficient rice are constrained by poor understanding of the mechanisms of tolerance to deficiency. Here we assess the contributions of root growth and root Zn uptake efficiency, and we seek to explain the results in terms of specific mechanisms. We made a field experiment in a highly Zn-deficient rice soil in the Philippines with deficiency-tolerant and -sensitive genotypes, and measured growth, Zn uptake and root development. We also measured the effect of planting density. Tolerant genotypes produced more crown roots per plant and had greater uptake rates per unit root surface area; the latter was at least as important as root number to overall tolerance. Tolerant and sensitive genotypes took up more Zn per plant at greater planting densities. The greater uptake per unit root surface area, and the planting density effect can only be explained by root-induced changes in the rhizosphere, either solubilizing Zn or neutralizing a toxin that impedes Zn uptake (possibly HCO3- or Fe2+, or both. Traits for these and crown root number are potential breeding targets.

  20. The effects of cold-hardening on Rubisco in rice seedling leaves

    Institute of Scientific and Technical Information of China (English)

    ZHAOJun; WANGYirou; LIMeiru; LIUHongxian; MIAOYougang; LILiren

    1998-01-01

    Rubisco is a key enzyme which controls the process of photosynthesis and photorespiration. It is very abundant in the leaf and is very sensitive to many environmental factors. We studied the changes, caused by cold hardening and chilling stress, in activity, protein content,

  1. Stress-inducible expression of AtDREB1A transcription factor greatly improves drought stress tolerance in transgenic indica rice.

    Science.gov (United States)

    Ravikumar, G; Manimaran, P; Voleti, S R; Subrahmanyam, D; Sundaram, R M; Bansal, K C; Viraktamath, B C; Balachandran, S M

    2014-06-01

    The cultivation of rice (Oryza sativa L.), a major food crop, requires ample water (30 % of the fresh water available worldwide), and its productivity is greatly affected by drought, the most significant environmental factor. Much research has focussed on identifying quantitative trait loci, stress-regulated genes and transcription factors that will contribute towards the development of climate-resilient/tolerant crop plants in general and rice in particular. The transcription factor DREB1A, identified from the model plant Arabidopsis thaliana, has been reported to enhance stress tolerance against drought stress. We developed transgenic rice plants with AtDREB1A in the background of indica rice cultivar Samba Mahsuri through Agrobacterium-mediated transformation. The AtDREB1A gene was stably inherited and expressed in T1 and T2 plants and in subsequent generations, as indicated by the results of PCR, Southern blot and RT-PCR analyses. Expression of AtDREB1A was induced by drought stress in transgenic rice lines, which were highly tolerant to severe water deficit stress in both the vegetative and reproductive stages without affecting their morphological or agronomic traits. The physiological studies revealed that the expression of AtDREB1A was associated with an increased accumulation of the osmotic substance proline, maintenance of chlorophyll, increased relative water content and decreased ion leakage under drought stress. Most of the homozygous lines were highly tolerant to drought stress and showed significantly a higher grain yield and spikelet fertility relative to the nontransgenic control plants under both stressed and unstressed conditions. The improvement in drought stress tolerance in combination with agronomic traits is very essential in high premium indica rice cultivars, such as Samba Mahsuri, so that farmers can benefit in times of seasonal droughts and water scarcity.

  2. Effect of brief mindfulness intervention on tolerance and distress of pain induced by cold-pressor task.

    Science.gov (United States)

    Liu, Xinghua; Wang, Sisi; Chang, Shaochen; Chen, Wenjun; Si, Mei

    2013-08-01

    A number of studies have demonstrated that short-term meditation intervention can lead to greater tolerance and lower pain or distress ratings of experimentally induced pain. However, few attempts have been made to examine the effects of short-term mindfulness-based intervention on the tolerance and distress of pain, when delivered in a therapist-free form. The present research explored the effect of brief mindfulness intervention using pre-recorded instruction on pain experimentally induced by the cold-pressor task. The effects of the mindfulness strategy, the distraction strategy and spontaneous strategy, all through the instructions of pre-recorded voices, were compared. The subjects were drawn from healthy college students and randomly assigned to the aforementioned three groups. Our results showed that compared with using spontaneous strategies, the mindfulness intervention significantly improved the participants' pain tolerance and reduced their immersion distress. The distraction strategy also significantly improved the participants' pain tolerance. However, it did not have a significant effect on the participants' level of distress during the immersion period. Our results suggest that brief mindfulness intervention without a therapist's personal involvement is capable of helping people cope with pain induced by the cold-pressor task.

  3. Biallelic and Genome Wide Association Mapping of Germanium Tolerant Loci in Rice (Oryza sativa L..

    Directory of Open Access Journals (Sweden)

    Partha Talukdar

    Full Text Available Rice plants accumulate high concentrations of silicon. Silicon has been shown to be involved in plant growth, high yield, and mitigating biotic and abiotic stresses. However, it has been demonstrated that inorganic arsenic is taken up by rice through silicon transporters under anaerobic conditions, thus the ability to efficiently take up silicon may be considered either a positive or a negative trait in rice. Germanium is an analogue of silicon that produces brown lesions in shoots and leaves, and germanium toxicity has been used to identify mutants in silicon and arsenic transport. In this study, two different genetic mapping methods were performed to determine the loci involved in germanium sensitivity in rice. Genetic mapping in the biparental cross of Bala × Azucena (an F6 population and a genome wide association (GWA study with 350 accessions from the Rice Diversity Panel 1 were conducted using 15 μM of germanic acid. This identified a number of germanium sensitive loci: some co-localised with previously identified quantitative trait loci (QTL for tissue silicon or arsenic concentration, none co-localised with Lsi1 or Lsi6, while one single nucleotide polymorphism (SNP was detected within 200 kb of Lsi2 (these are genes known to transport silicon, whose identity was discovered using germanium toxicity. However, examining candidate genes that are within the genomic region of the loci detected above reveals genes homologous to both Lsi1 and Lsi2, as well as a number of other candidate genes, which are discussed.

  4. Community phylogenetics at the biogeographical scale: cold tolerance, niche conservatism and the structure of North American forests.

    Science.gov (United States)

    Hawkins, Bradford A; Rueda, Marta; Rangel, Thiago F; Field, Richard; Diniz-Filho, José Alexandre F; Linder, Peter

    2014-01-01

    AimThe fossil record has led to a historical explanation for forest diversity gradients within the cool parts of the Northern Hemisphere, founded on a limited ability of woody angiosperm clades to adapt to mid-Tertiary cooling. We tested four predictions of how this should be manifested in the phylogenetic structure of 91,340 communities: (1) forests to the north should comprise species from younger clades (families) than forests to the south; (2) average cold tolerance at a local site should be associated with the mean family age (MFA) of species; (3) minimum temperature should account for MFA better than alternative environmental variables; and (4) traits associated with survival in cold climates should evolve under a niche conservatism constraint. LocationThe contiguous United States. MethodsWe extracted angiosperms from the US Forest Service's Forest Inventory and Analysis database. MFA was calculated by assigning age of the family to which each species belongs and averaging across the species in each community. We developed a phylogeny to identify phylogenetic signal in five traits: realized cold tolerance, seed size, seed dispersal mode, leaf phenology and height. Phylogenetic signal representation curves and phylogenetic generalized least squares were used to compare patterns of trait evolution against Brownian motion. Eleven predictors structured at broad or local scales were generated to explore relationships between environment and MFA using random forest and general linear models. ResultsConsistent with predictions, (1) southern communities comprise angiosperm species from older families than northern communities, (2) cold tolerance is the trait most strongly associated with local MFA, (3) minimum temperature in the coldest month is the environmental variable that best describes MFA, broad-scale variables being much stronger correlates than local-scale variables, and (4) the phylogenetic structures of cold tolerance and at least one other trait

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

    Science.gov (United States)

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

    2016-08-01

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

  6. Abscisic acid, H2O2 and nitric oxide interactions mediated cold-induced S-adenosylmethionine synthetase in Medicago sativa subsp. falcata that confers cold tolerance through up-regulating polyamine oxidation.

    Science.gov (United States)

    Guo, Zhenfei; Tan, Jiali; Zhuo, Chunliu; Wang, Congying; Xiang, Bin; Wang, Zengyu

    2014-06-01

    S-adenosylmethionine synthetase (SAMS) is the key enzyme catalysing the formation of S-adenosylmethionine (SAM), a precursor of polyamines and ethylene. To investigate the potential role of SAMS in cold tolerance, we isolated MfSAMS1 from the cold-tolerant germplasm Medicago sativa subsp. falcata and analysed the association of SAM-derived polyamines with cold tolerance. The expression of MfSAMS1 in leaves was greatly induced by cold, abscisic acid (ABA), H2O2 and nitric oxide (NO). Our data revealed that ABA, H2O2 and NO interactions mediated the cold-induced MfSAMS1 expression and cold acclimation in falcata. SAM, putrescine, spermidine and spermine levels, ethylene production and polyamine oxidation were sequentially altered in response to cold, indicating that SAMS-derived SAM is preferentially used in polyamine synthesis and homeostasis during cold acclimation. Antioxidant enzyme activities were also induced in response to cold and showed correlation with polyamine oxidation. Overexpression of MfSAMS1 in tobacco resulted in elevated SAM levels, but polyamine levels and ethylene production in the transgenic plants were not significantly changed. Compared to the wild type, transgenic plants had increased levels of apoplastic H2O2, higher transcript levels of genes involved in polyamine synthesis and oxidation, and higher activities of polyamine oxidation and antioxidant enzymes. The results showed that overexpression of MfSAMS1 promoted polyamine synthesis and oxidation, which in turn improved H2 O2 -induced antioxidant protection, as a result enhanced tolerance to freezing and chilling stress in transgenic plants. This is the first report demonstrating that SAMS plays an important role in plant tolerance to cold via up-regulating polyamine oxidation. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  7. The cold-induced two-component system CBO0366/CBO0365 regulates metabolic pathways with novel roles in group I Clostridium botulinum ATCC 3502 cold tolerance.

    Science.gov (United States)

    Dahlsten, Elias; Zhang, Zhen; Somervuo, Panu; Minton, Nigel P; Lindström, Miia; Korkeala, Hannu

    2014-01-01

    The two-component system CBO0366/CBO0365 was recently demonstrated to have a role in cold tolerance of group I Clostridium botulinum ATCC 3502. The mechanisms under its control, ultimately resulting in increased sensitivity to low temperature, are unknown. A transcriptomic analysis with DNA microarrays was performed to identify the differences in global gene expression patterns of the wild-type ATCC 3502 and a derivative mutant with insertionally inactivated cbo0365 at 37 and 15°C. Altogether, 150 or 141 chromosomal coding sequences (CDSs) were found to be differently expressed in the cbo0365 mutant at 37 or 15°C, respectively, and thus considered to be under the direct or indirect transcriptional control of the response regulator CBO0365. Of the differentially expressed CDSs, expression of 141 CDSs was similarly affected at both temperatures investigated, suggesting that the putative CBO0365 regulon was practically not affected by temperature. The regulon involved genes related to acetone-butanol-ethanol (ABE) fermentation, motility, arsenic resistance, and phosphate uptake and transport. Deteriorated growth at 17°C was observed for mutants with disrupted ABE fermentation pathway components (crt, bcd, bdh, and ctfA), arsenic detoxifying machinery components (arsC and arsR), or phosphate uptake mechanism components (phoT), suggesting roles for these mechanisms in cold tolerance of group I C. botulinum. Electrophoretic mobility shift assays showed recombinant CBO0365 to bind to the promoter regions of crt, arsR, and phoT, as well as to the promoter region of its own operon, suggesting direct DNA-binding transcriptional activation or repression as a means for CBO0365 in regulating these operons. The results provide insight to the mechanisms group I C. botulinum utilizes in coping with cold.

  8. QTL underlying iron and zinc toxicity tolerances at seedling stage revealed by two sets of reciprocal introgression populations of rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Huan Liu

    2016-08-01

    Full Text Available Iron and zinc are two trace elements that are essential for rice. But they are toxic at higher concentrations, leading to severe rice yield losses especially in acid soils and inland valleys. In this study, two reciprocal introgression line (IL populations sharing the same parents were used with high-density SNP bin markers to identify QTL tolerant to iron and zinc toxicities. The results indicated that the japonica variety 02,428 had stronger tolerance to iron and zinc toxicities than the indica variety Minghui 63. Nine and ten QTL contributing to iron and zinc toxicity tolerances, respectively, were identified in the two IL populations. The favorable alleles of most QTL came from 02,428. Among them, qFRRDW2, qZRRDW3, and qFRSDW11 appeared to be independent of genetic background. The region C11S49–C11S60 on chromosome 11 harbored QTL affecting multiple iron and zinc toxicity tolerance-related traits, indicating partial genetic overlap between the two toxicity tolerances. Our results provide essential information and materials for developing excellent rice cultivars with iron and/or zinc tolerance by marker-assisted selection (MAS.

  9. Monitoring expression profiles of rice genes under cold, drought, and high-salinity stresses and abscisic acid application using cDNA microarray and RNA gel-blot analyses.

    Science.gov (United States)

    Rabbani, M Ashiq; Maruyama, Kyonoshin; Abe, Hiroshi; Khan, M Ayub; Katsura, Koji; Ito, Yusuke; Yoshiwara, Kyoko; Seki, Motoaki; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

    2003-12-01

    To identify cold-, drought-, high-salinity-, and/or abscisic acid (ABA)-inducible genes in rice (Oryza sativa), we prepared a rice cDNA microarray including about 1700 independent cDNAs derived from cDNA libraries prepared from drought-, cold-, and high-salinity-treated rice plants. We confirmed stress-inducible expression of the candidate genes selected by microarray analysis using RNA gel-blot analysis and finally identified a total of 73 genes as stress inducible including 58 novel unreported genes in rice. Among them, 36, 62, 57, and 43 genes were induced by cold, drought, high salinity, and ABA, respectively. We observed a strong association in the expression of stress-responsive genes and found 15 genes that responded to all four treatments. Venn diagram analysis revealed greater cross talk between signaling pathways for drought, ABA, and high-salinity stresses than between signaling pathways for cold and ABA stresses or cold and high-salinity stresses in rice. The rice genome database search enabled us not only to identify possible known cis-acting elements in the promoter regions of several stress-inducible genes but also to expect the existence of novel cis-acting elements involved in stress-responsive gene expression in rice stress-inducible promoters. Comparative analysis of Arabidopsis and rice showed that among the 73 stress-inducible rice genes, 51 already have been reported in Arabidopsis with similar function or gene name. Transcriptome analysis revealed novel stress-inducible genes, suggesting some differences between Arabidopsis and rice in their response to stress.

  10. Functional and numerical responses ofCyrtorhinus lividipennis to eggs ofNilaparvata lugens are not affected by genetically modiifed herbicide-tolerant rice

    Institute of Scientific and Technical Information of China (English)

    JIANG Xian-bin; LONG Li-ping; HUANG Qian; LING Yan; CHEN Yu-chong; XIAO Guo-ying; HUANG Suo-sheng; WU Bi-qiu; HUANG Feng-kuan; CAI Jian-he

    2015-01-01

    To safely and sustainably utilize genetic breeding techniques for crop production, greater understanding of the potential effects of geneticaly modiifed herbicide-tolerant (GMHT) crops on the ecological functions of predators is required. In the laboratory, we examined the functional and numerical responses ofCyrtorhinus lividipennis Reuter to eggs of brown plan-thopper (BPH), Nilaparvata lugens (Stål), which were reared on GMHT rice Bar68-1; the untransformed parental cultivar, D68; or a BPH-susceptive rice variety, Taichung Native 1. Al stages of nymphs and female adultof C. lividipennis, either on GMHT rice or control plants, exhibited typical type II functional responses when fed on BPH eggs; the attacking rate and handling time ofC. lividipennis on GMHT rice Bar68-1 was not signiifcantly different from that on D68. The numerical responses ofC. lividipennis on GMHT rice or controls ift Beddington’s model; there were no signiifcant differences in the parameters of numerical responses between GMHT rice Bar68-1 and D68. The results indicated that the functional and numerical responses ofC. lividipennis to BPH eggs are not affected by GMHT rice Bar68-1.

  11. Generation of Wheat Transcription Factor FOX Rice Lines and Systematic Screening for Salt and Osmotic Stress Tolerance.

    Directory of Open Access Journals (Sweden)

    Jinxia Wu

    Full Text Available Transcription factors (TFs play important roles in plant growth, development, and responses to environmental stress. In this study, we collected 1,455 full-length (FL cDNAs of TFs, representing 45 families, from wheat and its relatives Triticum urartu, Aegilops speltoides, Aegilops tauschii, Triticum carthlicum, and Triticum aestivum. More than 15,000 T0 TF FOX (Full-length cDNA Over-eXpressing rice lines were generated; of these, 10,496 lines set seeds. About 14.88% of the T0 plants showed obvious phenotypic changes. T1 lines (5,232 lines were screened for salt and osmotic stress tolerance using 150 mM NaCl and 20% (v/v PEG-4000, respectively. Among them, five lines (591, 746, 1647, 1812, and J4065 showed enhanced salt stress tolerance, five lines (591, 746, 898, 1078, and 1647 showed enhanced osmotic stress tolerance, and three lines (591, 746, and 1647 showed both salt and osmotic stress tolerance. Further analysis of the T-DNA flanking sequences showed that line 746 over-expressed TaEREB1, line 898 over-expressed TabZIPD, and lines 1812 and J4065 over-expressed TaOBF1a and TaOBF1b, respectively. The enhanced salt and osmotic stress tolerance of lines 898 and 1812 was confirmed by retransformation of the respective genes. Our results demonstrate that a heterologous FOX system may be used as an alternative genetic resource for the systematic functional analysis of the wheat genome.

  12. Construction of ammonium-tolerant strains of diazotroph associated with rice and its applications

    Institute of Scientific and Technical Information of China (English)

    CHENGQi; SONGWei; YOUChongbiao

    1992-01-01

    In rice field, especially in the fertilized field the combined nitrogen content is rather high. It is well known that the nitrogen compounds, particularly NH4+ inhibits the nitrogenase activity- of diazotrophs. So, the enhancement of nitrogen fixation ability of diazotrophs in the presence of ammonia by means of genetic manipulation will be of importance for agricultural use.

  13. 植物耐冷性基因工程%Genetic engineering of plant for cold tolerance

    Institute of Scientific and Technical Information of China (English)

    逯明辉; 陈劲枫

    2004-01-01

    Temperature not only determines the distribution of plant species but also affects the productivity and quality of crops.The mechanisms of cold tolerance in plants involved in many aspects,such as the change of composition of membrane lipids,the accumulation of compatible solutes,the enhanced activity of antioxidant enzymes and the induced expression of low temperature related genes.Cold tolerance in plant is controlled by multi-genes,and it is difficult to use conventional breeding approaches to improve the trait efficiently.The application of genetic engineering offers another feasible way in theory and practice to improve the cold tolerance.In this paper,the recent development of application of plant genetic engineering for cold tolerance in composition of membrane lipids,compatible solutes,antifreeze proteins,activity of antioxidant enzymes and transcriptional factors inducing the expression of plant low temperature related genes were summarized,aiming to provide some useful information and ideas to researchers who work on the plant breeding and the mechanism of cold stress.%温度决定物种的分布,同时还影响作物的产量和品质.植物耐冷的机制涉及到许多方面,包括膜脂组成的变化、可混溶溶质的积累、抗氧化酶活性的提高、低温相关基因的诱导表达等.由于植物的耐冷性状由多基因控制,采用传统的育种方法往往难以取得理想的结果,而植物基因工程技术的发展及应用则提供了另外可能的途径,可以通过转移耐冷性状形成的关键基因从而对植物进行改良.本文从膜脂组成、可混溶溶质、抗冻蛋白、抗氧化酶和诱导植物低温相关基因的转录因子等方面对植物耐冷性的基因工程研究进行了综述,以期为植物育种者和从事冷胁迫机制研究的工作者提供参考.

  14. 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.

  15. A cold-tolerant evergreen interspecific hybrid of Ocimum kilimandscharicum and Ocimum basilicum: analyzing trichomes and molecular variations.

    Science.gov (United States)

    Dhawan, Sunita Singh; Shukla, Preeti; Gupta, Pankhuri; Lal, R K

    2016-05-01

    Ocimum (Lamiaceae) is an important source of essential oils and aroma chemicals especially eugenol, methyl eugenol, linalool, methyl chavicol etc. An elite evergreen hybrid has been developed from Ocimum kilimandscharicum and Ocimum basilicum, which demonstrated adaptive behavior towards cold stress. A comparative molecular analysis has been done through RAPD, AFLP, and ISSR among O. basilicum and O. kilimandscharicum and their evergreen cold-tolerant hybrid. The RAPD and AFLP analyses demonstrated similar results, i.e., the hybrid of O. basilicum and O. kilimandscharicum shares the same cluster with O. kilimandscharicum, while O. basilicum behaves as an outgroup, whereas in ISSR analysis, the hybrid genotype grouped in the same cluster with O. basilicum. Ocimum genotypes were analyzed and compared for their trichome density. There were distinct differences on morphology, distribution, and structure between the two kinds of trichomes, i.e., glandular and non-glandular. Glandular trichomes contain essential oils, polyphenols, flavonoids, and acid polysaccharides. Hair-like trichomes, i.e., non-glandular trichomes, help in keeping the frost away from the living surface cells. O. basilicum showed less number of non-glandular trichomes on leaves compared to O. kilimandscharicum and the evergreen cold-tolerant hybrid. Trichomes were analyzed in O. kilimandscharicum, O. basilicum, and their hybrid. An increased proline content at the biochemical level represents a higher potential to survive in a stress condition like cold stress. In our analysis, the proline content is quite higher in tolerant variety O. kilimandscharicum, low in susceptible variety O. basilicum, and intermediate in the hybrid. Gene expression analysis was done in O. basilicum, O. kilimandscharicum and their hybrid for TTG1, GTL1, and STICHEL gene locus which regulates trichome development and its formation and transcription factors WRKY and MPS involved in the regulation of plant responses to freezing

  16. Rapid cold hardening increases cold and chilling tolerances more than acclimation in the adults of the sycamore lace bug, Corythucha ciliata (Say) (Hemiptera: Tingidae).

    Science.gov (United States)

    Ju, Rui-Ting; Xiao, Yu-Yu; Li, Bo

    2011-11-01

    The sycamore lace bug, Corythucha ciliata is a new, invasive pest of Platanus trees in China. Although C. ciliata is often subjected to acute low temperatures in early winter and spring in northern and eastern China, the cold tolerance of C. ciliata has not been well studied. The objectives of this study were to determine whether adults of C. ciliata are capable of rapid cold hardening (RCH), and to compare the benefits of RCH vs. cold acclimation (ACC) in the laboratory. When the adult females incubated at 26°C were transferred directly to the discriminating temperature (-12°C) for 2 h, survival was only 22%. However, exposure to 0°C for 4 h before transfer to -12°C for 2 h induced RCH, i.e., increased survival to 68%. RCH could also be induced by gradual cooling of the insects at rates between 0.1 and 0.25°C min(-1). The protection against cold shock obtained through RCH at 0°C for 4 h was lost within 1h if the adults were returned to 26°C before exposure to -12°C. Survival at both -12 and -5°C was greater for RCH-treated than for ACC-treated adults (for ACC, adults were kept at 15°C for 5 days), and the lethal temperature (2 h exposure) was lower for RCH-treated than for ACC-treated adults. The results suggest that RCH may help C. ciliata survive the acute low temperatures that often occur in early winter and early spring in northern and eastern China.

  17. Expression responses of five cold tolerant related genes to two temperature dropping treatments in sea cucumber Apostichopus japonicus

    Science.gov (United States)

    Li, Chengze; Chang, Yaqing; Pang, Zhenguo; Ding, Jun; Ji, Nanjing

    2015-03-01

    Environmental conditions, including ambient temperature, play important roles in survival, growth development, and reproduction of the Japanese sea cucumber, Apostichopus japonicus. Low temperatures result in slowed growth and skin ulceration disease. In a previous study, we investigated the effect of low temperature on gene expression profiles in A. japonicus by suppression subtractive hybridization (SSH). Genes encoding Ferritin, Lysozyme, Hsp70, gp96, and AjToll were selected from a subtracted cDNA library of A. japonicus under acute cold stress. The transcriptional expression profiles of these genes were investigated in different tissues (coelomocyte, respiratory tree, intestine, longitudinal muscle) after exposure to acute and mild temperature dropping treatments. The results show that (1) the five cold-tolerance-related genes were found in all four tissues and the highest mRNA levels were observed in coelomocyte and respiratory tree; (2) under the temperature dropping treatments, three types of transcriptional regulation patterns were observed: primary suppression followed by up-regulation at -2°C, suppressed expression throughout the two treatments, and more rarely an initial stimulation followed by suppression; and (3) gene expression suppression was more severe under acute temperature dropping than under mild temperature dropping treatment. The five cold-tolerance-related genes that were distributed mainly in coelomocyte and respiratory tissues were generally down-regulated by low temperature stress but an inverse up-regulation event was found at the extreme temperature (-2°C).

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-08-07

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

  19. Mapping QTLs for Salt Tolerance in Rice (Oryza sativa L.) by Bulked Segregant Analysis of Recombinant Inbred Lines Using 50K SNP Chip.

    Science.gov (United States)

    Tiwari, Sushma; Sl, Krishnamurthy; Kumar, Vinod; Singh, Balwant; Rao, A R; Mithra Sv, Amitha; Rai, Vandna; Singh, Ashok K; Singh, Nagendra K

    2016-01-01

    Soil salinity is a major constraint to rice production in large inland and coastal areas around the world. Modern high yielding rice varieties are particularly sensitive to high salt stress. There are salt tolerant landraces and traditional varieties of rice but with limited information on genomic regions (QTLs) and genes responsible for their tolerance. Here we describe a method for rapid identification of QTLs for reproductive stage salt tolerance in rice using bulked segregant analysis (BSA) of bi-parental recombinant inbred lines (RIL). The number of RILs required for the creation of two bulks with extreme phenotypes was optimized to be thirty each. The parents and bulks were genotyped using a 50K SNP chip to identify genomic regions showing homogeneity for contrasting alleles of polymorphic SNPs in the two bulks. The method was applied to 'CSR11/MI48' RILs segregating for reproductive stage salt tolerance. Genotyping of the parents and RIL bulks, made on the basis of salt sensitivity index for grain yield, revealed 6,068 polymorphic SNPs and 21 QTL regions showing homogeneity of contrasting alleles in the two bulks. The method was validated further with 'CSR27/MI48' RILs used earlier for mapping salt tolerance QTLs using low-density SSR markers. BSA with 50K SNP chip revealed 5,021 polymorphic loci and 34 QTL regions. This not only confirmed the location of previously mapped QTLs but also identified several new QTLs, and provided a rapid way to scan the whole genome for mapping QTLs for complex agronomic traits in rice.

  20. Mapping QTLs for Salt Tolerance in Rice (Oryza sativa L.) by Bulked Segregant Analysis of Recombinant Inbred Lines Using 50K SNP Chip

    Science.gov (United States)

    Kumar, Vinod; Singh, Balwant; Rao, AR; Mithra SV, Amitha; Singh, Ashok K.; Singh, Nagendra K.

    2016-01-01

    Soil salinity is a major constraint to rice production in large inland and coastal areas around the world. Modern high yielding rice varieties are particularly sensitive to high salt stress. There are salt tolerant landraces and traditional varieties of rice but with limited information on genomic regions (QTLs) and genes responsible for their tolerance. Here we describe a method for rapid identification of QTLs for reproductive stage salt tolerance in rice using bulked segregant analysis (BSA) of bi-parental recombinant inbred lines (RIL). The number of RILs required for the creation of two bulks with extreme phenotypes was optimized to be thirty each. The parents and bulks were genotyped using a 50K SNP chip to identify genomic regions showing homogeneity for contrasting alleles of polymorphic SNPs in the two bulks. The method was applied to ‘CSR11/MI48’ RILs segregating for reproductive stage salt tolerance. Genotyping of the parents and RIL bulks, made on the basis of salt sensitivity index for grain yield, revealed 6,068 polymorphic SNPs and 21 QTL regions showing homogeneity of contrasting alleles in the two bulks. The method was validated further with ‘CSR27/MI48’ RILs used earlier for mapping salt tolerance QTLs using low-density SSR markers. BSA with 50K SNP chip revealed 5,021 polymorphic loci and 34 QTL regions. This not only confirmed the location of previously mapped QTLs but also identified several new QTLs, and provided a rapid way to scan the whole genome for mapping QTLs for complex agronomic traits in rice. PMID:27077373

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

    Directory of Open Access Journals (Sweden)

    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. Dehydrin, alcohol dehydrogenase, and central metabolite levels are associated with cold tolerance in diploid strawberry (Fragaria spp.).

    Science.gov (United States)

    Davik, Jahn; Koehler, Gage; From, Britta; Torp, Torfinn; Rohloff, Jens; Eidem, Petter; Wilson, Robert C; Sønsteby, Anita; Randall, Stephen K; Alsheikh, Muath

    2013-01-01

    The use of artificial freezing tests, identification of biomarkers linked to or directly involved in the low-temperature tolerance processes, could prove useful in applied strawberry breeding. This study was conducted to identify genotypes of diploid strawberry that differ in their tolerance to low-temperature stress and to investigate whether a set of candidate proteins and metabolites correlate with the level of tolerance. 17 Fragaria vesca, 2 F. nilgerrensis, 2 F. nubicola, and 1 F. pentaphylla genotypes were evaluated for low-temperature tolerance. Estimates of temperatures where 50 % of the plants survived (LT₅₀) ranged from -4.7 to -12.0 °C between the genotypes. Among the F. vesca genotypes, the LT₅₀ varied from -7.7 °C to -12.0 °C. Among the most tolerant were three F. vesca ssp. bracteata genotypes (FDP821, NCGR424, and NCGR502), while a F. vesca ssp. californica genotype (FDP817) was the least tolerant (LT₅₀) -7.7 °C). Alcohol dehydrogenase (ADH), total dehydrin expression, and content of central metabolism constituents were assayed in select plants acclimated at 2 °C. The LT₅₀ estimates and the expression of ADH and total dehydrins were highly correlated (r(adh) = -0.87, r (dehyd) = -0.82). Compounds related to the citric acid cycle were quantified in the leaves during acclimation. While several sugars and acids were significantly correlated to the LT₅₀ estimates early in the acclimation period, only galactinol proved to be a good LT₅₀ predictor after 28 days of acclimation (r(galact) = 0.79). It is concluded that ADH, dehydrins, and galactinol show great potential to serve as biomarkers for cold tolerance in diploid strawberry.

  3. Potential Effects of Climate Change on the Distribution of Cold-Tolerant Evergreen Broadleaved Woody Plants in the Korean Peninsula.

    Science.gov (United States)

    Koo, Kyung Ah; Kong, Woo-Seok; Nibbelink, Nathan P; Hopkinson, Charles S; Lee, Joon Ho

    2015-01-01

    Climate change has caused shifts in species' ranges and extinctions of high-latitude and altitude species. Most cold-tolerant evergreen broadleaved woody plants (shortened to cold-evergreens below) are rare species occurring in a few sites in the alpine and subalpine zones in the Korean Peninsula. The aim of this research is to 1) identify climate factors controlling the range of cold-evergreens in the Korean Peninsula; and 2) predict the climate change effects on the range of cold-evergreens. We used multimodel inference based on combinations of climate variables to develop distribution models of cold-evergreens at a physiognomic-level. Presence/absence data of 12 species at 204 sites and 6 climatic factors, selected from among 23 candidate variables, were used for modeling. Model uncertainty was estimated by mapping a total variance calculated by adding the weighted average of within-model variation to the between-model variation. The range of cold-evergreens and model performance were validated by true skill statistics, the receiver operating characteristic curve and the kappa statistic. Climate change effects on the cold-evergreens were predicted according to the RCP 4.5 and RCP 8.5 scenarios. Multimodel inference approach excellently projected the spatial distribution of cold-evergreens (AUC = 0.95, kappa = 0.62 and TSS = 0.77). Temperature was a dominant factor in model-average estimates, while precipitation was minor. The climatic suitability increased from the southwest, lowland areas, to the northeast, high mountains. The range of cold-evergreens declined under climate change. Mountain-tops in the south and most of the area in the north remained suitable in 2050 and 2070 under the RCP 4.5 projection and 2050 under the RCP 8.5 projection. Only high-elevations in the northeastern Peninsula remained suitable under the RCP 8.5 projection. A northward and upper-elevational range shift indicates change in species composition at the alpine and subalpine

  4. Transcriptome profiling and physiological studies reveal a major role for aromatic amino acids in mercury stress tolerance in rice seedlings.

    Directory of Open Access Journals (Sweden)

    Yun-An Chen

    Full Text Available Mercury (Hg is a serious environmental pollution threat to the planet. The accumulation of Hg in plants disrupts many cellular-level functions and inhibits growth and development, but the mechanism is not fully understood. To gain more insight into the cellular response to Hg, we performed a large-scale analysis of the rice transcriptome during Hg stress. Genes induced with short-term exposure represented functional categories of cell-wall formation, chemical detoxification, secondary metabolism, signal transduction and abiotic stress response. Moreover, Hg stress upregulated several genes involved in aromatic amino acids (Phe and Trp and increased the level of free Phe and Trp content. Exogenous application of Phe and Trp to rice roots enhanced tolerance to Hg and effectively reduced Hg-induced production of reactive oxygen species. Hg induced calcium accumulation and activated mitogen-activated protein kinase. Further characterization of the Hg-responsive genes we identified may be helpful for better understanding the mechanisms of Hg in plants.

  5. Thellungiella halophilaThPIP1 gene enhances the tolerance of the transgenic rice to salt stress

    Institute of Scientific and Technical Information of China (English)

    QIANG Xiao-jing; YU Guo-hong; JIANG Lin-lin; SUN Lin-lin; ZHANG Shu-hui; LI Wei; CHENG Xian-guo

    2015-01-01

    Aquaporin proteins were demonstrated to play an important regulatory role in transporting water and other smal mole-cules. To better understand physiological functions of aquaporins in extremophile plants, a novelThPIP1 gene from the Thelungiela halophila was isolated and functionaly characterized in the transgenic rice. Data showed that the ThPIP1 protein encoded 284 amino acids, and was identiifed to be located on the plasma membrane. The expression ofThPIP1 genein the shoots and roots ofT. halophilaseedlings were induced by high salinity. The transgenic rice overexpressing ThPIP1 gene signiifcantly increased plants tolerance to salt stress through the pathway regulating the osmotic potentials, accumulation of organic smal molecules substances and the ratio of K+/Na+ in the plant cels. Moreover, split-ubiquitin yeast two-hybrid assay showed that ThPIP1 protein speciifcaly interacted with ThPIP2 and a non-speciifc lipid-transfer protein 2, suggesting thatThPIP1 probably play a key role in responding to the reactions of multiple external stimulus and in participating in different physiological processes of plants exposed to salt stress.

  6. Genome-wide analysis of autophagy-associated genes in foxtail millet (Setaria italica L.) and characterization of the function of SiATG8a in conferring tolerance to nitrogen starvation in rice.

    Science.gov (United States)

    Li, Weiwei; Chen, Ming; Wang, Erhui; Hu, Liqin; Hawkesford, Malcolm J; Zhong, Li; Chen, Zhu; Xu, Zhaoshi; Li, Liancheng; Zhou, Yongbin; Guo, Changhong; Ma, Youzhi

    2016-10-12

    Autophagy is a cellular degradation process that is highly evolutionarily-conserved in yeast, plants, and animals. In plants, autophagy plays important roles in regulating intracellular degradation and recycling of amino acids in response to nutrient starvation, senescence, and other environmental stresses. Foxtail millet (Setaria italica) has strong resistance to stresses and has been proposed as an ideal material for use in the study of the physiological mechanisms of abiotic stress tolerance in plants. Although the genome sequence of foxtail millet (Setaria italica) is available, the characteristics and functions of abiotic stress-related genes remain largely unknown for this species. A total of 37 putative ATG (autophagy-associated genes) genes in the foxtail millet genome were identified. Gene duplication analysis revealed that both segmental and tandem duplication events have played significant roles in the expansion of the ATG gene family in foxtail millet. Comparative synteny mapping between the genomes of foxtail millet and rice suggested that the ATG genes in both species have common ancestors, as their ATG genes were primarily located in similar syntenic regions. Gene expression analysis revealed the induced expression of 31 SiATG genes by one or more phytohormone treatments, 26 SiATG genes by drought, salt and cold, 24 SiATG genes by darkness and 25 SiATG genes by nitrogen starvation. Results of qRT-PCR showing that among 37 SiATG genes, the expression level of SiATG8a was the highest after nitrogen starvation treatment 24 h, suggesting its potential role in tolerance to nutrient starvation. Moreover, the heterologous expression of SiATG8a in rice improved nitrogen starvation tolerance. Compared to wild type rice, the transgenic rice performed better and had higher aboveground total nitrogen content when the plants were grown under nitrogen starvation conditions. Our results deepen understanding about the characteristics and functions of ATG genes in

  7. Divergent regulation of CBF regulon on cold tolerance and plant phenotype in cassava overexpressing Arabidopsis CBF3 gene

    Directory of Open Access Journals (Sweden)

    Dong An

    2016-12-01

    Full Text Available Cassava is a tropical origin plant that is sensitive to chilling stress. In order to understand the CBF cold response pathway, a well-recognized regulatory mechanism in temperate plants, in cassava, overexpression of an Arabidopsis CBF3 gene is studied. This gene renders cassava increasingly tolerant to cold and drought stresses but is associated with retarded plant growth, leaf curling, reduced storage root yield, and reduced anthocyanin accumulation in a transcript abundance-dependent manner. Physiological analysis revealed that the transgenic cassava increased proline accumulation, reduced malondialdehyde production, and electrolyte leakage under cold stress. These transgenic lines also showed high relative water content when faced with drought. The expression of partial CBF-targeted genes in response to cold displayed temporal and spatial variations in the wild-type and transgenic plants: highly inducible in leaves and less altered in apical buds. In addition, anthocyanin accumulation was inhibited by downregulating the expression of genes involved in its biosynthesis and by interplaying between the CBF3 and the endogenous transcription factors. Thus, the heterologous CBF3 modulates the expression of stress-related genes and carries out a series of physiological adjustments under stressful conditions, showing a varied regulation pattern of CBF regulon from that of cassava CBFs.

  8. Physiological indices for evaluating iron-toxicity tolerance of rice ( Oryza sativ, L. )%水稻耐铁毒性的生理指标研究

    Institute of Scientific and Technical Information of China (English)

    周建林; 唐建军

    2001-01-01

    This paper studied the content malodialdehyde (MDA) and the leakage rate of electrolyte in leaves of various rice varieties with different iron-toxicity tolerance and of Echinochloa crusgalli under excessive Fe2+ (160mg·L-1) stress. The results showed that both the MDA content and the leakage rate of electrolyte in leaves of plants were significantly and negatively correlated with the tolerance of test plants to iron toxicity. It was suggested that both MDA content and leakage rate of electrolyte could be used as the index for evaluating the tolerance to iron toxicity.

  9. Variations of the antioxidant system during development of the cold-tolerant beetle, Tenebrio molitor.

    Science.gov (United States)

    Gulevsky, Alexander K; Relina, Liana I; Grishchenkova, Yelena A

    2006-01-01

    Data relating to the peculiarities of antioxidant enzyme activities, glutathione (GSH) level and lipid peroxidation (LP) intermediates specific to at each ontogenic stage of Tenebrio molitor are presented. Metamorphosis is accompanied by a shift of prooxidant-antioxidant balance towards oxidative processes, since pupae have the highest levels of lipid peroxidation intermediates. Cold acclimation (4 degree C) can promote oxidative stress at the cold sensitive developmental stage--imagoes, which enhance their levels of diene conjugates and ketodienes after a 2-week cold acclimation. This enhancement is accompanied by an increase in catalase (CAT) activity. GSH levels undergo no changes in imagoes after cold acclimation. Neither larval nor pupal T. molitor show significant changes in LP product contents after cold acclimation. Chilling results in a significant increase in CAT activities in pupae, but not in larvae. GSH levels are reduced both in larvae and pupae after cold exposure. However, cold acclimation does not affect superoxide dismutase (SOD) activity in any of the developmental stages of T. molitor.

  10. Arroz e trigo: tolerância à salinidade em solução nutritiva Tolerance of rice and wheat cultivars to salinity

    Directory of Open Access Journals (Sweden)

    José Guilherme de Freitas

    1988-01-01

    , com base nas variações das porcentagens diárias médias do comprimento das raízes seminais ao cloreto de sódio, os cultivares de arroz foram classificados em tolerantes: IAC-165, Pratão Precoce, Dourado Precoce, IAC-1 64 e IAC-1 20; moderadamente tolerantes: IAC-1246, Pérola, IAC-25, Batatais e IAC-47; moderadamente sensíveis: IAC-899, IAC-435, IAC-4440 e IR-841, e sensível: IAC-1278. Para o trigo foram considerados como os mais tolerantes os cultivares IAS-55 e Siete Cerros.The water stress and the salinity in the soil are the most important causes of low grain yield of rice and wheat in Brazil, when cultivated on upland conditions. Selection for new cultivars showing tolerance to salt effects seems to be one of the methods to solve this problem. The osmotic agent usually used to this purpose is sodium chloride. One experiment was conducted in laboratory conditions using nutrient solutions. The rice genotypes utilized were: upland cultivars IAC-25, IAC-47, IAC-164, IAC-165, IAC-1246, Batatais, Dourado Precoce, Pérola and Pratão Precoce; and irrigated cultivars IAC-120, IAC-435, IAC-899, IAC-1278, IAC-4440 and IR-841. The wheat genotypes utilizated were: upland cultivars IAC-5, IAS-55, Siete Cerros and Paraguay-281. Nutrient solutions aeration and light for the seedlings were provided continuously. Six levels of sodium chloride (0.0, 0.1, 0.2, 0.3, 0.4 and 0.8 molal or osmotic potentials of 0.00, -0.47, -0.93, -1.39, -1.85 and -3.75 MPa were applied int the nutrient solutions. The plastic pots containing the treatment solutions were placed in waterbath with temperature of 30 ± 1°C, for rice, and 25 ± 1°C, for wheat. The rice and wheat seedlings were cultivated during 48 hours in distilled water and after this period -they were changed to pots, containing nutrient solutions with different sodium chloride concentrations and pH = 6.0. The rice plants were cultivated during twelve days and the wheat plants, ten days. The longest seminal root lengths, the

  11. Effect of LaCI3 on the chilling tolerance of rice seedlings

    Institute of Scientific and Technical Information of China (English)

    LIMeiru; LIUHongxian; WANGYirou

    1997-01-01

    The rice variety Tesanai 2 is susceptible to chilling. Exposure of the seedlings grown at 28±1℃ and under a photo flux density(PFD) of 30 μmol/m2s to 1℃ and under a PFD of 150μmol/m2s for 2 d caused a physiological disorder called chilling injury which reduced the survival rate to 50%.

  12. Overexpression of a glyoxalase gene, OsGly I, improves abiotic stress tolerance and grain yield in rice (Oryza sativa L.).

    Science.gov (United States)

    Zeng, Zhengming; Xiong, Fangjie; Yu, Xiaohong; Gong, Xiaoping; Luo, Juntao; Jiang, Yudong; Kuang, Haochi; Gao, Bijun; Niu, Xiangli; Liu, Yongsheng

    2016-12-01

    Glyoxalase I (Gly I) is a component of the glyoxalase system which is involved in the detoxification of methylglyoxal, a byproduct of glycolysis. In the present study, a gene of rice (Oryza sativa L., cv. Nipponbare) encoding Gly I was cloned and characterized. The quantitative real-time PCR analysis indicated that rice Gly I (OsGly I) was ubiquitously expressed in root, stem, leaf, leaf sheath and spikelet with varying abundance. OsGly I was markedly upregulated in response to NaCl, ZnCl2 and mannitol in rice seedlings. For further functional investigation, OsGly I was overexpressed in rice using Agrobacterium-mediated transformation. Transgenic rice lines exhibited increased glyoxalase enzyme activity, decreased methylglyoxal level and improved tolerance to NaCl, ZnCl2 and mannitol compared to wild-type plants. Enhancement of stress tolerance in transgenic lines was associated with reduction of malondialdehyde content which was derived from cellular lipid peroxidation. In addition, the OsGly I-overexpression transgenic plants performed higher seed setting rate and yield. Collectively, these results indicate the potential of bioengineering the Gly I gene in crops. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  13. ICE1 of Pyrus ussuriensis functions in cold tolerance by enhancing PuDREBa transcriptional levels through interacting with PuHHP1

    Science.gov (United States)

    Huang, Xiaosan; Li, Kongqing; Jin, Cong; Zhang, Shaoling

    2015-12-01

    ICE1 transcription factor plays an important role in plant cold stress via regulating the expression of stress-responsive genes. In this study, a PuICE1 gene isolated from Pyrus ussuriensis was characterized for its function in cold tolerance. The expression levels of the PuICE1 were induced by cold, dehydration and salt, with the greatest induction under cold conditions. PuICE1 was localized in the nucleus and could bind specifically to the MYC element in the PuDREBa promoter. The PuICE1 fused to the GAL4 DNA-binding domain to have transcriptional activation activity. Ectopic expression of the PuICE1 in tomato conferred enhanced tolerance to cold stress at cold temperatures, less electrolyte leakage, less MDA content, higher chlorophyll content, higher survival rate, higher proline content, higher activities of enzymes. In additon, steady-state mRNA levels of six stress-responsive genes coding for either functional or regulatory genes were induced to higher levels in the transgenic lines by cold stress. Yeast two-hybrid, transient assay, split luciferase complementation and BiFC assays all revealed that PuHHP1 protein can physically interact with PuICE1. Taken together, these results demonstrated that PuICE1 plays a positive role in cold tolerance, which may be due to enhancement of PuDREBa transcriptional levels through interacting with the PuHHP1.

  14. Transcriptome Profiling of Two Asparagus Bean (Vigna unguiculata subsp. sesquipedalis) Cultivars Differing in Chilling Tolerance under Cold Stress

    Science.gov (United States)

    Tan, Huaqiang; Huang, Haitao; Tie, Manman; Tang, Yi; Lai, Yunsong; Li, Huanxiu

    2016-01-01

    Cowpea (V. unguiculata L. Walp.) is an important tropical grain legume. Asparagus bean (V. unguiculata ssp. sesquipedialis) is a distinctive subspecies of cowpea, which is considered one of the top ten Asian vegetables. It can be adapted to a wide range of environmental stimuli such as drought and heat. Nevertheless, it is an extremely cold-sensitive tropical species. Improvement of chilling tolerance in asparagus bean may significantly increase its production and prolong its supply. However, gene regulation and signaling pathways related to cold response in this crop remain unknown. Using Illumina sequencing technology, modification of global gene expression in response to chilling stress in two asparagus bean cultivars—“Dubai bean” and “Ningjiang-3”, which are tolerant and sensitive to chilling, respectively—were investigated. More than 1.8 million clean reads were obtained from each sample. After de novo assembly, 88,869 unigenes were finally generated with a mean length of 635 bp. Of these unigenes, 41,925 (47.18%) had functional annotations when aligned to public protein databases. Further, we identified 3,510 differentially expressed genes (DEGs) in Dubai bean, including 2,103 up-regulated genes and 1,407 down-regulated genes. While in Ningjiang-3, we found 2,868 DEGs, 1,786 of which were increasing and the others were decreasing. 1,744 DEGs were commonly regulated in two cultivars, suggesting that some genes play fundamental roles in asparagus bean during cold stress. Functional classification of the DEGs in two cultivars using Mercator pipeline indicated that RNA, protein, signaling, stress and hormone metabolism were five major groups. In RNA group, analysis of TFs in DREB subfamily showed that ICE1-CBF3-COR cold responsive cascade may also exist in asparagus bean. Our study is the first to provide the transcriptome sequence resource for asparagus bean, which will accelerate breeding cold resistant asparagus bean varieties through genetic

  15. Transcriptome Profiling of Two Asparagus Bean (Vigna unguiculata subsp. sesquipedalis Cultivars Differing in Chilling Tolerance under Cold Stress.

    Directory of Open Access Journals (Sweden)

    Huaqiang Tan

    Full Text Available Cowpea (V. unguiculata L. Walp. is an important tropical grain legume. Asparagus bean (V. unguiculata ssp. sesquipedialis is a distinctive subspecies of cowpea, which is considered one of the top ten Asian vegetables. It can be adapted to a wide range of environmental stimuli such as drought and heat. Nevertheless, it is an extremely cold-sensitive tropical species. Improvement of chilling tolerance in asparagus bean may significantly increase its production and prolong its supply. However, gene regulation and signaling pathways related to cold response in this crop remain unknown. Using Illumina sequencing technology, modification of global gene expression in response to chilling stress in two asparagus bean cultivars-"Dubai bean" and "Ningjiang-3", which are tolerant and sensitive to chilling, respectively-were investigated. More than 1.8 million clean reads were obtained from each sample. After de novo assembly, 88,869 unigenes were finally generated with a mean length of 635 bp. Of these unigenes, 41,925 (47.18% had functional annotations when aligned to public protein databases. Further, we identified 3,510 differentially expressed genes (DEGs in Dubai bean, including 2,103 up-regulated genes and 1,407 down-regulated genes. While in Ningjiang-3, we found 2,868 DEGs, 1,786 of which were increasing and the others were decreasing. 1,744 DEGs were commonly regulated in two cultivars, suggesting that some genes play fundamental roles in asparagus bean during cold stress. Functional classification of the DEGs in two cultivars using Mercator pipeline indicated that RNA, protein, signaling, stress and hormone metabolism were five major groups. In RNA group, analysis of TFs in DREB subfamily showed that ICE1-CBF3-COR cold responsive cascade may also exist in asparagus bean. Our study is the first to provide the transcriptome sequence resource for asparagus bean, which will accelerate breeding cold resistant asparagus bean varieties through genetic

  16. Transcriptome Profiling of Two Asparagus Bean (Vigna unguiculata subsp. sesquipedalis) Cultivars Differing in Chilling Tolerance under Cold Stress.

    Science.gov (United States)

    Tan, Huaqiang; Huang, Haitao; Tie, Manman; Tang, Yi; Lai, Yunsong; Li, Huanxiu

    2016-01-01

    Cowpea (V. unguiculata L. Walp.) is an important tropical grain legume. Asparagus bean (V. unguiculata ssp. sesquipedialis) is a distinctive subspecies of cowpea, which is considered one of the top ten Asian vegetables. It can be adapted to a wide range of environmental stimuli such as drought and heat. Nevertheless, it is an extremely cold-sensitive tropical species. Improvement of chilling tolerance in asparagus bean may significantly increase its production and prolong its supply. However, gene regulation and signaling pathways related to cold response in this crop remain unknown. Using Illumina sequencing technology, modification of global gene expression in response to chilling stress in two asparagus bean cultivars-"Dubai bean" and "Ningjiang-3", which are tolerant and sensitive to chilling, respectively-were investigated. More than 1.8 million clean reads were obtained from each sample. After de novo assembly, 88,869 unigenes were finally generated with a mean length of 635 bp. Of these unigenes, 41,925 (47.18%) had functional annotations when aligned to public protein databases. Further, we identified 3,510 differentially expressed genes (DEGs) in Dubai bean, including 2,103 up-regulated genes and 1,407 down-regulated genes. While in Ningjiang-3, we found 2,868 DEGs, 1,786 of which were increasing and the others were decreasing. 1,744 DEGs were commonly regulated in two cultivars, suggesting that some genes play fundamental roles in asparagus bean during cold stress. Functional classification of the DEGs in two cultivars using Mercator pipeline indicated that RNA, protein, signaling, stress and hormone metabolism were five major groups. In RNA group, analysis of TFs in DREB subfamily showed that ICE1-CBF3-COR cold responsive cascade may also exist in asparagus bean. Our study is the first to provide the transcriptome sequence resource for asparagus bean, which will accelerate breeding cold resistant asparagus bean varieties through genetic engineering, and

  17. OsbHLH148, a basic helix-loop-helix protein, interacts with OsJAZ proteins in a jasmonate signaling pathway leading to drought tolerance in rice.

    Science.gov (United States)

    Seo, Ju-Seok; Joo, Joungsu; Kim, Min-Jeong; Kim, Yeon-Ki; Nahm, Baek Hie; Song, Sang Ik; Cheong, Jong-Joo; Lee, Jong Seob; Kim, Ju-Kon; Choi, Yang Do

    2011-03-01

    Jasmonates play important roles in development, stress responses and defense in plants. Here, we report the results of a study using a functional genomics approach that identified a rice basic helix-loop-helix domain gene, OsbHLH148, that conferred drought tolerance as a component of the jasmonate signaling module in rice. OsbHLH148 transcript levels were rapidly increased by treatment with methyl jasmonate (MeJA) or abscisic acid, and abiotic stresses including dehydration, high salinity, low temperature and wounding. Transgenic over-expression of OsbHLH148 in rice confers plant tolerance to drought stress. Expression profiling followed by DNA microarray and RNA gel-blot analyses of transgenic versus wild-type rice identified genes that are up-regulated by OsbHLH148 over-expression. These include OsDREB and OsJAZ genes that are involved in stress responses and the jasmonate signaling pathway, respectively. OsJAZ1, a rice ZIM domain protein, interacted with OsbHLH148 in yeast two-hybrid and pull-down assays, but it interacted with the putative OsCOI1 only in the presence of coronatine. Furthermore, the OsJAZ1 protein was degraded by rice and Arabidopsis extracts in the presence of coronatine, and its degradation was inhibited by MG132, a 26S proteasome inhibitor, suggesting 26S proteasome-mediated degradation of OsJAZ1 via the SCF(OsCOI1) complex. The transcription level of OsJAZ1 increased upon exposure of rice to MeJA. These results show that OsJAZ1 could act as a transcriptional regulator of the OsbHLH148-related jasmonate signaling pathway leading to drought tolerance. Thus, our study suggests that OsbHLH148 acts on an initial response of jasmonate-regulated gene expression toward drought tolerance, constituting the OsbHLH148-OsJAZ-OsCOI1 signaling module in rice.

  18. Overexpression of WsSGTL1 gene of Withania somnifera enhances salt tolerance, heat tolerance and cold acclimation ability in transgenic Arabidopsis plants.

    Directory of Open Access Journals (Sweden)

    Manoj K Mishra

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

  19. Overexpression of a novel cold-responsive transcript factor LcFIN1 from sheepgrass enhances tolerance to low temperature stress in transgenic plants.

    Science.gov (United States)

    Gao, Qiong; Li, Xiaoxia; Jia, Junting; Zhao, Pincang; Liu, Panpan; Liu, Zhujiang; Ge, Liangfa; Chen, Shuangyan; Qi, Dongmei; Deng, Bo; Lee, Byung-Hyun; Liu, Gongshe; Cheng, Liqin

    2016-03-01

    As a perennial forage crop broadly distributed in eastern Eurasia, sheepgrass (Leymus chinensis (Trin.) Tzvel) is highly tolerant to low-temperature stress. Previous report indicates that sheepgrass is able to endure as low as -47.5 °C,allowing it to survive through the cold winter season. However, due to the lack of sufficient studies, the underlying mechanism towards the extraordinary low-temperature tolerance is unclear. Although the transcription profiling has provided insight into the transcriptome response to cold stress, more detailed studies are required to dissect the molecular mechanism regarding the excellent abiotic stress tolerance. In this work, we report a novel transcript factor LcFIN1 (L. chinensis freezing-induced 1) from sheepgrass. LcFIN1 showed no homology with other known genes and was rapidly and highly induced by cold stress, suggesting that LcFIN1 participates in the early response to cold stress. Consistently, ectopic expression of LcFIN1 significantly increased cold stress tolerance in the transgenic plants, as indicated by the higher survival rate, fresh weight and other stress-related indexes after a freezing treatment. Transcriptome analysis showed that numerous stress-related genes were differentially expressed in LcFIN1-overexpressing plants, suggesting that LcFIN1 may enhance plant abiotic stress tolerance by transcriptional regulation. Electrophoretic mobility shift assays and CHIP-qPCR showed that LcCBF1 can bind to the CRT/DRE cis-element located in the promoter region of LcFIN1, suggesting that LcFIN1 is directly regulated by LcCBF1. Taken together, our results suggest that LcFIN1 positively regulates plant adaptation response to cold stress and is a promising candidate gene to improve crop cold tolerance. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  20. Overexpression of GhDof1 improved salt and cold tolerance and seed oil content in Gossypium hirsutum.

    Science.gov (United States)

    Su, Ying; Liang, Wei; Liu, Zhengjie; Wang, Yumei; Zhao, Yanpeng; Ijaz, Babar; Hua, Jinping

    2017-07-28

    A homologous GhDof1, which belongs to a large family of plant-specific transcription factor DOF, was isolated from Upland cotton (Gossypium hirsutum L.). GhDof1 protein was located in the nucleus of onion epidermal cells, the core domain of transcriptional activity existed in the C-terminal, and the activity elements of GhDof1 promoter existed in the regions of -645∼ -469bp and -286∼ -132bp of transcriptional start codon. GhDof1 constitutively expressed in leaves, roots and stems, accumulated highest in leaves. The salinity and cold treatments induced GhDof1 transcript accumulation. The GhDof1-overexpressed cotton showed significantly higher salt and cold tolerance over the wild-type plants. Under salt stress, the root growth of overexpressed GhDof1 lines was promoted. The expression levels of stress-responsive genes, GhP5CS, GhSOD and GhMYB, were differently up-regulated in transgenic lines. Oil contents increased in some transgenic plants, and protein contents reduced compared with transformed receptor. These results suggested that GhDof1 was a functional transcription factor for improving the abiotic tolerance and seed oil content in Upland cotton. Copyright © 2017 Elsevier GmbH. All rights reserved.

  1. Evolution of cold-tolerant fungal symbionts permits winter fungiculture by leafcutter ants at the northern frontier of a tropical ant-fungus symbiosis.

    Science.gov (United States)

    Mueller, Ulrich G; Mikheyev, Alexander S; Hong, Eunki; Sen, Ruchira; Warren, Dan L; Solomon, Scott E; Ishak, Heather D; Cooper, Mike; Miller, Jessica L; Shaffer, Kimberly A; Juenger, Thomas E

    2011-03-08

    The obligate mutualism between leafcutter ants and their Attamyces fungi originated 8 to 12 million years ago in the tropics, but extends today also into temperate regions in South and North America. The northernmost leafcutter ant Atta texana sustains fungiculture during winter temperatures that would harm the cold-sensitive Attamyces cultivars of tropical leafcutter ants. Cold-tolerance of Attamyces cultivars increases with winter harshness along a south-to-north temperature gradient across the range of A. texana, indicating selection for cold-tolerant Attamyces variants along the temperature cline. Ecological niche modeling corroborates winter temperature as a key range-limiting factor impeding northward expansion of A. texana. The northernmost A. texana populations are able to sustain fungiculture throughout winter because of their cold-adapted fungi and because of seasonal, vertical garden relocation (maintaining gardens deep in the ground in winter to protect them from extreme cold, then moving gardens to warmer, shallow depths in spring). Although the origin of leafcutter fungiculture was an evolutionary breakthrough that revolutionized the food niche of tropical fungus-growing ants, the original adaptations of this host-microbe symbiosis to tropical temperatures and the dependence on cold-sensitive fungal symbionts eventually constrained expansion into temperate habitats. Evolution of cold-tolerant fungi within the symbiosis relaxed constraints on winter fungiculture at the northern frontier of the leafcutter ant distribution, thereby expanding the ecological niche of an obligate host-microbe symbiosis.

  2. 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.

  3. Reproductive stage physiological and transcriptional responses to salinity stress in reciprocal populations derived from tolerant (Horkuch) and susceptible (IR29) rice

    Science.gov (United States)

    Razzaque, Samsad; Haque, Taslima; Elias, Sabrina M.; Rahman, Md. Sazzadur; Biswas, Sudip; Schwartz, Scott; Ismail, Abdelbagi M.; Walia, Harkamal; Juenger, Thomas E.; Seraj, Zeba I.

    2017-04-01

    Global increase in salinity levels has made it imperative to identify novel sources of genetic variation for tolerance traits, especially in rice. The rice landrace Horkuch, endemic to the saline coastal area of Bangladesh, was used in this study as the source of tolerance in reciprocal crosses with the sensitive but high-yielding IR29 variety for discovering transcriptional variation associated with salt tolerance in the resulting populations. The cytoplasmic effect of the Horkuch background in leaves under stress showed functional enrichment for signal transduction, DNA-dependent regulation and transport activities. In roots the enrichment was for cell wall organization and macromolecule biosynthesis. In contrast, the cytoplasmic effect of IR29 showed upregulation of apoptosis and downregulation of phosphorylation across tissues relative to Horkuch. Differential gene expression in leaves of the sensitive population showed downregulation of GO processes like photosynthesis, ATP biosynthesis and ion transport. Roots of the tolerant plants conversely showed upregulation of GO terms like G-protein coupled receptor pathway, membrane potential and cation transport. Furthermore, genes involved in regulating membrane potentials were constitutively expressed only in the roots of tolerant individuals. Overall our work has developed genetic resources and elucidated the likely mechanisms associated with the tolerance response of the Horkuch genotype.

  4. Reproductive stage physiological and transcriptional responses to salinity stress in reciprocal populations derived from tolerant (Horkuch) and susceptible (IR29) rice

    Science.gov (United States)

    Razzaque, Samsad; Haque, Taslima; Elias, Sabrina M.; Rahman, Md. Sazzadur; Biswas, Sudip; Schwartz, Scott; Ismail, Abdelbagi M.; Walia, Harkamal; Juenger, Thomas E.; Seraj, Zeba I.

    2017-01-01

    Global increase in salinity levels has made it imperative to identify novel sources of genetic variation for tolerance traits, especially in rice. The rice landrace Horkuch, endemic to the saline coastal area of Bangladesh, was used in this study as the source of tolerance in reciprocal crosses with the sensitive but high-yielding IR29 variety for discovering transcriptional variation associated with salt tolerance in the resulting populations. The cytoplasmic effect of the Horkuch background in leaves under stress showed functional enrichment for signal transduction, DNA-dependent regulation and transport activities. In roots the enrichment was for cell wall organization and macromolecule biosynthesis. In contrast, the cytoplasmic effect of IR29 showed upregulation of apoptosis and downregulation of phosphorylation across tissues relative to Horkuch. Differential gene expression in leaves of the sensitive population showed downregulation of GO processes like photosynthesis, ATP biosynthesis and ion transport. Roots of the tolerant plants conversely showed upregulation of GO terms like G-protein coupled receptor pathway, membrane potential and cation transport. Furthermore, genes involved in regulating membrane potentials were constitutively expressed only in the roots of tolerant individuals. Overall our work has developed genetic resources and elucidated the likely mechanisms associated with the tolerance response of the Horkuch genotype.

  5. Responses of the bed bug, Cimex lectularius, to temperature extremes and dehydration: levels of tolerance, rapid cold hardening and expression of heat shock proteins.

    Science.gov (United States)

    Benoit, J B; Lopez-Martinez, G; Teets, N M; Phillips, S A; Denlinger, D L

    2009-12-01

    This study of the bed bug, Cimex lectularius, examines tolerance of adult females to extremes in temperature and loss of body water. Although the supercooling point (SCP) of the bed bugs was approximately -20 degrees C, all were killed by a direct 1 h exposure to -16 degrees C. Thus, this species cannot tolerate freezing and is killed at temperatures well above its SCP. Neither cold acclimation at 4 degrees C for 2 weeks nor dehydration (15% loss of water content) enhanced cold tolerance. However, bed bugs have the capacity for rapid cold hardening, i.e. a 1-h exposure to 0 degrees C improved their subsequent tolerance of -14 and -16 degrees C. In response to heat stress, fewer than 20% of the bugs survived a 1-h exposure to 46 degrees C, and nearly all were killed at 48 degrees C. Dehydration, heat acclimation at 30 degrees C for 2 weeks and rapid heat hardening at 37 degrees C for 1 h all failed to improve heat tolerance. Expression of the mRNAs encoding two heat shock proteins (Hsps), Hsp70 and Hsp90, was elevated in response to heat stress, cold stress and during dehydration and rehydration. The response of Hsp90 was more pronounced than that of Hsp70 during dehydration and rehydration. Our results define the tolerance limits for bed bugs to these commonly encountered stresses of temperature and low humidity and indicate a role for Hsps in responding to these stresses.

  6. BrUGE1 transgenic rice showed improved growth performance with enhanced drought tolerance.

    Science.gov (United States)

    Abdula, Sailila E; Lee, Hye Jung; Kim, Joonki; Niño, Marjohn C; Jung, Yu-Jin; Cho, Young-Chan; Nou, Illsup; Kang, Kwon-Kyoo; Cho, Yong-Gu

    2016-03-01

    UDP-glucose 4-epimerase (UGE) catalyzes the reversible conversion of UDP-glucose to UDP-galactose. To understand the biological function of UGE from Brassica rapa, the gene BrUGE1 was cloned and introduced into the genome of wild type rice 'Gopum' using the Agrobacterium-mediated transformation method. Four lines which carried a single copy gene were selected and forwarded to T3 generation. Agronomic traits evaluation of the transgenic T3 lines (CB01, CB03, and CB06) under optimal field conditions revealed enriched biomass production particularly in panicle length, number of productive tillers, number of spikelets per panicle, and filled spikelets. These remarkably improved agronomic traits were ascribed to a higher photosynthetic rate complemented with higher CO2 assimilation. Transcripts of BrUGE1 in transgenic lines continuously accumulated at higher levels after the 20% PEG6000 treatment, implying its probable role in drought stress regulation. This was paralleled by rapid accumulation of soluble sugars which act as osmoprotectants, leading to delayed leaf rolling and drying. Our findings suggest the potential of BrUGE1 in improving rice growth performance under optimal and water deficit conditions.

  7. Plastid ribosomal protein S5 is involved in photosynthesis, plant development, and cold stress tolerance in Arabidopsis.

    Science.gov (United States)

    Zhang, Junxiang; Yuan, Hui; Yang, Yong; Fish, Tara; Lyi, Sangbom M; Thannhauser, Theodore W; Zhang, Lugang; Li, Li

    2016-04-01

    Plastid ribosomal proteins are essential components of protein synthesis machinery and have diverse roles in plant growth and development. Mutations in plastid ribosomal proteins lead to a range of developmental phenotypes in plants. However, how they regulate these processes is not fully understood, and the functions of some individual plastid ribosomal proteins remain unknown. To identify genes responsible for chloroplast development, we isolated and characterized a mutant that exhibited pale yellow inner leaves with a reduced growth rate in Arabidopsis. The mutant (rps5) contained a missense mutation of plastid ribosomal protein S5 (RPS5), which caused a dramatically reduced abundance of chloroplast 16S rRNA and seriously impaired 16S rRNA processing to affect ribosome function and plastid translation. Comparative proteomic analysis revealed that the rps5 mutation suppressed the expression of a large number of core components involved in photosystems I and II as well as many plastid ribosomal proteins. Unexpectedly, a number of proteins associated with cold stress responses were greatly decreased in rps5, and overexpression of the plastid RPS5 improved plant cold stress tolerance. Our results indicate that RPS5 is an important constituent of the plastid 30S subunit and affects proteins involved in photosynthesis and cold stress responses to mediate plant growth and development.

  8. Retorno da produção de arroz irrigado com cultivares convencionais após o uso do sistema Clearfield® Non-tolerant rice production after using the ClearfieldTM rice system

    Directory of Open Access Journals (Sweden)

    L.A. Avila

    2010-01-01

    (imazethapyr + imazapic semeado após três anos de uso consecutivo do sistema Clearfield foi de 30%. Não houve diferença entre os cultivares não tolerantes testados neste experimento quanto à suscetibilidade ao residual de imazethapyr + imazapic. Não houve aumento de fitotoxicidade nas plantas do arroz irrigado pela aplicação dos herbicidas no arroz irrigado não tolerante semeado na sucessão, porém ressalta-se a necessidade do uso de herbicidas que não sejam inibidores da enzima ALS para reduzir a pressão de seleção de plantas daninhas resistentes ou tolerantes a esses herbicidas.The herbicides imazethapyr and imazapic used in the Clearfield rice system can persist in the soil and affect non-tolerant rice cultivars sown in rotation. The effect on rice plants can vary according to the cultivar and herbicide used in rotation. Thus, a field experiment was conducted to evaluate cultivar and herbicide options when growing non-tolerant rice after using Clearfield rice system. The experiment was installed in the 2006/07 growing season, in a lowland area located in Santa Maria, Rio Grande do Sul, Southern Brazil. The experiment was in a randomized block design with three replications in a factorial scheme. Factor A included two succession systems of Clearfield rice and non-Clearfield rice in the first three growing seasons (2003/04, 2004/05 and 2005/06: Succession 1 - two agricultural growing seasons using the Clearfield system with application of the herbicide mixture imazethapyr and imazapic (75 and 25 g a.i.. ha-1 and one growing season with non-tolerant rice, without application of imidazolinones; and Succession 2 - three growing seasons using Clearfield system and herbicide application at the same rate specified previously. Factor B included rice cultivars used in the fourth year (BR IRGA 409, IRGA 417, IRGA 422 CL and BRS 7 "TAIM". Factor C included different herbicides used during the fourth growing season (2006/07, bispyribac-sodium, clomazone + propanyl

  9. Evaluation of the agronomic performance of atrazine-tolerant transgenic japonica rice parental lines for utilization in hybrid seed production.

    Science.gov (United States)

    Zhang, Luhua; Chen, Haiwei; Li, Yanlan; Li, Yanan; Wang, Shengjun; Su, Jinping; Liu, Xuejun; Chen, Defu; Chen, Xiwen

    2014-01-01

    Currently, the purity of hybrid seed is a crucial limiting factor when developing hybrid japonica rice (Oryza sativa L.). To chemically control hybrid seed purity, we transferred an improved atrazine chlorohydrolase gene (atzA) from Pseudomonas ADP into hybrid japonica parental lines (two maintainers, one restorer), and Nipponbare, by using Agrobacterium-mediated transformation. We subsequently selected several transgenic lines from each genotype by using PCR, RT-PCR, and germination analysis. In the presence of the investigated atrazine concentrations, particularly 150 µM atrazine, almost all of the transgenic lines produced significantly larger seedlings, with similar or higher germination percentages, than did the respective controls. Although the seedlings of transgenic lines were taller and gained more root biomass compared to the respective control plants, their growth was nevertheless inhibited by atrazine treatment compared to that without treatment. When grown in soil containing 2 mg/kg or 5 mg/kg atrazine, the transgenic lines were taller, and had higher total chlorophyll contents than did the respective controls; moreover, three of the strongest transgenic lines completely recovered after 45 days of growth. After treatment with 2 mg/kg or 5 mg/kg of atrazine, the atrazine residue remaining in the soil was 2.9-7.0% or 0.8-8.7% respectively, for transgenic lines, and 44.0-59.2% or 28.1-30.8%, respectively, for control plants. Spraying plants at the vegetative growth stage with 0.15% atrazine effectively killed control plants, but not transgenic lines. Our results indicate that transgenic atzA rice plants show tolerance to atrazine, and may be used as parental lines in future hybrid seed production.

  10. Evaluation of the agronomic performance of atrazine-tolerant transgenic japonica rice parental lines for utilization in hybrid seed production.

    Directory of Open Access Journals (Sweden)

    Luhua Zhang

    Full Text Available Currently, the purity of hybrid seed is a crucial limiting factor when developing hybrid japonica rice (Oryza sativa L.. To chemically control hybrid seed purity, we transferred an improved atrazine chlorohydrolase gene (atzA from Pseudomonas ADP into hybrid japonica parental lines (two maintainers, one restorer, and Nipponbare, by using Agrobacterium-mediated transformation. We subsequently selected several transgenic lines from each genotype by using PCR, RT-PCR, and germination analysis. In the presence of the investigated atrazine concentrations, particularly 150 µM atrazine, almost all of the transgenic lines produced significantly larger seedlings, with similar or higher germination percentages, than did the respective controls. Although the seedlings of transgenic lines were taller and gained more root biomass compared to the respective control plants, their growth was nevertheless inhibited by atrazine treatment compared to that without treatment. When grown in soil containing 2 mg/kg or 5 mg/kg atrazine, the transgenic lines were taller, and had higher total chlorophyll contents than did the respective controls; moreover, three of the strongest transgenic lines completely recovered after 45 days of growth. After treatment with 2 mg/kg or 5 mg/kg of atrazine, the atrazine residue remaining in the soil was 2.9-7.0% or 0.8-8.7% respectively, for transgenic lines, and 44.0-59.2% or 28.1-30.8%, respectively, for control plants. Spraying plants at the vegetative growth stage with 0.15% atrazine effectively killed control plants, but not transgenic lines. Our results indicate that transgenic atzA rice plants show tolerance to atrazine, and may be used as parental lines in future hybrid seed production.

  11. Evaluation of the Agronomic Performance of Atrazine-Tolerant Transgenic japonica Rice Parental Lines for Utilization in Hybrid Seed Production

    Science.gov (United States)

    Li, Yanlan; Li, Yanan; Wang, Shengjun; Su, Jinping; Liu, Xuejun; Chen, Defu; Chen, Xiwen

    2014-01-01

    Currently, the purity of hybrid seed is a crucial limiting factor when developing hybrid japonica rice (Oryza sativa L.). To chemically control hybrid seed purity, we transferred an improved atrazine chlorohydrolase gene (atzA) from Pseudomonas ADP into hybrid japonica parental lines (two maintainers, one restorer), and Nipponbare, by using Agrobacterium-mediated transformation. We subsequently selected several transgenic lines from each genotype by using PCR, RT-PCR, and germination analysis. In the presence of the investigated atrazine concentrations, particularly 150 µM atrazine, almost all of the transgenic lines produced significantly larger seedlings, with similar or higher germination percentages, than did the respective controls. Although the seedlings of transgenic lines were taller and gained more root biomass compared to the respective control plants, their growth was nevertheless inhibited by atrazine treatment compared to that without treatment. When grown in soil containing 2 mg/kg or 5 mg/kg atrazine, the transgenic lines were taller, and had higher total chlorophyll contents than did the respective controls; moreover, three of the strongest transgenic lines completely recovered after 45 days of growth. After treatment with 2 mg/kg or 5 mg/kg of atrazine, the atrazine residue remaining in the soil was 2.9–7.0% or 0.8–8.7% respectively, for transgenic lines, and 44.0–59.2% or 28.1–30.8%, respectively, for control plants. Spraying plants at the vegetative growth stage with 0.15% atrazine effectively killed control plants, but not transgenic lines. Our results indicate that transgenic atzA rice plants show tolerance to atrazine, and may be used as parental lines in future hybrid seed production. PMID:25275554

  12. SNP Discovery and Genetic Variation of Candidate Genes Relevant to Heat Tolerance and Agronomic Traits in Natural Populations of Sand Rice (Agriophyllum squarrosum).

    Science.gov (United States)

    Zhao, Pengshan; Zhang, Jiwei; Qian, Chaoju; Zhou, Qin; Zhao, Xin; Chen, Guoxiong; Ma, Xiao-Fei

    2017-01-01

    The extreme stress tolerance and high nutritional value of sand rice (Agriophyllum squarrosum) make it attractive for use as an alternative crop in response to concerns about ongoing climate change and future food security. However, a lack of genetic information hinders understanding of the mechanisms underpinning the morphological and physiological adaptations of sand rice. In the present study, we sequenced and analyzed the transcriptomes of two individuals representing semi-arid [Naiman (NM)] and arid [Shapotou (SPT)] sand rice genotypes. A total of 105,868 pairwise single nucleotide polymorphisms (SNPs) distributed in 24,712 Unigenes were identified among SPT and NM samples; the average SNP frequency was 0.3% (one SNP per 333 base pair). Characterization of gene annotation demonstrated that variations in genes involved in DNA recombination were associated with the survival of the NM population in the semi-arid environment. A set of genes predicted to be relevant to heat stress response and agronomic traits was functionally annotated using the accumulated knowledge from Arabidopsis and several crop plants, including rice, barley, maize, and sorghum. Four candidate genes related to heat tolerance (heat-shock transcription factor, HsfA1d), seed size (DA1-Related, DAR1), and flowering (early flowering 3, ELF3 and late elongated hypocotyl, LHY) were subjected to analysis of the genetic diversity in 10 natural populations, representing the core germplasm resource across the area of sand rice distribution in China. Only one SNP was detected in each of HsfA1d and DAR1, among 60 genotypes, with two in ELF3 and four in LHY. Nucleotide diversity ranged from 0.00032 to 0.00118. Haplotype analysis indicated that the NM population carried a specific allele for all four genes, suggesting that divergence has occurred between NM and other populations. These four genes could be further analyzed to determine whether they are associated with phenotype variation and identify

  13. Engineering carpel-specific cold stress tolerance: a case study in Arabidopsis

    Science.gov (United States)

    Freezing temperatures during winter generally do not injure floral buds of horticulturally important crops. Entry into dormancy coupled with cold acclimation provides adequate protection unless the temperatures are exceptionally low. This measure of protection is lost in spring when the floral bud...

  14. Foliar applied abscisic acid increases 'Chardonnay' grapevines (Vitis vinifera) bud freezing tolerance during Autumn cold acclimation

    Science.gov (United States)

    Economic loss due to cold weather events is a major constraint to winegrape-related industries where extreme and/or fluctuating winter temperatures induce injury and required remedial retraining and replanting increases production costs and lowers yield and fruit quality. The purpose of this study ...

  15. Integrating Small RNA Sequencing with QTL Mapping for Identification of miRNAs and Their Target Genes Associated with Heat Tolerance at the Flowering Stage in Rice

    Science.gov (United States)

    Liu, Qing; Yang, Tifeng; Yu, Ting; Zhang, Shaohong; Mao, Xingxue; Zhao, Junliang; Wang, Xiaofei; Dong, Jingfang; Liu, Bin

    2017-01-01

    Although, microRNAs (miRNAs) have been reported to be associated with heat tolerance at the seedling stage in rice, their involvement in heat tolerance at the flowering stage is still unknown. In this study, small RNA profiling was conducted in a heat-tolerant variety Gan-Xiang-Nuo (GXN) and a heat-sensitive variety Hua-Jing-Xian-74 (HJX), respectively. Totally, 102 miRNAs were differentially expressed (DE) under heat stress. Compared to HJX, GXN had more DE miRNAs and its DE miRNAs changed earlier under heat stress. Plant Ontology (PO) analysis of the target genes revealed that many DE miRNAs were involved in flower development. As a parallel experiment, QTL mapping was also conducted and four QTLs for heat tolerance at the flowering stage were identified using chromosome single-segment substitution lines derived from GXN and HJX. Further, through integrating analysis of DE miRNAs with QTLs, we identified 8 target genes corresponding to 26 miRNAs within the four QTL regions. Some meaningful target genes such as LOC_Os12g42400, SGT1, and pectinesterase were within the QTL regions. The negative correlation between miR169r-5p and its target gene LOC_Os12g42400 was confirmed under heat stress, and overexpression of miR169r-5p enhanced heat tolerance at flowering stage in rice. Our results demonstrate that the integrated analysis of genome-wide miRNA profiling with QTL mapping can facilitate identification of miRNAs and their target genes associated with the target traits and the limited candidates identified in this study offer an important source for further functional analysis and molecular breeding for heat tolerance in rice. PMID:28174587

  16. Starch-related alpha-glucan/water dikinase is involved in the cold-induced development of freezing tolerance in Arabidopsis.

    Science.gov (United States)

    Yano, Ryoichi; Nakamura, Masanobu; Yoneyama, Tadakatsu; Nishida, Ikuo

    2005-06-01

    Cold-induced soluble sugar accumulation enhances the degree of freezing tolerance in various cold-hardy plants including Arabidopsis (Arabidopsis thaliana), where soluble sugars accumulate in only a few hours at 2 degrees C. Hence, along with photosynthesis, starch degradation might play a significant role in cold-induced sugar accumulation and enhanced freezing tolerance. Starch-related alpha-glucan/water dikinase (EC 2.7.9.4), encoded by Arabidopsis STARCH EXCESS 1 (SEX1), is hypothesized to regulate starch degradation in plastids by phosphorylating starch, thereby ensuring better accessibility by starch-degrading enzymes. Here, we show that Arabidopsis sex1 mutants, when incubated at 2 degrees C for 1 d, were unable to accumulate maltooligosaccharides or normal glucose and fructose levels. In addition, they displayed impaired freezing tolerance. After 7 d at 2 degrees C, sex1 mutants did not show any of the above abnormal phenotypes but displayed slightly higher leaf starch contents. The impaired freezing tolerance of sex1 mutants was restored by overexpression of wild-type SEX1 cDNA using the cauliflower mosaic virus 35S promoter. The results demonstrate a genetic link between the SEX1 locus and plant freezing tolerance, and show that starch degradation is important for enhanced freezing tolerance during an early phase of cold acclimation. However, induction of starch degradation was not accompanied by significant changes in alpha-glucan/water dikinase activity in leaf extracts and preceded cold-induced augmentation of SEX1 transcripts. Therefore, we conclude that augmentation of SEX1 transcripts might be a homeostatic response to low temperature, and that starch degradation during an early phase of cold acclimation could be regulated by a component(s) of a starch degradation pathway(s) downstream of SEX1.

  17. A comparison of aquaporin function in mediating stomatal aperture gating among drought-tolerant and sensitive varieties of rice (Oryza sativa L.).

    Science.gov (United States)

    Vinnakota, Rajesh; Ramakrishnan, Anantha Maharasi; Samdani, A; Venugopal, M Anjali; Ram, B Sri; Krishnan, S Navaneetha; Murugesan, Dhandapani; Sankaranarayanan, Kavitha

    2016-11-01

    Climate change drastically affects the cultivation of rice, and its production is affected significantly by water stress. Adaptation of a plant to water deficit conditions is orchestrated by efficient water uptake and a stringently regulated water loss. Transpiration remains the major means of water loss from plants and is mediated by microscopic pores called stomata. Stomatal aperture gating is facilitated by ion channels and aquaporins (AQPs) which regulate the turgidity of the guard cells. In a similar manner, efficient water uptake by the roots is regulated by the presence of AQPs in the plasma membrane of root cells. In this study, we compare the efficiency of transmembrane water permeability in guard cells and root protoplasts from drought-tolerant and sensitive varieties of Oryza sativa L. In this report, we studied the transmembrane osmotic water permeability (Pos) of guard cell and root protoplasts of drought-sensitive and tolerant cultivars. The guard cells isolated from the drought-sensitive lowland rice variety ADT-39 show significant low osmotic permeability than the drought-tolerant rice varieties of Anna (lowland) and Dodda Byra Nellu (DBN) (upland local land rice). There is no significant difference in relative gene expression patterns of PIPs (Plasma membrane Intrinsic Proteins "PIP1" and "PIP2" subfamilies) in guard cells isolated from ADT-39 and Anna. While the expression levels of AQP genes remain the same between ADT-39 and Anna, there is a drastic difference in their osmotic permeability in the guard cells in spite of a higher number of stomata in Anna and DBN, hinting at a more efficient gating mechanism of AQP in the stomata of the drought-tolerant varieties studied.

  18. Efficient acquisition of iron confers greater tolerance to saline-alkaline stress in rice (Oryza sativa L.).

    Science.gov (United States)

    Li, Qian; Yang, An; Zhang, Wen-Hao

    2016-12-01

    To elucidate the mechanisms underlying tolerance to saline-alkaline stress in two rice genotypes, Dongdao-4 and Jigeng-88, we exposed them to medium supplemented with 10 mM Na2CO3 and 40 mM NaCl (pH 8.5). Dongdao-4 plants displayed higher biomass, chlorophyll content, and photosynthetic rates, and a larger root system than Jigeng-88 under saline-alkaline conditions. Dongdao-4 had a higher shoot Na(+)/K(+) ratio than Jigeng-88 under both control and saline-alkaline conditions. Dongdao-4 exhibited stronger rhizospheric acidification than Jigeng-88 under saline-alkaline conditions, resulting from greater up-regulation of H(+)-ATPases at the transcriptional level. Moreover, Fe concentrations in shoots and roots of Dongdao-4 were higher than those in Jigeng-88, and a higher rate of phytosiderophore exudation was detected in Dongdao-4 versus Jigeng-88 under saline-alkaline conditions. The Fe-deficiency-responsive genes OsIRO2, OsIRT1, OsNAS1, OsNAS2, OsYSL2, and OsYSL15 were more strongly up-regulated in Dongdao-4 than Jigeng-88 plants in saline-alkaline medium, implying greater tolerance of Dongdao-4 plants to Fe deficiency. To test this hypothesis, we compared the effects of Fe deficiency on the two genotypes, and found that Dongdao-4 was more tolerant to Fe deficiency. Exposure to Fe-deficient medium led to greater rhizospheric acidification and phytosiderophore exudation in Dongdao-4 than Jigeng-88 plants. Expression levels of OsIRO2, OsIRT1, OsNAS1, OsNAS2, OsYSL2, and OsYSL15 were higher in Dongdao-4 than Jigeng-88 plants under Fe-deficient conditions. These results demonstrate that a highly efficient Fe acquisition system together with a large root system may underpin the greater tolerance of Dongdao-4 plants to saline-alkaline stress.

  19. Cold-adapted organic solvent tolerant alkalophilic family I.3 lipase from an Antarctic Pseudomonas.

    Science.gov (United States)

    Ganasen, Menega; Yaacob, Norhayati; Rahman, Raja Noor Zaliha Raja Abd; Leow, Adam Thean Chor; Basri, Mahiran; Salleh, Abu Bakar; Ali, Mohd Shukuri Mohamad

    2016-11-01

    Lipolytic enzymes with cold adaptation are gaining increasing interest due to their biotechnological prospective. Previously, a cold adapted family I.3 lipase (AMS8 lipase) was isolated from an Antarctic Pseudomonas. AMS8 lipase was largely expressed in insoluble form. The refolded His-tagged recombinant AMS8 lipase was purified with 23.0% total recovery and purification factor of 9.7. The purified AMS8 lipase migrated as a single band with a molecular weight approximately 65kDa via electrophoresis. AMS8 lipase was highly active at 30°C at pH 10. The half-life of AMS8 lipase was reported at 4 and 2h under the incubation of 30 and 40°C, respectively. The lipase was stable over a broad range of pH. It showed enhancement effect in its relative activity under the presence of Li(+), Na(+), K(+), Rb(+) and Cs(+) after 30min treatment. Heavy metal ions such as Cu(2+), Fe(3+) and Zn(2+) inhibited AMS8 activity. This cold adapted alkalophilic AMS lipase was also active in various organic solvent of different polarity. These unique properties of this biological macromolecule will provide considerable potential for many biotechnological applications and organic synthesis at low temperature.

  20. ESKIMO1 is a key gene involved in water economy as well as cold acclimation and salt tolerance

    Directory of Open Access Journals (Sweden)

    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

  1. Analysis of Recombinant Proteins in Transgenic Rice Seeds: Identity, Localization, Tolerance to Digestion, and Plant Stress Response.

    Science.gov (United States)

    Wakasa, Yuhya; Takaiwa, Fumio

    2016-01-01

    Rice seeds are an ideal production platform for high-value recombinant proteins in terms of economy, scalability, safety, and stability. Strategies for the expression of large amounts of recombinant proteins in rice seeds have been established in the past decade and transgenic rice seeds that accumulate recombinant products such as bioactive peptides and proteins, which promote the health and quality of life of humans, have been generated in many laboratories worldwide. One of the most important advantages is the potential for direct oral delivery of transgenic rice seeds without the need for recombinant protein purification (downstream processing), which has been attributed to the high expression levels of recombinant products. Transgenic rice will be beneficial as a delivery system for pharmaceuticals and nutraceuticals in the future. This chapter introduces the strategy for producing recombinant protein in the edible part (endosperm) of the rice grain and describes methods for the analysis of transgenic rice seeds in detail.

  2. Regulation of galactolipid biosynthesis by overexpression of the rice MGD gene contributes to enhanced aluminum tolerance in tobacco

    Directory of Open Access Journals (Sweden)

    Meijuan eZhang

    2016-03-01

    Full Text Available Membrane lipid alterations affect Al tolerance in plants, but little is known about the regulation of membrane lipid metabolism in response to Al stress. Transgenic tobacco (Nicotiana tabacum overexpressing rice monogalactosyldiacylglycerol (MGDG synthase (OsMGD gene and wild-type tobacco plants were exposed to AlCl3, and the impact of Al toxicity on root growth, Al accumulation, plasma membrane integrity, lipid peroxidation and membrane lipid composition were investigated. Compared with the wild type, the transgenic plants exhibited rapid regrowth of roots after removal of Al and less damage to membrane integrity and lipid peroxidation under Al stress, meanwhile, the Al accumulation showed no difference between wild-type and transgenic plants. Lipid analysis showed that Al treatment dramatically decreased the content of MGDG and the ratio of MGDG to digalactosyldiacylglycerol (DGDG in wild-type plants, while it was unchanged in transgenic plants. The stable of MGDG level and the ratio of MGDG/DGDG contribute to maintain the membrane stability and permeability. Moreover, Al caused a significant increase in phospholipids in wild-type plants, resulting in a high proportion of phospholipids and low proportion of galactolipids, but these proportions were unaffected in transgenic plants. The high proportion of phospholipids could contribute to a higher rate of Al3+ binding in the membrane and thereby leads to more membrane perturbation and damage. These results show that the regulation of galactolipid biosynthesis could play an important role in maintaining membrane structure and function under Al stress.

  3. Searching for common responsive parameters for ozone tolerance in 18 rice cultivars in India: Results from ethylenediurea studies.

    Science.gov (United States)

    Pandey, Ashutosh K; Majumder, Baisakhi; Keski-Saari, Sarita; Kontunen-Soppela, Sari; Mishra, Ashvarya; Sahu, Nayan; Pandey, Vivek; Oksanen, Elina

    2015-11-01

    Eighteen rice (Oryza sativa) cultivars were screened for ozone (O3) tolerance and for the most responsive parameters with ethylenediurea (EDU) treatments at two experimental sites experiencing high ambient O3 conditions in the Indo-Gangetic Plains (IGP) of India. EDU was applied at 15 day intervals until the final harvest phase as a foliar spray at 300 ppm in order to protect the plants from the adverse effects of O3. Antioxidant activity, malondialdehyde content (MDA), chlorophyll content, gas exchange, and chlorophyll fluorescence (Fv/Fm) at the vegetative and flowering phases and harvest-related parameters were studied, for a total of 24 parameters. Seven of the studied cultivars had higher than average grainweightplant(-1) in all site and treatment combinations and can be recommended for cultivation in areas suffering from high O3 concentrations. The most responsive parameters with EDU treatment in high O3 across all cultivars were superoxide dismutase (SOD) and catalase (CAT) activities, the contents of oxidised (GSSG) and reduced (GSH) glutathione and MDA, and shoot weight plant(-1). These results indicated that the O3 scavenging activity of EDU is mediated through an antioxidant defence system rather than a direct effect on physiological parameters, such as photosynthesis and stomatal conductance.

  4. Responses of antioxidant enzymes to cold and high light are not correlated to freezing tolerance in natural accessions of Arabidopsis thaliana.

    Science.gov (United States)

    Distelbarth, H; Nägele, T; Heyer, A G

    2013-11-01

    Low temperatures and high light cause imbalances in primary and secondary reactions of photosynthesis, and thus can result in oxidative stress. Plants employ a range of low-molecular weight antioxidants and antioxidant enzymes to prevent oxidative damage, and antioxidant defence is considered an important component of stress tolerance. To figure out whether oxidative stress and antioxidant defence are key factors defining the different cold acclimation capacities of natural accessions of the model plant Arabidopsis thaliana, we investigated hydrogen peroxide (H2 O2 ) production, antioxidant enzyme activity and lipid peroxidation during a time course of cold treatment and exposure to high light in four differentially cold-tolerant natural accessions of Arabidopsis (C24, Nd, Rsch, Te) that span the European distribution range of the species. All accessions except Rsch (from Russia) had elevated H2 O2 in the cold, indicating that production of reactive oxygen species is part of the cold response in Arabidopsis. Glutathione reductase activity increased in all but Rsch, while ascorbate peroxidase and superoxide dismutase were unchanged and catalase decreased in all but Rsch. Under high light, the Scandinavian accession Te had elevated levels of H2 O2 . Te appeared most sensitive to oxidative stress, having higher malondialdehyde (MDA) levels in the cold and under high light, while only high light caused elevated MDA in the other accessions. Although the most freezing-tolerant, Te had the highest sensitivity to oxidative stress. No correlation was found between freezing tolerance and activity of antioxidant enzymes in the four accessions investigated, arguing against a key role for antioxidant defence in the differential cold acclimation capacities of Arabidopsis accessions. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  5. Tolerance

    DEFF Research Database (Denmark)

    Tønder, Lars

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

  6. Tolerance

    DEFF Research Database (Denmark)

    Tønder, Lars

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

  7. Zn uptake, translocation and grain Zn loading in rice (Oryza sativa L.) genotypes selected for Zn deficiency tolerance and high grain Zn.

    Science.gov (United States)

    Impa, Somayanda M; Morete, Mark J; Ismail, Abdelbagi M; Schulin, Rainer; Johnson-Beebout, Sarah E

    2013-07-01

    Zn deficiency is a widespread problem in rice (Oryza sativa L.) grown under flooded conditions, limiting growth and grain Zn accumulation. Genotypes with Zn deficiency tolerance or high grain Zn have been identified in breeding programmes, but little is known about the physiological mechanisms conferring these traits. A protocol was developed for growing rice to maturity in agar nutrient solution (ANS), with optimum Zn-sufficient growth achieved at 1.5 μM ZnSO4.7H2O. The redox potential in ANS showed a decrease from +350 mV to -200 mV, mimicking the reduced conditions of flooded paddy soils. In subsequent experiments, rice genotypes contrasting for Zn deficiency tolerance and grain Zn were grown in ANS with sufficient and deficient Zn to assess differences in root uptake of Zn, root-to-shoot Zn translocation, and in the predominant sources of Zn accumulation in the grain. Zn efficiency of a genotype was highly influenced by root-to-shoot translocation of Zn and total Zn uptake. Translocation of Zn from root to shoot was more limiting at later growth stages than at the vegetative stage. Under Zn-sufficient conditions, continued root uptake during the grain-filling stage was the predominant source of grain Zn loading in rice, whereas, under Zn-deficient conditions, some genotypes demonstrated remobilization of Zn from shoot and root to grain in addition to root uptake. Understanding the mechanisms of grain Zn loading in rice is crucial in selecting high grain Zn donors for target-specific breeding and also to establish fertilizer and water management strategies for achieving high grain Zn.

  8. Hydrogen Sulfide Regulates Salt Tolerance in Rice by Maintaining Na+/K+ Balance, Mineral Homeostasis and Oxidative Metabolism Under Excessive Salt Stress

    Science.gov (United States)

    Mostofa, Mohammad G.; Saegusa, Daisuke; Fujita, Masayuki; Tran, Lam-Son Phan

    2015-01-01

    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 rice salt stress tolerance. We showed 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, the ability to decrease the uptake of Na+ and the Na+/K+ ratio, as well as to balance 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 gasotransmitters like H2S for the management of salt stress, thus assisting rice plants to adapt to adverse environmental changes. PMID:26734015

  9. 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.

  10. Engineering carpel-specific cold stress tolerance: a case study in Arabidopsis.

    Science.gov (United States)

    Artlip, Timothy S; Wisniewski, Michael E; Takatsuji, Hiroshi; Bassett, Carole L

    2016-08-01

    Climate change predictions forecast an increase in early spring frosts that could result in severe damage to perennial crops. For example, the Easter freeze of April 2007 left several states in the United States reporting a complete loss of that year's peach crop. The most susceptible organ to early frost damage in fruit trees is the carpel, particularly during bloom opening. In this study, we explored the use of a carpel-specific promoter (ZPT2-10) from petunia (Petunia hybrida var. Mitchell) to drive expression of the peach dehydrin PpDhn1. In peach, this gene is exceptionally responsive to low temperature but has not been observed to be expressed in carpels. This study examined carpel-specific properties of a petunia promoter driving the expression of the GUS gene (uidA) in transgenic Arabidopsis flowers and developed a carpel-specific ion leakage test to assess freezing tolerance. A homozygous Arabidopsis line (line 1-20) carrying the petunia ZPT2-10 promoter::PpDhn1 construct was obtained and freezing tolerance in the transgenic line was compared with an untransformed control. Overexpression of PpDhn1 in line 1-20 provided as much as a 1.9°C increase in carpel freezing tolerance as measured by electrolyte leakage.

  11. Cold tolerance of Acacia karroo and A.nilotica, two tree species from South Africa, in Beijing

    Institute of Scientific and Technical Information of China (English)

    Yang Ying; Janusz Zwolinski; Wang Hua-fang; Yin Wei-lun

    2006-01-01

    Fynbos plant communities developed under geographic and climatic conditions unique to South Africa. Acacia karroo is the most widespread tree species, well known for its drought tolerance. A. nilotica exudes a good quality gum which is edible and suitable for confectionery. The two species have been introduced to China but little is known about their adaptability under the new environmental conditions. For our present study, the growth potential and physiological and biochemical parameters of the two species in response to cold stress were investigated. The results, measured as seed qualities (purity, thousand seed weights, germination,etc.) show differences between A. karroo and 4. nilotica. The seed germination rate was between 10% and 60%. Seedlings were established in fields, pots and plugs. Those in the field grew well during the growing season but completely died in the winter. Those in pots or plugs were moved to and managed in the greenhouse. The plants were green in winter. The electrical conductivity of cells, the contents of water soluble sugars, proteins, malondialdehyde (MDA) increased during eight hours of low temperature treatment at 4℃.The activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) decreased markedly during the eight hours of 4℃ treatment. We conclude that A. karroo and A. nilotica have little adaptability to the cold winter weather and cannot survive in the outdoors in the Beijing area, but could grow well indoors as ornamentals.

  12. Overexpression of SlGMEs leads to ascorbate accumulation with enhanced oxidative stress, cold, and salt tolerance in tomato.

    Science.gov (United States)

    Zhang, Chanjuan; Liu, Junxia; Zhang, Yuyang; Cai, Xiaofeng; Gong, Pengjuan; Zhang, Junhong; Wang, Taotao; Li, Hanxia; Ye, Zhibiao

    2011-03-01

    GDP-Mannose 3',5'-epimerase (GME; EC 5.1.3.18) catalyses the conversion of GDP-D-mannose to GDP-L-galactose, an important step in the ascorbic acid (AsA) biosynthesis pathway in higher plants. In this study, two members of the GME gene family were isolated from tomato (Solanum lycopersicum). Both SlGME genes encode 376 amino acids and share a 92% similarity with each other. Semi-quantitative RT-PCR indicated that SlGME1 was constantly expressed in various tissues, whereas SlGME2 was differentially expressed in different tissues. Transient expression of fused SlGME1-GFP (green fluorescent protein) and SlGME2-GFP in onion cells revealed the cytoplasmic localisation of the two proteins. Transgenic plants over-expressing SlGME1 and SlGME2 exhibited a significant increase in total ascorbic acid in leaves and red fruits compared with wild-type plants. They also showed enhanced stress tolerance based on less chlorophyll content loss and membrane-lipid peroxidation under methyl viologen (paraquat) stress, higher survival rate under cold stress, and significantly higher seed germination rate, fresh weight, and root length under salt stress. The present study demonstrates that the overexpression of two members of the GME gene family resulted in increased ascorbate accumulation in tomato and improved tolerance to abiotic stresses.

  13. Effects of cultivation patterns on rice yield and soil properties in cold waterlogged paddy fields%耕作模式对冷浸田水稻产量和土壤特性的影响

    Institute of Scientific and Technical Information of China (English)

    王思潮; 曹凑贵; 李成芳; 熊又升; 汪金平

    2014-01-01

    为探明不同耕作模式对冷浸田的影响机制,挖掘冷浸田的生产潜力,以冷浸田为研究对象,通过田间试验,以常规平作模式为对照,研究了垄作和稻鱼共作模式对冷浸田水稻产量以及土壤团聚体、温度、pH及有机质和还原性物质含量以及酶活性的影响。结果表明:相比对照(CK),垄作模式(T1)能显著降低土壤微团聚体(1 mm) and organic matter content increased respectively by 67.6%and 28.0%at rice maturity stage. Treatment T2 had less effect on soil physical and chemical properties in cold waterlogged paddy fields. However, it significantly increased soil available nutrients (mainly available potassium and phosphorus) contents. Soil available potassium content increased 18.2% and 69.2% at booting and mature stages, compared with CK. It provided good soil environment and nutrition for rice growth, promoted rice growth and development, and improved rice yield. Further analysis showed that treatments T1 and T2 significantly improved rice yield in cold waterlogged paddy fields and increased yield in the range of 8.8%-25.8%. The effect of T1 on increasing rice production was the most significant, with actual output reaching 7 623 kg·hm-2. In conclusion, treatment T1 effectively improved soil properties in cold waterlogged paddy fields and increased rice yield. The effect of increasing production of treatment T2 was mainly drived by increased water and soil available nutrients in cold paddy waterlogged fields.

  14. The rice R2R3-MYB transcription factor OsMYB55 is involved in the tolerance to high temperature and modulates amino acid metabolism.

    Directory of Open Access Journals (Sweden)

    Ashraf El-Kereamy

    Full Text Available Temperatures higher than the optimum negatively affects plant growth and development. Tolerance to high temperature is a complex process that involves several pathways. Understanding this process, especially in crops such as rice, is essential to prepare for predicted climate changes due to global warming. Here, we show that OsMYB55 is induced by high temperature and overexpression of OsMYB55 resulted in improved plant growth under high temperature and decreased the negative effect of high temperature on grain yield. Transcriptome analysis revealed an increase in expression of several genes involved in amino acids metabolism. We demonstrate that OsMYB55 binds to the promoter regions of target genes and directly activates expression of some of those genes including glutamine synthetase (OsGS1;2 glutamine amidotransferase (GAT1 and glutamate decarboxylase 3 (GAD3. OsMYB55 overexpression resulted in an increase in total amino acid content and of the individual amino acids produced by the activation of the above mentioned genes and known for their roles in stress tolerance, namely L-glutamic acid, GABA and arginine especially under high temperature condition. In conclusion, overexpression of OsMYB55 improves rice plant tolerance to high temperature, and this high tolerance is associated with enhanced amino acid metabolism through transcription activation.

  15. PtrBAM1, a β-amylase-coding gene of Poncirus trifoliata, is a CBF regulon member with function in cold tolerance by modulating soluble sugar levels.

    Science.gov (United States)

    Peng, Ting; Zhu, Xiaofang; Duan, Nian; Liu, Ji-Hong

    2014-12-01

    β-Amylase (BAM) catalyses starch breakdown to generate maltose, which can be incorporated into sugar metabolism. However, the role of BAM genes in cold tolerance is less characterized. In this study, we report the isolation and functional characterization of a chloroplast-localizing BAM-encoding gene PtrBAM1 from Poncirus trifoliata. PtrBAM1 was induced by cold, dehydration and salt, but repressed by maltose. Overexpression of PtrBAM1 in tobacco (Nicotiana nudicaulis) increased BAM activity, promoted starch degradation and enhanced the contents of maltose and soluble sugars, whereas opposite changes were observed when PtrBAM1 homolog in lemon (Citrus lemon) was knocked down. The tobacco overexpressing lines exhibited enhanced tolerance to cold at chilling or freezing temperatures. Under cold stress, higher BAM activity and greater accumulation of maltose and soluble sugars were observed in the overexpressing lines when compared with the wild-type or empty vector transformants. Bioinformatics analysis demonstrated that PtrBAM1 promoter contained a CBF-recognizing element. Yeast one-hybrid assay demonstrated that PtrCBF could interact with the promoter fragment containing the element. Taken together, these results demonstrate that PtrBAM1 is a member of CBF regulon and plays an important role in cold tolerance by modulating the levels of soluble sugars acting as osmolytes or antioxidants.

  16. Expression of acyl-lipid Delta12-desaturase gene in prokaryotic and eukaryotic cells and its effect on cold stress tolerance of potato.

    Science.gov (United States)

    Amiri, Reza Maali; Yur'eva, Natalia O; Shimshilashvili, Khristina R; Goldenkova-Pavlova, Irina V; Pchelkin, Vasiliy P; Kuznitsova, Elmira I; Tsydendambaev, Vladimir D; Trunova, Tamara I; Los, Dmitry A; Jouzani, Gholamreza Salehi; Nosov, Alexander M

    2010-03-01

    We report the expression profile of acyl-lipid Delta12-desaturase (desA) gene from Synechocystis sp. PCC6803 and its effect on cell membrane lipid composition and cold tolerance in prokaryotic (Escherichia coli) and eukaryotic (Solanum tuberosum) cells. For this purpose, a hybrid of desA and reporter gene encoding thermostable lichenase (licBM3) was constructed and used to transform these cells. The expression of this hybrid gene was measured using qualitative (Petri dish test, electrophoregram and zymogram) and quantitative methods (spectrometry and gas liquid chromatography assays). The maximum level of linoleic acid in the bacterial cells containing hybrid gene was 1.9% of total fatty acids. Cold stress tolerance assays using plant damage index and growth parameters showed that cold tolerance was enhanced in primary transgenic lines because of increased unsaturated fatty acid concentration in their lipids. The greatest content of 18:2 and 18:3 fatty acids in primary transgenic plants was observed for lines 2 (73%) and 3 (41%). Finally, our results showed that desaturase could enhance tolerance to cold stress in potato, and desaturase and lichenase retain their functionality in the structure of the hybrid protein where the enzymatic activity of target gene product was higher than in the case of reporter lichenase gene absence in the construction.

  17. Improved drought tolerance in wheat plants overexpressing a synthetic bacterial cold shock protein gene SeCspA

    Science.gov (United States)

    Yu, Tai-Fei; Xu, Zhao-Shi; Guo, Jin-Kao; Wang, Yan-Xia; Abernathy, Brian; Fu, Jin-Dong; Chen, Xiao; Zhou, Yong-Bin; Chen, Ming; Ye, Xing-Guo; Ma, You-Zhi

    2017-01-01

    Cold shock proteins (CSPs) enhance acclimatization of bacteria to adverse environmental circumstances. The Escherichia coli CSP genes CspA and CspB were modified to plant-preferred codon sequences and named as SeCspA and SeCspB. Overexpression of exogenous SeCspA and SeCspB in transgenic Arabidopsis lines increased germination rates, survival rates, and increased primary root length compared to control plants under drought and salt stress. Investigation of several stress-related parameters in SeCspA and SeCspB transgenic wheat lines indicated that these lines possessed stress tolerance characteristics, including lower malondialdehyde (MDA) content, lower water loss rates, lower relative Na+ content, and higher chlorophyll content and proline content than the control wheat plants under drought and salt stresses. RNA-seq and qRT-PCR expression analysis showed that overexpression of SeCsp could enhance the expression of stress-responsive genes. The field experiments showed that the SeCspA transgenic wheat lines had great increases in the 1000-grain weight and grain yield compared to the control genotype under drought stress conditions. Significant differences in the stress indices revealed that the SeCspA transgenic wheat lines possessed significant and stable improvements in drought tolerance over the control plants. No such improvement was observed for the SeCspB transgenic lines under field conditions. Our results indicated that SeCspA conferred drought tolerance and improved physiological traits in wheat plants. PMID:28281578

  18. STARCH RETROGRADATION AND PRODUCTION OF RESISTANT STARCH IN COOKED RICE

    OpenAIRE

    2008-01-01

    After rice cooking, retrogradation of starch in a cooked rice progresses quickly at under gelatinization temperature. Cold rice (aging rice) is tasteless, firm and digested slowly. My aim in this report is explained the relationship between cold rice tasteless and indexes of starch retrogradation. Starch gelatinization degree, starch whiteness index and resistant starch content that were indexes of starch retrogradation did not change remarkably of cold and aging rice that were very firm and ...

  19. Stress-inducible expression of barley Hva1 gene in transgenic mulberry displays enhanced tolerance against drought, salinity and cold stress.

    Science.gov (United States)

    Checker, Vibha G; Chhibbar, Anju K; Khurana, Paramjit

    2012-10-01

    Coping with different kinds of biotic and abiotic stresses is the foundation of sustainable agriculture. Although conventional breeding and marker-assisted selection are being employed in mulberry (Morus indica L.) to develop better varieties, nonetheless the longer time periods required for these approaches necessitates the use of precise biotechnological approaches for sustainable agriculture. In an attempt to improve stress tolerance of mulberry, an important plant of the sericulture industry, an encoding late embryogenesis abundant gene from barley (HVA1) was introduced into mulberry plants by Agrobacterium-mediated transformation. Transgenic mulberry with barley Hva1 under a constitutive promoter actin1 was shown to enhance drought and salinity tolerance. Here, we report that overexpression of barley Hva1 also confers cold tolerance in transgenic mulberry. Further, barley Hva1 gene under control of a stress-inducible promoter rd29A can effectively negate growth retardation under non-stress conditions and confer stress tolerance in transgenic mulberry. Transgenic lines display normal morphology to enhanced growth and an increased tolerance against drought, salt and cold conditions as measured by free proline, membrane stability index and PSII activity. Protein accumulation was detected under stress conditions confirming inductive expression of HVA1 in transgenics. Investigations to assess stress tolerance of these plants under field conditions revealed an overall better performance than the non-transgenic plants. Enhanced expression of stress responsive genes such as Mi dnaJ and Mi 2-cysperoxidin suggests that Hva1 can regulate downstream genes associated with providing abiotic stress tolerance. The investigation of transgenic lines presented here demonstrates the acquisition of tolerance against drought, salt and cold stress in plants overexpressing barley Hva1, indicating that Arabidopsis rd29A promoter can function in mulberry.

  20. 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

    2016-01-01

    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.

  1. Genes encoding plant-specific class III peroxidases are responsible for increased cold tolerance of the brassinosteroid-insensitive 1 mutant.

    Science.gov (United States)

    Kim, Beg Hab; Kim, Sun Young; Nam, Kyoung Hee

    2012-12-01

    We previously reported that one of the brassinosteroidinsensitive mutants, bri1-9, showed increased cold tolerance compared with both wild type and BRI1-overexpressing transgenic plants, despite its severe growth retardation. This increased tolerance in bri1-9 resulted from the constitutively high expression of stress-inducible genes under normal conditions. In this report, we focused on the genes encoding class III plant peroxidases (AtPrxs) because we found that, compared with wild type, bri1-9 plants contain higher levels of reactive oxygen species (ROS) that are not involved with the activation of NADPH oxidase and show an increased level of expression of a subset of genes encoding class III plant peroxidases. Treatment with a peroxidase inhibitor, salicylhydroxamic acid (SHAM), led to the reduction of cold resistance in bri1-9. Among 73 genes that encode AtPrxs in Arabidopsis, we selected four (AtPrx1, AtPrx22, AtPrx39, and AtPrx69) for further functional analyses in response to cold temperatures. T-DNA insertional knockout mutants showed increased sensitivity to cold stress as measured by leaf damage and ion leakage. In contrast, the overexpression of AtPrx22, AtPrx39, and AtPrx69 increased cold tolerance in the BRI1-GFP plants. Taken together, these results indicate that the appropriate expression of a particular subset of AtPrx genes and the resulting higher levels of ROS production are required for the cold tolerance.

  2. The mitochondrion-located protein OsB12D1 enhances flooding tolerance during seed germination and early seedling growth in rice.

    Science.gov (United States)

    He, Dongli; Zhang, Hui; Yang, Pingfang

    2014-07-31

    B12D belongs to a function unknown subgroup of the Balem (Barley aleurone and embryo) proteins. In our previous work on rice seed germination, we identified a B12D-like protein encoded by LOC_Os7g41350 (named OsB12D1). OsB12D1 pertains to an ancient protein family with an amino acid sequence highly conserved from moss to angiosperms. Among the six OsB12Ds, OsB12D1 is one of the major transcripts and is primarily expressed in germinating seed and root. Bioinformatics analyses indicated that OsB12D1 is an anoxic or submergence resistance-related gene. RT-PCR results showed OsB12D1 is induced remarkably in the coleoptiles or roots by flooding during seed germination and early seedling growth. The OsB12D1-overexpressed rice seeds could protrude radicles in 8 cm deep water, further exhibiting significant flooding tolerance compared to the wild type. Moreover, this tolerance was not affected by the gibberellin biosynthesis inhibitor paclobutrazol. OsB12D1 was identified in the mitochondrion by subcellular localization analysis and possibly enhances electron transport through mediating Fe and oxygen availability under flooded conditions. This work indicated that OsB12D1 is a promising gene that can help to enhance rice seedling establishment in farming practices, especially for direct seeding.

  3. The Mitochondrion-Located Protein OsB12D1 Enhances Flooding Tolerance during Seed Germination and Early Seedling Growth in Rice

    Directory of Open Access Journals (Sweden)

    Dongli He

    2014-07-01

    Full Text Available B12D belongs to a function unknown subgroup of the Balem (Barley aleurone and embryo proteins. In our previous work on rice seed germination, we identified a B12D-like protein encoded by LOC_Os7g41350 (named OsB12D1. OsB12D1 pertains to an ancient protein family with an amino acid sequence highly conserved from moss to angiosperms. Among the six OsB12Ds, OsB12D1 is one of the major transcripts and is primarily expressed in germinating seed and root. Bioinformatics analyses indicated that OsB12D1 is an anoxic or submergence resistance-related gene. RT-PCR results showed OsB12D1 is induced remarkably in the coleoptiles or roots by flooding during seed germination and early seedling growth. The OsB12D1-overexpressed rice seeds could protrude radicles in 8 cm deep water, further exhibiting significant flooding tolerance compared to the wild type. Moreover, this tolerance was not affected by the gibberellin biosynthesis inhibitor paclobutrazol. OsB12D1 was identified in the mitochondrion by subcellular localization analysis and possibly enhances electron transport through mediating Fe and oxygen availability under flooded conditions. This work indicated that OsB12D1 is a promising gene that can help to enhance rice seedling establishment in farming practices, especially for direct seeding.

  4. Analysis of genes specifically expressed under salt stress in salt-tolerant mutant of rice by using DDRT-PCR technique

    Institute of Scientific and Technical Information of China (English)

    张弛; 陈受宜

    1996-01-01

    Differential display reverse transcription-PCR (DDRT-PCR) technique was used to identify those genes that are expressed differentially between wild type rice variety 77-170 (Oryza Sativa vas Japonica) and its salt-tolerant mutant (M-20) under salt stress. Totally 13 salt-inducible cDNA fragments of 200-600 bp were identified and doned, and were designated as SIGR1 - SIGR13 (salt-induced gene in rice). Northern blot analysis showed that expression of SIGR6 and SIGR8 was salt-inducible in both wild type and mutant, and expression of SIGR12 in M-20 was much higher than that in 77-170 under salt stress. It was also shown that expression of SIGR3, SIGR4, SIGR7, SIGRIO and SIGR13 was salt-inducible, and the genes were highly homologous with Rab1d which was an ABA-inducible gene of rice. The great potential application of DDRT-PCR technique in plant molecular biology research may promote the investigation of expression of salt-induced protein in rice.

  5. Evaluation of Cold Tolerance in Field Grown Mentha (Mentha piperita‎‏ L.‎ under ‎Laboratory Conditions by Electrolyte Leakage Test

    Directory of Open Access Journals (Sweden)

    T Kheirkhah

    2015-09-01

    Full Text Available In order to determine cold tolerance of field grown Mentha (Mentha Piperita L. under controlled conditions, using electrolyte leakage index, an experiment was carried out at the College of Agriculture, Ferdowsi University of Mashhad, based on a completely randomized design with four replications. Experimental factors included six freezing temperatures (Zero, -4, -8, -12, -16 and -20 °C, seven harvest ‎time (November, December, January, February, March, April and May and ‎four Peppermint organs (leaves, Stems, Stolons and Rhizomes. So, field grown ‎and acclimated Pepermint was harvested from the faculty field every month. ‎After separating the Peppermint organs, they were subjected to freezing ‎temperatures. The membrane stability index was measured through ‎electrolyte leakage (EL and also lethal temperature 50 ‎according to EL (LT50el was determined. The results showed that electrolyte leakages were affected significantly by freezing temperature. By reduction of freezing temperature electrolyte leakages percentage increased. Among different organs of peppermint, stolon and leaf were the most cold tolerant and the most cold sensitive according to EL and LT50el , respectively. Also cold tolerance varied according to different harvest time in all organs. However, in May, all organs had lowest cold tolerance. Also leaves and stolons had the highest and the lowest LT50el, respectively. For all organs the highest LT50el‎ was observed in May. According to the high correlation between electrolyte leakages percent and LT50el (r = 0.96**, it seems that using this index for evaluation of freezing tolerance injury in Mentha piperita could be useful.

  6. Using liquid chromatography-mass spectrometry based metabolomics to discriminate between cold pressed rice bran oils produced from two different cultivars of Oryza sativa L. ssp. indica in Thailand

    Institute of Scientific and Technical Information of China (English)

    Tossaton CHAROONRATANA; Thanapat SONGSAK; Apirak SAKUNPAK; Pathamaporn PATHOMPAK; Laksana CHAROENCHAI

    2015-01-01

    A newly developed liquid chromatography⁃mass spectrometry ( LC⁃MS) method for the analysis of cold pressed rice bran oil ( RBO) was established and used to discriminate between RBOs produced from two different cultivars of major Thai fragrant rice species. The cold pressed RBO was prepared using the screw com⁃pression method. The LC⁃MS data were preprocessed with MZmine 2�10 program before evaluating with princi⁃pal component analysis using SIMCA 13 software. The LC⁃MS method was able to detect and quantify several kinds of valuable constituents such as fatty acids, vitamin E, and γ⁃oryzanol. The chromatographic condition was feasible;short time for analysis and simple method were achieved. From score plot and loading plot of principle component analysis ( PCA) , two rice cultivar samples were clearly separated, and it was revealed that Khao⁃Hom⁃Pathum was more suitable than Khao⁃Hom⁃Mali for cold pressed RBO production since it contained high total γ⁃oryzanol and less saturated free fatty acids. As with the fixed price of all the rice brans, this infor⁃mation can be used in order to, if possible, preserve the price of rice brans from different cultivars.

  7. Transgenerational inheritance of modified DNA methylation patterns and enhanced tolerance induced by heavy metal stress in rice (Oryza sativa L..

    Directory of Open Access Journals (Sweden)

    Xiufang Ou

    Full Text Available BACKGROUND: DNA methylation is sensitive and responsive to stressful environmental conditions. Nonetheless, the extent to which condition-induced somatic methylation modifications can impose transgenerational effects remains to be fully understood. Even less is known about the biological relevance of the induced epigenetic changes for potentially altered well-being of the organismal progenies regarding adaptation to the specific condition their progenitors experienced. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed DNA methylation pattern by gel-blotting at genomic loci representing transposable elements and protein-coding genes in leaf-tissue of heavy metal-treated rice (Oryza sativa plants (S0, and its three successive organismal generations. We assessed expression of putative genes involved in establishing and/or maintaining DNA methylation patterns by reverse transcription (RT-PCR. We measured growth of the stressed plants and their unstressed progenies vs. the control plants. We found (1 relative to control, DNA methylation patterns were modified in leaf-tissue of the immediately treated plants, and the modifications were exclusively confined to CHG hypomethylation; (2 the CHG-demethylated states were heritable via both maternal and paternal germline, albeit often accompanying further hypomethylation; (3 altered expression of genes encoding for DNA methyltransferases, DNA glycosylase and SWI/SNF chromatin remodeling factor (DDM1 were induced by the stress; (4 progenies of the stressed plants exhibited enhanced tolerance to the same stress their progenitor experienced, and this transgenerational inheritance of the effect of condition accompanying heritability of modified methylation patterns. CONCLUSIONS/SIGNIFICANCE: Our findings suggest that stressful environmental condition can produce transgenerational epigenetic modifications. Progenies of stressed plants may develop enhanced adaptability to the condition, and this acquired trait is

  8. Chemical stability of a cold-active cellulase with high tolerance toward surfactants and chaotropic agent

    Directory of Open Access Journals (Sweden)

    Thaís V. Souza

    2016-03-01

    Full Text Available CelE1 is a cold-active endo-acting glucanase with high activity at a broad temperature range and under alkaline conditions. Here, we examined the effects of pH on the secondary and tertiary structures, net charge, and activity of CelE1. Although variation in pH showed a small effect in the enzyme structure, the activity was highly influenced at acidic conditions, while reached the optimum activity at pH 8. Furthermore, to estimate whether CelE1 could be used as detergent additives, CelE1 activity was evaluated in the presence of surfactants. Ionic and nonionic surfactants were not able to reduce CelE1 activity significantly. Therefore, CelE1 was found to be promising candidate for use as detergent additives. Finally, we reported a thermodynamic analysis based on the structural stability and the chemical unfolding/refolding process of CelE1. The results indicated that the chemical unfolding proceeds as a reversible two-state process. These data can be useful for biotechnological applications.

  9. Does morphological and anatomical plasticity during the vegetative stage make wheat more tolerant of water deficit stress than rice?

    NARCIS (Netherlands)

    Kadam, N.N.; Yin, X.; Bindraban, P.S.; Struik, P.C.; Jagadish, K.S.V.

    2015-01-01

    Water scarcity and the increasing severity of water deficit stress are major challenges to sustaining irrigated rice (Oryza sativa) production. Despite the technologies developed to reduce the water requirement, rice growth is seriously constrained under water deficit stress compared with other

  10. Physical Integration of Root QTLs with the japonica Genome and Prediction of Probable Candidate Genes for Drought Tolerance in Rice

    Institute of Scientific and Technical Information of China (English)

    K. Ulaganathan; P.S. Priya; A. Snehalatharani; M. Sashikanth; A.R. Krishna; S. Singh

    2007-01-01

    @@ Drought is becoming an increasingly important constraint limiting world's rice production (Bennett, 2003).About half of the world's rice is grown in rainfed environments where the rainfall is the major source of water supply, and yields may be seriously restricted by water deficit.

  11. Putrescine Is Involved in Arabidopsis Freezing Tolerance and Cold Acclimation by Regulating Abscisic Acid Levels in Response to Low Temperature1

    Science.gov (United States)

    Cuevas, Juan C.; López-Cobollo, Rosa; Alcázar, Rubén; Zarza, Xavier; Koncz, Csaba; Altabella, Teresa; Salinas, Julio; Tiburcio, Antonio F.; Ferrando, Alejandro

    2008-01-01

    The levels of endogenous polyamines have been shown to increase in plant cells challenged with low temperature; however, the functions of polyamines in the regulation of cold stress responses are unknown. Here, we show that the accumulation of putrescine under cold stress is essential for proper cold acclimation and survival at freezing temperatures because Arabidopsis (Arabidopsis thaliana) mutants defective in putrescine biosynthesis (adc1, adc2) display reduced freezing tolerance compared to wild-type plants. Genes ADC1 and ADC2 show different transcriptional profiles upon cold treatment; however, they show similar and redundant contributions to cold responses in terms of putrescine accumulation kinetics and freezing sensitivity. Our data also demonstrate that detrimental consequences of putrescine depletion during cold stress are due, at least in part, to alterations in the levels of abscisic acid (ABA). Reduced expression of NCED3, a key gene involved in ABA biosynthesis, and down-regulation of ABA-regulated genes are detected in both adc1 and adc2 mutant plants under cold stress. Complementation analysis of adc mutants with ABA and reciprocal complementation tests of the aba2-3 mutant with putrescine support the conclusion that putrescine controls the levels of ABA in response to low temperature by modulating ABA biosynthesis and gene expression. PMID:18701673

  12. Physical, chemical and microbiological properties of mixed hydrogenated palm kernel oil and cold-pressed rice bran oil as ingredients in non-dairy creamer

    Directory of Open Access Journals (Sweden)

    Kunakorn Katsri

    2014-02-01

    Full Text Available The physical, chemical and microbiological properties of hydrogenated palm kernel oil (PKO and cold-pressed rice bran oil (RBOas ingredients in the production of liquid and powdered non-dairy creamer (coffee whitener were studied. The mixing ratios between hydrogenated PKO and cold-pressed RBO were statistically designed as of 100:0, 90:10,80:20, 70:30, 60:40, 50:50, 40:60, 30:70, 20:80, 10:90 and 0:100.The color, absorbanceand viscosity of the mixtures were investigated. As the ratio of cold-pressed RBO increased, the color became darker (L*of 93.06 to 86.25 and the absorbance significantly increased, while the viscosity of the mixtures of 20:80, 10:90 and 0:100 (54 cp. were the highest amongst the ratios tested.The hydrogenated PKO and cold-pressed RBO mixtures were further chemically tested for fatty acids, -oryzanol, -tocopherol, trans-fat contents andantioxidant activity. There were 10 fatty acids present in hydrogenated PKO with saturated fatty acid being the most predominant. Comparatively, there were only 5 fatty acids found in cold-pressed RBO with monounsaturated fatty acid being the major fatty acid. -Oryzanol and -tocopherol contents were higher with increasingcold-pressed RBO from 0-100% (0 to 1,155.00 mg/100g oil and 0.09 to 30.82 mg/100g oil, respectively. Antioxidant activity was increased with increasing cold-pressed RBO from 0-100% (9.26 to 94.24%.The pure hydrogenated PKO contained higher trans-fat content than that of the 90:10 and 80:20 mixtures (2.73, 1.93 and 1.85mg/100g oil,respectively while other samples had no trans-fat. No microorganisms were present in any of the samples.Therefore, substitution of hydrogenated PKO by cold-pressed RBO from 30-100% would offer more nutritional values and better chemical and physical properties of non-dairy creamer.

  13. Cold tolerance and supercooling capacity in overwintering adults of elm leaf beetle Xanthogaleruca luteola (Coleoptera: Chrysomelidae).

    Science.gov (United States)

    Soudi, Sh; Moharramipour, S

    2011-12-01

    Elm leaf beetle, Xanthogaleruca luteola (Muller) is one of the key pests of elm trees all over the world, and survives winter in reproductive diapause in sheltered locations. Seasonal variation of whole body supercooling points (SCPs), LT50 (temperature at which 50% of the test individuals die) and survival rate after exposure to subzero temperatures were determined in field collected adults during October 2008 to May 2009 and October 2009 to May 2010. The SCP of adults decreased significantly from October (median=-13.8°C) to January (median=-20.7°C) in first year, relatively similar results was observed in the second year. The lowest LT50 was observed in overwintering adults collected in January (-16.81°C) in the first year and December (-15.59°C) in the second year. Mortality at -15°C for 24 h was >70% in early autumn in both years whereas it decreased to lower than 45% in early winter, the highest mortality (100%) was observed in adults collected in May in both years. Cold acclimated adults (30 d, 5°C) in November 2008 exhibited significantly higher SCP (-12.21±0.64°C) than nonacclimated adults (-15.57±1.35°C). A 30-d exposure to 5°C caused >20% mortality in November, while <9% mortality was observed in adults collected in December and January 2008. Overwintering adults died upon freezing and the lower lethal temperatures were within the range of SCP, indicating that X. luteola is a freeze intolerant insect.

  14. The α-subunit of the rice heterotrimeric G protein, RGA1, regulates drought tolerance during the vegetative phase in the dwarf rice mutant d1.

    Science.gov (United States)

    Ferrero-Serrano, Ángel; Assmann, Sarah M

    2016-05-01

    Essential in the Green Revolution was the development of high-yielding dwarf varieties of rice (Oryza sativa L.), but their selection was not based on responses to water limitation. We studied physiological responses to progressive drought of the dwarf rice mutant, d1, in which the RGA1 gene, which encodes the GTP-binding α-subunit of the heterotrimeric G protein, is non-functional. Wild-type (WT) plants cease net carbon fixation 11 days after water is withheld, while d1 plants maintain net photosynthesis for an additional week. During drought, d1 plants exhibit greater stomatal conductance than the WT, but both genotypes exhibit the same transpirational water loss per unit leaf area. This is explained by a smaller driving force for water loss in d1 owing to its lower leaf temperatures, consistent with its more erect architecture. As drought becomes more severe, WT plants show an accelerated decline in photosynthesis, which may be exacerbated by the higher leaf temperatures in the WT. We thus show how a rice mutant with dwarf and erect leaves has a decreased susceptibility to water stress. Accordingly, it may be useful to incorporate RGA1 mutation in breeding or biotechnological strategies for development of drought-resistant rice.

  15. The rice OsNAC6 transcription factor orchestrates multiple molecular mechanisms involving root structural adaptions and nicotianamine biosynthesis for drought tolerance.

    Science.gov (United States)

    Lee, Dong-Keun; Chung, Pil Joong; Jeong, Jin Seo; Jang, Geupil; Bang, Seung Woon; Jung, Harin; Kim, Youn Shic; Ha, Sun-Hwa; Choi, Yang Do; Kim, Ju-Kon

    2016-11-28

    Drought has a serious impact on agriculture worldwide. A plant's ability to adapt to rhizosphere drought stress requires reprogramming of root growth and development. Although physiological studies have documented the root adaption for tolerance to the drought stress, underlying molecular mechanisms is still incomplete, which is essential for crop engineering. Here, we identified OsNAC6-mediated root structural adaptations, including increased root number and root diameter, which enhanced drought tolerance. Multiyear drought field tests demonstrated that the grain yield of OsNAC6 root-specific overexpressing transgenic rice lines was less affected by drought stress than were nontransgenic controls. Genome-wide analyses of loss- and gain-of-function mutants revealed that OsNAC6 up-regulates the expression of direct target genes involved in membrane modification, nicotianamine (NA) biosynthesis, glutathione relocation, 3'-phophoadenosine 5'-phosphosulphate accumulation and glycosylation, which represent multiple drought tolerance pathways. Moreover, overexpression of NICOTIANAMINE SYNTHASE genes, direct targets of OsNAC6, promoted the accumulation of the metal chelator NA and, consequently, drought tolerance. Collectively, OsNAC6 orchestrates novel molecular drought tolerance mechanisms and has potential for the biotechnological development of high-yielding crops under water-limiting conditions.

  16. Coupled expression of Cu/Zn-superoxide dismutase and catalase in cassava improves tolerance against cold and drought stresses.

    Science.gov (United States)

    Xu, Jia; Duan, Xiaoguang; Yang, Jun; Beeching, John R; Zhang, Peng

    2013-06-01

    Recently we reported that the joint expression of cassava Cu/Zn superoxide dismutase (MeCu/ZnSOD) and catalase (MeCAT1) prolonged the shelf life of cassava storage-roots by the stabilization of reactive oxygen species (ROS) homeostasis after harvest. Since oxidative damage is a major feature of plants exposed to environmental stresses, transgenic cassava showing increased expression of the cytosolic MeCu/ZnSOD and the peroxisomal MeCAT1 should have improved resistance against other abiotic stresses. After cold treatment, the transgenic cassava maintained higher SOD and CAT activities and lower malendialdehyde content than those of wild type plants (WT). Detached leaves of transgenic cassava also showed slower transpirational water loss than those of WT. When plants were not watered for 30 d, transgenic lines exhibited a significant increase in water retention ability, accumulated 13% more proline and 12% less malendialdehyde than WT's, and showed enhanced activity of SOD and CAT. These results imply that manipulation of the antioxidative mechanism allows the development of staple crops with improved tolerance to abiotic stresses.

  17. Tolerância de cultivares de arroz irrigado (Oryza sativa ao herbicida nicosulfuron e à mistura formulada de imazethapyr + imazapic Tolerance of rice (Oryza sativa cultivars to nicosulfuron and to the formulated mixture imazethapyr + imazapic

    Directory of Open Access Journals (Sweden)

    L.C. Fontona

    2007-12-01

    Full Text Available O objetivo deste estudo foi avaliar a tolerância de cultivares de arroz irrigado ao herbicida nicosulfuron e à mistura formulada de imazethapyr + imazapic. Para isso, foram conduzidos experimentos em casa de vegetação da Faculdade de Agronomia Eliseu Maciel (UFPel, no município de Capão do Leão (RS. Os tratamentos constaram de dois cultivares de arroz irrigado (IRGA 417 e IRGA 422CL e de sete doses dos herbicidas imazethapyr + imazapic e nicosulfuron, aplicados em arroz (estádios de desenvolvimento V2 ou V4. As variáveis analisadas foram fitotoxicidade dos herbicidas, estatura de planta, massa seca da parte aérea e área foliar. Houve interações significativas entre os fatores estudados para as variáveis-respostas avaliadas. Incrementos nas doses dos herbicidas resultaram em respostas crescentes de fitotoxicidade ao arroz, resultando em redução no crescimento das plantas. O cultivar IRGA 417 foi suscetível à ação dos herbicidas. Por sua vez, a tolerância do cultivar IRGA 422CL não é restrita à mistura formulada de imazethapyr + imazapic, ocorrendo também para o herbicida nicosulfuron.The objective of this study was to evaluate the tolerance of rice cultivars to the formulated mixture of nicosulfuron and imazethapyr + imazapic. Greenhouse experiments were carried out at the Faculdade de Agronomia Eliseu Maciel (UFPel in Capão do Leão (RS. The treatments consisted of two rice cultivars ('IRGA 417' and 'IRGA 422CL' and seven rates of the herbicides imazethapyr + imazapic and nicosulfuron, applied on rice (stages V2 or V4. The variables evaluated were herbicide injury, plant height, shoot dry biomass and leaf area. Significant interactions were found among the factors tested for the response-variables evaluated. Increased herbicide rates resulted in increased rice injury responses leading to decreases in plant height, biomass, and leaf area. 'IRGA 417' cultivar was susceptible to the herbicides. On the other hand, the

  18. Exploiting transcriptome data for the development and characterization of gene-based SSR markers related to cold tolerance in oil palm (Elaeis guineensis).

    Science.gov (United States)

    Xiao, Yong; Zhou, Lixia; Xia, Wei; Mason, Annaliese S; Yang, Yaodong; Ma, Zilong; Peng, Ming

    2014-12-19

    The oil palm (Elaeis guineensis, 2n = 32) has the highest oil yield of any crop species, as well as comprising the richest dietary source of provitamin A. For the tropical species, the best mean growth temperature is about 27°C, with a minimal growth temperature of 15°C. Hence, the plantation area is limited into the geographical ranges of 10°N to 10°S. Enhancing cold tolerance capability will increase the total cultivation area and subsequently oil productivity of this tropical species. Developing molecular markers related to cold tolerance would be helpful for molecular breeding of cold tolerant Elaeis guineensis. In total, 5791 gene-based SSRs were identified in 51,452 expressed sequences from Elaeis guineensis transcriptome data: approximately one SSR was detected per 10 expressed sequences. Of these 5791 gene-based SSRs, 916 were derived from expressed sequences up- or down-regulated at least two-fold in response to cold stress. A total of 182 polymorphic markers were developed and characterized from 442 primer pairs flanking these cold-responsive SSR repeats. The polymorphic information content (PIC) of these polymorphic SSR markers across 24 lines of Elaeis guineensis varied from 0.08 to 0.65 (mean = 0.31 ± 0.12). Using in-silico mapping, 137 (75.3%) of the 182 polymorphic SSR markers were located onto the 16 Elaeis guineensis chromosomes. Total coverage of 473 Mbp was achieved, with an average physical distance of 3.4 Mbp between adjacent markers (range 96 bp - 20.8 Mbp). Meanwhile, Comparative analysis of transcriptome under cold stress revealed that one ICE1 putative ortholog, five CBF putative orthologs, 19 NAC transcription factors and four cold-induced orhologs were up-regulated at least two fold in response to cold stress. Interestingly, 5' untranslated region of both Unigene21287 (ICE1) and CL2628.Contig1 (NAC) both contained an SSR markers. In the present study, a series of SSR markers were developed based on sequences

  19. Reactive oxygen species trigger a regulatory module invovled in the early responses of rice seedlings to cold stress

    Science.gov (United States)

    Plants respond to low temperature through an intricately coordinated transcriptional network controlled by specific groups of transcription factors. Major regulatory pathways in plants that evolved to withstand freezing by cold acclimation have been elucidated in Arabidopsis. A prominent pathway i...

  20. Methionine-rich storage protein gene in the rice stem borer, Chilo suppressalis, is expressed during diapause in response to cold acclimation.

    Science.gov (United States)

    Sonoda, S; Fukumoto, K; Izumi, Y; Ashfaq, M; Yoshida, H; Tsumuki, H

    2006-12-01

    Gene expressions of acclimatized and non-acclimatized diapausing larvae were examined in Chilo suppressalis using a subtraction technique. A gene encoding a methionine-rich storage protein, CsSP1, was cloned and its complete cDNA sequence was determined. Potentially, CsSP1 encoded a 758-amino acid protein, with a calculated molecular weight of 88.8 kDa. The expression level of CsSP1 was higher in nondiapausing larvae than in diapausing ones. The CsSP1 expression was up-regulated in diapausing larvae when the temperature of cold acclimation was shifted to 5 degrees C. The up-regulated level was maintained at 40 days after incubation at 5 degrees C. In nondiapausing larvae, CsSP1 expression was down-regulated when the temperature was below developmental zero. Involvement of CsSP1 in diapause, cold tolerance acquisition and postdiapause development in C. suppressalis is discussed.

  1. A STRESS-RESPONSIVE NAC1-regulated protein phosphatase gene rice protein phosphatase18 modulates drought and oxidative stress tolerance through abscisic acid-independent reactive oxygen species scavenging in rice.

    Science.gov (United States)

    You, Jun; Zong, Wei; Hu, Honghong; Li, Xianghua; Xiao, Jinghua; Xiong, Lizhong

    2014-12-01

    Plants respond to abiotic stresses through a complexity of signaling pathways, and the dephosphorylation mediated by protein phosphatase (PP) is an important event in this process. We identified a rice (Oryza sativa) PP2C gene, OsPP18, as a STRESS-RESPONSIVE NAC1 (SNAC1)-regulated downstream gene. The ospp18 mutant was more sensitive than wild-type plants to drought stress at both the seedling and panicle development stages. Rice plants with OsPP18 suppressed through artificial microRNA were also hypersensitive to drought stress. Microarray analysis of the mutant revealed that genes encoding reactive oxygen species (ROS) scavenging enzymes were down-regulated in the ospp18 mutant, and the mutant exhibited reduced activities of ROS scavenging enzymes and increased sensitivity to oxidative stresses. Overexpression of OsPP18 in rice led to enhanced osmotic and oxidative stress tolerance. The expression of OsPP18 was induced by drought stress but not induced by abscisic acid (ABA). Although OsPP18 is a typical PP2C with enzymatic activity, it did not interact with SNF1-RELATED PROTEIN KINASE2 protein kinases, which function in ABA signaling. Meanwhile, the expression of ABA-responsive genes was not affected in the ospp18 mutant, and the ABA sensitivities of the ospp18 mutant and OsPP18-overexpressing plants were also not altered. Together, these findings suggest that OsPP18 is a unique PP2C gene that is regulated by SNAC1 and confers drought and oxidative stress tolerance by regulating ROS homeostasis through ABA-independent pathways.

  2. Rice potassium transporter OsHAK1 is essential for maintaining potassium-mediated growth and functions in salt tolerance over low and high potassium concentration ranges.

    Science.gov (United States)

    Chen, Guang; Hu, Qingdi; Luo, Le; Yang, Tianyuan; Zhang, Song; Hu, Yibing; Yu, Ling; Xu, Guohua

    2015-12-01

    Potassium (K) absorption and translocation in plants rely upon multiple K transporters for adapting varied K supply and saline conditions. Here, we report the expression patterns and physiological roles of OsHAK1, a member belonging to the KT/KUP/HAK gene family in rice (Oryza sativa L.). The expression of OsHAK1 is up-regulated by K deficiency or salt stress in various tissues, particularly in the root and shoot apical meristem, the epidermises and steles of root, and vascular bundles of shoot. Both oshak1 knockout mutants in comparison to their respective Dongjin or Manan wild types showed a dramatic reduction in K concentration and stunted root and shoot growth. Knockout of OsHAK1 reduced the K absorption rate of unit root surface area by ∼50-55 and ∼30%, and total K uptake by ∼80 and ∼65% at 0.05-0.1 and 1 mm K supply level, respectively. The root net high-affinity K uptake of oshak1 mutants was sensitive to salt stress but not to ammonium supply. Overexpression of OsHAK1 in rice increased K uptake and K/Na ratio. The positive relationship between K concentration and shoot biomass in the mutants suggests that OsHAK1 plays an essential role in K-mediated rice growth and salt tolerance over low and high K concentration ranges.

  3. Yield and its attributes responses of drought tolerant upland ‘NERICA’ rice to different nutrient supplying treatments in rainforest transitory agroecology

    Directory of Open Access Journals (Sweden)

    Olalekan Suleiman Sakariyawo

    2017-01-01

    Full Text Available A screen house trial was conducted to evaluate reproductive growth responses of drought tolerant upland rice cultivars (NERICAs 1-4, WAB 56-104 and Moroberekan to arbuscular mycorrhizal (AMF inoculation under water deficit. A field trial was organized in randomized complete block test with three replicates, conducted in the late cropping season of 2012. We evaluated upland rice cultivars to different nutrient sources (AMF, AMF + 60 kg N ha-1 + 30 kg K ha-1, 60 kg N ha-1+ 30 kg K ha-1 and control. In the screen house inoculated rice had higher (P < 0.05 grain yield plant-1 (19.29 g plant-1 and its attributes than non-inoculated, except number of grain per panicle (108. On the field combination of AMF + 60 kg N ha-1 + 30 kg K ha-1 produced higher (P < 0.05 reproductive growth. Varietal variability (P < 0.05 was observed on AM colonisation and reproductive growth in both trials, with ‘NERICA 2’was the most promising cultivar under tested agroecology condition.

  4. Nitrogen accumulation and translocation characteristics of direct-seed-ed rice in cold area%寒地直播稻氮素积累与转运特征

    Institute of Scientific and Technical Information of China (English)

    罗盛国; 周婷; 尹宇龙; 王欢; 赵广欣; 王丽娟

    2015-01-01

    采用稻花香2号为试验材料进行田间试验,研究寒地直播稻与移栽稻氮素积累、转运及产量差异.结果表明,在抽穗期施入粒肥能够提高直播稻生育后期叶片含氮量和氮积累量,增强光合生产能力.抽穗后,起垄直播稻和免耕直播稻氮同化量比移栽稻高139.9%(P<0.01)和160.1%(P<0.01),氮同化贡献率比移栽稻高133.3%(P<0.01)和177.8%(P<0.01).直播稻生育后期仍能进行氮积累,抽穗后30 d至成熟期起垄直播稻和免耕直播稻氮素积累量分别为2.17和3.81 kg·hm-2,而移栽稻在抽穗后30 d至成熟期无氮积累.直播稻和移栽稻产量差异不显著.%The paper was conducted using Daohuaxiang2 as tested rice variety to study the difference in N accumulation, translocation and yield between direct-seeded and transplanted rice in cold area. Results showed that top dressing N fertilizer at heading stage improved N content and N accumulation of direct-seed-ed rice at late growth stage and enhanced photosynthetic production capacity. After heading, N assimilation of ridge direct-seeded rice and no-til age direct-seeded rice were 139.9% (P<0.01) and 160.1% (P<0.01) higher than that of transplanted rice, and N assimilation contribution rates were 133.3% (P<0.01) and 177.8%(P<0.01) higher than that of transplanted rice. N accumulation was stil proceeding at the late stage of direct-seeded rice, from 30-day after heading to maturity, the N accumulation of ridge direct-seeded rice and no til age direct-seeded rice were 2.17 and 3.81 kg·hm-2, respectively, but no N accumulation with trans-planted rice. There was no significant difference in yield between direct-seeded rice and transplanted rice.

  5. Evaluation of Cold Tolerance in Field Grown Mentha (Mentha piperita‎‏ L.)‎ under ‎Laboratory Conditions by Electrolyte Leakage Test

    OpenAIRE

    T Kheirkhah; A Nezami; M Kafi; Gh. A. Asadi

    2015-01-01

    In order to determine cold tolerance of field grown Mentha (Mentha Piperita L.) under controlled conditions, using electrolyte leakage index, an experiment was carried out at the College of Agriculture, Ferdowsi University of Mashhad, based on a completely randomized design with four replications. Experimental factors included six freezing temperatures (Zero, -4, -8, -12, -16 and -20 °C), seven harvest ‎time (November, December, January, February, March, April and May) and ‎four Peppermint or...

  6. Meat Processing Plant Microbiome and Contamination Patterns of Cold-Tolerant Bacteria Causing Food Safety and Spoilage Risks in the Manufacture of Vacuum-Packaged Cooked Sausages

    OpenAIRE

    Hultman, Jenni; Rahkila, Riitta; Ali, Javeria; Rousu, Juho; Björkroth, K. Johanna

    2015-01-01

    Refrigerated food processing facilities are specific man-made niches likely to harbor cold-tolerant bacteria. To characterize this type of microbiota and study the link between processing plant and product microbiomes, we followed and compared microbiota associated with the raw materials and processing stages of a vacuum-packaged, cooked sausage product affected by a prolonged quality fluctuation with occasional spoilage manifestations during shelf life. A total of 195 samples were subjected ...

  7. Salt Tolerance of Rice Variation Germplasm with Transformed Common Wild Rice (Oryza rufipogon) DNA%导入普通野生稻DNA的水稻变异种质的耐盐性鉴定

    Institute of Scientific and Technical Information of China (English)

    吕学莲; 白海波; 李树华; 蔡正云; 高晓原

    2012-01-01

    The research aimed to study salt tolerance of rice variation germplasm with transformed common wild rice DNA, and screen out the materials with high salt tolerance, so as to provide germplasm for salt-tolerant rice breeding. Ten rice variation germplasms of 'Ningjing 23' were used to study germination and seedling growth. The results showed that, when treated with 170 mmol/L NaCl, the germination level and germination rate of materials D42, D5-54, D5-27, D-10, D102, DJ18 and D68 were high, and its relative salt harm rate were low. With the solution containing 120 mmol/L NaCl, the salt tolerance of D5-27, DJ18, D5-54 and D-10 were strong, and the ratio of salt treatment and non-salt treatment of ground and underground, fresh and dry weights were high. The increased soluble sugar content of materials D5-27, DJ18, D5-54 and D-10 were higher than its receptor. Materials D42, D5-54, D5-27, D-10, D102, DJ18 and D68 had high salt tolerance in germinating stage, and materials D5-27, DJ18, D5-54 and D-10 had high salt tolerance in seedling stage.%旨在研究导入普通野生稻DNA的水稻后代的耐盐性,从中筛选出耐盐性较强的材料,为水稻耐盐育种提供种质资源.以普通野生稻DNA导入到宁夏栽培水稻‘宁粳23号’中获得的10份变异后代为材料,研究各材料在盐胁迫下的发芽特性和幼苗生长情况.结果表明在170 mmol/L NaCl处理下,材料D42、D5-54、D5-27、D-10、D102、DJ18和D68的发芽势和发芽率均较高,相对盐害率较低,在盐浓度为120 mmol/L时,材料D5-27、DJ18、D5-54和D-10的耐盐性为强,地上和地下鲜、干重的盐处理与非盐处理的比值较高,材料D5-27、DJ18、D5-54和D-10的可溶性糖积累量高于其受体.材料D42、D5-54、D5-27、D-10、D102、DJ18和D68的芽期耐盐性较强,材料D5-27、DJ18、D5-54和D-10属于苗期较耐盐的材料.

  8. 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.

  9. Overexpression of Rice Sphingosine-1-Phoshpate Lyase Gene OsSPL1 in Transgenic Tobacco Reduces Salt and Oxidative Stress Tolerance

    Institute of Scientific and Technical Information of China (English)

    Huijuan Zhang; Jing Zhai; Jibo Mo; Dayong Li; Fengming Song

    2012-01-01

    Sphingolipids,including sphingosine-1-phosphate (S1P),have been shown to function as signaling mediators to regulate diverse aspects of plant growth,development,and stress response.In this study,we performed functional analysis of a rice (Oryza sativa) S1P lyase gene OsSPL1 in transgenic tobacco plants and explored its possible involvement in abiotic stress response.Overexpression of OsSPL1 in transgenic tobacco resulted in enhanced sensitivity to exogenous abscisic acid (ABA),and decreased tolerance to salt and oxidative stress,when compared with the wild type.Furthermore,the expression levels of some selected stress-related genes in OsSPL1-overexpressing plants were reduced after application of salt or oxidative stress,indicating that the altered responsiveness of stress-related genes may be responsible for the reduced tolerance in OsSPL1-overexpressing tobacco plants under salt and oxidative stress.Our results suggest that rice OsSPL1 plays an important role in abiotic stress responses.

  10. MaJAZ1 Attenuates the MaLBD5-Mediated Transcriptional Activation of Jasmonate Biosynthesis Gene MaAOC2 in Regulating Cold Tolerance of Banana Fruit.

    Science.gov (United States)

    Ba, Liang-jie; Kuang, Jian-fei; Chen, Jian-ye; Lu, Wang-jin

    2016-02-01

    Previous studies indicated that methyl jasmonate (MeJA) treatment could effectively reduce the chilling injury of many fruits, including banana, but the underlying mechanism is poorly understood. In this study, one lateral organ boundaries (LOB) domain (LBD) gene, designated as MaLBD5, was isolated and characterized from banana fruit. Expression analysis revealed that accumulation of MaLBD5 was induced by cold temperature and MeJA treatment. Subcellular localization and transactivation assays showed that MaLBD5 was localized to the nucleus and possessed transcriptional activation activity. Protein-protein interaction analysis demonstrated that MaLBD5 physically interacted with MaJAZ1, a potential repressor of jasmonate signaling. Furthermore, transient expression assays indicated that MaLBD5 transactivated a jasmonate biosynthesis gene, termed MaAOC2, which was also induced by cold and MeJA. More interestingly, MaJAZ1 attenuated the MaLBD5-mediated transactivation of MaAOC2. These results suggest that MaLBD5 and MaJAZ1 might act antagonistically in relation to MeJA-induced cold tolerance of banana fruit, at least partially via affecting jasmonate biosynthesis. Collectively, our findings expand the knowledge of the transcriptional regulatory network of MeJA-mediated cold tolerance of banana fruit.

  11. A cold-induced myo-inositol transporter-like gene confers tolerance to multiple abiotic stresses in transgenic tobacco plants.

    Science.gov (United States)

    Sambe, Mame Abdou Nahr; He, Xueying; Tu, Qinghua; Guo, Zhenfei

    2015-03-01

    A full length cDNA encoding a myo-inositol transporter-like protein, named as MfINT-like, was cloned from Medicago sativa subsp. falcata (herein falcata), a species with greater cold tolerance than alfalfa (M. sativa subsp. sativa). MfINT-like is located on plasma membranes. MfINT-like transcript was induced 2-4 h after exogenous myo-inositol treatment, 24-96 h with cold, and 96 h by salinity. Given that myo-inositol accumulates higher in falcata after 24 h of cold treatment, myo-inositol is proposed to be involved in cold-induced expression of MfINT-like. Higher levels of myo-inositol was observed in leaves of transgenic tobacco plants overexpressing MfINT-like than the wild-type but not in the roots of plants grown on myo-inositol containing medium, suggesting that transgenic plants had higher myo-inositol transport activity than the wild-type. Transgenic plants survived better to freezing temperature, and had lower ion leakage and higher maximal photochemical efficiency of photosystem II (Fv /Fm ) after chilling treatment. In addition, greater plant fresh weight was observed in transgenic plants as compared with the wild-type when plants were grown under drought or salinity stress. The results suggest that MfINT-like mediated transport of myo-inositol is associated with plant tolerance to abiotic stresses.

  12. GsLRPK, a novel cold-activated leucine-rich repeat receptor-like protein kinase from Glycine soja, is a positive regulator to cold stress tolerance.

    Science.gov (United States)

    Yang, Liang; Wu, Kangcheng; Gao, Peng; Liu, Xiaojuan; Li, Guangpu; Wu, Zujian

    2014-02-01

    Plant LRR-RLKs serve as protein interaction platforms, and as regulatory modules of protein activation. Here, we report the isolation of a novel plant-specific LRR-RLK from Glycine soja (termed GsLRPK) by differential screening. GsLRPK expression was cold-inducible and shows Ser/Thr protein kinase activity. Subcellular localization studies using GFP fusion protein indicated that GsLRPK is localized in the plasma membrane. Real-time PCR analysis indicated that temperature, salt, drought, and ABA treatment can alter GsLRPK gene transcription in G. soja. However, just protein induced by cold stress not by salinity and ABA treatment in tobacco was found to possess kinase activity. Furthermore, we found that overexpression of GsLRPK in yeast and Arabidopsis can enhance resistance to cold stress and increase the expression of a number of cold responsive gene markers.

  13. Linking hydrogen-mediated boron toxicity tolerance with improvement of root elongation, water status and reactive oxygen species balance: a case study for rice.

    Science.gov (United States)

    Wang, Yu; Duan, Xingliang; Xu, Sheng; Wang, Ren; Ouyang, Zhaozeng; Shen, Wenbiao

    2016-12-01

    Boron is essential for plant growth but hazardous when present in excess. As the antioxidant properties of hydrogen gas (H2) were recently described in plants, oxidative stress induced by excess boron was investigated along with other biological responses during rice (Oryza sativa) seed germination to study the beneficial role of H2 METHODS: Rice seeds were pretreated with exogenous H2 Using physiological, pharmacological and molecular approaches, the production of endogenous H2, growth status, reactive oxygen species (ROS) balance and relative gene expression in rice were measured under boron stress to investigate mechanisms of H2-mediated boron toxicity tolerance. In our test, boron-inhibited seed germination and seedling growth, and endogenous H2 production, were obviously blocked by exogenously applying H2 The re-establishment of ROS balance was confirmed by reduced lipid peroxidation and ROS accumulation. Meanwhile, activities of catalase (CAT) and peroxidase (POX) were increased. Suppression of pectin methylesterase (PME) activity and downregulation of PME transcripts by H2 were consistent with the alleviation of root growth inhibition caused by boron. Water status was improved as well. This result was confirmed by the upregulation of genes encoding specific aquaporins (AQPs), the maintenance of low osmotic potential and high content of soluble sugar. Increased transcription of representative AQP genes (PIP2;7 in particular) and BOR2 along with decreased BOR1 mRNA may contribute to lowering boron accumulation. Hydrogen provides boron toxicity tolerance mainly by improving root elongation, water status and ROS balance. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Older Thinopyrum intermedium (Poaceae) plants exhibit superior photosynthetic tolerance to cold stress and greater increases in two photosynthetic enzymes under freezing stress compared with young plants.

    Science.gov (United States)

    Jaikumar, Nikhil S; Snapp, Sieglinde S; Sharkey, Thomas D

    2016-08-01

    Effects of plant age on resource acquisition and stress tolerance processes is a largely unstudied subject in herbaceous perennials. In a field experiment, we compared rates of photosynthesis (A), ribulose-1,5-bisphosphate (RuBP) carboxylation capacity (V Cmax), maximum electron transport rate (J max), and triose phosphate utilization (TPU), as well as concentrations of Rubisco and sucrose-phosphate synthase (SPS) in 5-year-old and 2-year-old intermediate wheatgrass (Thinopyrum intermedium) under both optimal growing conditions and cold stress in early spring and autumn. This species is a relative of wheat undergoing domestication. An additional experiment compared photosynthetic rates in different cohorts at mid-season and under colder conditions. We hypothesized that photosynthetic capacity in older plants would be lower under favorable conditions but higher under cold stress. Our hypothesis was generally supported. Under cold stress, 5-year-old plants exhibited higher A, TPU, and temperature-adjusted V Cmax than younger plants, as well as 50% more SPS and 37% more Rubisco. In contrast, at mid-season, photosynthetic capacities in older plants were lower than in younger plants in one experiment, and similar in the other, independent of differences in water status. Both cohorts increased A, temperature-adjusted TPU and J max, [Rubisco], and [SPS] under cold stress, but changes were greater in older plants. Photosynthetic differences were largest at 1.2 ºC in very early spring, where older plants had 200% higher A and maintained up to 17% of their peak photosynthetic capacity. We find evidence of increased cold tolerance in older cohorts of wheatgrass, consistent with a growing body of research in woody perennials.

  15. Estimating Broad Sense Heritability and Investigating the Mechanism of Genetic Transmission of Cold Tolerance Using Mannitol as a Measure of Post-freeze Juice Degradation in Sugarcane and Energycane (Saccharum spp.).

    Science.gov (United States)

    Hale, Anna L; Viator, Ryan P; Eggleston, Gillian; Hodnett, George; Stelly, David M; Boykin, Debbie; Miller, Donnie K

    2016-03-01

    In approximately 25% of the sugarcane-producing countries worldwide, conventional sugarcane (Saccharum spp. hybrids) is exposed to damaging freezes. A study was conducted during the 2009 and 2010 harvest seasons to compare late-season freeze tolerance among three groups: commercial Louisiana sugarcane genotypes, early generation genotypes selected for cold tolerance in the U.S. Department of Agriculture sugarcane breeding programs at Houma, LA, and Canal Point, FL, and potential energycane genotypes selected for high total biomass per acre. Mannitol concentrations in cane juice following freezing temperatures were determined to evaluate levels of cold tolerance. Genotypes selected for cold tolerance in Houma, LA, had significantly more late-season freeze tolerance than commercial sugarcane genotypes and genotypes selected in Canal Point, FL. Genotypes showing the most cold tolerance were Ho02-146 and Ho02-152, and those that were most highly susceptible were US87-1006 and US87-1003 (early-generation breeding genotypes) and L99-233 (commercial genotype). Broad-sense heritability for late-season cold tolerance in the two-year study was estimated at g(2) = 0.78. The enzymatic mannitol analysis successfully differentiated high-fiber energycane genotypes from those from other sources.

  16. Overexpression of transcription factor OsWR2 1 regulates wax/cutin biosynthesis and enhances drought tolerance in rice

    Science.gov (United States)

    Drought is the major abiotic stress limiting crop production. Plant cuticle represents the outer-most layer of the epidermis and previous studies demonstrate its association with plant response to climatological drought. We report here the functional characterization of the rice ((Oryza sativa L.) W...

  17. TALEN-Based Mutagenesis of Lipoxygenase LOX3 Enhances the Storage Tolerance of Rice (Oryza sativa) Seeds.

    Science.gov (United States)

    Ma, Lei; Zhu, Fugui; Li, Zhenwei; Zhang, Jianfu; Li, Xin; Dong, Jiangli; Wang, Tao

    2015-01-01

    The deterioration of rice grain reduces the quality of rice, resulting in serious economic losses for farmers. Lipoxygenases (LOXs) catalyze the dioxygenation of polyunsaturated fatty acids with at least one cis,cis-1,4-pentadiene to form hydroperoxide, which is a major factor influencing seed longevity and viability. Recently, genome editing, an essential tool employed in reverse genetics, has been used experimentally to investigate basic plant biology or to modify crop plants for the improvement of important agricultural traits. In this study, we performed targeted mutagenesis in rice using transcription activator-like effector nucleases (TALENs) to improve seed storability. A modified ligation-independent cloning method (LIC) was employed to allow for the quick and efficient directional insertion of TALEN monomer modules into destination vectors used in plants. We demonstrated the feasibility and flexibility of the technology by developing a set of modular vectors for genome editing. After construction and validation, the TALEN pairs were used to create stable transgenic rice lines via Agrobacterium-mediated transformation. One heterozygous mutant (4%) was recovered from 25 transgenic NPTII-resistant lines, and the mutation was transmitted to the next generation. Further molecular and protein level experiments verified LOX3 deficiency and demonstrated the improvement of seed storability. Our work provides a flexible genome editing tool for improving important agronomic traits, as well as direct evidence that Lox3 has only a limited impact on seed longevity.

  18. TALEN-Based Mutagenesis of Lipoxygenase LOX3 Enhances the Storage Tolerance of Rice (Oryza sativa Seeds.

    Directory of Open Access Journals (Sweden)

    Lei Ma

    Full Text Available The deterioration of rice grain reduces the quality of rice, resulting in serious economic losses for farmers. Lipoxygenases (LOXs catalyze the dioxygenation of polyunsaturated fatty acids with at least one cis,cis-1,4-pentadiene to form hydroperoxide, which is a major factor influencing seed longevity and viability. Recently, genome editing, an essential tool employed in reverse genetics, has been used experimentally to investigate basic plant biology or to modify crop plants for the improvement of important agricultural traits. In this study, we performed targeted mutagenesis in rice using transcription activator-like effector nucleases (TALENs to improve seed storability. A modified ligation-independent cloning method (LIC was employed to allow for the quick and efficient directional insertion of TALEN monomer modules into destination vectors used in plants. We demonstrated the feasibility and flexibility of the technology by developing a set of modular vectors for genome editing. After construction and validation, the TALEN pairs were used to create stable transgenic rice lines via Agrobacterium-mediated transformation. One heterozygous mutant (4% was recovered from 25 transgenic NPTII-resistant lines, and the mutation was transmitted to the next generation. Further molecular and protein level experiments verified LOX3 deficiency and demonstrated the improvement of seed storability. Our work provides a flexible genome editing tool for improving important agronomic traits, as well as direct evidence that Lox3 has only a limited impact on seed longevity.

  19. OsCLT1, a CRT-like transporter 1, is required for glutathione homeostasis and arsenic tolerance in rice.

    Science.gov (United States)

    Yang, Jian; Gao, Ming-Xing; Hu, Han; Ding, Xiao-Meng; Lin, Hong-Wei; Wang, Lei; Xu, Ji-Ming; Mao, Chuan-Zao; Zhao, Fang-Jie; Wu, Zhong-Chang

    2016-07-01

    Arsenic (As) contamination in a paddy environment can cause phytotoxicity and elevated As accumulation in rice (Oryza sativa). The mechanism of As detoxification in rice is still poorly understood. We isolated an arsenate (As(V))-sensitive mutant of rice. Genomic resequencing and complementation identified OsCLT1, encoding a CRT-like transporter, as the causal gene for the mutant phenotype. OsCLT1 is localized to the envelope membrane of plastids. The glutathione and γ-glutamylcysteine contents in roots of Osclt1 and RNA interference lines were decreased markedly compared with the wild-type (WT). The concentrations of phytochelatin PC2 in Osclt1 roots were only 32% and 12% of that in WT after As(V) and As(III) treatments, respectively. OsCLT1 mutation resulted in lower As accumulation in roots but higher As accumulation in shoots when exposed to As(V). Under As(III) treatment, Osclt1 accumulated a lower As concentration in roots but similar As concentration in shoots to WT. Further analysis showed that the reduction of As(V) to As(III) was decreased in Osclt1. Osclt1 was also hypersensitive to cadmium (Cd). These results indicate that OsCLT1 plays an important role in glutathione homeostasis, probably by mediating the export of γ-glutamylcysteine and glutathione from plastids to the cytoplasm, which in turn affects As and Cd detoxification in rice.

  20. Genetic, physiological and modelling approaches towards tolerance to salinity and low nitrogen supply in rice (Oryza sativa L.)

    NARCIS (Netherlands)

    Manneh, B.

    2004-01-01

    Keywords:   Rice, O ryza sativa , yield potential, yield gap, salinity, nitrogen supply, agro-ecosystems, Recombinant Inbred Line, genotype × environment interaction, yield components, adaptability, molecular markers, QTL, biomass, leaf area, leaf N, dry matter a

  1. 中国椰子耐寒生理研究进展与展望%Study on Coconut cold-tolerance physiology

    Institute of Scientific and Technical Information of China (English)

    牛聪; 杨伟波; 唐龙祥

    2011-01-01

    低温是限制椰子种植业发展的主要因素,严重制约着中国椰子产业的发展。综述了寒害对中国椰子产业的影响,以及椰子抗寒生理的研究现状,并根据已经开展的棕榈科植物抗寒生理研究的情况,对椰子抗寒生理的研究进行了展望。%Low temperature is one of the most important factors that influence the coconut production which severely restricts the promotion of the new coconut varieties. The paper summarizes the cold injury to the Hainan coconut industry and the research status of coconut cold-tolerance physiology. And the coconut cold-tolerance physioiogical studies is prospected according to the researches on other palms.

  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. Constitutive over-expression of rice chymotrypsin protease inhibitor gene OCPI2 results in enhanced growth, salinity and osmotic stress tolerance of the transgenic Arabidopsis plants.

    Science.gov (United States)

    Tiwari, Lalit Dev; Mittal, Dheeraj; Chandra Mishra, Ratnesh; Grover, Anil

    2015-07-01

    Protease inhibitors are involved primarily in defense against pathogens. In recent years, these proteins have also been widely implicated in response of plants to diverse abiotic stresses. Rice chymotrypsin protease inhibitor gene OCPI2 is highly induced under salt and osmotic stresses. The construct containing the complete coding sequence of OCPI2 cloned downstream to CaMV35S promoter was transformed in Arabidopsis and single copy, homozygous transgenic lines were produced. The transgenic plants exhibited significantly enhanced tolerance to NaCl, PEG and mannitol stress as compared to wild type plants. Importantly, the vegetative and reproductive growth of transgenic plants under unstressed, control conditions was also enhanced: transgenic plants were more vigorous than wild type, resulting into higher yield in terms of silique number. The RWC values and membrane stability index of transgenic in comparison to wild type plants was higher. Higher proline content was observed in the AtOCPI2 lines, which was associated with higher transcript expression of pyrroline-5-carboxylate synthase and lowered levels of proline dehydrogenase genes. The chymotrypsin protease activities were lower in the transgenic as against wild type plants, under both unstressed, control as well as stressed conditions. It thus appears that rice chymotrypsin protease inhibitor gene OCPI2 is a useful candidate gene for genetic improvement of plants against salt and osmotic stress.

  4. Altered architecture and enhanced drought tolerance in rice via the down-regulation of indole-3-acetic acid by TLD1/OsGH3.13 activation.

    Science.gov (United States)

    Zhang, Sheng-Wei; Li, Chen-Hui; Cao, Jia; Zhang, Yong-Cun; Zhang, Su-Qiao; Xia, Yu-Feng; Sun, Da-Ye; Sun, Ying

    2009-12-01

    Plant architecture is determined by genetic and developmental programs as well as by environmental factors. Sessile plants have evolved a subtle adaptive mechanism that allows them to alter their growth and development during periods of stress. Phytohormones play a central role in this process; however, the molecules responsible for integrating growth- and stress-related signals are unknown. Here, we report a gain-of-function rice (Oryza sativa) mutant, tld1-D, characterized by (and named for) an increased number of tillers, enlarged leaf angles, and dwarfism. TLD1 is a rice GH3.13 gene that encodes indole-3-acetic acid (IAA)-amido synthetase, which is suppressed in aboveground tissues under normal conditions but which is dramatically induced by drought stress. The activation of TLD1 reduced the IAA maxima at the lamina joint, shoot base, and nodes, resulting in subsequent alterations in plant architecture and tissue patterning but enhancing drought tolerance. Accordingly, the decreased level of free IAA in tld1-D due to the conjugation of IAA with amino acids greatly facilitated the accumulation of late-embryogenesis abundant mRNA compared with the wild type. The direct regulation of such drought-inducible genes by changes in the concentration of IAA provides a model for changes in plant architecture via the process of drought adaptation, which occurs frequently in nature.

  5. The phenome analysis of mutant alleles in Leucine-Rich Repeat Receptor-Like Kinase genes in rice reveals new potential targets for stress tolerant cereals.

    Science.gov (United States)

    Dievart, Anne; Perin, Christophe; Hirsch, Judith; Bettembourg, Mathilde; Lanau, Nadège; Artus, Florence; Bureau, Charlotte; Noel, Nicolas; Droc, Gaétan; Peyramard, Matthieu; Pereira, Serge; Courtois, Brigitte; Morel, Jean-Benoit; Guiderdoni, Emmanuel

    2016-01-01

    Plants are constantly exposed to a variety of biotic and abiotic stresses that reduce their fitness and performance. At the molecular level, the perception of extracellular stimuli and the subsequent activation of defense responses require a complex interplay of signaling cascades, in which protein phosphorylation plays a central role. Several studies have shown that some members of the Leucine-Rich Repeat Receptor-Like Kinase (LRR-RLK) family are involved in stress and developmental pathways. We report here a systematic analysis of the role of the members of this gene family by mutant phenotyping in the monocotyledon model plant rice, Oryza sativa. We have then targeted 176 of the ∼320 LRR-RLK genes (55.7%) and genotyped 288 mutant lines. Position of the insertion was confirmed in 128 lines corresponding to 100 LRR-RLK genes (31.6% of the entire family). All mutant lines harboring homozygous insertions have been screened for phenotypes under normal conditions and under various abiotic stresses. Mutant plants have been observed at several stages of growth, from seedlings in Petri dishes to flowering and grain filling under greenhouse conditions. Our results show that 37 of the LRR-RLK rice genes are potential targets for improvement especially in the generation of abiotic stress tolerant cereals.

  6. Expression of a codon-optimized dsdA gene in tobacco plastids and rice nuclear confers D-serine tolerance

    Directory of Open Access Journals (Sweden)

    Yanmei eLi

    2016-05-01

    Full Text Available D-serine is toxic to plants. D-serine ammonia lyase, which is encoded by the dsdA gene, can attenuate this toxicity with high specificity. In the present study, we explored the function of codon-optimized dsdA with tobacco plastids and rice nuclear transformation system. It was shown that the dsdA gene was site-specifically integrated into the tobacco chloroplast genome and displayed a high level of expression. Genetic analysis of the progenies showed that the dsdA gene is maternally inherited and confers sufficient D-serine resistance in tobacco. The effective screening concentrations of D-serine for seed germination, callus regeneration and foliar spray were 10 mM, 30 mM and 75 mM, respectively. In addition, calluses from homozygous transgenic rice lines also showed significant tolerance to D-serine (up to 75 mM. Our study proves the feasibility of using dsdA gene as a selectable marker in both chloroplast and nuclear transformation systems.

  7. Expression of a Codon-Optimized dsdA Gene in Tobacco Plastids and Rice Nucleus Confers D-Serine Tolerance.

    Science.gov (United States)

    Li, Yanmei; Wang, Rui; Hu, Zongliang; Li, Hongcai; Lu, Shizhan; Zhang, Juanjuan; Lin, Yongjun; Zhou, Fei

    2016-01-01

    D-serine is toxic to plants. D-serine ammonia lyase, which is encoded by the dsdA gene, can attenuate this toxicity with high specificity. In the present study, we explored the function of codon-optimized dsdA with tobacco plastids and rice nuclear transformation system. It was shown that dsdA gene was site-specifically integrated into the tobacco plastid genome and displayed a high level of expression. Genetic analysis of the progenies showed that dsdA gene is maternally inherited and confers sufficient D-serine resistance in tobacco. The effective screening concentrations of D-serine for seed germination, callus regeneration and foliar spray were 10, 30, and 75 mM, respectively. In addition, calluses from homozygous transgenic rice lines also showed significant tolerance to D-serine (up to 75 mM). Our study proves the feasibility of using dsdA gene as a selectable marker in both plastid and nuclear transformation systems.

  8. Evaluation of the tolerance to Finale® in the germination and regeneration of Cuban rice varieties (IACuba-17 and IACuba-19

    Directory of Open Access Journals (Sweden)

    Daymí Abreu

    2005-01-01

    Full Text Available Selection agent used during the shoot selection has an important role on the transgenic plant generation efficiency. In this work, the tolerance to the herbicide Finale® in two Cuban rice cultivars, IACuba17 and IACuba-19 was evaluated, and determined that 10 days exposure to 5 and 10 mg.l-1 of Finale® were enough to avoid seedlings of IAC-17 and IAC-19, respectively. Cultivated calluses (0, 2, 4 and 6 days in the absence of Finale®in the regeneration medium were used to evaluate the minimal concentration of Finale®that totally inhibits shoot regeneration. Pre-induced calluses cultured during two days and 3 mg.l-1 of Finale® in the regeneration medium was the most efficient combination to select shoots during the generation of transgenic plants resistant to the herbicide. Our shoot selection procedure reduces to 3 weeks the time to obtain shoots during the generation of transgenic rice plants. Key words: germination, mature seeds, Oryza, phosphinothricin, regeneration, selection markers

  9. Constitutive over-expression of rice ClpD1 protein enhances tolerance to salt and desiccation stresses in transgenic Arabidopsis plants.

    Science.gov (United States)

    Mishra, Ratnesh Chandra; Richa; Grover, Anil

    2016-09-01

    Caseinolytic proteases (Clps) perform the important role of removing protein aggregates from cells, which can otherwise prove to be highly toxic. ClpD system is a two-component protease complex composed of a regulatory ATPase module ClpD and a proteolytic component ClpP. Under desiccation stress condition, rice ClpD1 (OsClpD1) gene encoding for the regulatory subunit, was represented by four variant transcripts differing mainly in the expanse of their N-terminal amino acids. These transcripts were expressed in a differential manner in response to salt, mannitol and polyethylene glycol stresses in rice. Purified OsClpD1.3 protein exhibited intrinsic chaperone activity, shown using citrate synthase as substrate. Arabidopsis (Col-0) plants over-expressing OsClpD1.3 open reading frame downstream to CaMV35S promoter (ClpD1.3 plants) showed higher tolerance to salt and desiccation stresses as compared to wild type plants. ClpD1.3 seedlings also showed enhanced growth during the early stages of seed germination under unstressed, control conditions. The free proline levels and starch breakdown activities were higher in the ClpD1.3 seedlings as compared to the wild type Arabidopsis seedlings. It thus emerges that increasing the potential of ClpD1 chaperoning activity may be of advantage in protection against abiotic stresses. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. Comparative proteomic and metabolomic analyses reveal mechanisms of improved cold stress tolerance in bermudagrass (Cynodon dactylon (L.) Pers.) by exogenous calcium

    Institute of Scientific and Technical Information of China (English)

    Haitao Shi; Tiantian Ye; Bao Zhong; Xun Liu; Zhulong Chan

    2014-01-01

    As an important second messenger, calcium is involved in plant cold stress response, including chil ing (<20 °C) and freezing (<0 °C). In this study, exogenous application of calcium chloride (CaCl2) improved both chil ing and freezing stress tolerances, while ethylene glycol‐bis‐(b‐aminoethyl) ether‐N,N,N,N‐tetraacetic acid (EGTA) reversed CaCl2 effects in bermudagrass (Cynodon dactylon (L.) Pers.). Pysiological analyses showed that CaCl2 treatment al eviated the reactive oxygen species (ROS) burst and cel damage triggered by chil ing stress, via activating antioxidant enzymes, non‐enzymatic glutathione antioxidant pool, while EGTA treatment had the opposite effects. Additional y, comparative proteomic analysis identified 51 differential y expressed proteins that were enriched in redox, tricarboxylicacid cycle, glycolysis, photosynthesis, oxidative pentose phosphate pathway, and amino acid metabolisms. Consistently, 42 metabolites including amino acids, organic acids, sugars, and sugar alcohols were regulated by CaCl2 treatment under control and cold stress conditions, further confirming the common modulation of CaCl2 treatment in carbon metabolites and amino acid metabolism. Taken together, this study reported first evidence of the essential and protective roles of endogenous and exogenous calcium in bermudagrass response to cold stress, partial y via activation of the antioxidants and modulation of several differential y expressed proteins and metabolic homeostasis in the process of cold acclimation.

  11. Overexpression of Rice Glutaredoxin OsGrx_C7 and OsGrx_C2.1 Reduces Intracellular Arsenic Accumulation and Increases Tolerance in Arabidopsis thaliana

    Science.gov (United States)

    Verma, Pankaj K.; Verma, Shikha; Pande, Veena; Mallick, Shekhar; Deo Tripathi, Rudra; Dhankher, Om P.; Chakrabarty, Debasis

    2016-01-01

    Glutaredoxins (Grxs) are a family of small multifunctional proteins involved in various cellular functions, including redox regulation and protection under oxidative stress. Despite the high number of Grx genes in plant genomes (48 Grxs in rice), the biological functions and physiological roles of most of them remain unknown. Here, the functional characterization of the two arsenic-responsive rice Grx family proteins, OsGrx_C7 and OsGrx_C2.1 are reported. Over-expression of OsGrx_C7 and OsGrx_C2.1 in transgenic Arabidopsis thaliana conferred arsenic (As) tolerance as reflected by germination, root growth assay, and whole plant growth. Also, the transgenic expression of OsGrxs displayed significantly reduced As accumulation in A. thaliana seeds and shoot tissues compared to WT plants during both AsIII and AsV stress. Thus, OsGrx_C7 and OsGrx_C2.1 seem to be an important determinant of As-stress response in plants. OsGrx_C7 and OsGrx_C2.1 transgenic showed to maintain intracellular GSH pool and involved in lowering AsIII accumulation either by extrusion or reducing uptake by altering the transcript of A. thaliana AtNIPs. Overall, OsGrx_C7 and OsGrx_C2.1 may represent a Grx family protein involved in As stress response and may allow a better understanding of the As induced stress pathways and the design of strategies for the improvement of stress tolerance as well as decreased As content in crops. PMID:27313586

  12. Overexpression of rice glutaredoxin OsGrx_C7 and OsGrx_C2.1 reduces intracellular arsenic accumulation and increases tolerance in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Pankaj Kumar Verma

    2016-06-01

    Full Text Available Glutaredoxins (Grxs are a family of small multifunctional proteins involved in various cellular functions, including redox regulation and protection under oxidative stress. Despite the high number of Grx genes in plant genomes (48 Grxs in rice, the biological functions and physiological roles of most of them remain unknown. Here, the functional characterization of the two arsenic-responsive rice Grx family proteins, OsGrx_C7 and OsGrx_C2.1 are reported. Over-expression of OsGrx_C7 and OsGrx_C2.1 in transgenic Arabidopsis thaliana conferred arsenic (As tolerance as reflected by germination, root growth assay, and whole plant growth. Also, the transgenic expression of OsGrxs displayed significantly reduced As accumulation in A. thaliana seeds and shoot tissues compared to WT plants during both AsIII and AsV stress. Thus, OsGrx_C7 and OsGrx_C2.1 seem to be an important determinant of As-stress response in plants. OsGrx_C7 and OsGrx_C2.1 transgenic showed to maintain intracellular GSH pool and involved in lowering AsIII accumulation either by extrusion or reducing uptake by altering the transcript of A. thaliana AtNIPs. Overall, OsGrx_C7 and OsGrx_C2.1 may represent a Grx family protein involved in As stress response and may allow a better understanding of the As induced stress pathways and the design of strategies for the improvement of stress tolerance as well as decreased As content in crops.

  13. A Pilot Randomized Controlled Clinical Trial to Assess Tolerance and Efficacy of Navy Bean and Rice Bran Supplementation for Lowering Cholesterol in Children

    Directory of Open Access Journals (Sweden)

    Erica C. Borresen MPH

    2017-02-01

    Full Text Available Background: Navy beans and rice bran demonstrate efficacy to regulate serum cholesterol in hypercholesterolemic adults; however, the cardiovascular disease (CVD protective properties of these foods in children are unknown and merit investigation. Objective: The objectives were to determine whether cooked navy bean powder (NBP and/or heat-stabilized rice bran (RB supplementation is tolerable, improves dietary fiber intake in children, and modulates lipid profiles. Methods: Children aged 8 to 13 years at risk for CVD due to abnormal lipids were recruited. Elevated cholesterol levels were defined as total cholesterol ≥180 mg/dL and high-density lipoprotein (HDL 100 mg/dL and HDL <60 mg/dL. Participants completed a pilot 4-week, randomized controlled, 4-arm dietary intervention. They consumed study-provided muffins or a smoothie daily that included 0 g NBP or RB (control, 17.5 g NBP, 15 g RB, or a combination 9 g NBP + 8 g RB. Fasting blood was collected at baseline and week 4. Participants also completed 3-day food logs and gastrointestinal health questionnaires. Results: Thirty-eight children completed the trial (n = 9 control, n = 10 NBP, n = 9 RB, and n = 10 NBP + RB groups. Only 3 participants withdrew due to noncompliance of required food consumption. Participants in the intervention groups significantly increased intake of NBP and RB at week 4 (p≤.01. The NBP and NBP + RB groups increased total fiber intake from baseline to week 4 (p=.02 and p=<.01, respectively. HDL-cholesterol was higher in NBP-group participants compared to control at week 4 (P = .02. Conclusion: Increasing NBP and/or RB intake is tolerable for children, and our findings suggest higher daily intakes are needed for a longer duration to induce favorable changes across multiple serum lipid parameters.

  14. Ectopic expression of PgRab7 in rice plants (Oryza sativa L.) results in differential tolerance at the vegetative and seed setting stage during salinity and drought stress.

    Science.gov (United States)

    Tripathy, Manas Kumar; Tiwari, Budhi Sagar; Reddy, Malireddy K; Deswal, Renu; Sopory, Sudhir K

    2017-01-01

    In this work, we have overexpressed a vesicle trafficking protein, Rab7, from a stress-tolerant plant, Pennisetum glaucum, in a high-yielding but stress-sensitive rice variety Pusa Basmati-1 (PB-1). The transgenic rice plants were tested for tolerance against salinity and drought stress. The transgenic plants showed considerable tolerance at the vegetative stage against both salinity (200 mM NaCl) and drought stress (up to 12 days after withdrawing water). The protection against salt and drought stress may be by regulating Na(+) ion homeostasis, as the transgenic plants showed altered expression of multiple transporter genes, including OsNHX1, OsNHX2, OsSOS1, OsVHA, and OsGLRs. In addition, decreased generation and maintenance of lesser reactive oxygen species (ROS), with maintenance of chloroplast grana and photosynthetic machinery was observed. When evaluated for reproductive growth, 89-96 % of seed setting was maintained in transgenic plants during drought stress; however, under salt stress, a 33-53 % decrease in seed setting was observed. These results indicate that PgRab7 overexpression in rice confers differential tolerance at the seed setting stage during salinity and drought stress and could be a favored target for raising drought-tolerant crops.

  15. A DESD-box helicase functions in salinity stress tolerance by improving photosynthesis and antioxidant machinery in rice (Oryza sativa L. cv. PB1).

    Science.gov (United States)

    Gill, Sarvajeet Singh; Tajrishi, Marjan; Madan, Meenu; Tuteja, Narendra

    2013-05-01

    The exact mechanism of helicase-mediated salinity tolerance is not yet understood. We have isolated a DESD-box containing cDNA from Pisum sativum (Pea) and named it as PDH45. It is a unique member of DEAD-box helicase family; containing DESD instead of DEAD/H. PDH45 overexpression driven by constitutive cauliflower mosaic virus-35S promoter in rice transgenic [Oryza sativa L. cv. Pusa Basmati 1 (PB1)] plants confers salinity tolerance by improving the photosynthesis and antioxidant machinery. The Na(+) ion concentration and oxidative stress parameters in leaves of the NaCl (0, 100 or 200 mM) treated PDH45 overexpressing T1 transgenic lines were lower as compared to wild type (WT) rice plants under similar conditions. The 200 mM NaCl significantly reduced the leaf area, plant dry mass, net photosynthetic rate (PN), stomatal conductance (gs), intercellular CO2 (Ci), chlorophyll (Chl) content in WT plants as compared to the transgenics. The T1 transgenics exhibited higher glutathione (GSH) and ascorbate (AsA) contents under salinity stress. The activities of antioxidant enzymes viz. superoxide dismutase (SOD), ascorbate peroxidase (APX), guaiacol peroxidase (GPX) and glutathione reductase (GR) were significantly higher in transgenics; suggesting the existence of an efficient antioxidant defence system to cope with salinity induced-oxidative damage. Yeast two-hybrid assay indicated that the PDH45 protein interacts with Cu/Zn SOD, adenosine-5'-phosphosulfate-kinase, cysteine proteinase and eIF(4G), thus confirming the involvement of ROS scavenging machinery in the transgenic plants to provide salt tolerance. Furthermore, the T2 transgenics were also able to grow, flower, and set viable seeds under continuous salinity stress of 200 mM NaCl. This study provides insights into the mechanism of PDH45 mediated salinity stress tolerance by controlling the generation of stress induced reactive oxygen species (ROS) and also by protecting the photosynthetic machinery through a

  16. Cold Response of Dedifferentiated Barley Cells at the Gene Expression, Hormone Composition, and Freezing Tolerance Levels: Studies on Callus Cultures

    OpenAIRE

    Vashegyi, I.; Marozsan-Toth, Z.; Galiba, G.; Dobrev, P. (Petre); Vaňková, R. (Radomíra); Toth, B.

    2013-01-01

    In this study, data is presented how dark-grown, embryogenic barley callus cells respond to cold without any light-dependent, chloroplast-related mechanism, independently of the systemic signals. The expression of HvCBF9, HvCBF14, and HvCOR14b genes, members of one of the most important cold-inducible regulatory system, was measured by real-time PCR. Characteristic of the cold response was similar in the crowns of seedlings and in dark-grown callus cultures, however, gene expression levels we...

  17. Heart-type Fatty Acid-binding Protein Is Essential for Efficient Brown Adipose Tissue Fatty Acid Oxidation and Cold Tolerance*

    OpenAIRE

    Vergnes, Laurent; Chin, Robert; Young, Stephen G.; Reue, Karen

    2010-01-01

    Brown adipose tissue has a central role in thermogenesis to maintain body temperature through energy dissipation in small mammals and has recently been verified to function in adult humans as well. Here, we demonstrate that the heart-type fatty acid-binding protein, FABP3, is essential for cold tolerance and efficient fatty acid oxidation in mouse brown adipose tissue, despite the abundant expression of adipose-type fatty acid-binding protein, FABP4 (also known as aP2). Fabp3−/− mice exhibit ...

  18. Responses of Antioxidant System to Cold Water Stress in Weedy and Cultivated Rice with Different Chilling Sensitivity%不同耐冷性杂草稻和栽培稻抗氧化系统对冷水胁迫的响应

    Institute of Scientific and Technical Information of China (English)

    王国骄; 王嘉宇; 马殿荣; 苗微; 赵明辉; 陈温福

    2015-01-01

    ,CAT和GR活性极显著升高;WR03-45和丽江新团黑谷剑叶的抗氧化剂(AsA和GSH)含量及AsA/DHA值和GSH/GSSG值在冷水胁迫下显著高于对照;WR03-45和丽江新团黑谷剑叶产生速率、H2O2含量和MDA含量与对照相比无显著差异。【结论】冷水胁迫下,耐冷性强的水稻通过提高抗氧化酶活性和抗氧化剂含量,减少ROS的积累以及膜脂过氧化,增强对冷水胁迫的耐性。水稻的耐冷性与胁迫下抗氧化系统清除ROS的能力有关,杂草稻WR03-45作为一种强耐冷性的种质资源可以用于栽培稻耐冷性的遗传改良。%[Objective] Rice is most sensitive to temperature from booting stage to heading and flowering stages, so cold damage during this stages severely limited rice growth and the further expansion of acreage in Northeast China. Study on the physiological mechanism of rice cold tolerance will provide an important safeguard for the rice production in Northeast China. The aim of this study was to understand the changes of reactive oxygen species metabolism, antioxidant enzyme activities and antioxidants contents in flag leaves of weedy and cultivated rice with different chilling sensitivity at flowing stage under cold water stress, and provide a theoretical basis for the breeding and cultivation of rice tolerance to cold. [Method] Two chilling-tolerant genotypes, weedy rice WR03-45 and cultivated rice Lijiangxintuanheigu, and two chilling-sensitive genotypes, weedy rice WR03-26 and cultivated rice Xiuzinuo, were used and grown in plastic pots. The time of booting stage of main spike was calculated according to length of the flag leaf collar. The tested materials were subjected to low temperature in cold water pool at booting stage, and the control was the tested materials without cold water treatment. In order to study the effects of cold water stress on reactive oxygen species (ROS) metabolism, antioxidant enzyme activities and antioxidants contents of

  19. Use of a Remote Controlled Plane to Identify Cold Tolerant Clones from Early Stages of a Selection Program

    Science.gov (United States)

    Stress tolerance is one of the most important selection traits for sugarcane. However, it is a time consuming and laborious process to identify stress tolerant clones from among the thousands of clones in the early stages of a selection program. Additionally, some of the weather-related stress event...

  20. 不同施肥措施对寒地水稻产量及品质的影响%Effect of Different Fertilization Methods on Yield and Quality of Cold Rice

    Institute of Scientific and Technical Information of China (English)

    闵凡华; 杨桂杰; 周庆华

    2011-01-01

    为了研究寒地水稻后期最佳施肥方法,采用大区对比试验设计,采用寒地水稻不同叶面施肥措施。试验结果表明:寒地水稻随着叶面肥喷施次数的增加,各处理之间的发病率逐渐降低,理论产量逐渐增加,稻谷的加工品质逐渐变差,但对其外观品质无显著影响。喷施2次叶面肥的经济效益最好,增产率6.70%,公顷效益27 604.16元,净增效益1 734.19元/hm2。%Through plot experimental comparison design, different foliar fertilization methods of cold rice were studied in order to get the most appropriate fertilization methods in the late of cold rice. The ex-perimental results showed that with the increasing of foliar spraying, the incidence were gradually de-creased, the theoretical yield gradually increased, the processing quality of rice were gradual deteriora-tion, but there were no significant effect of appearance quality among the treatments of the cold rice. The best economic benefit was gotten from 2 foliar sprays, in which yield was increased by 6.70%, economic benefits was 27604.16 yuan/hm2, net benefit was 1734.19 yuan/hm2.

  1. Tolerância ao frio e caracterização de híbridos entre leucaena leucocephala e L. diversifolia Cold tolerance and characterization of hybrids between leucaena leucocephala and L. diversifolia

    Directory of Open Access Journals (Sweden)

    Carine Simioni

    1999-09-01

    Full Text Available O objetivo deste experimento foi identificar material promissor para ser utilizado como uma forrageira alternativa nas condições do sul do Brasil. Uma população de híbridos, em gerações avançadas, entre Leucaena leucocephala e L. diversifolia (ambas espécies tetraplóides, com