STUDIES ON THE ROLE OF HEAT SHOCK TRANSCRIPTION FACTORS AND PROTEINS ON HIGH TEMPERATURE TOLERANCE IN WHEAT GENOTYPES (Triticum aestivum L.)
KrishiKosh
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Title |
STUDIES ON THE ROLE OF HEAT SHOCK TRANSCRIPTION FACTORS AND PROTEINS ON HIGH TEMPERATURE TOLERANCE IN WHEAT GENOTYPES (Triticum aestivum L.)
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Creator |
KRISHNA KUMAR G
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Contributor |
R.K. Sairam
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Subject |
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Description |
T-8514
India is the second largest producer of wheat in the world. High temperature spells towards the end of the crop season are a major determinant of wheat yield, especially under Indian conditions. The present study was conducted with three contrasting wheat genotypes in terms of temperature tolerance viz. Halna, DBW 14 and HD 2687 sown on 25th November, 15th December and 10th January of 2010-11. The observations were taken at 30 days after sowing, booting, anthesis and 10 days after anthesis. Late sowing induced high temperature stress led to the reduction in relative water content (RWC), membrane stability index (MSI), chlorophyll content, carotenoid content and photosynthetic rate in all the varieties. The reduction was higher at anthesis and 10 days after anthesis, when compared to 30 days after sowing and booting. Comparatively higher reductions were observed in susceptible genotype, HD 2687 compared to Halna and DBW 14. High temperature stress induced oxidative stress, measured in terms of lipid peroxidation was found to be significantly higher under high temperature stress treatment especially more so in HD 2687. Crop duration, plant height, plant biomass, number of tillers, number of ears per plant and grain weight per panicle were also negatively affected by high temperature stress. The tolerant genotypes Halna and DBW 14 maintained comparatively high grain weight per ear, 1000 grain wt and grain yield per plant, under high temperature stress. Biochemical analysis of grains revealed that high temperature stress treatment led to significant reduction in starch content and increase in soluble sugar and grain protein content. However, Halna maintained optimal level of starch with little temperature induced increase in soluble sugars and grain protein in comparison with other genotypes. Expression analysis of heat shock transcription factors revealed that tolerant genotypes Halna and DBW 14 were having higher levels of heat stress induced expression of heat shock transcription factors HSFA2b, HSFA4a and HSF8. Halna and DBW 14 also maintained higher levels of expression of small heat shock protein (sHSP) like 17.3, 16.9B and high molecular weight HSP70, HSP80 and HSP101C. Sequence comparison of HSPs and HSFs revealed the homology of nucleotide sequences between Triticum aestivum, Oryza sativa, Hordeum vulgare and Arabidopsis thaliana, indicating the conservation of nucleotide sequences of HSPs and HSFs across genera. The amino acid sequences deduced from the nucleotide sequences also showed significant sequence homology across genera. From the study, it can be concluded that the efficient up-regulation of HSFs and HSPs played a major role in imparting high temperature stress tolerance in wheat. |
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Date |
2016-12-01T11:15:17Z
2016-12-01T11:15:17Z 2011 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/88560
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Format |
application/pdf
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Publisher |
IARI, DIVISION OF PLANT PHYSIOLOGY
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