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Drought is one of the serious problems facing the world, is also the main factors restricting China's agricultural production, improve crop drought resistance is the focus of one of the hot issues in the modern agricultural research work. Cotton is our country and even the world's most important economic crops in Xinjiang under the arid desert climate is relatively dry, but also one of the largest cotton production base in China, cotton is a water crops, agriculture water crisis has become increasingly prominent, severe drought constraints forward to the further development of the cotton in Xinjiang. Lack of effective means choice and Cotton drought tolerant traits complexity have been people using traditional conventional breeding methods to solve the problems of cotton varieties of drought often heavy workload and cost of large and selection is not efficient. With the academic development of molecular biology, the use of molecular genetics, molecular biology methods such as cultivating stress-resistant varieties by means of genetic engineering has become an important content of modern agricultural research. Drought-tolerant varieties of cotton Jinmian the 13th, the research for the study of materials, screening and cloning and drought stress-related genes by cDNA-AFLP analysis by the expression of the target gene fragment in different plant stress point in time and in different tissues further resolve the mechanism of drought-tolerant plants, provide candidate genes for cotton resilience breeding and theoretical basis. The main findings are as follows: water Peifa Pei Yang Jin Cotton normal growth in the 13th and PEG6000 (20% and 30%) treatment 1h, 2h, 4h, 6 h, 8 h, 10 h, 12 h and 24 h seedlings, leaf total RNA extracted quality. 2, the choice of the 64 primer pairs, normal growth and drought treatment at different time points blade transcripts of cDNA-AFLP analysis. Isolated from a total of 232 differentially expressed transcripts derived fragments (TDFs), the 102 TDFs cloning, sequencing, and sequence analysis. The results showed that: there are 57 TDFs with NCBI sequence homology, eight repetitive sequences than on TDFs 19 homologous sequences, but the lack of biological function known potential biological functions of TDFs30. Another and the 45 TDFs no homologous sequence or homology, predicted some unknown genes. 3, the comparison results show that the known possible biological function of 30 TDFs respectively attributable to the signal transduction, metabolism, photosynthesis adjustment adversity response etc.. Photosynthesis regulatory protein gene including light regulation protein gene (TDF89); signal transduction genes include the ATP-binding protein gene (TDF3), the phosphatidylglycerol phospholipase C of genes (TDF45 TDF62), a serine / threonine protein kinase (TDF64, ), the F-box domain protein (TDF75), receptor protein kinase (TDF93); nucleic acid metabolism-related genes the presumed reverse transcriptase (TDF34) of retrotransposons protein (TDF7); biosynthesis key enzyme gene the starch branching the enzyme the gene (TDF1 and TDF2); protein synthesis and modification of related genes, including RNA helicase protein (TDF80), eukaryotic translation initiation factor EIF4A (TDF87); adversity response related genes including rice penetration response protein (TDF12. ), anti Rust protein (TDF29), cold stress-related protein (TDF31), drought induced the relevant the protein (TDF42 TDF81) intends to respond to the regulation of genes (PRR) (TDF52), the drug secreted proteins (TDF101); metabolic pathway enzymes class of genes including acetyl coenzyme A carboxylase (TDF43) the cytochrome P450 the gene (TDF5 TDF44), carbamoyl phosphate synthase (TDF60) the phosphoenolpyruvate carboxykinase kinase (TDF61) phosphotransferase Enzyme (TDF70) , NADH dehydrogenase (TDF78), alcohol dehydrogenase gene (TDF97); ion transport proteins tonoplast H-ATPase (TDF33); transcription factor EREBP transcription factor (TDF76). 4, to select three closely related with cotton drought-tolerant cDNA fragment (TDF42, TDF61, TDF62), using semi-quantitative RT-PCR analysis of its in cotton leaves different stress point in time, and the expression levels in different tissues, the results show that the phosphorylation The the enol pyruvate kinase (TDF61) low expression levels in normal water supply, the first enhanced under drought stress conditions weakened, the highest value in 8 hours. Expression levels in the eight hours of roots, stems, leaves leaves the highest, followed by the stems, roots in the lowest; expression under water stress conditions cDNA fragment (TDF42), essentially no expression in normal water supply, gradually increased with time, reached the highest value in 10 hours and, after gradually weakened. Root in 10 hours, the highest expression level, followed by the stems, leaves minimum; phospholipase C (TDF62) expressed in the case of normal supply is also low, with the amount of stress time prolonged expression gradually increased to the highest in 12 hours After the expression of basic in a stable, 12 hours, the amount of the gene expression of root and stem is not very different. Therefore, the initial guess three TDFs related to cotton drought-resistant. The above results show that the use of cDNA-AFLP technique separation of differentially expressed fragments related gene is feasible.
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