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Verticillium wilt (Verticillium wilt) is the major diseases of the world's cotton, a serious threat, and hinder the development of cotton production. China major cotton producing country in the world, cotton production has an important impact on the development of the national economy, and China's cotton production has been affected by blight, verticillium wilt constraints, especially the impact of verticillium wilt of cotton production is the most serious. Therefore, how to control the cotton verticillium wilt become a problem to be solved on cotton production in China. The use of resistant varieties is undoubtedly an economical and effective environmental protection measures, while cultivating resistant varieties must first clear the resistance mechanism and looking for high resistance to verticillium wilt gene. The growing molecular biological technology provides a powerful tool for the study of cotton resistance genes, resistance to verticillium wilt molecular breeding to provide new sources of genes for cotton. In the present study, in order to study the upland cotton inoculated with Verticillium dahliae disease resistance gene expression, we constructed a cDNA library the upland cotton resistant varieties Jimian 20 Verticillium dahliae induced by suppression subtractive hybridization. Inoculated with Verticillium dahliae 8h, 12h, 24h and 48h materials for the test side, non-inoculated control materials to build SSH library as driver. SSH library constructed save 800 positive clones, the average fragment size of 400bp. 20 randomly selected positive clones were sequenced EST will receive in GenBank with BLASTn and BLASTx their sequence homology comparison. The results showed that the 20 ESTs can find homologous sequences of known function, wherein the BLASTn comparison result, the known function 12, representing all the EST 60% The BLASTX comparison result there are 14 known function, accounting for 70% of all EST. The sequence with GenBank dbEST library for comparison, and found that the vast majority the EST can find high homology cDNA and and these cDNA from the cDNA library specific expression in plants under biotic and abiotic stress conditions. Homologous sequences can be found in the EST BLASTx and BLASTn results Beavn classification criteria of Arabidopsis functional classification. Of Verticillium dahliae obtained genes induced homologous genes of known function related to a variety of metabolites of the pathogen defense response and signal transduction pathways. Such as: B9 number sequence and the sequence of the A21 with the serine / threonine protein kinase homologous, the 4th sequence homology and glutathione-S-transferase enzymes, the 16th sequence homology with the ACC oxidase, the 10th sequence of disease resistance response related gene family homology. These homologous genes involved in R gene-mediated signal transduction pathway, salicylic acid-mediated signal transduction pathway, jasmonic acid and ethylene signal transduction pathway, the plant defend the prime synthesis and cell wall modification. By gene expression analysis of this trial can be seen, some of the signaling, transcription factor class, class of secondary metabolites, and cell structure genes in a variety of plant materials and a variety of stress-induced expression. This indicates that the consistency of plant stress basic defense mechanism for the external environment. Finally, part of the resistance genes screened for the study, cotton resistance to verticillium wilt possible molecular mechanisms conducted a preliminary study.
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