Sequencing Analysis Of Gossypium Arboreum L. CDNA Library In The Whole Life And Stress-Associated Gene Cloning

Cotton (Gossypium) is an important fiber economic crop for domestically and abroad. As an accession of Gossypium arboretum, Shixiya I has good genetic stability and drought resistance. The bolls of Shixiya I are difficult to shed and perish. It is supposed to be the standard line of G. arboreum L., and is also a greatful genetic material for the research on drought resistance of cotton. In this research, large scale ESTs for normalized full-length cDNA library of Shixiya I in the whole-life cycle was sequenced. Drought-resistance genes were found by the bioinformatical analysis. Among the genes, some related to WRKY were cloned and predicted. These results will be lay the foundation for the researches on the mechanism of drought-resistance and isolate the related genes for cotton breeding.1.21594 ESTs were obtained from the large-scale EST sequencing of cDNA library. 17545 readable sequences that were more than 100 bp were produced by the analysis with Phrad software. There were 8596 unigenes, including of 3042 contigs and 5554 singlets. Some sequences which appeared for 2 times occupied 50.62% in 3042 contigs. The results indicated that the effect of normalization of the library was significant, showing the cDNA library had good quality and could facilitate further research work. All ESTs have been submitted to NCBI, which will make up for the deficiency of drought-related ESTs in cotton and also lay a good and important foundation for the cotton functional genomics research and the exploitation of important stress-tolerant genetic resources.2. According to the accession of SWISSPORT database, the unigenes had been functionally classified based on Cluster of Orthologous Groups of proteins. Genes with function annotation or putative function annotation were divided into 24 categories. Among them, genes related to general function prediction were the most (16.83%). The second was related to posttranslational modification, protein turnover, chaperones (12.27%), The third was related to translation, ribosomal structure and biogenesis (10.14%). The genes related to carbohydrate transport and metabolism (9.43%), energy production and conversion (9.07%), amino acid transport and metabolism (7.5%) were included, and so on.3. The results of the bioinformatical analysis showed that many drought-tolerant genes had been captured from the library, including 9 ESTs related to WRKY. We had obtained 4 ORFs, among which one was named as Ga73993050. Via the molecular function prediction, the ORF was found to be encoded 250 amino acids, lyophobic and had high homology of WRKY superfamily. And it was localizated to Chloroplast by the Subcellular prediction.