Construction Of Suppression Hybridization Librarfrom Cabbage Induced By Black Rot And Analysis Of Expressed Sequence Tags

The cabbage (Brassica oleracea var. capitata), which was also called head cabbage or heading cabbage .Because of hardy, adaptable and easy to transport storage-resistant, high yield, good quality and so on .It was a common vegetable crop in China. With the production of large-scale cultivation The cabbage arised increasingly serious pests and diseases. In recent years, Black rot caused by Xanthomonas campestris pv. Campestris (Xcc), was one of the most serious diseases of the cabbage causing serious reduction in yield and quality. In this reserch, a suppression subtractive hybridization (SSH) cDNA library was constructed. After analysis of reserve northern blot, PCR, double digestion on plasmid. and then 92 cDNA positive clones were randomly selected and sequenced. 87 ESTs with high quality were obtained. Similarity analysis was based on BLASTx and BLASTn softwares in GenBank. 83 of the ESTs were identified encoding putative proteins. 3 of the ESTs were found no significant similarity and they may represent new genes or high variant non-coding regions of cDNAs. 83of the ESTs were different similarity with some protein sequences and genes which were from so many plant species,such as Arabidopsis thaliana,Citrullus lanatus Triticum aestivum L.Oryza sativa,Phaseolus vulgaris, Vitis vinifera,Cucumis sativus,Zea mays,Brassica oleracea,Nicotiana tobacum,Linumusitatissimum and so on.By the ESTs function classification found:The genes were related with primery metabolism,energy metabolism, protein synthesis, disease/defense, and single. Transduction secondary metabolism.After ESTS analysis,we found some Signal transduction-related protein such as serine/threonine kinase,MAP3K alpha protein kinase and Some enzymes of primary metabolism such as peptidylprolyl isomerase malate dehydrogenase. putative rubisco activase chlorophyll a/b-binding protein are photosynthesis-related proteins.In this experiment we found 8 ESTs of Cabbage and Arabidopsis resistance gene analogues and some homology and play a very important part in it .In addition, in the ESTs obtained, there are some ESTs for abiotic stress-induced protein, such as heat shock protein, This result suggested that a possible common mechanism exists during the stress reaction of plants towards different environments.These ESTs contained other aspects, such as Secondary metabolism, disease resistance and defense genes, protein synthesis, energy metabolism genes, These genes should be related to cabbage resistance mechanism.