Cloning Of Superoxide Dismutase Genes And Their Expression Analysis Under Cold Stress In Camellia Sinensis Cv. Tieguanyin

Camellia sinensis (L.) O.Kuntze is a kind of important industrial crop in China, which is thermophilic. Temperature is the main element affects the distribution, growth and reproduction of tea. In this experiment, six members of SOD gene family were cloned, the promoter of CsCSDl gene was isolated, expression pattern of SOD genes were analyzed under chilling stress. The main results were as follows:1 Half lethal temperature of Camellia sinensis cv Tieguanyin is -5.8℃ Half lethal temperature of Camellia sinensis cv Tieguanyin is -5.8℃, identified by Chlorophyll fluorescence parameter Fv/Fm.2 Cloning and gene structure analysis of SOD genes from Camellia sinensisCsCSDl, CsCSD2, CsCSD3, CsFSDl, CsFSD3 and CsMSD genes was cloned from Camellia sinensis. Their ORF full length are 459bp,636bp,471bp,903bp,813bp and 693bp, and encoded amino acid sequence length are 152,211,156,300,270 and 230. Gene structural analysis found out that CsCSDl contains five introns, CsCSD2 does not contain introns, CsCSD3 contains six introns, CsFSD3 contains within seven intron.3 Bioinformatics analysis of SOD proteinSubcellular lacalizations analysis of SOD showed that CsCSDl is located in cytoplasm, CsCSD2, CsFSD1 and CsFSD3 are located in chloroplast, CsCSD3 is located in peroxisomes, and CsMSD1 is located in mitochondria. The secondary structure of CsCSD contains low α- helix and high random coil, the secondary structure of CsFSD and CsMSD contains high α- helix and lowβ-turn. Sequence alignments showed that six members of SOD genes was divided into six groups.4 Expression analysis of SOD under cold stress in Camellia sinensis Under cold stress, CsSOD members exhibited 3 different expression patterns.5 Cloning and cis element Analysis of tea CsCSDl gene promoterCis-element analysis of CsCSD1 gene promoter found out that the presence of abscisic acid response element ABRE related to low temperature stress responses. According to cis-element analysis of the promoter, we think under cold stress CsCSD1 gene low temperature signal transduction by ABA dependent pathway.