Genomic Organization And Differential Expression Analysis Of Tea Dehydrin In Tea Plant [C. Sinensis (L.) O. Kuntze]

As an important economic crop, cold damage is the limited factor for tea quality and yield in our country. Therefore, understanding the mechanism of cold resistance and freeze injuries, as well as investigating the cold-resistance genes from the tea plant, becomes a hot topic in the research field of tea cultivation and breeding in recent years. In this dissertation, the CsDHN1 and CsDHN2 genes DNA sequences and promoter sequences were cloned and analyzed. Also the different expression of dehydrins in different organs, seasons and overwintering period were analyzed by Western blot. So, this study lay the foundation for better understnding the relation between dehydrin and tea resistance and regulation mechanism. The main conclusions are as follows:1) The genomic DNA of CsDHN1 and CsDHN2 genes were cloned successfully. CsDHN1 contains two exons and one intron in the DNA sequence of 1910bp. CsDHN2 contains three exons and two introns in the DNA sequence of 1821bp. All the exon/intron junctions of CsDHN1 and CsDHN2 genes contain the gt/ag consensus spicing site.2) The promoters of CsDHN1 and CsDHN2 genes were cloned by PCR based on genome walker method. And they were 1048bp and 589bp. The rusults meet the relevant characteristics of eukaryotic promoters.3) A protein extraction method for tea plant dehydrin Western blot was found. It was the most suitable method of protein samples preparation for Western blot detecting of tea plant dehydrin and the obtained Western blot mapping information was more, less background, better repeatability, higher yield and efficiency.4) Ten dehydrins, molecular weight ranged from 14 to 86 kDa, were found in different organs of tea plant, whoes expression shows a big difference. Three dehydrins,14kDa,23kDa and 34kDa were the most intense bands dected in seed protein. It showed that they are the specific dehydrin expressed in seed and probably associate with dehydration. Four dehydrins, 21 kDa,50kDa,58kDa and 68kDa were the most intense bands dected in bud and young leaves.While the 86kDa dehydrin didn’t show any expression in mature leaves, it may be affected by development.5)Seven dehydrins, molecular weight ranged from 21 to 68 kDa were found in different seasons of tea plant, whose expression show seasonal differences and species differences. Three dehydrins,21 kDa,28kDa and 68kDa were the most intense bands dected in winter a spring which may be related to low temperature. A molecular weight of 40kDa dehydrin v detected in Camellia sinensis cv. "Wancha91 but not in Camellia sinensis cv. "Wuniuzao".6) Six dehydrins, molecular weight ranged from 21 to 68 kDa were found in tea plant during overwintering period. Their expression regularity was that firstlly increased and then decresed with the change of temperature, and the protein expression amount reached the high est in November or December.Three dehydrins,21 kDa,28kDa and 40kDa expressed higher levels during overwintering period, while 68kDa dehydrin was only detected after November. A molecular weight of 50kDa dehydrin was only detected in November and December. A molecular weight of 58kDa dehydrin was only detected in November, December and January. They may have high correlation with low temperature.