茶树CsCCD1和CsCCD4基因的克隆和表达分析

Cloning and Expression Analysis of CsCCD1 and CsCCD4 Gene in Tea Plant(Camellia sinensis)

该研究以‘铁观音'茶树为材料,同源克隆了茶树类胡萝卜素裂解双加氧酶基因CsCCD1和CsCCD4 (NCBI登录号分别为MH119136和MH119137)全长cDNA。序列分析结果显示,CsCCD1序列全长1 766bp,包含1 641bp开放阅读框(ORF),编码545个氨基酸,定位于细胞质中,不存在跨膜结构和信号肽;CsCCD4序列全长1 942bp,包含1 842bp ORF,编码612个氨基酸,不存在跨膜结构,但在N端具有叶绿体转运肽,定位于质体中。进化树分析显示,CsCCD1和CsCCD4与杜鹃聚为一类。荧光定量检测显示,CsCCD1和CsCCD4在叶、茎和花中表达量较高。在乌龙茶做青过程中,CsCCD1和CsCCD4基因都是从鲜叶到晒青表达量下调,而CsCCD1在一摇和二摇显著上调表达,在三摇后下降;CsCCD4只在一摇后上调表达,之后表达量迅速降低。推测CsCCD1和CsCCD4基因可能与乌龙茶做青香气品质形成关系密切。

The full-length cDNA sequence of the carotenoid cleavage dioxygenases CsCCD1 and CsCCD4（NCBI accession number：MH119136 and MH119137）were cloned,respectively,by homology cloning techniques from the leaves of tea cultivar‘Tieguanyin＇.The sequence analysis showed that the length of CsCCD1 was 1 766 bp,which contained a 1 641 bp ORF encoding 545 amino acids.Prediction results showed that it did not contain the transmembrane structure and signal peptides,and had high probability to locate on the cytoplasm.Additionally,the length of CsCCD4 was 1 942 bp,which contained a 1 842 bp ORF encoding 612 amino acids.Prediction results showed that it did not contain the transmembrane structure but had a N-terminal chloroplast targeting transit peptides.Phylogenetic tree analysis showed that both CsCCD1 and CsCCD4 could be clustered into the same category with RjCCD1 and RjCCD4 of Rhododendron japonicum,respectively.Tissue-specific expression pattern analysis showed that both CsCCD1 and CsCCD4 were highly expressed in leaf,stem and flower.During the green-making procedure of Oolong tea,expression of gene CsCCD1 and CsCCD4 down-regulated from leaves to solar withering.Expres-sion of gene CsCCD1 up-regulated from first tumblings to second tumblings,down-regulated rapidly after third tumblings.Expression of gene CsCCD4 up-regulated after first tumblings,and then drops rapidly.Indicate that they might be related to aroma formation in green-making procedure of Oolong tea.