茶树乙醇脱氢酶基因CsADH2的克隆与表达分析

Cloning and Expression of CsADH2 in Tea Plant (Camellia sinensis)

在茶树转录组测序基础上,采用RT-PCR技术,克隆了茶树乙醇脱氢酶基因,命名为CsADH2。生物信息学分析结果表明,该基因全长1 540bp,其开放阅读框(ORF)长度为1 182bp,编码393个氨基酸,亚细胞定位预测位于细胞质。编码的氨基酸序列与猕猴桃、向日葵和莴苣的ADH相似性分别达到85%、85%和84%。荧光定量PCR结果表明,CsADH2在茶树各组织中均有表达,在茶树叶片中的表达量最高,在茶树根的表达量最低;在白茶萎凋过程中,CsADH2相对表达量在萎凋2h时开始上升,萎凋2～8h相对表达量下降;12h诱导表达上升至最高,为0h时的6倍;CsADH2相对表达量在24～48h处于降低趋势,但仍然显著高于0h的相对表达量,表明CsADH2可能与白茶加工萎凋过程中脂肪族类香气物质的形成有关。

Based on the transcriptome database on tea plants(Camellia sinensis),the full-length cDNAs of the alcohol dehydrogenase gene(CsADH2)was cloned from Fudingdabai using RT-PCR.A bioinformatics analysis showed that the cDNA had a full length of 1 540 bp with a 1 182 bp ORF encoding 393 amino acids and located probably in the cytoplasm.The amino acids of CsADH2 was 85%homogenous to those of Actinidia deliciosa and Helianthus annuus L,and 84%to that of Lactuca sativa Linn.The results of qRT-PCR showed that CsADH2 expressed differently in different tissues of a tea plant with the highest in the leaves and the lowest in the roots.During white tea withering,the expression of CsADH2 began to up-regulate in the first 2 h and down-regulated when treated for 2-8 h.The expression peaked at 12 th h reaching a level 6 times as high as that at the beginning.The expression was down-regulated in 24-48 h,but still was significantly higher than that of 0 h.It appeared that CsADH2 played an important role in the formation of the aromatic lipids in tea.