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

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.