Identification of Genes Induced in Response to Low-Temperature Treatment in Tea Leaves

A suppression subtractive hybridization analysis approach was undertaken to identify genes involved in cold acclimation of tea (Camellia sinensis (L.) O. Kuntze), a broad-leaved, woody evergreen species. A total of ten complementary DNA (cDNA) clones, induced by low temperature in tea leaves, were identified. These transcripts could be classified into three functional groups. Three transcripts encoded transcriptional factors. Among these, Cs-COR375 contained a putative open reading frame encoding a zinc-finger protein with two EPF-type zinc fingers, while Cs-COR041 and Cs-COR178 were corresponded to CBF-like genes. The predicted products of Cs-COR044, Cs-COR196, and Cs-COR213 cDNAs were cell structure proteins. Cs-COR044 encoded a putative 86 amino acid protein consisting of a hydrophobic N-terminal half and a hydrophilic C-terminal half relatively rich in glycine and proline. The protein was predicted to be exported to the apoplast and likely to be localized in the cell wall. Cs-COR196 and Cs-COR213 encoded for two putative early light-induced proteins, a group of nuclear-encoded thylakoid membrane proteins accumulating in response to various stresses. The predicted proteins encoded by the remaining four transcripts were putatively involved in primary and secondary metabolism. The product encoded by Cs-COR018 was beta-amylase, involved in cold acclimation of various plant species. Cs-COR126 coded for chalcone synthase, while Cs-COR054 and Cs-COR113 coded for two different flavonol synthases.