Molecular Identification and Characterization of Hydroxycinnamoyl Transferase in Tea Plants ( L.).

Tea ( L.) contains abundant secondary metabolites, which are regulated by numerous enzymes. Hydroxycinnamoyl transferase (HCT) is involved in the biosynthesis pathways of polyphenols and flavonoids, and it can catalyze the transfer of hydroxyconnamoyl coenzyme A to substrates such as quinate, flavanol glycoside, or anthocyanins, thus resulting in the production of chlorogenic acid or acylated flavonol glycoside. In this study, the gene was cloned from the Chin-Shin Oolong tea plant, and its protein functions and characteristics were analyzed. The full-length cDNA of CsHCT contains 1311 base pairs and encodes 436 amino acid sequences. Amino acid sequence was highly conserved with other HCTs from , , , and . Quantitative real-time polymerase chain reaction analysis showed that is highly expressed in the stem tissues of both tea plants and seedlings. The expression level was relatively high at high altitudes. The abiotic stress experiment suggested that low temperature, drought, and high salinity induced transcription. Furthermore, the results of hormone treatments indicated that abscisic acid (ABA) induced a considerable increase in the expression level. This may be attributed to CsHCT involvement in abiotic stress and ABA signaling pathways.