关键词: 茶, 鲜叶, 花, 萜类合成酶基因, 萜类化合物, 代谢谱, 表达谱

Abstract: Monoterpenes and sesquiterpenes are the major tea aromatic compounds and important for tea quality. In this study，efforts were made to elucidate the molecular mechanism controlling volatile terpenoid biosynthesis in fresh tea leaves. Volatile terpenoid profiles in tea leaves and flowers were constructed using GC–MS technology. Tea leaves and flowers at different developmental stages exhibited distinct profiles of volatile terpenoids. Young leaves had more abundant terpenoids than old leaves，and theamount of glycosidically bound terpenoids were higher than free ones. Bioinformatics approaches were employed to map tea terpenoid synthase genes from previously obtained tea transcriptome data. Genes encoding for the following ten terpenoid synthases in tea were found：Linalool synthase，myrcene synthase，(E)-β-ocimene synthase，(R)-limonene synthase，(-)-α-terpineol synthase，(+)-α-phellandrene synthase，germacrene D synthase，(E,E)-α-farnesene synthase，linalool/nerolidol synthase and nerolidol/geranyl linalool synthase. Gene expression profiling revealed spatiotemporal patterns of the tested genes in tea plants. Moreover，their expression patterns were positively correlated to the abundance of volatile terpenoids. Additionally，the expression of six terpenoid synthase genes were induced by methyl jasmonate（MeJA），suggesting that emission profile of aromatic terpenoids might be enhanced in practice through these gene expression manipulation.

Key words: Camellia sinensis, fresh leaf, flower, terpenoid synthase gene, volatlie terpenoid biosynthesis, metabolic profiling, expression profile