论文部分内容阅读
类黄酮是茶树的主要次生代谢产物,对决定茶叶品质及其健康功效具有重要作用。利用LC-TOF/MS、qRT-PCR等技术研究了茶树类黄酮合成积累的组织器官特异性。结果显示,茶树不同器官中,鲜叶中的酚酸、儿茶素和黄酮醇化合物种类较多且含量较高,原花青素含量低但种类多,而在根中则相反。从基因表达差异上看,从鲜叶到茎到根,4CL、CHI、F3H and F3’5’H表达依次降低。酶学实验显示,从鲜叶到茎到根,DFR/LAR和ANR酶活在鲜叶和茎中无明显差异,而在根中只检测到微弱的DFR/LAR活性。在不同发育时期鲜叶中,儿茶素含量在一叶中最高,芽其次;黄酮醇的含量在一叶和二叶中较高;花青素的含量随着鲜叶发育依次减少。qRT-PCR结果显示,PAL、C4H、CHS、F3’H、F3’5’H、DFR、LAR和ANR基因的表达与不同发育时期鲜叶中儿茶素和黄酮醇积累规律一致。酶学实验显示,随着鲜叶的发育,DFR/LAR的活性依次降低,ANR的活性呈增高趋势,它们的变化与酯型C和EGC含量趋势相吻合。
Flavonoids are the major secondary metabolites of tea tree and play an important role in determining the quality of tea and its health effects. The tissue-organ specificities of tea tree flavonoids were studied by LC-TOF / MS and qRT-PCR. The results showed that there were more and more phenolic acids, catechins and flavonols compounds in fresh leaves than in different organs of tea plant, lower content of proanthocyanidins but more variety, and opposite in roots. From the point of view of gene expression, the expression of 4CL, CHI, F3H and F3’5’H decreased from fresh leaf to stem to root. Enzymatic experiments showed that DFR / LAR and ANR activity did not differ significantly from fresh leaves to stems in fresh leaves and stems, whereas only weak DFR / LAR activity was detected in the roots. Among the fresh leaves at different developmental stages, the content of catechins was the highest in one leaf, followed by the buds; the content of flavonols was higher in one leaf and two leaves; the content of anthocyanins decreased with the development of fresh leaves in turn. qRT-PCR results showed that the expression of PAL, C4H, CHS, F3’H, F3’5’H, DFR, LAR and ANR genes were consistent with the accumulation of catechins and flavonols in fresh leaves at different developmental stages. Enzymatic experiments showed that with the development of fresh leaves, DFR / LAR activity decreased in turn, ANR activity showed an upward trend, and their changes with the ester type C and EGC content trend coincide.