光照强度调控茶树飞燕草素类花色苷合成的分子机制

Anthocyanins are the main components of tea polyphenols, but the high content of anthocyanins in tea shoots has a negative effect on the quality of green tea. Our previous research found that the biosynthesis of delphinidin-related anthocyanins can be induced by high light in tea plant. However, the mechanism behind the induction of delphinidin derivatives by light is not clear. In this project we will identify the composition of delphinidin-related anthocyanins and screen the key genes involved in the regulation of delphinidin-related anthocyanins synthesis, especially the genes related to glycosilation (UGTs), by integrated analysis of molecular biology and metabolomics. Confirmation of the expression pattern of UGTs in response to light intensity and the role of UGTs in plant by over-expression in Arabidopsis will also be investigated. Expected results from this project will unravel the effect of light on delphinidin-related anthocyanins synthesis and its regulation roles, and also consequently provide a theoretical basis for the directional control of anthocyanins synthesis and improve the quality of green tea in summer.

花色苷是茶多酚的主要组分，但高含量花色苷对茶叶品质产生负面影响。申请人前期发现茶树飞燕草素类花色苷受光照强度显著调节，但其作用机制尚不清楚。本项目拟采用非靶向和靶向代谢组学方法对不同光照强度处理下茶树的花色苷组分进行定性定量分析，对参与其代谢的主要结构基因、转录因子、糖基化关键基因进行差异表达分析，通过基因表达与代谢组学的联合分析、关键基因拟南芥超量表达验证等方法，明确光照强度对茶树飞燕草素类花色苷代谢的影响和关键调节途径，为定向调控茶叶品质提供理论基础。

花色苷是茶多酚的主要组分，但高含量花色苷对茶叶品质产生负面影响。为了明确光照强度对茶树飞燕草素类花色苷代谢的影响和关键调节途径。本项目基于不同光照强度处理和光暴露处理两组茶树叶片的代谢物分析，研究了光照强度调节茶树合成的飞燕草素类花色苷组分及其含量变化，并在此基础上进行了基因转录分析和关键基因筛选工作，进一步验证了光照强度调节飞燕草素类花色苷代谢的关键调控基因及功能。研究结果明确紫色叶片茶树受光照强度调节的呈色花色苷主要物质成分是飞燕草-己糖-对香豆酰（delphinidin-hexose-coumaroyl）和儿茶素聚合物（proanthocyanldin）。基因表达分析表明，调节花色苷代谢的关键基因为Flavonol synthase (FLS)和糖苷化UDP-glycosyltransferase (UGTs)。超表达植物材料验证发现飞燕草花色苷积累的影响不显著，这可能与茶树花色苷分解代谢相关。本研究明确了光照强度对茶树飞燕草素类花色苷代谢的影响和关键调节途径，为定向调控茶叶品质提供理论基础。