Effects Of Zinc On Aroma Metabolism Of Tea Tree(Camellia Sinensis)

Tea tree(Camellia sinensis)is an important economic crop,and its growth environment plays a very important role in the tea quality,especially the metal elements in the soil,which are key factors for the growth and development of tea trees and formation of tea quality.A lot of studies have explored the influence of metal elements on the growth and development of tea trees,as well as the effects of tea quality factors such as theanine,caffeine,tea polyphenols,soluble sugars,etc.However,the influence of metal elements on the metabolism of aroma and how to form tea aroma quality has not been reported yet.Based on the experiment of zinc-treated tea seedlings,this paper detected and identified the content of the aroma and their precursors of tea leaves,analyzed the correlation between zinc and aroma,analyzed how zinc affects the changes of aroma and its precursors of tea leaves.Through the transcriptome-metabolome association analysis,a glycosyltransferase gene Cs UGT14 that changes significantly in the process of tea plant response to zinc changes was discovered and its function was verified.This study analyzed the content of aroma and metal elements in 16 tea cultivars in the previous research.Obtain the correlation network diagram of aroma and metal elements through association analysis.It can be seen that Fe,Ni,Zn have a positive correlation with aroma such as benzyl alcohol and methyl salicylate in tea leaves,respectively.The result of experiment of zinc-treated tea seedlings proved that,compared with the normal concentration of zinc,some aromatic aroma substances,especially benzyl alcohol,in tea plants which are grown at high or low zinc concentrations were significantly reduced,while the corresponding benzyl alcohol primulin content in tea plants was significantly increased.Through the transcriptome-metabolome association analysis,we selected and cloned a glycosyltransferase gene Cs UGT14 that changes significantly in the tea plant response to changes in zinc,and verified its function.The in vitro enzyme reaction results proved that the gene expressed glycosyltransferase can catalyze benzyl alcohol to produce the corresponding glycoside.