Transcriptome and phytochemical analyses reveal the roles of characteristic metabolites in the taste formation of white tea during the withering process  

作　　者：ZHOU Cheng-zhe ZHU Chen LI Xiao-zhen CHEN Lan XIE Si-yi CHEN Guang-wu ZHANG Huan LAI Zhong-xiong LIN Yu-ling GUO Yu-qiong 

机构地区：[1]College of Horticulture,Fujian Agriculture and Forestry University,Fuzhou 350002,P.R.China [2]Institute of Horticultural Biotechnology,Fujian Agriculture and Forestry University,Fuzhou 350002,P.R.China [3]Key Laboratory of Tea Science of Fujian Province/Tea Industry Research Institute,Fujian Agriculture and Forestry University,Fuzhou 350002,P.R.China

出　　处：《Journal of Integrative Agriculture》2022年第3期862-877,共16页农业科学学报（英文版）

基　　金：supported by the China Agriculture Research System of MOF and MARA (CARS-19);the Scientific Research Foundation of Graduate School of Fujian Agriculture and Forestry University, China (102–1122YS010);the Rural Revitalization Tea Industry Technical Service Project of Fujian Agriculture and Forestry University, China (11899170145);the “Double First-class” Scientific and Technological Innovation Capacity and Enhancement Cultivation Plan of Fujian Agriculture and Forestry University, China (KSYLP004);6.18 Tea Industry Technology Branch of Collaborative Innovation Institute, China (K1520001A);the Fujian Agriculture and Forestry University Construction Project for Technological Innovation and Service System of Tea Industry Chain, China (K1520005A01);the Construction of Plateau Discipline of Fujian Province, China (102/71201801101);the Biochemical Analysis and Biological Study of Tea Plant Germplasm Resources of Fujian Agriculture and Forestry University, China (K1518023A);the Innovation Training Program for College Students of Fujian Agriculture and Forestry University, China (102–111ZC20061)。

摘　　要：In the postharvest processing of tea leaves,withering is the first indispensable manufacturing process which produces the mellow,umami and sweet taste of white tea.In this study,we aimed to determine the dynamic changes of the main metabolites and clarify the key differentially expressed genes(DEGs) involved in forming the characteristic taste of white tea during withering.Phytochemical analyses revealed that the contents of total catechins and starch decreased continuously,whereas the contents of theaflavin,γ-aminobutyric acid(GABA),maltose,and soluble sugars increased significantly during withering(from 0–48 h).Meanwhile,the elevation of α-amylase(AMY),β-amylase(BAM),total amylase,and glutamate decarboxylase(GAD) activities may be correlated with the accumulation of GABA and maltose.By transcriptome sequencing,we detected 9 707,15 921,17 353,and 17 538 DEGs at 12,24,36,and 48 h of the withering process,respectively,compared with 0 h sample(fresh leaves).The transcript levels of most of the DEGs involved in catechin biosynthesis were significantly inhibited,whereas those involved in catechin oxidation were significantly up-regulated,which could be correlated to a decrease in catechin content and an increase in theaflavin content.The DEGs involved in GABA biosynthesis were considerably up-regulated,and the down-regulation of SPMS could reduce the competition for converting spermidine to GABA.The up-regulation of the AMY and BAM genes could trigger starch degradation,resulting in the increase of soluble sugar content.These results provide new insights into the importance of the withering process to the characteristic taste of white tea.

关 键 词：white tea WITHERING transcriptome analysis phytochemical analysis 

分 类 号：TS272.2[农业科学—茶叶生产加工]