Journal of Integrative Agriculture ›› 2024, Vol. 23 ›› Issue (6): 1940-1955.DOI: 10.1016/j.jia.2024.03.060

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茶树中CHSs(查尔酮合成酶)基因的扩增行为并调节黄酮类化合物的合成以应对紫外胁迫

  

  • 收稿日期:2023-05-15 接受日期:2023-12-05 出版日期:2024-06-20 发布日期:2024-05-30

Duplicated chalcone synthase (CHS) genes modulate flavonoid production in tea plants in response to light stress

Mingzhuo Li1, 4*, Wenzhao Wang3*, Yeru Wang2*, Lili Guo2, Yajun Liu2, Xiaolan Jiang1, Liping Gao2#, Tao Xia1#   

  1. 1 State Key Laboratory of Tea Plant Biochemistry and Utilization, Anhui Agricultural University, Hefei 230036, China

    2 School of Life Sciences, Anhui Agricultural University, Hefei 230036, China

    3 College of Horticulture, Northwest A&F University, Yangling 712100, China

    4 Department of Plant and Microbial Biology, North Carolina State University, Raleigh 27606, NC, USA

  • Received:2023-05-15 Accepted:2023-12-05 Online:2024-06-20 Published:2024-05-30
  • About author:Mingzhuo Li, E-mail: mli34@ncsu.edu; #Correspondence Liping Gao, E-mail: gaolp62@126.com; Tao Xia, Tel: +86-551-65785043, E-mail: xiatao62@126.com, xiatao62@ahau.edu.cn *These authors contributed equally to this study.
  • Supported by:
    This study was supported by the National Natural Science Foundation of China (U21A20232, 32372756, and 32202551).

摘要: 在茶树中,丰富的黄酮化合物是茶叶中的主要健康成分,并决定了茶饮料中涩味的风味特征。虽然茶树中黄酮生物合成途径的下游机制已经得到了广泛研究,但茶树中黄酮合成途径的上游基因,查尔酮合成酶(CHS)在茶树中的这一次生代谢过程中的作用还不太清楚。在本研究中,我们比较了黄酮代谢途径的演化特征,发现茶树中CHS基因发生了基因扩增现象。本文中我们筛选了三个CsCHS基因和一个CsCHS-like基因,作为进一步功能研究的可能候选者。茶树的CsCHS基因有效地在拟南芥chs-突变体中恢复了黄酮类化合物的合成,但CHS-like基因并没有此功能。此外,转基因烟草CsCHS植物与其野生型对照相比表现积累了更多含量的黄酮类化合物。更值得注意的是,我们对选定的CHS基因的启动子和基因表达水平进行了检测,反映出茶树中CHS基因对UV-B逆境产生不同响应。我们的研究表明,如UV-B暴露等环境因素可能是CHS基因复制事件背后的关键驱动因素。

Abstract: In tea plants, the abundant flavonoid compounds are responsible for the health benefits for the human body and define the astringent flavor profile.  While the downstream mechanisms of flavonoid biosynthesis have been extensively studied, the role of chalcone synthase (CHS) in this secondary metabolic process in tea plants remains less clear.  In this study, we compared the evolutionary profile of the flavonoid metabolism pathway and discovered that gene duplication of CHS occurred in tea plants.  We identified three CsCHS genes, along with a CsCHS-like gene, as potential candidates for further functional investigation.  Unlike the CsCHS-like gene, the CsCHS genes effectively restored flavonoid production in Arabidopsis chs-mutants.  Additionally, CsCHS transgenic tobacco plants exhibited higher flavonoid compound accumulation compared to their wild-type counterparts.  Most notably, our examination of promoter and gene expression levels for the selected CHS genes revealed distinct responses to UV-B stress in tea plants.  Our findings suggest that environmental factors such as UV-B exposure could have been the key drivers behind the gene duplication events in CHS.

Key words: tea , flavonoids biosynthesis ,  CHS ,  gene duplication ,  UV-B stress