CsHCT-Mediated Lignin Synthesis Pathway Involved in the Response of Tea Plants to Biotic and Abiotic Stresses
CsHCT-Mediated Lignin Synthesis Pathway Involved in the Response of Tea Plants to Biotic and Abiotic Stresses
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CsHCT 介导的木质素合成途径参与茶树对生物和非生物胁迫的响应
DOI：
10.1021/acs.jafc.1c02771
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发表时间：
2021-08-19
影响因子：
6.1
通讯作者：
Xia, Tao
中科院分区：
文献类型：
--
作者：
Chen, Yifan;Yi, Ning;Xia, Tao
许多研究表明，木质素和类黄酮等酚类化合物可以增强植物的抗性。茶树富含类黄酮化合物。这些化合物是否与茶树抗性有关尚不清楚。本研究在实验结果的基础上得出了一个有趣的结论：在非生物胁迫下（蔗糖处理除外），茶树苯丙素和木质素途径的基因表达增加，类黄酮途径的基因表达减少。CsHCTs是位于木质素和类黄酮途径分支点的基因，最适合调控木质素途径和类黄酮合成中碳流量的比例。体外和体内的酶促和基因修饰实验证明，CsHCTs编码羟基肉桂酰辅酶A:shikimate/quinate羟基肉桂酰转移酶。此外，基因修饰结果表明，过表达CsHCTs的烟草和拟南芥植株的酚酸和木质素含量增加，而黄酮醇苷含量降低。这两种转基因植物都显示出对许多非生物胁迫和细菌感染的抗性。我们推测CsHCTs参与调节碳从类黄酮途径到绿原酸、咖啡莽草酸和木质素途径的代谢流，以增加对生物和非生物胁迫的抵抗力。
Many studies have shown that phenolic compounds such as lignin and flavonoids enhance plant resistance. Tea plants are rich in flavonoid compounds. Whether these compounds are related to tea plant resistance is unclear. In this study, an interesting conclusion was drawn on the basis of experimental results: in response to abiotic stress (except for sucrose treatment), gene expression was increased in the phenylpropanoid and lignin pathways and was reduced in the flavonoid pathway in tea plants. CsHCTs, the genes located at the branch point of the lignin and flavonoid pathways, are most suitable for regulating the ratio of carbon flow in the lignin pathway and flavonoid synthesis. Enzymatic and genetic modification experiments proved that CsHCTs encode hydroxycinnamoyl-coenzyme A:shikimate/quinate hydroxycinnamoyl transferase in vitro and in vivo. Furthermore, the genetic modification results showed that the contents of phenolic acids and lignin were increased in tobacco and Arabidopsis plants overexpressing CsHCTs, whereas the content of flavonol glycosides was decreased. Both types of transgenic plants showed resistance to many abiotic stresses and bacterial infections. We speculate that CsHCTs participate in regulation of the metabolic flow of carbon from the flavonoid pathway to the chlorogenic acid, caffeoylshikimic acid, and lignin pathways to increase resistance to biotic and abiotic stresses.