Coordination of plant growth and abiotic stress responses by tryptophan synthase β subunit 1 through modulation of tryptophan and ABA homeostasis in Arabidopsis  

作　　者：Wen-Cheng Liu Ru-Feng Song Si-Qiu Zheng Ting-Ting Li Bing-Lei Zhang Xiang Gao Ying-Tang Lu 

机构地区：[1]State Key Laboratory of Hybrid Rice,College of Life Sciences,Renmin Hospital of Wuhan University,Wuhan University,Wuhan 430072,China [2]State Key Laboratory of Crop Stress Adaptation and Improvement,School of Life Sciences,Henan University,Kaifeng 475004,China

出　　处：《Molecular Plant》2022年第6期973-990,共18页分子植物（英文版）

基　　金：supported by National Natural Science Foundation of China(#no.31830007,#no.32000150.and#no.31670251);the Natural Science Foundation of Henan Province(#no.222300420401)。

摘　　要：To adapt to changing environments, plants have evolved elaborate regulatory mechanisms balancing their growth with stress responses. It is currently unclear whether and how the tryptophan (Trp), the growth-related hormone auxin, and the stress hormone abscisic acid (ABA) are coordinated in this trade-off. Here, we show that tryptophan synthase β subunit 1 (TSB1) is involved in the coordination of Trp and ABA, thereby affecting plant growth and abiotic stress responses. Plants experiencing high salinity or drought display reduced TSB1 expression, resulting in decreased Trp and auxin accumulation and thus reduced growth. In comparison with the wild type, amiR-TSB1 lines and TSB1 mutants exhibited repressed growth under non-stress conditions but had enhanced ABA accumulation and stress tolerance when subjected to salt or drought stress. Furthermore, we found that TSB1 interacts with and inhibits β-glucosidase 1 (BG1), which hydrolyses glucose-conjugated ABA into active ABA. Mutation of BG1 in the amiR-TSB1 lines compromised their increased ABA accumulation and enhanced stress tolerance. Moreover, stress-induced H2O2 disrupted the interaction between TSB1 and BG1 by sulfenylating cysteine-308 of TSB1, relieving the TSB1-mediated inhibition of BG1 activity. Taken together, we revealed that TSB1 serves as a key coordinator of plant growth and stress responses by balancing Trp and ABA homeostasis.

关 键 词：TRYPTOPHAN AUXIN growth ABA abiotic stress TSB1 

分 类 号：Q94[生物学—植物学]