Abscisic acid receptors maintain abscisic acid homeostasis by modulating UGT71C5 glycosylation activity

作     者：Yanlin Ma Jing Cao Qiaoqiao Chen Jiahan He Zhibin Liu Jianmei Wang Xufeng Li Yi Yang Yanlin Ma;Jing Cao;Qiaoqiao Chen;Jiahan He;Zhibin Liu;Jianmei Wang;Xufeng Li;Yi Yang

作者机构：Key Laboratory of Bio-Resources and Eco-Environment of Ministry of EducationCollege of Life SciencesSichuan UniversityChengdu 610065China 

出 版 物：《Journal of Integrative Plant Biology》 (植物学报（英文版）)

年 卷 期：2021年第63卷第3期

页      面：543-552页

核心收录：

学科分类：0710[理学-生物学] 09[农学] 0903[农学-农业资源与环境] 0901[农学-作物学] 0703[理学-化学] 0902[农学-园艺学] 

基　　金：supported by grants from the National Natural Science Foundation of China(31671455 to Y.Y.)。 

主　　题：ABA glucosyl ester ABA receptors glycosylation activity ABA homoeostasis kinetic analysis 

摘      要：Uridine diphosphate-glucosyltransferases(UGTs)maintain abscisic acid(ABA)homeostasis in Arabidopsis thaliana by converting ABA to abscisic acid-glucose ester(ABA-GE).UGT71C5 plays an important role in the generation of ABA-GE.Abscisic acid receptors are crucial upstream components of the ABA signaling pathway,but how UGTs and ABA receptors function together to modulate ABA levels is unknown.Here,we demonstrated that the ABA receptors RCAR12/13 and UGT71 C5 maintain ABA homeostasis in Arabidopsis following rehydration under drought stress.Biochemical analyses show that UGT71C5 directly interacted with RCAR8/12/13 in yeast cells,and the interactions between UGT-71C5 and RCAR12/13 were enhanced by ABA treatment.Enzyme activity analysis showed that ABA-GE contents were significantly elevated in the presence of RCAR12 or RCAR13,suggesting that these ABA receptors enhance the activity of UGT71C5.Determination of the content of ABA and ABA-GE in Arabidopsis following rehydration under drought stress revealed that ABA-GE contents were significantly higher in Arabidopsis plants overexpressing RCAR12 and RCAR13 than in nontransformed plants and plants overexpressing RCAR11 following rehydration under drought stress.These observations suggest that RCAR12 and RCAR13 enhance the activity of UGT71C5 to glycosylate excess ABA into ABA-GE following rehydration under drought stress,representing a rapid mechanism for regulating plant growth and development.