Yang Jing-Fang, Chen Mo-Xian, Zhang Jian-Hua, Hao Ge-Fei, Yang Guang-Fu
Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, P.R. China.
International Joint Research Center for Intelligent Biosensor Technology and Health, Central China Normal University, Wuhan, P. R. China.
J Exp Bot. 2020 Feb 19;71(4):1322-1336. doi: 10.1093/jxb/erz511.
The plant hormone abscisic acid (ABA) plays a crucial role during the plant life cycle as well as in adaptive responses to environmental stresses. The core regulatory components of ABA signaling in plants are the pyrabactin resistance1/PYR1-like/regulatory component of ABA receptor family (PYLs), which comprise the largest plant hormone receptor family known. They act as negative regulators of members of the protein phosphatase type 2C family. Due to the biological importance of PYLs, many researchers have focused on their genetic redundancy and consequent functional divergence. However, little is understood of their evolution and its impact on the generation of regulatory diversity. In this study, we identify positive selection and functional divergence in PYLs through phylogenetic reconstruction, gene structure and expression pattern analysis, positive selection analysis, functional divergence analysis, and structure comparison. We found the correlation of desensitization of PYLs under specific modifications in the molecular recognition domain with functional diversification. Hence, an interesting antagonistic co-evolutionary mechanism is proposed for the functional diversification of ABA receptor family proteins. We believe a compensatory evolutionary pathway may have occurred.
植物激素脱落酸（ABA）在植物生命周期以及对环境胁迫的适应性反应中起着至关重要的作用。植物ABA信号传导的核心调控成分是脱落酸受体家族（PYLs）的吡唑啉酮抗性1/PYR1样/调控成分，这是已知的最大的植物激素受体家族。它们作为2C型蛋白磷酸酶家族成员的负调控因子。由于PYLs的生物学重要性，许多研究人员专注于它们的遗传冗余性以及随之而来的功能差异。然而，对它们的进化及其对调控多样性产生的影响了解甚少。在本研究中，我们通过系统发育重建、基因结构和表达模式分析、正选择分析、功能差异分析以及结构比较，确定了PYLs中的正选择和功能差异。我们发现分子识别域中特定修饰下PYLs的脱敏与功能多样化之间存在相关性。因此，针对ABA受体家族蛋白的功能多样化，提出了一种有趣的拮抗协同进化机制。我们认为可能发生了一种补偿性进化途径。
