Chen Lijuan, Xiao Jiahui, Song Yuxiao, Li You, Liu Jun, Cai Huiren, Wang Hong-Bin, Liu Bing
Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.
Institute of Medical Plant Physiology and Ecology, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, China.
Front Plant Sci. 2021 Oct 26;12:736560. doi: 10.3389/fpls.2021.736560. eCollection 2021.
A phosphorylation/dephosphorylation cycle at tyrosine 428 of CHITIN ELICITOR RECEPTOR KINASE 1 (CERK1) plays an essential role in chitin triggered immunity in . In this study, we used a differential peptide pull-down (PPD) assay to identify factors that could participate downstream of this cycle. We identified ZYGOTIC ARREST 1 (ZAR1) and showed that it interacts with CERK1 specifically when the tyrosine 428 (Y428) residue of CERK1 is dephosphorylated. ZAR1 was originally characterized as an integrator for calmodulin and G-protein signals to regulate zygotic division in . Our current results established that ZAR1 also negatively contributed to defense against the fungus and played a redundant role with its homolog ZAR2 in this process. The double mutant exhibited stronger resistance to compared with single mutant, single mutant, and wild-type plants. Moreover, the inducible expression of numerous defense response genes upon infection was increased in the double mutant, consistent with a repressive role for ZAR proteins in the defense response. Therefore, our findings provided insight into the function of ZAR1 in multiple defenses and developmental regulation pathways.
几丁质激发子受体激酶1（CERK1）第428位酪氨酸的磷酸化/去磷酸化循环在几丁质触发的免疫反应中起着至关重要的作用。在本研究中，我们使用差异肽下拉（PPD）分析来鉴定可能参与该循环下游的因子。我们鉴定出合子停滞1（ZAR1），并表明当CERK1的第428位酪氨酸（Y428）残基去磷酸化时，它与CERK1特异性相互作用。ZAR1最初被表征为钙调蛋白和G蛋白信号的整合因子，用于调节合子分裂。我们目前的结果表明，ZAR1在抗真菌防御中也起负作用，并在此过程中与其同源物ZAR2发挥冗余作用。与ZAR1单突变体、ZAR2单突变体和野生型植物相比，ZAR1/ZAR2双突变体对真菌表现出更强的抗性。此外，在ZAR1/ZAR2双突变体中，真菌感染后许多防御反应基因的诱导表达增加，这与ZAR蛋白在防御反应中的抑制作用一致。因此，我们的研究结果为ZAR1在多种防御和发育调控途径中的功能提供了见解。
