The Zygotic Division Regulator ZAR1 Plays a Negative Role in Defense Against Botrytis cinerea in Arabidopsis.

Lijuan Chen,Yuxiao Song,You Li,Hong-Bin Wang,Jiahui Xiao,Jun Liu,Bing Liu,Huiren Cai

doi:10.3389/fpls.2021.736560

Abstract

A phosphorylation/dephosphorylation cycle at tyrosine 428 of CHITIN ELICITOR RECEPTOR KINASE 1 (CERK1) plays an essential role in chitin triggered immunity in Arabidopsis thaliana. 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 Arabidopsis. Our current results established that ZAR1 also negatively contributed to defense against the fungus Botrytis cinerea and played a redundant role with its homolog ZAR2 in this process. The zar1-3 zar2-1 double mutant exhibited stronger resistance to B. cinerea compared with zar1-3 single mutant, zar2-1 single mutant, and wild-type plants. Moreover, the inducible expression of numerous defense response genes upon B. cinerea infection was increased in the zar1-3zar2-1 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.

Highlights

Plants confront attacks from various pathogens and have developed immunity mechanisms to defend against pathogen infection
We reported that the leucine-rich repeat receptor-like kinase (RLK) (LRR-RLK) ZYGOTIC ARREST 1 (ZAR1) could interact with CHITIN ELICITOR RECEPTOR KINASE 1 (CERK1) when it harbored the dephosphorylated Y428 residue and that ZAR1 negatively contributed to the defense against Botrytis cinerea in Arabidopsis
Plants have evolved various cell-surface RLKs that perceive diverse signals, such as phytohormones and peptides derived from plants, and pattern molecules derived from microbes

Summary

INTRODUCTION

Plants confront attacks from various pathogens and have developed immunity mechanisms to defend against pathogen infection. In Arabidopsis, the chitin elicitor receptor kinase 1 (CERK1)/LysM-RLK1 is an indispensable receptor-like kinase (RLK) for chitin-triggered immunity signaling (Miya et al, 2007; Wan et al, 2008; Liu et al, 2012). Both heterodimerization between CERK1 and LYK5 and chitintriggered homodimerization of CERK1 play essential roles in chitin signaling in Arabidopsis (Liu et al, 2012; Cao et al, 2014). We reported that the leucine-rich repeat RLK (LRR-RLK) ZYGOTIC ARREST 1 (ZAR1) could interact with CERK1 when it harbored the dephosphorylated Y428 residue and that ZAR1 negatively contributed to the defense against Botrytis cinerea in Arabidopsis

MATERIALS AND METHODS

RESULTS

DISCUSSION

DATA AVAILABILITY STATEMENT