Alternaria TeA toxin activates a chloroplast retrograde signaling pathway to facilitate JAdependent pathogenicity  

作　　者：Jiale Shi He Wang Mengping Li Liru Mi Yazhi Gao Sheng Qiang Yu Zhang Dan Chen Xinbin Dai Hongyu Ma Huan Lu Chanhong Kim Shiguo Chen 

机构地区：[1]Weed Research Laboratory,Nanjing Agricultural University,Nanjing 210095,China [2]Shanghai Center for Plant Stress Biology,Center for Excellence in Molecular Plant Sciences,Chinese Academy of Sciences,Shanghai 200032,China [3]Bioinformatics and Computational Biology Laboratory,Noble Research Institute,2510 Sam Noble Parkway,Ardmore,OK 73401,USA [4]College of Plant Protection,Nanjing Agricultural University,Nanjing 210095,China [5]Department of Botany and Plant Biology,University of Geneva,Geneva,Switzerland

出　　处：《Plant Communications》2024年第3期123-140,共18页植物通讯（英文）

基　　金：funded by the National Key R&D Program (2021YFD1700100,2017YFD0201304);the Jiangsu Agricultural Science and Technology Innovation Fund (CX (21)3093)to S.C.;the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB27040102);the National Natural Science Foundation of China (NSFC) (31871397)to C.K.

摘　　要：The chloroplast is a critical battleground in the arms race between plants and pathogens.Among microbe-secreted mycotoxins,tenuazonic acid(TeA),produced by the genus Alternaria and other phytopathogenic fungi,inhibits photosynthesis,leading to a burst of photosynthetic singlet oxygen(1O2)that is implicated in damage and chloroplast-to-nucleus retrograde signaling.Despite the signicant crop damage caused by Alternaria pathogens,our understanding of the molecular mechanism by which TeA promotes pathoge-nicity and cognate plant defense responses remains fragmentary.We now reveal that A.alternata induces necrotrophic foliar lesions by harnessing EXECUTER1(EX1)/EX2-mediated chloroplast-to-nucleus retro-grade signaling activated by TeA toxin–derived photosynthetic 1O2 in Arabidopsis thaliana.Mutation of the 1O2-sensitive EX1-W643 residue or complete deletion of the EX1 singlet oxygen sensor domain compro-mises expression of 1O2-responsive nuclear genes and foliar lesions.We also found that TeA toxin rapidly induces nuclear genes implicated in jasmonic acid(JA)synthesis and signaling,and EX1-mediated retro-grade signaling appears to be critical for establishing a signaling cascade from 1O2 to JA.The present study sheds new light on the foliar pathogenicity of A.alternata,during which EX1-dependent 1O2 signaling in-duces JA-dependent foliar cell death.

关 键 词：TeA mycotoxin Alternaria pathogen CHLOROPLAST singlet oxygen retrograde signaling jasmonic acid 

分 类 号：Q94[生物学—植物学]