Paladin, a tyrosine phosphatase-like protein, is required for XA21-mediated immunity in rice  

作　　者：Tsung-Chi Chen Mawsheng Chern Michael Steinwand Deling Ruan Yu Wang Arkin Isharani Pamela Ronald 

机构地区：[1]Department of Plant Pathology and the Genome Center,University of California,Davis,CA 95616,USA

出　　处：《Plant Communications》2021年第4期116-126,共11页植物通讯（英文）

基　　金：supported by the following grants to P.R.:NIH no.GM59962,NIH no.GM122968,NSF no.1237975,NSF IOS-1656501,and NSF-NIFA no.2017-03128;supported by the following grant to T.-C.C.:a Taiwan Government Scholarship.Support for M.S.;provided by the Corteva Open Innovations Program;supported by the Office of Science,Office of Biological and Environmental Research of the U.S.Department of Energy under contract no.DE-AC02-05CH11231.

摘　　要：XA21 encodes a rice immune receptor that confers robust resistance to most strains of the Gram-negative bacterium Xanthomonas oryzae pv.oryzae(Xoo).XA21-mediated immunity is triggered by recognition of a small protein called RaxX-sY(required for activation of XA21-mediated immunity X,tyrosine-sulfated)secreted by Xoo.To identify components regulating XA21-mediated immunity,we generated and screened a mutant population of fast-neutron-mutagenized rice expressing Ubi:Myc-XA21 for those susceptible to Xoo.Here,we report the characterization of one of these rice mutants,named sxi2(suppressor of XA21-mediated immunity-2).Whole-genome sequencing revealed that sxi2 carries a deletion of the PALADIN(PALD)gene encoding a protein with three putative protein tyrosine phosphatase-like domains(PTP-A,-B,and-C).Expression of PALD in the sxi2 genetic background was sufficient to complement the susceptible phenotype,which requires the catalytic cysteine of the PTP-A active site to restore resistance.PALD coimmunoprecipitated with the full-length XA21 protein,whose levels are positively regulated by the presence of the PALD transgene.Furthermore,we foundd that sxi2 retains many hallmarks of XA21-mediated immunity,similar to the wild type.These results reveal that PALD,a previously uncharacterized class of phosphatase,functions in rice innate immunity,and suggest that the conserved cysteine in the PTP-A domain of PALD is required for its immune function.

关 键 词：XA21 rice bacterial blight disease Xanthomonas oryzae pv.oryzae fast-neutron mutagenesis PALD 

分 类 号：S511[农业科学—作物学]