Plant proteins that belong to the nonexpressor of pathogenesis-related(NPR)gene family are paralogous receptors ofthe plantdefense hormone salicylic acidandessential regulators of hormone-dependent plant immunity agai...Plant proteins that belong to the nonexpressor of pathogenesis-related(NPR)gene family are paralogous receptors ofthe plantdefense hormone salicylic acidandessential regulators of hormone-dependent plant immunity against diseases caused by various pathogens.Previous studies have established NPR1 and NPR3 as a transcriptional activator and a transcriptional repressor,respectively,of defense-gene expres-sion to promote and inhibit broad-spectrum resistance against different strains of pathogens.However,the regulatory mechanism that underlies the opposing roles of NPR1 and NPR3 in defense-gene activation re-mains unclear.Here,we report that a rice transcript splicing factor,Oryza sativa RNA-binding protein 11(OsRBP11),promotes alternative splicing of OsNPR3 to modulate the defense function of OsNPR1 in rice plants infected by Xanthomonas oryzae pathovars,which are important bacterial pathogens of rice.We discovered that 11 transcription activator-like effectors identified in representative bacterial strains acti-vate OsRBP11 expression.The OsRBP11 protein,in turn,facilitates alternative splicing of the OsNPR3 mRNA precursor,leading to the production of truncated OsNPR3 protein variants.The OsNPR3 variants exacerbate bacterial diseases by sequestering OsNPR1 from defense-gene activation.By contrast,both artificial andnatural variations inOsRBP11preventthe alternative splicing of OsNPR3,restore thedefense function of OsNPR1,and enhance rice resistance to different bacterial strains.These findings not only reveal a novel regulatory pathway exploited by bacterial pathogens to facilitate their pathogenicity and subvert plant defense but also provide a genetic basis for biotechnological strategies aimed at developing broad-spectrum resistance in crops.展开更多
基金supported by Natural Science Foundation of China grants 32302374,31772247,32372483,and 32370210 to X.C.,H.D.,M.-X.Z.and S.Z.respectively,as well as by Biological Breeding-Major Projects 2023ZD04074 to H.Z+2 种基金Yunnan Seed Laboratory Key Project grant 202205AR070001 to Z.CDouble First Class Discipline Construction Fund of Shandong Agricultural University to H.Dthe Natural Science Foundation of Shandong Province grants ZR2023QC118,ZR2020MC113,ZR2020MC120,and ZR2020QC126 to X.C.,L.C.,S.Z.,and L.Z.,respectively.
文摘Plant proteins that belong to the nonexpressor of pathogenesis-related(NPR)gene family are paralogous receptors ofthe plantdefense hormone salicylic acidandessential regulators of hormone-dependent plant immunity against diseases caused by various pathogens.Previous studies have established NPR1 and NPR3 as a transcriptional activator and a transcriptional repressor,respectively,of defense-gene expres-sion to promote and inhibit broad-spectrum resistance against different strains of pathogens.However,the regulatory mechanism that underlies the opposing roles of NPR1 and NPR3 in defense-gene activation re-mains unclear.Here,we report that a rice transcript splicing factor,Oryza sativa RNA-binding protein 11(OsRBP11),promotes alternative splicing of OsNPR3 to modulate the defense function of OsNPR1 in rice plants infected by Xanthomonas oryzae pathovars,which are important bacterial pathogens of rice.We discovered that 11 transcription activator-like effectors identified in representative bacterial strains acti-vate OsRBP11 expression.The OsRBP11 protein,in turn,facilitates alternative splicing of the OsNPR3 mRNA precursor,leading to the production of truncated OsNPR3 protein variants.The OsNPR3 variants exacerbate bacterial diseases by sequestering OsNPR1 from defense-gene activation.By contrast,both artificial andnatural variations inOsRBP11preventthe alternative splicing of OsNPR3,restore thedefense function of OsNPR1,and enhance rice resistance to different bacterial strains.These findings not only reveal a novel regulatory pathway exploited by bacterial pathogens to facilitate their pathogenicity and subvert plant defense but also provide a genetic basis for biotechnological strategies aimed at developing broad-spectrum resistance in crops.
