Ubiquitination-mediated protein degradation is integral to plant immunity,with E3 ubiquitin ligases acting as key factors in this process.Here,we report the functions of OsATL32,a plasma membrane-localized Arabidopsis...Ubiquitination-mediated protein degradation is integral to plant immunity,with E3 ubiquitin ligases acting as key factors in this process.Here,we report the functions of OsATL32,a plasma membrane-localized Arabidopsis Tóxicos En Levadura(ATL)-type E3 ubiquitin ligase,in rice(Oryza sativa)immunity and its associated regulatory network.We found that the expression of OsATL32 is downregulated in both compatible and incompatible interactions between rice and the rice blast fungus Magnaporthe oryzae.The OsATL32 protein level declines in response to infection by a compatible M.oryzae strain or to chitin treatment.OsATL32 negatively regulates rice resistance to blast and bacterial leaf blight diseases,as well as chitin-triggered immunity.Biochemical and genetic studies revealed that OsATL32 suppresses pathogen-induced reactive oxygen species(ROS)accumulation by mediating ubiquitination and degradation of the ROS-producing OsRac5–OsRbohB module,which enhances rice immunity against M.oryzae.The protein phosphatase PHOSPHATASE AND TENSIN HOMOLOG enhances rice blast resistance by dephosphorylating OsATL32 and promoting its degradation,preventing its negative effect on rice immunity.This study provides insights into the molecular mechanism by which the E3 ligase OsATL32 targets a ROS-producing module to undermine rice immunity.展开更多
基金supported by grants from the National Natural Science Foundation of China(32072403 and 31871945)the National Key Research and Development Program of China(2016YFD0100600).
文摘Ubiquitination-mediated protein degradation is integral to plant immunity,with E3 ubiquitin ligases acting as key factors in this process.Here,we report the functions of OsATL32,a plasma membrane-localized Arabidopsis Tóxicos En Levadura(ATL)-type E3 ubiquitin ligase,in rice(Oryza sativa)immunity and its associated regulatory network.We found that the expression of OsATL32 is downregulated in both compatible and incompatible interactions between rice and the rice blast fungus Magnaporthe oryzae.The OsATL32 protein level declines in response to infection by a compatible M.oryzae strain or to chitin treatment.OsATL32 negatively regulates rice resistance to blast and bacterial leaf blight diseases,as well as chitin-triggered immunity.Biochemical and genetic studies revealed that OsATL32 suppresses pathogen-induced reactive oxygen species(ROS)accumulation by mediating ubiquitination and degradation of the ROS-producing OsRac5–OsRbohB module,which enhances rice immunity against M.oryzae.The protein phosphatase PHOSPHATASE AND TENSIN HOMOLOG enhances rice blast resistance by dephosphorylating OsATL32 and promoting its degradation,preventing its negative effect on rice immunity.This study provides insights into the molecular mechanism by which the E3 ligase OsATL32 targets a ROS-producing module to undermine rice immunity.
