A KNOX II transcription factor suppresses the NLR immune receptor BRG8-mediated immunity in rice  

作　　者：Siliang Xu Xinghua Wei Qinqin Yang Dongxiu Hu Yuanyuan Zhang Xiaoping Yuan Fengyu Kang Zhaozhong Wu Zhiqin Yan Xueqin Luo Yanfei Sun Shan Wang Yue Feng Qun Xu Mengchen Zhang Yaolong Yang 

机构地区：[1]China National Center for Rice Improvement/State Key Laboratory of Rice Biology and Breeding,China National Rice Research Institute,Hangzhou 310006,China [2]National Nanfan Research Institute(Sanya),Chinese Academy of Agricultural Sciences,Sanya 572024,China

出　　处：《Plant Communications》2024年第10期121-138,共18页植物通讯（英文）

基　　金：supported by the National Natural Science Foundation of China(32201739);the Natural Science Foundation of Zhejiang Province(LQ22C130006);the National Key Research and Development Program of China(2021YFD1200503);the Key Research and Development Program of Zhejiang Province(2021C02056);the Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP2013-CNRRI).

摘　　要：Nucleotide-binding site and leucine-rich repeat(NLR)proteins are activated by detecting pathogen effectors,which in turn trigger host defenses and cell death.Although many NLRs have been identified,the mechanisms responsible for NLR-triggered defense responses are still poorly understood.In this study,through a genome-wide association study approach,we identified a novel NLR gene,Blast Resistance Gene 8(BRG8),which confers resistance to rice blast and bacterial blight diseases.BRG8 overexpression and complementation lines exhibit enhanced resistance to both pathogens.Subcellular localization assays showed that BRG8 is localized in both the cytoplasm and the nucleus.Additional evidence revealed that nuclear-localized BRG8 can enhance rice immunity without a hypersensitive response(HR)-like phenotype.We also demonstrated that the coiled-coil domain of BRG8 not only physically interacts with itself but also interacts with the KNOX II protein HOMEOBOX ORYZA SATIVA59(HOS59).Knockout mutants of HOS59 in the BRG8 background show enhanced resistance to Magnaporthe oryzae strain CH171 and Xoo strain CR4,similar to that of the BRG8 background.By contrast,overexpression of HOS59 in the BRG8 background will compromise the HR-like phenotype and resistance response.Further analysis revealed that HOS59 promotes the degradation of BRG8 via the 26S proteasome pathway.Collectively,our study highlights HOS59 as an NLR immune regulator that fine-tunes BRG8-mediated immune responses against pathogens,providing new insights into NLR associations and functions in plant immunity.

关 键 词：RICE NLR protein KNOX II protein rice blast bacterial blight 

分 类 号：Q94[生物学—植物学]