SGT1(suppressor of the G2allele of skp1)是多种植物抗病基因介导的抗病信号途径中的重要元件。该研究利用RT-PCR和RACE方法克隆出甘薯近缘野生种三浅裂野牵牛的SGT1基因,命名为ItSGT1。该基因含有一个长度为1 087bp的开放阅读框,编码...SGT1(suppressor of the G2allele of skp1)是多种植物抗病基因介导的抗病信号途径中的重要元件。该研究利用RT-PCR和RACE方法克隆出甘薯近缘野生种三浅裂野牵牛的SGT1基因,命名为ItSGT1。该基因含有一个长度为1 087bp的开放阅读框,编码361个氨基酸,分子量约为40.1kD,等电点为5.05。Blast及多序列比对分析表明,该基因与其他植物中的SGT1具有较高的相似性,且具有SGTl蛋白典型的功能域结构,即TPR区、VR1区、CS区、VR2区和SGS区。Southern杂交结果显示,SGT1基因在三浅裂野牵牛基因组中是多拷贝基因。组织特异性表达分析表明,ItSGT1基因在三浅裂野牵牛的根、茎和叶中均有表达。展开更多
Suppressor of G2 allele of skp1(SGT1)is a highly conserved eukaryotic protein that plays a vital role in growth,development,and immunity in both animals and plants.Although some SGT1 interactors have been identified,t...Suppressor of G2 allele of skp1(SGT1)is a highly conserved eukaryotic protein that plays a vital role in growth,development,and immunity in both animals and plants.Although some SGT1 interactors have been identified,the molecular regulatory network of SGT1 remains unclear.SGT1 serves as a co-chaperone to stabilize protein complexes such as the nucleotide-binding leucine-rich repeat(NLR)class of immune receptors,thereby positively regulating plant immunity.SGT1 has also been found to be asso-ciated with the SKP1-Cullin-F-box(SCF)E3 ubiquitin ligase complex.However,whether SGT1 targets im-mune repressors to coordinate plant immune activation remains elusive.In this study,we constructed a toolbox for TurbolD-and split-TurbolD-based proximity labeling(PL)assays in Nicotiana benthamiana and used the PL toolbox to explore the SGT1 interactome during pre-and post-immune activation.The comprehensive SGT1 interactome network we identified highlights a dynamic shift from proteins associ-ated with plant development to those linked with plant immune responses.We found that SGT1 interacts with Necrotic Spotted Lesion1(NSL1),which negatively regulates salicylic acid-mediated defenseby inter-fering with the nucleocytoplasmic trafficking of non-expressor of pathogenesis-related genes 1(NPR1)during N NLR-mediated response to tobacco mosaic virus.SGT1 promotes the SCF-dependent degrada-tion of NSL1 to facilitate immune activation,while salicylate-induced protein kinase-mediated phosphory-lation of SGT1further potentiates this process.Besides NNLR,NSL1also functions in several other NLR-mediated immunity.Collectively,our study unveils the regulatory landscape of SGT1 and reveals a novel SGT1-NSL1 signaling module that orchestrates plant innate immunity.展开更多
Effector proteins delivered inside plant cells are powerful weapons for bacterial pathogens,but this exposes the pathogen to potential recognition by the plant immune system.Therefore,the effector repertoire of a give...Effector proteins delivered inside plant cells are powerful weapons for bacterial pathogens,but this exposes the pathogen to potential recognition by the plant immune system.Therefore,the effector repertoire of a given pathogen must be balanced for a successful infection.Ralstonia solanacearum is an aggressive pathogen with a large repertoire of secreted effectors.One of these effectors,RipE1,is conserved in most R.solanacearum strains sequenced to date.In this work,we found that RipE1 triggers immunity in N.benthamiana,which requires the immune regulator SGT1,but not EDS1 or NRCs.Interestingly,RipE1-triggered immunity induces the accumulation of salicylic acid(SA)and the overexpression of several genes encoding phenylalanine-ammonia lyases(PALs),suggesting that the unconventional PALmediated pathway is responsible for the observed SA biosynthesis.Surprisingly,RipE1 recognition also induces the expression of jasmonic acid(JA)-responsive genes and JA biosynthesis,suggesting that both SA and JA may act cooperatively in response to RipE1.We further found that RipE1 expression leads to the accumulation of glutathione in plant cells,which precedes the activation of immune responses.R.solanacearum secretes another effector,RipAY,which is known to inhibit immune responses by degrading cellular glutathione.Accordingly,RipAY inhibits RipE1-triggered immune responses.This work shows a strategy employed by R.solanacearum to counteract the perception of its effector proteins by plant immune system.展开更多
文摘SGT1(suppressor of the G2allele of skp1)是多种植物抗病基因介导的抗病信号途径中的重要元件。该研究利用RT-PCR和RACE方法克隆出甘薯近缘野生种三浅裂野牵牛的SGT1基因,命名为ItSGT1。该基因含有一个长度为1 087bp的开放阅读框,编码361个氨基酸,分子量约为40.1kD,等电点为5.05。Blast及多序列比对分析表明,该基因与其他植物中的SGT1具有较高的相似性,且具有SGTl蛋白典型的功能域结构,即TPR区、VR1区、CS区、VR2区和SGS区。Southern杂交结果显示,SGT1基因在三浅裂野牵牛基因组中是多拷贝基因。组织特异性表达分析表明,ItSGT1基因在三浅裂野牵牛的根、茎和叶中均有表达。
基金supported by grants from the National Natural Science Foundation of China(32320103003 and 32122070)the“High-end Foreign Experts Recruitment Plan”of Ministry of Science and Technology(G2023108007L)+3 种基金Chinese Universities Scientific Fund(2023TC074)Pinduoduo-China Agricultural University Research Fund(PC2023B02012)China National Postdoctoral Program for Innovative Talents(BX20240421)2115 Talent Development Program of China Agricultural University.
文摘Suppressor of G2 allele of skp1(SGT1)is a highly conserved eukaryotic protein that plays a vital role in growth,development,and immunity in both animals and plants.Although some SGT1 interactors have been identified,the molecular regulatory network of SGT1 remains unclear.SGT1 serves as a co-chaperone to stabilize protein complexes such as the nucleotide-binding leucine-rich repeat(NLR)class of immune receptors,thereby positively regulating plant immunity.SGT1 has also been found to be asso-ciated with the SKP1-Cullin-F-box(SCF)E3 ubiquitin ligase complex.However,whether SGT1 targets im-mune repressors to coordinate plant immune activation remains elusive.In this study,we constructed a toolbox for TurbolD-and split-TurbolD-based proximity labeling(PL)assays in Nicotiana benthamiana and used the PL toolbox to explore the SGT1 interactome during pre-and post-immune activation.The comprehensive SGT1 interactome network we identified highlights a dynamic shift from proteins associ-ated with plant development to those linked with plant immune responses.We found that SGT1 interacts with Necrotic Spotted Lesion1(NSL1),which negatively regulates salicylic acid-mediated defenseby inter-fering with the nucleocytoplasmic trafficking of non-expressor of pathogenesis-related genes 1(NPR1)during N NLR-mediated response to tobacco mosaic virus.SGT1 promotes the SCF-dependent degrada-tion of NSL1 to facilitate immune activation,while salicylate-induced protein kinase-mediated phosphory-lation of SGT1further potentiates this process.Besides NNLR,NSL1also functions in several other NLR-mediated immunity.Collectively,our study unveils the regulatory landscape of SGT1 and reveals a novel SGT1-NSL1 signaling module that orchestrates plant innate immunity.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(grant XDB27040204)the National Natural Science Foundation of China(grant 31571973)the Chinese 1000 Talents Program,and the Shanghai Center for Plant Stress Biology(Chinese Academy of Sciences).
文摘Effector proteins delivered inside plant cells are powerful weapons for bacterial pathogens,but this exposes the pathogen to potential recognition by the plant immune system.Therefore,the effector repertoire of a given pathogen must be balanced for a successful infection.Ralstonia solanacearum is an aggressive pathogen with a large repertoire of secreted effectors.One of these effectors,RipE1,is conserved in most R.solanacearum strains sequenced to date.In this work,we found that RipE1 triggers immunity in N.benthamiana,which requires the immune regulator SGT1,but not EDS1 or NRCs.Interestingly,RipE1-triggered immunity induces the accumulation of salicylic acid(SA)and the overexpression of several genes encoding phenylalanine-ammonia lyases(PALs),suggesting that the unconventional PALmediated pathway is responsible for the observed SA biosynthesis.Surprisingly,RipE1 recognition also induces the expression of jasmonic acid(JA)-responsive genes and JA biosynthesis,suggesting that both SA and JA may act cooperatively in response to RipE1.We further found that RipE1 expression leads to the accumulation of glutathione in plant cells,which precedes the activation of immune responses.R.solanacearum secretes another effector,RipAY,which is known to inhibit immune responses by degrading cellular glutathione.Accordingly,RipAY inhibits RipE1-triggered immune responses.This work shows a strategy employed by R.solanacearum to counteract the perception of its effector proteins by plant immune system.
