Wheat production is under continuous threat by various fungal pathogens.Identification of multipledisease resistance genes may lead to effective disease control via the development of cultivars with broad-spectrum res...Wheat production is under continuous threat by various fungal pathogens.Identification of multipledisease resistance genes may lead to effective disease control via the development of cultivars with broad-spectrum resistance.Plant Lysin-motif(LysM)-type pattern-recognition receptors,which elicit innate immunity by recognizing fungal pathogen associated molecular patterns such as chitin,are potential candidates for such resistance.In this study,we cloned a LysM receptor-like kinase gene,CERK1-V,from the diploid wheat relative Haynaldia villosa.CERK1-V expression was induced by chitin and Blumeria graminis f.sp.tritici,the causal agent of wheat powdery mildew.Heterologous overexpression of CERK1-V in wheat inhibited the development of three fungal pathogens,thereby increased resistance to powdery mildew,yellow rust,and Fusarium head blight.CERK1-V physically interacted with the wheat Lys M protein Ta CEBi Ps.CERK1-V/Ta CEBi Ps interaction promoted chitin recognition and activated chitin signal transduction in wheat.Transgenic plants with excessively high CERK1-V expression showed high resistance but abnormal plant growth,whereas plants with moderate expression level showed adequate resistance level with no marked impairment of plant growth.In transgenic lines,RNA-seq showed that gene expression involved in plant innate immunity was activated.Expression of genes involved in photosynthesis,ER stress and multiple phytohormone pathways was also activated.Optimized expression of CERK1-V in wheat can confer disease resistance without compromising growth or defense fitness.展开更多
溶解素基序(LysM)是在多种蛋白质中普遍存在的结构域.植物LysM蛋白能够感知几丁质及其寡糖等分子配体,从而启动植物对病原菌的免疫反应.在水稻、拟南芥等植物免疫应答过程中,LysM蛋白作为一种重要的模式识别受体,通过不同形式的寡聚化,...溶解素基序(LysM)是在多种蛋白质中普遍存在的结构域.植物LysM蛋白能够感知几丁质及其寡糖等分子配体,从而启动植物对病原菌的免疫反应.在水稻、拟南芥等植物免疫应答过程中,LysM蛋白作为一种重要的模式识别受体,通过不同形式的寡聚化,激活多种类受体胞质激酶及其下游的MAPK(mitogen activated protein kinase)级联反应传递信号.同时,蛋白质可逆磷酸化和蛋白质降解途径可以负调节LysM蛋白介导的防御信号转导.文章综述了植物免疫过程中LysM蛋白介导的信号转导分子机制.展开更多
Symbiotic microorganisms improve nutrient uptake by plants.To initiate mutualistic symbiosis with arbus-cular mycorrhizal(AM)fungi,plants perceive Myc factors,including lipochitooligosaccharides(LCOs)and short-chain c...Symbiotic microorganisms improve nutrient uptake by plants.To initiate mutualistic symbiosis with arbus-cular mycorrhizal(AM)fungi,plants perceive Myc factors,including lipochitooligosaccharides(LCOs)and short-chain chitooligosaccharides(CO4/CO5),secreted by AM fungi.However,the molecular mechanism of Myc factor perception remains elusive.In this study,we identified a heteromer of LysM receptor-like kinases consisting of OsMYR1/OsLYK2 and OsCERK1 that mediates the perception of AM fungi in rice.CO4 directly binds to OsMYR1,promoting the dimerization and phosphorylation of this receptor complex.Compared with control plants,Osmyr1 and Oscerk1 mutant rice plants are less sensitive to Myc factors and show decreased AM colonization.We engineered transgenic rice by expressing chimeric receptors that respectively replaced the ectodomains of OsMYR1 and OsCERK1 with those from the homologous Nod factor receptors MtNFP and MtL YK3 of Medicago truncatula.Transgenic plants displayed increased cal-cium oscillations in response to Nod factors compared with control rice.Our study provides significant mechanistic insights into AM symbiotic signal perception in rice.Expression of chimeric Nod/Myc recep-tors achieves a potentially important step toward generating cereals that host nitrogen-fixing bacteria.展开更多
Under nutrient-limiting conditions, plants will enter into symbiosis with arbuscular mycorrhizal (AM) fungi for the enhancement of mineral nutrient acquisition from the surrounding soil. AM fungi live in close, intr...Under nutrient-limiting conditions, plants will enter into symbiosis with arbuscular mycorrhizal (AM) fungi for the enhancement of mineral nutrient acquisition from the surrounding soil. AM fungi live in close, intracellular association with plant roots where they transfer phosphate and nitrogen to the plant in exchange for carbon. They are obligate fungi, relying on their host as their only carbon source. Much has been discovered in the last decade concerning the signaling events during initiation of the AM symbiosis, including the identification of signaling molecules generated by both partners. This signaling occurs through symbiosis-specific gene products in the host plant, which are indispensable for normal AM development. At the same time, plants have adapted complex mechanisms for avoiding infection by pathogenic fungi, including an innate immune response to general microbial molecules, such as chitin present in fungal cell walls. How it is that AM fungal colonization is maintained without eliciting a defensive response from the host is still uncertain. In this review, we present a summary of the molecular signals and their elicited responses during initiation of the AM symbiosis, including plant immune responses and their suppression.展开更多
Application of crab shell chitin or pentamer chitin oligosaccharide to Arabidopsis seedlings increased toler- ance to salinity in wild-type but not in knockout mutants of the LysM Receptor-Like Kinasel (CERK1/LysM R...Application of crab shell chitin or pentamer chitin oligosaccharide to Arabidopsis seedlings increased toler- ance to salinity in wild-type but not in knockout mutants of the LysM Receptor-Like Kinasel (CERK1/LysM RLK1) gene, known to play a critical role in signaling defense responses induced by exogenous chitin. Arabidopsis plants overexpress- ing the endochitinase chit36 and hexoaminidase excyl genes from the fungus Trichoderma asperelleoides T203 showed increased tolerance to salinity, heavy-metal stresses, and Botrytis cinerea infection. Resistant lines, overexpressing fungal chitinases at different levels, were outcrossed to lysm rlkl mutants. Independent homozygous hybrids lost resistance to biotic and abiotic stresses, despite enhanced chitinase activity. Expression analysis of 270 stress-related genes, including those induced by reactive oxygen species (ROS) and chitin, revealed constant up-regulation (at least twofold) of 10 genes in the chitinase-overexpressing line and an additional 76 salt-induced genes whose expression was not elevated in the lysm rlkl knockout mutant or the hybrids harboring the mutation. These findings elucidate that chitin-induced signaling mediated by LysM RLK1 receptor is not limited to biotic stress response but also encompasses abiotic-stress signaling and can be conveyed by ectopic expression of chitinases in plants.展开更多
基金supported by the National Natural Science Foundation of China(31661143005,31801350 and 32011530167)National Key Research and Development Program of China(2016YFD0102001-004)China Postdoctoral Science Foundation(2018M642266)。
文摘Wheat production is under continuous threat by various fungal pathogens.Identification of multipledisease resistance genes may lead to effective disease control via the development of cultivars with broad-spectrum resistance.Plant Lysin-motif(LysM)-type pattern-recognition receptors,which elicit innate immunity by recognizing fungal pathogen associated molecular patterns such as chitin,are potential candidates for such resistance.In this study,we cloned a LysM receptor-like kinase gene,CERK1-V,from the diploid wheat relative Haynaldia villosa.CERK1-V expression was induced by chitin and Blumeria graminis f.sp.tritici,the causal agent of wheat powdery mildew.Heterologous overexpression of CERK1-V in wheat inhibited the development of three fungal pathogens,thereby increased resistance to powdery mildew,yellow rust,and Fusarium head blight.CERK1-V physically interacted with the wheat Lys M protein Ta CEBi Ps.CERK1-V/Ta CEBi Ps interaction promoted chitin recognition and activated chitin signal transduction in wheat.Transgenic plants with excessively high CERK1-V expression showed high resistance but abnormal plant growth,whereas plants with moderate expression level showed adequate resistance level with no marked impairment of plant growth.In transgenic lines,RNA-seq showed that gene expression involved in plant innate immunity was activated.Expression of genes involved in photosynthesis,ER stress and multiple phytohormone pathways was also activated.Optimized expression of CERK1-V in wheat can confer disease resistance without compromising growth or defense fitness.
文摘溶解素基序(LysM)是在多种蛋白质中普遍存在的结构域.植物LysM蛋白能够感知几丁质及其寡糖等分子配体,从而启动植物对病原菌的免疫反应.在水稻、拟南芥等植物免疫应答过程中,LysM蛋白作为一种重要的模式识别受体,通过不同形式的寡聚化,激活多种类受体胞质激酶及其下游的MAPK(mitogen activated protein kinase)级联反应传递信号.同时,蛋白质可逆磷酸化和蛋白质降解途径可以负调节LysM蛋白介导的防御信号转导.文章综述了植物免疫过程中LysM蛋白介导的信号转导分子机制.
基金This work is supported by the NSFC(31730103,31825003,31522007)the National Key Basic Research Programme in China(2015CB158300)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB27040207)the International Partnership Program of Chinese Academy of Sciences(153D31KYSB20160074)the National Key Laboratory of Plant Molecular Genetics to E.W.
文摘Symbiotic microorganisms improve nutrient uptake by plants.To initiate mutualistic symbiosis with arbus-cular mycorrhizal(AM)fungi,plants perceive Myc factors,including lipochitooligosaccharides(LCOs)and short-chain chitooligosaccharides(CO4/CO5),secreted by AM fungi.However,the molecular mechanism of Myc factor perception remains elusive.In this study,we identified a heteromer of LysM receptor-like kinases consisting of OsMYR1/OsLYK2 and OsCERK1 that mediates the perception of AM fungi in rice.CO4 directly binds to OsMYR1,promoting the dimerization and phosphorylation of this receptor complex.Compared with control plants,Osmyr1 and Oscerk1 mutant rice plants are less sensitive to Myc factors and show decreased AM colonization.We engineered transgenic rice by expressing chimeric receptors that respectively replaced the ectodomains of OsMYR1 and OsCERK1 with those from the homologous Nod factor receptors MtNFP and MtL YK3 of Medicago truncatula.Transgenic plants displayed increased cal-cium oscillations in response to Nod factors compared with control rice.Our study provides significant mechanistic insights into AM symbiotic signal perception in rice.Expression of chimeric Nod/Myc recep-tors achieves a potentially important step toward generating cereals that host nitrogen-fixing bacteria.
基金Financial support for this research program was provided by the US National Science Foundation (IOS‐0842720)an award from the US National Science Foundation Graduate Research Fellowship (DGE‐1144153)
文摘Under nutrient-limiting conditions, plants will enter into symbiosis with arbuscular mycorrhizal (AM) fungi for the enhancement of mineral nutrient acquisition from the surrounding soil. AM fungi live in close, intracellular association with plant roots where they transfer phosphate and nitrogen to the plant in exchange for carbon. They are obligate fungi, relying on their host as their only carbon source. Much has been discovered in the last decade concerning the signaling events during initiation of the AM symbiosis, including the identification of signaling molecules generated by both partners. This signaling occurs through symbiosis-specific gene products in the host plant, which are indispensable for normal AM development. At the same time, plants have adapted complex mechanisms for avoiding infection by pathogenic fungi, including an innate immune response to general microbial molecules, such as chitin present in fungal cell walls. How it is that AM fungal colonization is maintained without eliciting a defensive response from the host is still uncertain. In this review, we present a summary of the molecular signals and their elicited responses during initiation of the AM symbiosis, including plant immune responses and their suppression.
文摘Application of crab shell chitin or pentamer chitin oligosaccharide to Arabidopsis seedlings increased toler- ance to salinity in wild-type but not in knockout mutants of the LysM Receptor-Like Kinasel (CERK1/LysM RLK1) gene, known to play a critical role in signaling defense responses induced by exogenous chitin. Arabidopsis plants overexpress- ing the endochitinase chit36 and hexoaminidase excyl genes from the fungus Trichoderma asperelleoides T203 showed increased tolerance to salinity, heavy-metal stresses, and Botrytis cinerea infection. Resistant lines, overexpressing fungal chitinases at different levels, were outcrossed to lysm rlkl mutants. Independent homozygous hybrids lost resistance to biotic and abiotic stresses, despite enhanced chitinase activity. Expression analysis of 270 stress-related genes, including those induced by reactive oxygen species (ROS) and chitin, revealed constant up-regulation (at least twofold) of 10 genes in the chitinase-overexpressing line and an additional 76 salt-induced genes whose expression was not elevated in the lysm rlkl knockout mutant or the hybrids harboring the mutation. These findings elucidate that chitin-induced signaling mediated by LysM RLK1 receptor is not limited to biotic stress response but also encompasses abiotic-stress signaling and can be conveyed by ectopic expression of chitinases in plants.