Obligate biotrophic fungi cause serious and widespread diseases of crop plants, but are challenging to investigate because they cannot be cultured in vitro. The two economically important groups of biotrophic fungi pa...Obligate biotrophic fungi cause serious and widespread diseases of crop plants, but are challenging to investigate because they cannot be cultured in vitro. The two economically important groups of biotrophic fungi parasitizing wheat are the rust and powdery mildew pathogens, but their obligate biotrophic lifestyles and pathogenicity mechanisms are not well understood at the molecular level. With the advent of next generation sequencing technology, increasing numbers of pathogen genomes are becoming available. Research in plant pathology has entered a new genomics era. This review summarizes recent progress in understanding the biology and pathogenesis of biotrophic fungal pathogens attacking wheat based on pathogen genomics. We particularly focus on the three wheat rust and the powdery mildew fungi in regard to genome sequencing, avirulence gene cloning, effector discovery, and pathogenomics. We predict that coordinated study of both wheat and its pathogens should reveal new insights in biotrophic adaptation, pathogenicity mechanisms,and population dynamics of these fungi that will assist in development of new strategies for breeding wheat varieties with durable resistance.展开更多
Understanding differences in disease position(i.e.the average height of infected leaves)among fungal pathogens is crucial for predicting and managing plant diseases.However,we know little about how disease position va...Understanding differences in disease position(i.e.the average height of infected leaves)among fungal pathogens is crucial for predicting and managing plant diseases.However,we know little about how disease position varies across disease and host plant types,and whether the local climate(i.e.temperature and precipitation)affects disease position.Here,we investigated disease position in herbaceous plants across key grassland ecosystems in China,including the Qinghai-Tibetan Plateau,Inner Mongolia Plateau,and North China Plain.We tested how fungal pathogen characteristics(e.g.disease types and pathogen lifestyles),host plant characteristics(e.g.biomass,natural height and plant growth type),and climatic conditions(e.g.mean annual temperature[MAT]and precipitation[MAP])affected disease position.Disease position tended to be higher for biotrophic versus necrotrophic pathogens,and this pattern was strongest in forbs and legumes.Disease position was also environment-dependent;higher temperatures and precipitation significantly increased disease position,but these effects varied among disease types.For both biotrophic and necrotrophic pathogens,larger host plants had lower mean disease positions.In this study,we provide evidence for how disease types and climatic conditions impact disease position;our findings emphasize the importance of disease position for understanding patterns of infection and managing disease outbreaks in a changing world.展开更多
Jasmonic acid （JA） is a natural hormone regulator involved in development, responses against woundingand pathogen attack. Upon perception of pathogens, JA is synthesized and mediates a signaling cascade initiating v...Jasmonic acid （JA） is a natural hormone regulator involved in development, responses against woundingand pathogen attack. Upon perception of pathogens, JA is synthesized and mediates a signaling cascade initiating various defense responses. Traditionally, necrotrophic fungi have been shown to be the primary activators of JA- dependent defenses through the JA-receptor, COIl. Conversely, plants infected with biotrophic fungi have classically been associated with suppressing JA-mediated responses. However, recent evidence has shown that certain biotrophic fungal species also trigger activation of JA-mediated responses and mutants deficient in JA signaling show an increase in susceptibility to certain biotrophic fungal pathogens. These findings suggest a new role for JA in defense against fungal biotrophs. This review will focus on recent research advancing our knowledge of JA-dependant responses involved in defense against both biotrophic and necrotrophic fungi.展开更多
Pytohormone abscisic acid （ABA） plays important roles in defense responses. Nonetheless, how ABA regulates plant resistance to biotrophic fungi remains largely unknown. Arabidopsis ABA-deficient mutants, aba2-1 and ...Pytohormone abscisic acid （ABA） plays important roles in defense responses. Nonetheless, how ABA regulates plant resistance to biotrophic fungi remains largely unknown. Arabidopsis ABA-deficient mutants, aba2-1 and aba3-1, displayed enhanced resistance to the biotrophic powdery mildew fungus Golovinomyces cichoracearum. Moreover, exogenously administered ABA increased the susceptibility of Arabidopsis to G. cichoracearum. Arabidopsis ABA perception components mutants, abil-1 and abi2-1, also displayed similar phenotypes to ABA-deficient mutants in resistance to G. cichoracearum. However, the resistance to G. cichoracearum is not changed in downstream ABA signaling transduction mutants, abi3-1, abi4-1, and abi5-1. Microscopic examination revealed that hyphal growth and conidiophore production of G. cichoracearum were compromised in the ABA deficient mutants, even though pre-penetration and penetration growth of the fimgus were not affected. In addition, salicylic acid （SA） and MPK3 are found to be involved in ABA-regulated resistance to G. cichoracearurn. Our work demonstrates that ABA negatively regulates post-penetration resistance of Arabidopsis to powdery mildew fungus G. cichoracearum, probably through antagonizing the function of SA.展开更多
Dear Editor,Wheat powdery mildew,caused by the biotrophic pathogen Blumeria graminis f.sp.tritici(Bgt),is a devastating disease that threatens global wheat production.Resistance genes play a critical role in protectin...Dear Editor,Wheat powdery mildew,caused by the biotrophic pathogen Blumeria graminis f.sp.tritici(Bgt),is a devastating disease that threatens global wheat production.Resistance genes play a critical role in protecting wheat against Bgt infection.Among these,Pm21,a broad-spectrum resistance gene derived from Haynaldia villosa,encodes a classic coiled-coil nucleotide-binding leucine-rich repeat(CCNB-LRR)protein(Xing et al.,2018).However,the regulatory mechanisms governing Pm21-mediated resistance remain poorly understood.展开更多
Salicylic acid(SA)is widely recognized as the active ingredient in the commonly used medication aspirin.In plants,SA is best known for its crucial role in plant defense against biotrophic and hemibiotrophic pathogens(...Salicylic acid(SA)is widely recognized as the active ingredient in the commonly used medication aspirin.In plants,SA is best known for its crucial role in plant defense against biotrophic and hemibiotrophic pathogens(Fu and Dong,2013;Peng et al.,2021).In addition,SA has been documented to play important roles in plant adaptation to abiotic stresses,plant growth and development,stomatal closure,thermogenesis,and structuring root microbiome(Vlot et al.,2009;Wang et al.,2025).展开更多
Dear Editor,Wheat is one of the most important food crops.In recent years,factors such as global warming have led to the frequent occurrence of extreme weather,altering the epidemic patterns of crop diseases and pests...Dear Editor,Wheat is one of the most important food crops.In recent years,factors such as global warming have led to the frequent occurrence of extreme weather,altering the epidemic patterns of crop diseases and pests and posing severe challenges to food security(Savary et al.2019).Wheat yellow rust(YR),also known as stripe rust,is caused by the biotrophic fungus Puccinia striiformis Westend f.sp.tritici(Pst)and remains one of the most devastating diseases threatening global wheat production(Chen 2020;Hovmoller et al.2023).展开更多
Wheat powdery mildew(Pm),caused by biotrophic fungus Blumeria graminis f.sp.tritici(Bgt),remains a major threat to global wheat production.While over 70 Pm resistance loci have been identified,only a few have been eff...Wheat powdery mildew(Pm),caused by biotrophic fungus Blumeria graminis f.sp.tritici(Bgt),remains a major threat to global wheat production.While over 70 Pm resistance loci have been identified,only a few have been effectively deployed in breeding programs,mainly due to rapid pathogen evolution(Kunz et al.,2023).Cloning Pm resistance genes will facilitate the elucidation of Pm resistance mechanisms at the molecular level and their effective utilization in wheat breeding.Recent advances in wheat genomics have accelerated the cloning of 22 Pm genes,predominantly encoding nucleotide-binding leucine-rich repeat recoptor(NLR)proteins(Ma et al.,2024).Five Bgt avirulent(Avr)genes(AvrPm1,AvrPm2,AvrPm3,AvrPm8,and AvrPm17)have been cloned,all encoding Y/F/WxC-motif-containing proteins(Muller et al.,2022).However,the molecular mechanisms underlying most cloned Pm genes remain largely uncharacterized.展开更多
Plants have evolved multiple layers of defense against various pathogens in the environment. Receptor-like kinases/proteins （RLKs/RLPs） are on the front lines of the battle between plants and pathogens since they ar...Plants have evolved multiple layers of defense against various pathogens in the environment. Receptor-like kinases/proteins （RLKs/RLPs） are on the front lines of the battle between plants and pathogens since they are present at the plasma membrane and perceive signature molecules from either the invading pathogen or damaged plant tissue. With a few notable exceptions, most RLKs/RLPs are positive regulators of plant innate immunity. In this review, we summarize recently discovered RLKs/RLPs that are involved in plant defense responses against various classes of pathogens, We also describe what is currently known about the mechanisms of RLK-mediated initiation of signaling via protein-protein interactions and phosphorylation.展开更多
Wheat stripe rust caused by Puccinia striiformis f.sp.tritici(Pst)poses a great threat to wheat production worldwide.The rapid change in virulence of Pst leads to a loss of resistance in currently resistant wheat cult...Wheat stripe rust caused by Puccinia striiformis f.sp.tritici(Pst)poses a great threat to wheat production worldwide.The rapid change in virulence of Pst leads to a loss of resistance in currently resistant wheat cultivars,which results in frequent disease epidemics.Therefore,a major focus is currently placed on investigating the molecular mechanisms underlying this rapid variation of pathogenicity and coevolving wheat resistance.Limited by the lack of a system for stable transformation of Pst and the difficulties in wheat transformation,it is not easy to generate deeper insights into the wheat-Pst interaction using established genetic methods.Nevertheless,considerable effort has been made to unravel the wheat-Pst interaction and significant progress is being made.Histology and cytology have revealed basic details of infection strategies and defense responses during wheat-Pst interactions,identified cellular components involved in wheat-Pst interactions,and have helped to elucidate their role in the infection process or in plant defense responses.Transcriptome and genome sequencing has revealed the molecular features and dynamics of the wheat-Pst pathosystem.Extensive molecular analyses have led to the identification of major components in the wheat resistance response and in Pst virulence.Studies of wheat-Pst interactions have now entered a new phase in which cellular and molecular approaches are being used.This review focuses on the cellular biology of wheat-Pst interactions and integrates the emerging data from molecular analyses with the histocytological observations.展开更多
Fusarium head blight(FHB)caused by the ascomycete fungus Fusarium graminearum can result in significant crop losses and render the crops harmful to human health due to contamination with mycotoxin.Although the pathoge...Fusarium head blight(FHB)caused by the ascomycete fungus Fusarium graminearum can result in significant crop losses and render the crops harmful to human health due to contamination with mycotoxin.Although the pathogenesis of F.graminearum is widely investigated by molecular genetics approaches,detailed studies about its cellular and developmental processes at the initial stages of infection are very limited.We applied live-cell imaging approach to characterize the spatial and temporal development of growing hyphae and plant responses during F.graminearum and wheat coleoptile interactions.The present investigation demonstrates that F.graminearum uses two strategies to penetrate the host epidermal cells.The pathogen breaks through the host cell wall with appressoria-like structures derived from surficial hyphae,and also with the narrow pegs from thick and bulbous intracellular hyphae.Live cell imaging in the presence of the endocytic tracker FM4–64 showed that the plasma and intermembranes of the invaded wheat coleoptile cells were intact.Invasive hyphae exhibit branching,budding,pseudohyphae-like growth,cell-to-cell spreading ability,and were sealed within a plant membrane,indicating a biotrophic lifestyle of this fungus inside the invaded cells.Time-lapse imaging suggested that there were callose depositions at the plant cell walls in the form of continuous lines and also on the outer linings of the fungal invasive hyphae at colonization stage.In addition,our studies demonstrate that the activation of the toxisomerelated gene(TRI4)requires external stimuli and is spatio-temporally modulated.Generally,this study provides new insights into the colonization strategies and host response features during F.graminearum-plant interactions.Further tracing of cellular details will significantly contribute to our understanding of molecular mechanisms of F.graminearum-host interactions.展开更多
NUcleoside Diphosphate-linked to moiety X(NUDIX)hydrolases are ubiquitous enzymes that maintain metabolic homeostasis by hydrolyzing potentially toxic nucleoside diphosphates.In plants and other eukaryotes,inositol py...NUcleoside Diphosphate-linked to moiety X(NUDIX)hydrolases are ubiquitous enzymes that maintain metabolic homeostasis by hydrolyzing potentially toxic nucleoside diphosphates.In plants and other eukaryotes,inositol pyrophosphates(PP-InsPs)act as central signaling molecules,linking cellular phosphate status to gene expression via SPX-domain receptors.A recent study(McCombe et al.,Science 387:955–962,2025)showed that several plant pathogenic fungi secrete NUDIX effector proteins that hydrolyze PP-InsPs and manipulate host phosphate signaling.In the blast fungus Magnaporthe oryzae,a cytoplasmic NUDIX effector(MoNUDIX)hydrolyzes PP-InsPs,triggers a phosphate starvation response and suppresses immunity in rice,thereby facilitating disease progression.In contrast,the lentil anthracnose pathogen Colletotrichum lentis secretes CtNUDIX into the apoplast,where it disrupts PP-InsP-dependent endocytic machinery and elicits a hypersensitive cell death response.Collectively,these findings demonstrate how NUDIX effectors exemplify mechanistic diversification within a single effector family:manipulating phosphate signaling promotes biotrophic colonization,whereas disrupting host membrane integrity induces a switch to necrotrophy.展开更多
基金supported by the National Basic Research Program of China (2013CB127700)National Natural ScienceFoundation of China (31371882, 31401693)the 111 Project of the Ministry of Education of China (B07049)
文摘Obligate biotrophic fungi cause serious and widespread diseases of crop plants, but are challenging to investigate because they cannot be cultured in vitro. The two economically important groups of biotrophic fungi parasitizing wheat are the rust and powdery mildew pathogens, but their obligate biotrophic lifestyles and pathogenicity mechanisms are not well understood at the molecular level. With the advent of next generation sequencing technology, increasing numbers of pathogen genomes are becoming available. Research in plant pathology has entered a new genomics era. This review summarizes recent progress in understanding the biology and pathogenesis of biotrophic fungal pathogens attacking wheat based on pathogen genomics. We particularly focus on the three wheat rust and the powdery mildew fungi in regard to genome sequencing, avirulence gene cloning, effector discovery, and pathogenomics. We predict that coordinated study of both wheat and its pathogens should reveal new insights in biotrophic adaptation, pathogenicity mechanisms,and population dynamics of these fungi that will assist in development of new strategies for breeding wheat varieties with durable resistance.
基金supported by the National Natural Science Foundation of China(Grants No.32422054,32371611)the Fundamental Research Funds for the Central Universities(Grants No.lzujbky-2023-ey12,lzujbky-2024-it75)+2 种基金the National Key R&D Program of China(Grants No.2023YFF0806800)the Gansu Science and Technology Project(Grants No.23ZDNA009)the Project of the Qinghai Science and Technology Department(Grants No.2024-SF-102)。
文摘Understanding differences in disease position(i.e.the average height of infected leaves)among fungal pathogens is crucial for predicting and managing plant diseases.However,we know little about how disease position varies across disease and host plant types,and whether the local climate(i.e.temperature and precipitation)affects disease position.Here,we investigated disease position in herbaceous plants across key grassland ecosystems in China,including the Qinghai-Tibetan Plateau,Inner Mongolia Plateau,and North China Plain.We tested how fungal pathogen characteristics(e.g.disease types and pathogen lifestyles),host plant characteristics(e.g.biomass,natural height and plant growth type),and climatic conditions(e.g.mean annual temperature[MAT]and precipitation[MAP])affected disease position.Disease position tended to be higher for biotrophic versus necrotrophic pathogens,and this pattern was strongest in forbs and legumes.Disease position was also environment-dependent;higher temperatures and precipitation significantly increased disease position,but these effects varied among disease types.For both biotrophic and necrotrophic pathogens,larger host plants had lower mean disease positions.In this study,we provide evidence for how disease types and climatic conditions impact disease position;our findings emphasize the importance of disease position for understanding patterns of infection and managing disease outbreaks in a changing world.
文摘Jasmonic acid （JA） is a natural hormone regulator involved in development, responses against woundingand pathogen attack. Upon perception of pathogens, JA is synthesized and mediates a signaling cascade initiating various defense responses. Traditionally, necrotrophic fungi have been shown to be the primary activators of JA- dependent defenses through the JA-receptor, COIl. Conversely, plants infected with biotrophic fungi have classically been associated with suppressing JA-mediated responses. However, recent evidence has shown that certain biotrophic fungal species also trigger activation of JA-mediated responses and mutants deficient in JA signaling show an increase in susceptibility to certain biotrophic fungal pathogens. These findings suggest a new role for JA in defense against fungal biotrophs. This review will focus on recent research advancing our knowledge of JA-dependant responses involved in defense against both biotrophic and necrotrophic fungi.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB11030500 to Jin-Long Qiu)the National Natural Science Foundation of China(31071673 to Jin-Long Qiu)
文摘Pytohormone abscisic acid （ABA） plays important roles in defense responses. Nonetheless, how ABA regulates plant resistance to biotrophic fungi remains largely unknown. Arabidopsis ABA-deficient mutants, aba2-1 and aba3-1, displayed enhanced resistance to the biotrophic powdery mildew fungus Golovinomyces cichoracearum. Moreover, exogenously administered ABA increased the susceptibility of Arabidopsis to G. cichoracearum. Arabidopsis ABA perception components mutants, abil-1 and abi2-1, also displayed similar phenotypes to ABA-deficient mutants in resistance to G. cichoracearum. However, the resistance to G. cichoracearum is not changed in downstream ABA signaling transduction mutants, abi3-1, abi4-1, and abi5-1. Microscopic examination revealed that hyphal growth and conidiophore production of G. cichoracearum were compromised in the ABA deficient mutants, even though pre-penetration and penetration growth of the fimgus were not affected. In addition, salicylic acid （SA） and MPK3 are found to be involved in ABA-regulated resistance to G. cichoracearurn. Our work demonstrates that ABA negatively regulates post-penetration resistance of Arabidopsis to powdery mildew fungus G. cichoracearum, probably through antagonizing the function of SA.
基金supported by the National Key Research and Development Program of China(2023YFD1200400)the National Natural Science Foundation of China(31771779,31971933,32272084)+2 种基金the Important National Science&Technology Specific Projects of Transgenic Research(2018ZX0800905B)the“JBGS”Project of Seed Industry Revitalization in Jiangsu Province(JBGS[2021]013)supported by the high-performance computing platform of Bioinformatics Center,Nanjing Agricultural University。
文摘Dear Editor,Wheat powdery mildew,caused by the biotrophic pathogen Blumeria graminis f.sp.tritici(Bgt),is a devastating disease that threatens global wheat production.Resistance genes play a critical role in protecting wheat against Bgt infection.Among these,Pm21,a broad-spectrum resistance gene derived from Haynaldia villosa,encodes a classic coiled-coil nucleotide-binding leucine-rich repeat(CCNB-LRR)protein(Xing et al.,2018).However,the regulatory mechanisms governing Pm21-mediated resistance remain poorly understood.
基金supported by the National Science Foundation(IOS-2207677 to Z.Q.F.)the National Natural Science Foundation of China(32472527 to F.L.and 32300164 and 32460045 to K.L.)the Guizhou Provincial Basic Research Program(Natural Science)(Qian Ke He Ji Chu-ZK[2023]General 095 to K.L.).
文摘Salicylic acid(SA)is widely recognized as the active ingredient in the commonly used medication aspirin.In plants,SA is best known for its crucial role in plant defense against biotrophic and hemibiotrophic pathogens(Fu and Dong,2013;Peng et al.,2021).In addition,SA has been documented to play important roles in plant adaptation to abiotic stresses,plant growth and development,stomatal closure,thermogenesis,and structuring root microbiome(Vlot et al.,2009;Wang et al.,2025).
基金supported by the National Key R&D Program of China(Grant No.2021YFD1401000)the National Natural Science Foundation of China(Grant Nos.32201745,32272088,32472103,31961143019,and 32421004)+1 种基金the Natural Science Basic Research Plan of Shaanxi Province,China(Grant Nos.2019JCW-18 and 2020JCW-16)the Yazhouwan National Laboratory Project(Grant No.2310JM01).
文摘Dear Editor,Wheat is one of the most important food crops.In recent years,factors such as global warming have led to the frequent occurrence of extreme weather,altering the epidemic patterns of crop diseases and pests and posing severe challenges to food security(Savary et al.2019).Wheat yellow rust(YR),also known as stripe rust,is caused by the biotrophic fungus Puccinia striiformis Westend f.sp.tritici(Pst)and remains one of the most devastating diseases threatening global wheat production(Chen 2020;Hovmoller et al.2023).
基金supported by the National Key Research and Development Program of China(2023YFD1200402,2023YFF1000603,and 2024YFE0115100)the National Natural Science Foundation of China(32472184,32302369,and 32472130)+6 种基金the Fundamental Research Funds for the Central University(XUEKEN2022012)the Zhongshan Biological Breeding Laboratory(ZSBBL-KY2023-02-2)the Seed Industry Revitalization Project of Jiangsu Province(JBGS(2021)006)the Jiangsu Agricultural Technology System(JATS[2023]422)the Joint Key Project of Improved Wheat Variety of Anhui Province(2021-)the Marie Curie Fellowship grant award"AEGILWHEAT"(H2020-MSCA-IF-2016-746253)the Hungarian National Research,Development and Innovation Office(K135057).
文摘Wheat powdery mildew(Pm),caused by biotrophic fungus Blumeria graminis f.sp.tritici(Bgt),remains a major threat to global wheat production.While over 70 Pm resistance loci have been identified,only a few have been effectively deployed in breeding programs,mainly due to rapid pathogen evolution(Kunz et al.,2023).Cloning Pm resistance genes will facilitate the elucidation of Pm resistance mechanisms at the molecular level and their effective utilization in wheat breeding.Recent advances in wheat genomics have accelerated the cloning of 22 Pm genes,predominantly encoding nucleotide-binding leucine-rich repeat recoptor(NLR)proteins(Ma et al.,2024).Five Bgt avirulent(Avr)genes(AvrPm1,AvrPm2,AvrPm3,AvrPm8,and AvrPm17)have been cloned,all encoding Y/F/WxC-motif-containing proteins(Muller et al.,2022).However,the molecular mechanisms underlying most cloned Pm genes remain largely uncharacterized.
文摘Plants have evolved multiple layers of defense against various pathogens in the environment. Receptor-like kinases/proteins （RLKs/RLPs） are on the front lines of the battle between plants and pathogens since they are present at the plasma membrane and perceive signature molecules from either the invading pathogen or damaged plant tissue. With a few notable exceptions, most RLKs/RLPs are positive regulators of plant innate immunity. In this review, we summarize recently discovered RLKs/RLPs that are involved in plant defense responses against various classes of pathogens, We also describe what is currently known about the mechanisms of RLK-mediated initiation of signaling via protein-protein interactions and phosphorylation.
基金the National Basic Research Program of China(2013CB127700)the National Natural Science Foundation of China(31401693)the China Postdoctoral Science Foundation(2014M550514).
文摘Wheat stripe rust caused by Puccinia striiformis f.sp.tritici(Pst)poses a great threat to wheat production worldwide.The rapid change in virulence of Pst leads to a loss of resistance in currently resistant wheat cultivars,which results in frequent disease epidemics.Therefore,a major focus is currently placed on investigating the molecular mechanisms underlying this rapid variation of pathogenicity and coevolving wheat resistance.Limited by the lack of a system for stable transformation of Pst and the difficulties in wheat transformation,it is not easy to generate deeper insights into the wheat-Pst interaction using established genetic methods.Nevertheless,considerable effort has been made to unravel the wheat-Pst interaction and significant progress is being made.Histology and cytology have revealed basic details of infection strategies and defense responses during wheat-Pst interactions,identified cellular components involved in wheat-Pst interactions,and have helped to elucidate their role in the infection process or in plant defense responses.Transcriptome and genome sequencing has revealed the molecular features and dynamics of the wheat-Pst pathosystem.Extensive molecular analyses have led to the identification of major components in the wheat resistance response and in Pst virulence.Studies of wheat-Pst interactions have now entered a new phase in which cellular and molecular approaches are being used.This review focuses on the cellular biology of wheat-Pst interactions and integrates the emerging data from molecular analyses with the histocytological observations.
基金funded by Natural Science Foundation of China(Grant No.31772106,31601596).
文摘Fusarium head blight(FHB)caused by the ascomycete fungus Fusarium graminearum can result in significant crop losses and render the crops harmful to human health due to contamination with mycotoxin.Although the pathogenesis of F.graminearum is widely investigated by molecular genetics approaches,detailed studies about its cellular and developmental processes at the initial stages of infection are very limited.We applied live-cell imaging approach to characterize the spatial and temporal development of growing hyphae and plant responses during F.graminearum and wheat coleoptile interactions.The present investigation demonstrates that F.graminearum uses two strategies to penetrate the host epidermal cells.The pathogen breaks through the host cell wall with appressoria-like structures derived from surficial hyphae,and also with the narrow pegs from thick and bulbous intracellular hyphae.Live cell imaging in the presence of the endocytic tracker FM4–64 showed that the plasma and intermembranes of the invaded wheat coleoptile cells were intact.Invasive hyphae exhibit branching,budding,pseudohyphae-like growth,cell-to-cell spreading ability,and were sealed within a plant membrane,indicating a biotrophic lifestyle of this fungus inside the invaded cells.Time-lapse imaging suggested that there were callose depositions at the plant cell walls in the form of continuous lines and also on the outer linings of the fungal invasive hyphae at colonization stage.In addition,our studies demonstrate that the activation of the toxisomerelated gene(TRI4)requires external stimuli and is spatio-temporally modulated.Generally,this study provides new insights into the colonization strategies and host response features during F.graminearum-plant interactions.Further tracing of cellular details will significantly contribute to our understanding of molecular mechanisms of F.graminearum-host interactions.
基金supported by the National Natural Science Foundation of China(Grant No.32172363)the Chinese Universities Scientific Fund(Grant No.10092004).
文摘NUcleoside Diphosphate-linked to moiety X(NUDIX)hydrolases are ubiquitous enzymes that maintain metabolic homeostasis by hydrolyzing potentially toxic nucleoside diphosphates.In plants and other eukaryotes,inositol pyrophosphates(PP-InsPs)act as central signaling molecules,linking cellular phosphate status to gene expression via SPX-domain receptors.A recent study(McCombe et al.,Science 387:955–962,2025)showed that several plant pathogenic fungi secrete NUDIX effector proteins that hydrolyze PP-InsPs and manipulate host phosphate signaling.In the blast fungus Magnaporthe oryzae,a cytoplasmic NUDIX effector(MoNUDIX)hydrolyzes PP-InsPs,triggers a phosphate starvation response and suppresses immunity in rice,thereby facilitating disease progression.In contrast,the lentil anthracnose pathogen Colletotrichum lentis secretes CtNUDIX into the apoplast,where it disrupts PP-InsP-dependent endocytic machinery and elicits a hypersensitive cell death response.Collectively,these findings demonstrate how NUDIX effectors exemplify mechanistic diversification within a single effector family:manipulating phosphate signaling promotes biotrophic colonization,whereas disrupting host membrane integrity induces a switch to necrotrophy.
