The wall-associated kinases(WAKs)play a crucial role in rice resistance,but their relationship to yield-related traits remains poorly understood.In this study,we analyzed the rice wall-associated kinase galacturonan-b...The wall-associated kinases(WAKs)play a crucial role in rice resistance,but their relationship to yield-related traits remains poorly understood.In this study,we analyzed the rice wall-associated kinase galacturonan-binding(WAKg)gene family and evaluated its association with both disease resistance and grain yield.A total of 108 OsWAKg genes were identified in rice.Promoter cis-element analysis revealed that the promoter regions of OsWAKg genes contain abundant resistance-and hormone-related elements.Induced expression analysis of 18 OsWAKg genes highly expressed in both rice leaves and roots showed that 14 genes were pathogen-induced,9 were induced by development-related hormones,and 8 were responded to both stimuli.Transgenic validation confirmed that OsWAKg16 and OsWAKg52 positively regulate rice disease resistance and yield.Moreover,OsWAKg52 regulates rice disease resistance through multiple pattern-triggered immunity responses.These findings demonstrate that OsWAKgs significantly contribute to the coordinated regulation of disease resistance and grain yield,providing new insights into rice WAKg gene family and potential genetic resources for synergistic crop improvement.展开更多
Plants recognize microbe-associated molecular patterns(MAMPs)to activate immune responses and defense priming to defend against pathogen infections.Transcriptional regulation of gene expression is crucial for plant im...Plants recognize microbe-associated molecular patterns(MAMPs)to activate immune responses and defense priming to defend against pathogen infections.Transcriptional regulation of gene expression is crucial for plant immunity and is mediated by multiple factors,including DNA methylation.However,it remains unknown whether and how DNA demethylation contributes to immune responses in MAMPtriggered immunity.Here,we report that active DNA demethylation is required for MAMP-triggered immunity to bacterial pathogens.The rdd-2 triple mutant carrying mutations in ROS1,DML2,and DML3 that encode DNA glycosylases,which are key DNA demethylation enzymes,exhibits compromised immune responses triggered by the MAMPs fig22 and elf18.Genome-wide methylome analysis reveals that fig22 induces rapid and specific DNA demethylation in an RDD-dependent manner.The expression levels of salicylic acid signaling-related and phytoalexin biosynthesis-related genes are tightly associated with the fig22-induced promoter demethylation.The compromised accumulation of priming compounds and antimicrobial metabolites ultimately leads to a defense priming defect in the rdd-2 mutant.Our results reveal the critical role of active DNA demethylation in the MAMP-triggered immune response and provide unique insight into the molecular mechanism of fig22-modulated DNA demethylation.展开更多
The flagellin-sensing mechanism is one of the most extensively studied topics in plant defense systems.This widespread interest arises from the ability of flagellin to trigger robust and extensive responses,establishi...The flagellin-sensing mechanism is one of the most extensively studied topics in plant defense systems.This widespread interest arises from the ability of flagellin to trigger robust and extensive responses,establishing it as a cornerstone for research into other defense mechanisms.Plants recognize bacterial flagellin epitopes through plasma-membrane-localized pattern-recognition receptors,initiating pattern-triggered immunity as the frontline defense against bacterial pathogens.In this review,we comprehensively summarize flagellin-sensing mechanisms and signal transduction pathways in plants.We compare the flagellin-sensing mechanisms of plants and mammals,focusing on epitope processing and recognition.We present detailed downstream signaling events,from receptor complex formation to transcriptional reprogramming.Furthermore,we highlight the evolutionary arms race between plants and bacteria and incorporate emerging insights into how flagellin-triggered responses are modulated by receptor networking,phytocytokines,and environmental factors.These findings suggest that flagellin-mediated immune responses are highly dynamic and context dependent.By synthesizing current knowledge and recent discoveries,this review provides updated perspectives on plant–microbe interactions and aims to inspire future research in plant immunity.展开更多
Receptor-like cytoplasmic kinases(RLCKs)function as a central player in plant receptor kinases-mediated signaling,which regulate various aspects of plant immunity and growth.RLCKs receive signals from pattern recognit...Receptor-like cytoplasmic kinases(RLCKs)function as a central player in plant receptor kinases-mediated signaling,which regulate various aspects of plant immunity and growth.RLCKs receive signals from pattern recognition receptors(PRRs)to activate pattern-triggered immunity(PTI),including reactive oxygen species(ROS)production,Ca^(2+)influx,mitogen-activated protein kinase(MAPK)cascades,cellulose synthesis,phosphatidic acid(PA)production,hormone synthesis and signaling,and transcriptional remodeling.Besides,RLCK also participate in effector-triggered immunity(ETI)and the interplay between ETI and PTI.Increasing evidences show that much more RLCKs are involved in plant immune responses and form an intertwined signaling network.This review summarizes the recent findings about RLCKs-mediated signaling in plant immune responses and emphasizes signal convergence and divergence involved which provides new insights into the RLCKs signaling network in diverse biological processes.展开更多
Phytophthora pathogens are devastating agricultural threats that cannot synthesize sterols and must scavenge them from host plants.This study exploits their sterol auxotrophy by engineering a dual-function elicitin pr...Phytophthora pathogens are devastating agricultural threats that cannot synthesize sterols and must scavenge them from host plants.This study exploits their sterol auxotrophy by engineering a dual-function elicitin protein,SOJ5^(V84F),for enhanced disease control.The^(V84F)mutation in the sterol-binding pocket of the Phytophthora sojae elicitin SOJ5 abolishes sterol binding but retains interaction with the pathogen’s sterol-sensing receptor kinase SSRK1.SOJ5^(V84F)acts as a dominant-negative inhibitor:it competitively disrupts SSRK1-mediated sterol signaling(calcium influx,MAPK activation)and significantly inhibits P.sojae growth in an SSRK1-dependent manner.Crucially,SOJ5^(V84F)retains its ability as a microbe-associated molecular pattern to robustly elicit reactive oxygen species burst in soybean,pepper,tomato,and potato plants.Consequently,pre-treatment with SOJ5^(V84F)provided superior protection compared to wild-type SOJ5 against P.sojae in soybean,and against Phytophthora capsici and Phytophthora infestans in pepper,tomato,and potato under greenhouse conditions.This work demonstrates that engineered SOJ5^(V84F)combines direct pathogen inhibition with host immune activation,establishing a novel dual-mechanism strategy for protein-based biocontrol against sterol-auxotrophic oomycetes.展开更多
After three decades of the amazing progress made on molecular studies of plant-microbe interactions(MPMI),we have begun to ask ourselves"what are the major questions still remaining?"as if the puzzle has onl...After three decades of the amazing progress made on molecular studies of plant-microbe interactions(MPMI),we have begun to ask ourselves"what are the major questions still remaining?"as if the puzzle has only a few pieces missing.Such an exercise has ultimately led to the realization that we still have many more questions than answers.Therefore,it would be an impossible task for us to project a coherent"big picture"of the MPMI field in a single review.Instead,we provide our opinions on where we would like to go in our research as an invitation to the community to join us in this exploration of new MPMI frontiers.展开更多
Beyond their function as structural barriers,plant cell walls are essential elements for the adaptation of plants to environmental conditions.Cell walls are dynamic structures whose composition and integrity can be al...Beyond their function as structural barriers,plant cell walls are essential elements for the adaptation of plants to environmental conditions.Cell walls are dynamic structures whose composition and integrity can be altered in response to environmental challenges and developmental cues.These wall changes are perceived by plant sensors/receptors to trigger adaptative responses during development and upon stress perception.Plant cell wall damage caused by pathogen infection,wounding,or other stresses leads to the release of wall molecules,such as carbohydrates(glycans),that function as damage-associated molecular patterns(DAMPs).DAMPs are perceived by the extracellular ectodomains(ECDs)of pattern recognition receptors(PRRs)to activate pattern-triggered immunity(PTI)and disease resistance.Similarly,glycans released from the walls and extracellular layers of microorganisms interacting with plants are recognized as microbe-associated molecular patterns(MAMPs)by specific ECD-PRRs triggering PTI responses.The number of oligosaccharides DAMPs/MAMPs identified that are perceived by plants has increased in recent years.However,the structural mechanisms underlying glycan recognition by plant PRRs remain limited.Currently,this knowledge is mainly focused on receptors of the LysM-PRR family,which are involved in the perception of various molecules,such as chitooligosaccharides from fungi and lipo-chitooligosaccharides(i.e.,Nod/MYC factors from bacteria and mycorrhiza,respectively)that trigger differential physiological responses.Nevertheless,additional families of plant PRRs have recently been implicated in oligosaccharide/polysaccharide recognition.These include receptor kinases(RKs)with leucine-rich repeat and Malectin domains in their ECDs(LRR-MAL RKs),Catharanthus roseus RECEPTOR-LIKE KINASE 1-LIKE group(CrRLK1L)with Malectin-like domains in their ECDs,as well as wall-associated kinases,lectin-RKs,and LRR-extensins.The characterization of structural basis of glycans recognition by these new plant receptors will shed light on their similarities with those of mammalians involved in glycan perception.The gained knowledge holds the potential to facilitate the development of sustainable,glycan-based crop protection solutions.展开更多
The interaction between plants and pathogens represents a dynamic competition between a robust immune system and efficient infectious strategies. Plant innate immunity is composed of complex and highly regulated molec...The interaction between plants and pathogens represents a dynamic competition between a robust immune system and efficient infectious strategies. Plant innate immunity is composed of complex and highly regulated molecular networks, which can be triggered by the perception of either conserved or race-specific pathogenic molecular signatures. Small RNAs are emerging as versatile regulators of plant development, growth and response to biotic and abiotic stresses. They act in different tiers of plant immunity, including the pathogen-associated molecular pattern-triggered and the effector-triggered immunity. On the other hand, pathogens have evolved effector molecules to suppress or hijack the host small RNA pathways. This leads to an arms race between plants and pathogens at the level of small RNA-mediated defense. Here, we review recent advances in small RNA-mediated defense responses and discuss the challenging questions in this area.展开更多
In plants,the antagonism between growth and defense is hardwired by hormonal signaling.The perception of pathogen-associatedmolecularpatterns(PAMPs)frominvadingmicroorganismsinhibits auxin signalingand plant growth.Co...In plants,the antagonism between growth and defense is hardwired by hormonal signaling.The perception of pathogen-associatedmolecularpatterns(PAMPs)frominvadingmicroorganismsinhibits auxin signalingand plant growth.Conversely,pathogens manipulate auxin signaling to promote disease,but how this hormone inhibits immunity is not fully understood.Ustilago maydis is a maize pathogen that induces auxin signaling in its host.We characterized a U.maydis effector protein,Naked1(Nkd1),that is translocated into the host nucleus.Through its native ethylene-responsive element binding factor-associated amphiphilic repression(EAR)motif,Nkd1 binds to the transcriptional co-repressors TOPLESS/TOPLESS-related(TPL/TPRs)and prevents the recruitment of a transcriptional repressor involved in hormonal signaling,leading to the derepression of auxin and jasmonate signaling and thereby promoting susceptibility to(hemi)biotrophic pathogens.A moderate upregulation of auxin signaling inhibits the PAMP-triggered reactive oxygen species(ROS)burst,an early defense response.Thus,our findings establish a clear mechanism for auxin-induced pathogen susceptibility.Engineered Nkd1 variants with increased expression or increased EAR-mediated TPL/TPR binding trigger typical salicylic-acid-mediated defense reactions,leading to pathogen resistance.This implies that moderate binding of Nkd1 to TPL is a result of a balancing evolutionary selection process to enable TPL manipulation while avoiding host recognition.展开更多
Plant plasma membrane-resident immune receptors regulate plant immunity by recognizing microbe-associated molecular patterns(MAMPs),damage-associated molecular patterns(DAMPs),and phytocytokines.Phytocytokines are pla...Plant plasma membrane-resident immune receptors regulate plant immunity by recognizing microbe-associated molecular patterns(MAMPs),damage-associated molecular patterns(DAMPs),and phytocytokines.Phytocytokines are plant endogenous peptides,which are usually produced in the cytosol and released into the apoplast when plant encounters pathogen infections.Phytocytokines regulate plant immunity through activating an overlapping signaling pathway with MAMPs/DAMPs with some unique features.Here,we highlight the current understanding of phytocytokine production,perception and functions in plant immunity,and discuss how plants and pathogens manipulate phytocytokine signaling for their own benefits during the plant-pathogen warfare.展开更多
Recognition of a pathogen by the plant immune system often triggers a form of regulated cell death traditionally known as the hypersensitive response(HR).This type of cell death occurs precisely at the site of pathoge...Recognition of a pathogen by the plant immune system often triggers a form of regulated cell death traditionally known as the hypersensitive response(HR).This type of cell death occurs precisely at the site of pathogen recognition,and it is restricted to a few cells.Extensive research has shed light on how plant immune receptors are mechanistically activated.However,two central key questions remain largely unresolved:how does cell death zonation take place,and what are the mechanisms that underpin this phenomenon?Consequently,bona fide transcriptional indicators of HR are lacking,which prevents deeper insight into its mechanisms before cell death becomes macroscopic and precludes early or live observation.In this study,to identify the transcriptional indicators of HR we used the paradigmatic Arabidopsis thaliana–Pseudomonas syringae pathosystem and performed a spatiotemporally resolved gene expression analysis that compared infected cells that will undergo HR upon pathogen recognition with bystander cells that will stay alive and activate immunity.Our data revealed unique and time-dependent differences in the repertoire of differentially expressed genes,expression profiles,and biological processes derived from tissue undergoing HR and that of its surroundings.Furthermore,we generated a pipeline based on concatenated pairwise comparisons between time,zone,and treatment that enabled us to define 13 robust transcriptional HR markers.Among these genes,the promoter of an uncharacterized AAA-ATPase was used to obtain a fluorescent reporter transgenic line that displays a strong spatiotemporally resolved signal specifically in cells that will later undergo pathogen-triggered cell death.This valuable set of genes can be used to define cells that are destined to die upon infection with HR-triggering bacteria,opening new avenues for specific and/or high-throughput techniques to study HR processes at a single-cell level.展开更多
Mitogen-activated protein kinase(MAPK) cascades play pivotal roles in plant defense against phytopathogens downstream of immune receptor complexes. The amplitude and duration of MAPK activation must be strictly contro...Mitogen-activated protein kinase(MAPK) cascades play pivotal roles in plant defense against phytopathogens downstream of immune receptor complexes. The amplitude and duration of MAPK activation must be strictly controlled, but the underlying mechanism remains unclear. Here, we identified Arabidopsis CPL1(C-terminal domain phosphatase-like 1)as a negative regulator of microbe-associated molecular pattern(MAMP)-triggered immunity via a forward-genetic screen. Disruption of CPL1 significantly enhanced plant resistance to Pseudomonas pathogens induced by the bacterial peptide fg22. Furthermore, fg22-induced MPK3/MPK4/MPK6 phosphorylation was dramatically elevated in cpl1 mutants but severely impaired in CPL1 overexpression lines, suggesting that CPL1 might interfere with fg22-induced MAPK activation. Indeed, CPL1 directly interacted with MPK3 and MPK6, as well as the upstream MKK4 and MKK5. A firefy luciferase-based complementation assay indicated that the interaction between MKK4/MKK5 and MPK3/MPK6 was significantly reduced in the presence of CPL1. These results suggest that CPL1 plays a novel regulatory role in suppressing MAMP-induced MAPK cascade activation and MAMP-triggered immunity to bacterial pathogens.展开更多
Powdery mildew(PM)fungi are biotrophic pathogens that rely on living hosts to survive and thrive.However,their colonization is restricted by host defenses at both the penetration and post-penetration stages.The tobacc...Powdery mildew(PM)fungi are biotrophic pathogens that rely on living hosts to survive and thrive.However,their colonization is restricted by host defenses at both the penetration and post-penetration stages.The tobacco PM strain Golovinomyces cichoracearum(Gc)SICAU1 has overcome penetration resistance of Arabidopsis but its growth is arrested by post-penetration resistance.While Gc SICAU1 only poorly grows in Arabidopsis Col-0 wild-type plants,it can sustainably grow for more than 20 days on the same infected leaves of the double mutant pad4–1 sid2–1 that is defective in both the synthesis and signaling of salicylic acid(SA).To understand the underlying molecular mechanisms,we conducted a comparative transcriptome analysis between Col-0 and pad4–1 sid2–1 in response to Gc SICAU1.We found that 4811 genes were differentially expressed more than four-fold between any two of the measured seven time points(0,1,3,6,8,10 and 12 days post-inoculation).Gene expression pattern analysis suggests that differential expression of 348 genes and 190 genes may explain resistance in Col-0 and susceptibility in pad4–1 sid2–1,respectively.Gene Ontology(GO)analysis suggests that Gc SICAU1 might be arrested in Col-0 by both pattern-triggered immunity and SA-dependent defense.By contrast,its sustained growth in pad4–1 sid2–1 may be attributable to the activation of a detoxification pathway that is normally repressed by the SA-signaling pathway.Taken together,our results suggest that multiple distinct,yet interconnected pathways control the growth of tobacco powdery mildew in Arabidopsis.展开更多
Fungal pathogens are among the main destructive microorganisms for crops and ecosystems worldwide,causing substantial agricultural and economic losses.Plant cell surface-localized lysin motif(LysM)-containing receptor...Fungal pathogens are among the main destructive microorganisms for crops and ecosystems worldwide,causing substantial agricultural and economic losses.Plant cell surface-localized lysin motif(LysM)-containing receptor-like kinases(RLKs)or receptor-like proteins(RLPs)enhance plant resistance to fungal pathogens via sensing chitin,which is a conserved component of the fungal cell wall.Other types of RLKs also regulate chitin signaling via distinct mechanisms in plants.In this study,we identified a G-type lectin RLK,NbERK1,which positively regulated chitin signaling and resistance to the fungal pathogen Sclerotinia sclerotiorum in the model plant Nicotiana benthamiana.In addition,the LysM-RLK NbCERK1/NbLYK4 was shown to mediate plant resistance to S.sclerotiorum positively.Further,the association of chitin-induced NbCERK1-NbLYK4 was found to be essential for chitin perception and signaling.Importantly,NbERK1 was associated with NbCERK1/NbLYK4 and positively regulated chitin-induced NbCERK1-NbLYK4 association.Moreover,chitin could induce the dissociation of NbERK1 from the NbCERK1-NbLYK4 complex.Also,the kinase activity of NbERK1 was likely essential for this dissociation and plant resistance-enhancing activity of NbERK1.Together,these results suggest that NbERK1 is a novel component of the chitin receptor complex and enhances plant resistance to fungal pathogens via regulating chitin signaling.展开更多
The mitogen-activated protein kinase kinase kinase kinase(M4K)family is evolutionarily conserved across plants and animals.In Arabidopsis,the protein kinase SIK1,an M4K member,is known to positively modulate reactive ...The mitogen-activated protein kinase kinase kinase kinase(M4K)family is evolutionarily conserved across plants and animals.In Arabidopsis,the protein kinase SIK1,an M4K member,is known to positively modulate reactive oxygen species(ROS)production during pattern-triggered immunity(PTI)by stabilizing BIK1,a key receptor-like cytoplasmic kinase(RLCK).While homologs of SIK1 exhibit conserved protein domain architectures across a range of land plants,their functional conservation remains incompletely understood.This study investigates the functional conservation and divergence of SIK1 homologs,focusing particularly on NbM4K3 in Nicotiana benthamiana.Silencing NbM4K3 resulted in an impairment of the flg22-induced ROS burst and expression of PTI marker genes.Additionally,silencing NbM4K3 led to diminished protein accumulation of RLCKs,while overexpression of the RLCKs prominently enhanced the flg22-induced ROS burst in NbM4K3-silenced plants.Furthermore,NbM4K3-silenced plants exhibited a compromised hypersensitive response(HR),reduced ROS accumulation,and diminished expression of effector-triggered immunity(ETI)marker genes when challenged with the avirulent strains Ralstonia solanacearum GMI1000 and Pseudomonas syringae DC3000,suggesting that NbM4K3 is a positive regulator of ETI.The attenuated HR phenotype observed in NbM4K3-silenced plants upon expression of RipP1 or RipE1,two avirulent type III effectors of GMI1000,further supports the affirmative role of NbM4K3 in ETI.In summary,our data indicate that the M4K NbM4K3 positively regulates both PTI and ETI in N.benthamiana,potentially by stabilizing RLCKs.These findings not only strengthen the role of M4K family in plant immunity but also suggest its potential in improving disease resistance in plants.展开更多
In plant immunity,a well-orchestrated cascade is initiated by the dimerization of receptor-like kinases(RLKs),followed by the phosphorylation of receptor-like cytoplasmic kinases(RLCKs)and subsequent activation of NAD...In plant immunity,a well-orchestrated cascade is initiated by the dimerization of receptor-like kinases(RLKs),followed by the phosphorylation of receptor-like cytoplasmic kinases(RLCKs)and subsequent activation of NADPH oxidases for ROS generation.Recent findings by Zhong et al.illustrated that a maize signaling module comprising ZmWAKLZmWIK-ZmBLK1-ZmRBOH4 governs quantitative disease resistance to grey leaf spot,a pervasive fungal disease in maize worldwide,unveiling the conservation of this signaling quartet in plant immunity.展开更多
Plant cells perceive pathogen invasion by recognizing microbial patterns using plasma-membrane-localized patternrecognition receptors(PRRs)to initiate pattern-triggered immunity(PTI),which confers a moderate immunity ...Plant cells perceive pathogen invasion by recognizing microbial patterns using plasma-membrane-localized patternrecognition receptors(PRRs)to initiate pattern-triggered immunity(PTI),which confers a moderate immunity to most microbes.For instance,the PRR FLS2(FLAGELLIN SENSING 2)recognizes bacterial flagellin in the presence of the coreceptor BAK1 and activates a series of PTI responses,such as reactive oxygen species(ROS)burst and mitogenactivated protein kinase(MAPK)activation.We previously showed that soybean malectin/malectin-like domain-containing receptor-like kinase(MRLK)protein GmLMM1 negatively regulates PTI by suppressing FLS2-BAK1 interaction.GmLMM1 replicates in tandem with five other GmMRLKs on chromosome 13.Here,we show that GmMRLK32,the closest homolog to GmLMM1 among the tandem genes of GmLMM1,negatively regulates PTI and disease resistance against bacterial and oomycete pathogens.The Gmmrlk32 mutant showed enhanced flg22-induced ROS burst and MAPK activation.We revealed that GmMRLK32 interacts with GmFLS2 and GmBAK1,and suppresses flg22-induced GmFLS2-GmBAK1 dimerization in a manner similar to that of GmLMM1.We further showed that GmMRLK32 specifically interacts with GmLMM1 to regulate PTI.In Nicotiana benthamiana plants,co-expression of GmMRLK32 and GmLMM1 showed a stronger PTI inhibitory effect on PTI activation than expression of GmMRLK32 or GmLMM1 alone.We uncovered a novel mechanism by which GmMRLK32 and GmLMM1 coordinately regulate PTI by forming hetero-oligomer.展开更多
Casein kinase 2(CK2),a key multifunctional protein kinase in plant cells,is ubiquitously expressed and plays a crucial role in survival under various stress conditions.However,the role of CK2 in the interaction betwee...Casein kinase 2(CK2),a key multifunctional protein kinase in plant cells,is ubiquitously expressed and plays a crucial role in survival under various stress conditions.However,the role of CK2 in the interaction between wheat and Puccinia triticina(Pt)remains ambiguous.In our previous study,a CK2 gene,known as TaCK2α,was identified in the nearisogenic wheat line TcLr19 inoculated with Pt through RNA-Sequence analysis.In the current study,quantitative real-time polymerase chain reaction(qPCR)analysis revealed that the expression of TaCK2αwas upregulated by the Pt race THTS and signaling molecules,indicating its potential involvement in the wheat-Pt interaction,particularly in relation to salicylic acid(SA)signaling.Antifungal activity assays and virus-induced gene silencing(VIGS)analysis further validated the role of TaCK2αin regulating wheat resistance to Pt.Using a combination of pulldown assays and mass spectrometry(MS),24 potential interacting targets of TaCK2αwere identified in wheat.Among these targets,the interaction between TaCK2αand TaCK2βwas confirmed through Yeast two-hybrid(Y2H)and Co-Immunoprecipitation(Co-IP).Additionally,the subcellular localization of TaCK2αwas found to be altered by CK2β.TaCK2αplays a positive role in reactive oxygen species(ROS)induction and callose deposition in wheat,whereas TaCK2βcontributes to the pattern-triggered immunity(PTI)response by interacting with TaCK2α.Collectively,our results demonstrate that TaCK2αtargets TaCK2βto mediate wheat resistance against Pt through PTI,providing a solid basis for further investigation into the molecular mechanisms underlying CK2-dependent wheat resistance to biotic stress.展开更多
Plant cell-surface-localized pattern-recognition receptors(PRRs)recognize conserved microbial patterns to activate pattern-triggered immunity(PTI),which confers mild and broad-spectrum resistance to most microbes.Rapi...Plant cell-surface-localized pattern-recognition receptors(PRRs)recognize conserved microbial patterns to activate pattern-triggered immunity(PTI),which confers mild and broad-spectrum resistance to most microbes.Rapid alkalinization factor(RALF)peptides are a family of secreted peptides that have been reported to regulate many biological processes,including plant immunity.However,little is known for the roles of RALFs in soybean immunity and disease resistance.In total,24 RALFs have been identified in the soybean Glycine max,and we showed that these GmRALFs are either transcriptionally induced or suppressed in response to pathogen infection.We characterized the roles of GmRALFs in plant immunity by transiently expressing them in Nicotiana benthamiana.We examined the effect of GmRALFs on PTI responses,including the ROS burst induced by bacterial flg22 or fungal chitin,and oomycete INF1-induced cell death.We further examined the disease resistance to pathogenic bacteria,fungi,and oomycete in plants.We identified several GmRALFs that positively or negatively regulate plant immunity.Of these GmRALFs,GmRALF1 and its homolog in N.benthamiana exhibited strong immune suppression in all PTI and disease resistance assays.Finally,we obtained Gmralf1 mutant lines using CRISPR-Cas9 approach.These mutants exhibited significantly enhanced PTI and resistance to Phytophthora sojae and Pseudmonas syringae infection.In conclusion,our study revealed the common and specific roles of GmRALFs in PTI responses and resistance to various pathogens,and identified GmRALF1 as a candidate susceptibility gene with potential applications for improving soybean disease resistance.展开更多
基金partly granted from the National Natural Science Foundation of China(Grant Nos.32470391 and 32401801)the Joint Open Competitive Project of the Yazhou Bay Laboratory and the China National Seed Company Limited(Grant No.B23YQ1515)+1 种基金the International Cooperation Projects in Hubei Province,China(Grant No.2023EHA045)the Natural Science Foundation of Wuhan University of Bioengineering,China(Grant No.2024KQ07).
文摘The wall-associated kinases(WAKs)play a crucial role in rice resistance,but their relationship to yield-related traits remains poorly understood.In this study,we analyzed the rice wall-associated kinase galacturonan-binding(WAKg)gene family and evaluated its association with both disease resistance and grain yield.A total of 108 OsWAKg genes were identified in rice.Promoter cis-element analysis revealed that the promoter regions of OsWAKg genes contain abundant resistance-and hormone-related elements.Induced expression analysis of 18 OsWAKg genes highly expressed in both rice leaves and roots showed that 14 genes were pathogen-induced,9 were induced by development-related hormones,and 8 were responded to both stimuli.Transgenic validation confirmed that OsWAKg16 and OsWAKg52 positively regulate rice disease resistance and yield.Moreover,OsWAKg52 regulates rice disease resistance through multiple pattern-triggered immunity responses.These findings demonstrate that OsWAKgs significantly contribute to the coordinated regulation of disease resistance and grain yield,providing new insights into rice WAKg gene family and potential genetic resources for synergistic crop improvement.
基金supported by the National Natural Science Foundation of China (31770278, 31970125 to B.L.)Fundamental Research Funds for the Central Universities, Huazhong Agricultural University Scientific & Technological Self-innovation Foundation (2021ZKPY011, 2017RC001 to B.L.)
文摘Plants recognize microbe-associated molecular patterns(MAMPs)to activate immune responses and defense priming to defend against pathogen infections.Transcriptional regulation of gene expression is crucial for plant immunity and is mediated by multiple factors,including DNA methylation.However,it remains unknown whether and how DNA demethylation contributes to immune responses in MAMPtriggered immunity.Here,we report that active DNA demethylation is required for MAMP-triggered immunity to bacterial pathogens.The rdd-2 triple mutant carrying mutations in ROS1,DML2,and DML3 that encode DNA glycosylases,which are key DNA demethylation enzymes,exhibits compromised immune responses triggered by the MAMPs fig22 and elf18.Genome-wide methylome analysis reveals that fig22 induces rapid and specific DNA demethylation in an RDD-dependent manner.The expression levels of salicylic acid signaling-related and phytoalexin biosynthesis-related genes are tightly associated with the fig22-induced promoter demethylation.The compromised accumulation of priming compounds and antimicrobial metabolites ultimately leads to a defense priming defect in the rdd-2 mutant.Our results reveal the critical role of active DNA demethylation in the MAMP-triggered immune response and provide unique insight into the molecular mechanism of fig22-modulated DNA demethylation.
基金supported by grants from the Institute for Basic Science(IBS-R021-D1-2025-a00)the National Research Foundation of Korea(RS-2024-00338015)to H.-S.L.and by the Startup Fund from Duke Kunshan University to E.Y.K.D.-H.Lsupported by a postdoctoral fellowship from the National Research Foundation of Korea(NRF-2021R1A6A3A03039464).No conflict of interest is declared.
文摘The flagellin-sensing mechanism is one of the most extensively studied topics in plant defense systems.This widespread interest arises from the ability of flagellin to trigger robust and extensive responses,establishing it as a cornerstone for research into other defense mechanisms.Plants recognize bacterial flagellin epitopes through plasma-membrane-localized pattern-recognition receptors,initiating pattern-triggered immunity as the frontline defense against bacterial pathogens.In this review,we comprehensively summarize flagellin-sensing mechanisms and signal transduction pathways in plants.We compare the flagellin-sensing mechanisms of plants and mammals,focusing on epitope processing and recognition.We present detailed downstream signaling events,from receptor complex formation to transcriptional reprogramming.Furthermore,we highlight the evolutionary arms race between plants and bacteria and incorporate emerging insights into how flagellin-triggered responses are modulated by receptor networking,phytocytokines,and environmental factors.These findings suggest that flagellin-mediated immune responses are highly dynamic and context dependent.By synthesizing current knowledge and recent discoveries,this review provides updated perspectives on plant–microbe interactions and aims to inspire future research in plant immunity.
基金supported by the Key R&D Program of Zhejiang(2024SSY0104)Top-tier Innovation and Entrepreneurship Team Project of Hangzhou(TD2023019)to S.M.+2 种基金by the Postdoctoral Fellowship Program of CPSF to L.B.(GZC20241029)and to Y.X.(GZC20241030)by National Key Research and Development Program(2023YFD1401503)the Shanghai Collaborative Innovation Center of Agri-Seeds grant(ZXWH2150201/023)to J.F.
文摘Receptor-like cytoplasmic kinases(RLCKs)function as a central player in plant receptor kinases-mediated signaling,which regulate various aspects of plant immunity and growth.RLCKs receive signals from pattern recognition receptors(PRRs)to activate pattern-triggered immunity(PTI),including reactive oxygen species(ROS)production,Ca^(2+)influx,mitogen-activated protein kinase(MAPK)cascades,cellulose synthesis,phosphatidic acid(PA)production,hormone synthesis and signaling,and transcriptional remodeling.Besides,RLCK also participate in effector-triggered immunity(ETI)and the interplay between ETI and PTI.Increasing evidences show that much more RLCKs are involved in plant immune responses and form an intertwined signaling network.This review summarizes the recent findings about RLCKs-mediated signaling in plant immune responses and emphasizes signal convergence and divergence involved which provides new insights into the RLCKs signaling network in diverse biological processes.
基金supported by grants from the National Natural Science Foundation of China(32230089 and 32472502)the Natural Science Foundation of Jiangsu Province(BK20251533)+3 种基金the Postdoctoral Fellowship Program and China Postdoctoral Science Foundation(BX20250018)the Fundamental Research Funds for the Central Universities(KJYQ2025050)the China Postdoctoral Science Foundation(2024M761446)the China Agriculture Research System(CARS-21).
文摘Phytophthora pathogens are devastating agricultural threats that cannot synthesize sterols and must scavenge them from host plants.This study exploits their sterol auxotrophy by engineering a dual-function elicitin protein,SOJ5^(V84F),for enhanced disease control.The^(V84F)mutation in the sterol-binding pocket of the Phytophthora sojae elicitin SOJ5 abolishes sterol binding but retains interaction with the pathogen’s sterol-sensing receptor kinase SSRK1.SOJ5^(V84F)acts as a dominant-negative inhibitor:it competitively disrupts SSRK1-mediated sterol signaling(calcium influx,MAPK activation)and significantly inhibits P.sojae growth in an SSRK1-dependent manner.Crucially,SOJ5^(V84F)retains its ability as a microbe-associated molecular pattern to robustly elicit reactive oxygen species burst in soybean,pepper,tomato,and potato plants.Consequently,pre-treatment with SOJ5^(V84F)provided superior protection compared to wild-type SOJ5 against P.sojae in soybean,and against Phytophthora capsici and Phytophthora infestans in pepper,tomato,and potato under greenhouse conditions.This work demonstrates that engineered SOJ5^(V84F)combines direct pathogen inhibition with host immune activation,establishing a novel dual-mechanism strategy for protein-based biocontrol against sterol-auxotrophic oomycetes.
基金grants from the National Institutes of Health(NIH 1R35GM118036)National Science Foundation(IOS 1645589)+5 种基金Howard Hughes Medical Institute to X.D.,grants from the NIH(NIH 1R35GM136402)National Science Foundation(NSF 1937855-0)United States Department of Agriculture(USDA,2019-70016-2979)G.C.,a grant from National Natural Science Foundation of China(31830019)J.-M.Z.,and a grant from National Natural Science Foundation of China(31922075)Youth Innovation Promotion Association of the Chinese Academy of Sciences to J.Z.
文摘After three decades of the amazing progress made on molecular studies of plant-microbe interactions(MPMI),we have begun to ask ourselves"what are the major questions still remaining?"as if the puzzle has only a few pieces missing.Such an exercise has ultimately led to the realization that we still have many more questions than answers.Therefore,it would be an impossible task for us to project a coherent"big picture"of the MPMI field in a single review.Instead,we provide our opinions on where we would like to go in our research as an invitation to the community to join us in this exploration of new MPMI frontiers.
基金supported by grant PID2021-126006OB-I00 to A.M.and L.J.grant PID20220-113588RB-I00 to S.M.-S+6 种基金funded by MCIN/AEI/10.13039/501100011033by ERDF A way of making Europe.D.J.B.supported by PRE2019-091276 and P.F.-C.by postdoctoral fellowships financially supported by the Severo Ochoa Program for Centres of Excellence in R&D(grants SEV-2016-0672 and CEX2020-000999-S)funded by MCIN/AEI/10.13039/501100011033.M.M.-D.was recipient of PhD fellow(PRE2019-08812)funded by MCIN/AEI/10.13039/501100011033.E.G.-Rwas supported by Autonomous Region of Madrid fellowship(S2017/BMD-3673)the European Commission-Next Generation EU(Regulation EU2020/2094)through CSIC’s Global Health Platform PTI Salud Global.
文摘Beyond their function as structural barriers,plant cell walls are essential elements for the adaptation of plants to environmental conditions.Cell walls are dynamic structures whose composition and integrity can be altered in response to environmental challenges and developmental cues.These wall changes are perceived by plant sensors/receptors to trigger adaptative responses during development and upon stress perception.Plant cell wall damage caused by pathogen infection,wounding,or other stresses leads to the release of wall molecules,such as carbohydrates(glycans),that function as damage-associated molecular patterns(DAMPs).DAMPs are perceived by the extracellular ectodomains(ECDs)of pattern recognition receptors(PRRs)to activate pattern-triggered immunity(PTI)and disease resistance.Similarly,glycans released from the walls and extracellular layers of microorganisms interacting with plants are recognized as microbe-associated molecular patterns(MAMPs)by specific ECD-PRRs triggering PTI responses.The number of oligosaccharides DAMPs/MAMPs identified that are perceived by plants has increased in recent years.However,the structural mechanisms underlying glycan recognition by plant PRRs remain limited.Currently,this knowledge is mainly focused on receptors of the LysM-PRR family,which are involved in the perception of various molecules,such as chitooligosaccharides from fungi and lipo-chitooligosaccharides(i.e.,Nod/MYC factors from bacteria and mycorrhiza,respectively)that trigger differential physiological responses.Nevertheless,additional families of plant PRRs have recently been implicated in oligosaccharide/polysaccharide recognition.These include receptor kinases(RKs)with leucine-rich repeat and Malectin domains in their ECDs(LRR-MAL RKs),Catharanthus roseus RECEPTOR-LIKE KINASE 1-LIKE group(CrRLK1L)with Malectin-like domains in their ECDs,as well as wall-associated kinases,lectin-RKs,and LRR-extensins.The characterization of structural basis of glycans recognition by these new plant receptors will shed light on their similarities with those of mammalians involved in glycan perception.The gained knowledge holds the potential to facilitate the development of sustainable,glycan-based crop protection solutions.
基金funded by the grant from National Basic Research Program of China (973 Program, 2012CB910503) to Hai Huangby the Gordon and Betty Moore Foundation through Grant GBMF 2550.02 to the Life Sciences Research Foundation to Li Yang
文摘The interaction between plants and pathogens represents a dynamic competition between a robust immune system and efficient infectious strategies. Plant innate immunity is composed of complex and highly regulated molecular networks, which can be triggered by the perception of either conserved or race-specific pathogenic molecular signatures. Small RNAs are emerging as versatile regulators of plant development, growth and response to biotic and abiotic stresses. They act in different tiers of plant immunity, including the pathogen-associated molecular pattern-triggered and the effector-triggered immunity. On the other hand, pathogens have evolved effector molecules to suppress or hijack the host small RNA pathways. This leads to an arms race between plants and pathogens at the level of small RNA-mediated defense. Here, we review recent advances in small RNA-mediated defense responses and discuss the challenging questions in this area.
基金The research leading to these results received funding from the European Research Council under the European Union Seventh Framework Pro-gramme ERC-2013-STG grant agreement 335691the Austrian Science Fund(FWF)P27818-B22,I 3033-B22+1 种基金the Austrian Academy of Sciences(OEAW)the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)under Germany’s Excellence Strategy-EXC 2070-390732324.
文摘In plants,the antagonism between growth and defense is hardwired by hormonal signaling.The perception of pathogen-associatedmolecularpatterns(PAMPs)frominvadingmicroorganismsinhibits auxin signalingand plant growth.Conversely,pathogens manipulate auxin signaling to promote disease,but how this hormone inhibits immunity is not fully understood.Ustilago maydis is a maize pathogen that induces auxin signaling in its host.We characterized a U.maydis effector protein,Naked1(Nkd1),that is translocated into the host nucleus.Through its native ethylene-responsive element binding factor-associated amphiphilic repression(EAR)motif,Nkd1 binds to the transcriptional co-repressors TOPLESS/TOPLESS-related(TPL/TPRs)and prevents the recruitment of a transcriptional repressor involved in hormonal signaling,leading to the derepression of auxin and jasmonate signaling and thereby promoting susceptibility to(hemi)biotrophic pathogens.A moderate upregulation of auxin signaling inhibits the PAMP-triggered reactive oxygen species(ROS)burst,an early defense response.Thus,our findings establish a clear mechanism for auxin-induced pathogen susceptibility.Engineered Nkd1 variants with increased expression or increased EAR-mediated TPL/TPR binding trigger typical salicylic-acid-mediated defense reactions,leading to pathogen resistance.This implies that moderate binding of Nkd1 to TPL is a result of a balancing evolutionary selection process to enable TPL manipulation while avoiding host recognition.
基金supported by National Science Foundation(NSF)(IOS-1951094)and National Institutes of Health(NIH)(R01GM092893)to P.H.,the Natural Science Foundation of Shandong Province(ZR2020MC022)and Youth Innovation Technology Project of Higher School in Shandong Province(2020KJF013)to S.H.The funding agencies have no roles in the design of the study and collection,analysis,and interpretation of data and in writing the manuscript.
文摘Plant plasma membrane-resident immune receptors regulate plant immunity by recognizing microbe-associated molecular patterns(MAMPs),damage-associated molecular patterns(DAMPs),and phytocytokines.Phytocytokines are plant endogenous peptides,which are usually produced in the cytosol and released into the apoplast when plant encounters pathogen infections.Phytocytokines regulate plant immunity through activating an overlapping signaling pathway with MAMPs/DAMPs with some unique features.Here,we highlight the current understanding of phytocytokine production,perception and functions in plant immunity,and discuss how plants and pathogens manipulate phytocytokine signaling for their own benefits during the plant-pathogen warfare.
文摘Recognition of a pathogen by the plant immune system often triggers a form of regulated cell death traditionally known as the hypersensitive response(HR).This type of cell death occurs precisely at the site of pathogen recognition,and it is restricted to a few cells.Extensive research has shed light on how plant immune receptors are mechanistically activated.However,two central key questions remain largely unresolved:how does cell death zonation take place,and what are the mechanisms that underpin this phenomenon?Consequently,bona fide transcriptional indicators of HR are lacking,which prevents deeper insight into its mechanisms before cell death becomes macroscopic and precludes early or live observation.In this study,to identify the transcriptional indicators of HR we used the paradigmatic Arabidopsis thaliana–Pseudomonas syringae pathosystem and performed a spatiotemporally resolved gene expression analysis that compared infected cells that will undergo HR upon pathogen recognition with bystander cells that will stay alive and activate immunity.Our data revealed unique and time-dependent differences in the repertoire of differentially expressed genes,expression profiles,and biological processes derived from tissue undergoing HR and that of its surroundings.Furthermore,we generated a pipeline based on concatenated pairwise comparisons between time,zone,and treatment that enabled us to define 13 robust transcriptional HR markers.Among these genes,the promoter of an uncharacterized AAA-ATPase was used to obtain a fluorescent reporter transgenic line that displays a strong spatiotemporally resolved signal specifically in cells that will later undergo pathogen-triggered cell death.This valuable set of genes can be used to define cells that are destined to die upon infection with HR-triggering bacteria,opening new avenues for specific and/or high-throughput techniques to study HR processes at a single-cell level.
基金supported by the National Natural Science Foundation of China (grant no. 31671991 to FC)。
文摘Mitogen-activated protein kinase(MAPK) cascades play pivotal roles in plant defense against phytopathogens downstream of immune receptor complexes. The amplitude and duration of MAPK activation must be strictly controlled, but the underlying mechanism remains unclear. Here, we identified Arabidopsis CPL1(C-terminal domain phosphatase-like 1)as a negative regulator of microbe-associated molecular pattern(MAMP)-triggered immunity via a forward-genetic screen. Disruption of CPL1 significantly enhanced plant resistance to Pseudomonas pathogens induced by the bacterial peptide fg22. Furthermore, fg22-induced MPK3/MPK4/MPK6 phosphorylation was dramatically elevated in cpl1 mutants but severely impaired in CPL1 overexpression lines, suggesting that CPL1 might interfere with fg22-induced MAPK activation. Indeed, CPL1 directly interacted with MPK3 and MPK6, as well as the upstream MKK4 and MKK5. A firefy luciferase-based complementation assay indicated that the interaction between MKK4/MKK5 and MPK3/MPK6 was significantly reduced in the presence of CPL1. These results suggest that CPL1 plays a novel regulatory role in suppressing MAMP-induced MAPK cascade activation and MAMP-triggered immunity to bacterial pathogens.
基金supported by the National Natural Science Foundation of China grants(31672090 and 31371931)to W-MWthe National Science Foundation grant(IOS-1146589 and IOS-1457033)to SX。
文摘Powdery mildew(PM)fungi are biotrophic pathogens that rely on living hosts to survive and thrive.However,their colonization is restricted by host defenses at both the penetration and post-penetration stages.The tobacco PM strain Golovinomyces cichoracearum(Gc)SICAU1 has overcome penetration resistance of Arabidopsis but its growth is arrested by post-penetration resistance.While Gc SICAU1 only poorly grows in Arabidopsis Col-0 wild-type plants,it can sustainably grow for more than 20 days on the same infected leaves of the double mutant pad4–1 sid2–1 that is defective in both the synthesis and signaling of salicylic acid(SA).To understand the underlying molecular mechanisms,we conducted a comparative transcriptome analysis between Col-0 and pad4–1 sid2–1 in response to Gc SICAU1.We found that 4811 genes were differentially expressed more than four-fold between any two of the measured seven time points(0,1,3,6,8,10 and 12 days post-inoculation).Gene expression pattern analysis suggests that differential expression of 348 genes and 190 genes may explain resistance in Col-0 and susceptibility in pad4–1 sid2–1,respectively.Gene Ontology(GO)analysis suggests that Gc SICAU1 might be arrested in Col-0 by both pattern-triggered immunity and SA-dependent defense.By contrast,its sustained growth in pad4–1 sid2–1 may be attributable to the activation of a detoxification pathway that is normally repressed by the SA-signaling pathway.Taken together,our results suggest that multiple distinct,yet interconnected pathways control the growth of tobacco powdery mildew in Arabidopsis.
基金supported by the National Natural Science Foundation of China(32100155)the Natural Science Foundation of Jiangsu Province(BK20221000)+1 种基金the Fundamental Research Funds for the Central Universities(KYLH201703)the Jiangsu Funding Program for Excellent Postdoctoral Talent(2022ZB343).
文摘Fungal pathogens are among the main destructive microorganisms for crops and ecosystems worldwide,causing substantial agricultural and economic losses.Plant cell surface-localized lysin motif(LysM)-containing receptor-like kinases(RLKs)or receptor-like proteins(RLPs)enhance plant resistance to fungal pathogens via sensing chitin,which is a conserved component of the fungal cell wall.Other types of RLKs also regulate chitin signaling via distinct mechanisms in plants.In this study,we identified a G-type lectin RLK,NbERK1,which positively regulated chitin signaling and resistance to the fungal pathogen Sclerotinia sclerotiorum in the model plant Nicotiana benthamiana.In addition,the LysM-RLK NbCERK1/NbLYK4 was shown to mediate plant resistance to S.sclerotiorum positively.Further,the association of chitin-induced NbCERK1-NbLYK4 was found to be essential for chitin perception and signaling.Importantly,NbERK1 was associated with NbCERK1/NbLYK4 and positively regulated chitin-induced NbCERK1-NbLYK4 association.Moreover,chitin could induce the dissociation of NbERK1 from the NbCERK1-NbLYK4 complex.Also,the kinase activity of NbERK1 was likely essential for this dissociation and plant resistance-enhancing activity of NbERK1.Together,these results suggest that NbERK1 is a novel component of the chitin receptor complex and enhances plant resistance to fungal pathogens via regulating chitin signaling.
基金supported by the National Natural Science Foundation of China(32072399,32302296,32372483)the Technology Innovation Leading Program of Shaanxi(2023QYPY2-01)+1 种基金the Fundamental Research Funds for the Central Universities(GK202201017,GK202207024)the Natural Science Basic Research Program of Shaanxi(2024JC-YBMS-143).
文摘The mitogen-activated protein kinase kinase kinase kinase(M4K)family is evolutionarily conserved across plants and animals.In Arabidopsis,the protein kinase SIK1,an M4K member,is known to positively modulate reactive oxygen species(ROS)production during pattern-triggered immunity(PTI)by stabilizing BIK1,a key receptor-like cytoplasmic kinase(RLCK).While homologs of SIK1 exhibit conserved protein domain architectures across a range of land plants,their functional conservation remains incompletely understood.This study investigates the functional conservation and divergence of SIK1 homologs,focusing particularly on NbM4K3 in Nicotiana benthamiana.Silencing NbM4K3 resulted in an impairment of the flg22-induced ROS burst and expression of PTI marker genes.Additionally,silencing NbM4K3 led to diminished protein accumulation of RLCKs,while overexpression of the RLCKs prominently enhanced the flg22-induced ROS burst in NbM4K3-silenced plants.Furthermore,NbM4K3-silenced plants exhibited a compromised hypersensitive response(HR),reduced ROS accumulation,and diminished expression of effector-triggered immunity(ETI)marker genes when challenged with the avirulent strains Ralstonia solanacearum GMI1000 and Pseudomonas syringae DC3000,suggesting that NbM4K3 is a positive regulator of ETI.The attenuated HR phenotype observed in NbM4K3-silenced plants upon expression of RipP1 or RipE1,two avirulent type III effectors of GMI1000,further supports the affirmative role of NbM4K3 in ETI.In summary,our data indicate that the M4K NbM4K3 positively regulates both PTI and ETI in N.benthamiana,potentially by stabilizing RLCKs.These findings not only strengthen the role of M4K family in plant immunity but also suggest its potential in improving disease resistance in plants.
基金support from the National Natural Science Foundation of China(32302370 to P.W.)USDA NIFA(grant 2020-67013-31615 to P.H.).
文摘In plant immunity,a well-orchestrated cascade is initiated by the dimerization of receptor-like kinases(RLKs),followed by the phosphorylation of receptor-like cytoplasmic kinases(RLCKs)and subsequent activation of NADPH oxidases for ROS generation.Recent findings by Zhong et al.illustrated that a maize signaling module comprising ZmWAKLZmWIK-ZmBLK1-ZmRBOH4 governs quantitative disease resistance to grey leaf spot,a pervasive fungal disease in maize worldwide,unveiling the conservation of this signaling quartet in plant immunity.
基金supported by grants from the Chinese Natural Science Foundation(32270282)Double First-class Discipline Promotion Project(2021B10564001).
文摘Plant cells perceive pathogen invasion by recognizing microbial patterns using plasma-membrane-localized patternrecognition receptors(PRRs)to initiate pattern-triggered immunity(PTI),which confers a moderate immunity to most microbes.For instance,the PRR FLS2(FLAGELLIN SENSING 2)recognizes bacterial flagellin in the presence of the coreceptor BAK1 and activates a series of PTI responses,such as reactive oxygen species(ROS)burst and mitogenactivated protein kinase(MAPK)activation.We previously showed that soybean malectin/malectin-like domain-containing receptor-like kinase(MRLK)protein GmLMM1 negatively regulates PTI by suppressing FLS2-BAK1 interaction.GmLMM1 replicates in tandem with five other GmMRLKs on chromosome 13.Here,we show that GmMRLK32,the closest homolog to GmLMM1 among the tandem genes of GmLMM1,negatively regulates PTI and disease resistance against bacterial and oomycete pathogens.The Gmmrlk32 mutant showed enhanced flg22-induced ROS burst and MAPK activation.We revealed that GmMRLK32 interacts with GmFLS2 and GmBAK1,and suppresses flg22-induced GmFLS2-GmBAK1 dimerization in a manner similar to that of GmLMM1.We further showed that GmMRLK32 specifically interacts with GmLMM1 to regulate PTI.In Nicotiana benthamiana plants,co-expression of GmMRLK32 and GmLMM1 showed a stronger PTI inhibitory effect on PTI activation than expression of GmMRLK32 or GmLMM1 alone.We uncovered a novel mechanism by which GmMRLK32 and GmLMM1 coordinately regulate PTI by forming hetero-oligomer.
基金funded by Hebei Natural Science Foundation of China(No.C2020204028)the National Natural Science Foundation of China(32172384,31501623)Local Science and Technology Development Fund Projects of Hebei Province Guided by the Central Government(246Z6504G).
文摘Casein kinase 2(CK2),a key multifunctional protein kinase in plant cells,is ubiquitously expressed and plays a crucial role in survival under various stress conditions.However,the role of CK2 in the interaction between wheat and Puccinia triticina(Pt)remains ambiguous.In our previous study,a CK2 gene,known as TaCK2α,was identified in the nearisogenic wheat line TcLr19 inoculated with Pt through RNA-Sequence analysis.In the current study,quantitative real-time polymerase chain reaction(qPCR)analysis revealed that the expression of TaCK2αwas upregulated by the Pt race THTS and signaling molecules,indicating its potential involvement in the wheat-Pt interaction,particularly in relation to salicylic acid(SA)signaling.Antifungal activity assays and virus-induced gene silencing(VIGS)analysis further validated the role of TaCK2αin regulating wheat resistance to Pt.Using a combination of pulldown assays and mass spectrometry(MS),24 potential interacting targets of TaCK2αwere identified in wheat.Among these targets,the interaction between TaCK2αand TaCK2βwas confirmed through Yeast two-hybrid(Y2H)and Co-Immunoprecipitation(Co-IP).Additionally,the subcellular localization of TaCK2αwas found to be altered by CK2β.TaCK2αplays a positive role in reactive oxygen species(ROS)induction and callose deposition in wheat,whereas TaCK2βcontributes to the pattern-triggered immunity(PTI)response by interacting with TaCK2α.Collectively,our results demonstrate that TaCK2αtargets TaCK2βto mediate wheat resistance against Pt through PTI,providing a solid basis for further investigation into the molecular mechanisms underlying CK2-dependent wheat resistance to biotic stress.
基金supported by grants from the Natural Science Foundation of Guangdong Province(2024B1515020118)National Science Foundation of China(32270282)Double First-class Discipline Promotion Project(2021B10564001).
文摘Plant cell-surface-localized pattern-recognition receptors(PRRs)recognize conserved microbial patterns to activate pattern-triggered immunity(PTI),which confers mild and broad-spectrum resistance to most microbes.Rapid alkalinization factor(RALF)peptides are a family of secreted peptides that have been reported to regulate many biological processes,including plant immunity.However,little is known for the roles of RALFs in soybean immunity and disease resistance.In total,24 RALFs have been identified in the soybean Glycine max,and we showed that these GmRALFs are either transcriptionally induced or suppressed in response to pathogen infection.We characterized the roles of GmRALFs in plant immunity by transiently expressing them in Nicotiana benthamiana.We examined the effect of GmRALFs on PTI responses,including the ROS burst induced by bacterial flg22 or fungal chitin,and oomycete INF1-induced cell death.We further examined the disease resistance to pathogenic bacteria,fungi,and oomycete in plants.We identified several GmRALFs that positively or negatively regulate plant immunity.Of these GmRALFs,GmRALF1 and its homolog in N.benthamiana exhibited strong immune suppression in all PTI and disease resistance assays.Finally,we obtained Gmralf1 mutant lines using CRISPR-Cas9 approach.These mutants exhibited significantly enhanced PTI and resistance to Phytophthora sojae and Pseudmonas syringae infection.In conclusion,our study revealed the common and specific roles of GmRALFs in PTI responses and resistance to various pathogens,and identified GmRALF1 as a candidate susceptibility gene with potential applications for improving soybean disease resistance.
