hrp mutants were produced from strain JXOIII of Xanthomonas oryzae pv. oryzae (Xoo) and strain RS105 of X.o. pv. oryzicola (Xooc), respectively, by using diethyl sulfate (DES) as a mutagenic che ...hrp mutants were produced from strain JXOIII of Xanthomonas oryzae pv. oryzae (Xoo) and strain RS105 of X.o. pv. oryzicola (Xooc), respectively, by using diethyl sulfate (DES) as a mutagenic che mical. All the hrp mutants lost their pathogenicity on a susceptible host plant, rice (Shanyou63), and elicitation of the hypersensitive response (HR) on a nonhost plant, tobacco (NC89). Extracellular enzyme (amy lase, pectate lyase, proteinase, cellulase and lipase) activities of all the hrp mutants were similar to those of the corresponding wild type strains. The response of tobacco to cell sonicated integrations of the wild type strains and the hrp mutants demonstrated that there existed an HR eliciting substance which was heat stable and sensitive to protease. No HR appeared on tobacco after infiltration of the lipopolysaccharide (LPS) of both the wild strains and hrp mutants into tobacco leaves. The ability of the Xooc hrp mutants to induce HR on tobacco and cause streak disease on rice was restored by complementation with pUHRX245 from JXOIII genomic DNA library and by pUHRS138 from RS105 genomic DNA library, respectively. Subcloning of a 38.6 kb hrp fragment insert in pUHRX245 and a 39.3 kb insert in pUHRS138 revealed that a 3.3 kb Sac Ⅰ fragment from pUHRX245 and a 4.5 kb Bam HⅠ Kpn Ⅰ fragment from pUHRS138 were the minimal functional portions required for restoration of the ability of Xooc hrp mutants to induce HR on tobacco and cause disease on rice. The disease symptom caused by the conjugant (M1005 plus 3.3 kb) on rice was similar to that caused by the wild type of Xooc. It suggests that the two fragments contain the same hrp gene(s) and are responsible reciprocally for HR induction on tobacco and pathogenicity on rice.展开更多
Harpins play a key role in inducing disease resistance in crops,and identifying their core functional regions and establishing a system for their efficient expression would be very valuable.In this study,large amounts...Harpins play a key role in inducing disease resistance in crops,and identifying their core functional regions and establishing a system for their efficient expression would be very valuable.In this study,large amounts of soluble fusion proteins of harpin HrpZ and its subpeptides were obtained via the optimized induction conditions(28℃ with 0.5 mmol·L^(-1) IPTG for 6 h)in Escherichia coli BL21(DE3).Hypersensitive response(HR)assays demonstrated that the C-terminal 66 aa of HrpZ(HrpZ_C_2_2)elicited a strong HR in tobacco(Nicotiana benthamiana)and grape(Flame Seedless)leaves.Additionally,treatment with HrpZ,and particularly HrpZ_C_2_2,significantly reduced the disease incidence and severity index of field vine leaves and those inoculated with downy mildew.The determination of the physiological parameters indicated that HrpZ,and especially HrpZ_C_2_2,improved the photosynthesis-and chlorophyll fluorescence-related parameters,enhanced the activity of defense-related enzymes,including SOD,POD,CAT and PAL,and increased the H_(2)O_(2) level.Collectively,we efficiently expressed a core peptide of HrpZ and elucidated its strong ability to elicit a HR and resistance to downy mildew.This research provides insight into understanding the structure and function of HrpZ and will advance the application of HrpZ_C_2_2 to increase the resistance of grapevine to downy mildew.展开更多
Nonhost resistance is a phenomenon that enables plants to protect themselves against the majority of potential pathogens, and thus has a great potential for application in plant protection. We recently found that CfHN...Nonhost resistance is a phenomenon that enables plants to protect themselves against the majority of potential pathogens, and thus has a great potential for application in plant protection. We recently found that CfHNNI1 （for Cladosporium fulvum host and nonhost plant necrosis inducer 1） is an inducer of plant hypersensitive response （HR） and nonhost resistance. In this study, its functional mechanism was analyzed. CfHNN11 was a single copy gene in C. fulvum genome. The functional ORF of the CfHNN11 cDNA was ATG3-TAG780, which showed homology with genes encoding bZIP transcription factors. The functional ORF included in frame an inner one ATG273-TAG780, which was sufficient to induce HR in plants. CfIINN11 induced plant HR in a dose-dependent manner. CfHNNIl-induced necrosis in NahG transgenic tomato plants was significantly stronger than that in their wild type controls. However, the necrosis in Nr and defl tomato mutants was similar to that in their corresponding wild type plants. These data demonstrate that induction of HR and nonhost resistance by CfHNNI1 is negatively regulated by salicylic acid signalling pathway but independent of ethylene and jasmonic acid signalling pathways.展开更多
Alpha-picolinic acid (PA),a metabolite of tryptophan and an inducer of apoptosis in the animal cell,has been reported to be a toxin produced by some of plant fungal pathogens and used in screening for disease resistan...Alpha-picolinic acid (PA),a metabolite of tryptophan and an inducer of apoptosis in the animal cell,has been reported to be a toxin produced by some of plant fungal pathogens and used in screening for disease resistant mutants. Here,we report that PA is an efficient apoptosis agent triggering cell death of hypersensitive-like response in planta. Confirmed by Fluorescence Activated Cell Sorter (FACS),rice suspension cells and leaves exhibited programmed cell death induced by PA. The PA-induced cell death was associated with the accumulation of reactive oxygen species that could be blocked by diphenylene iodonium chloride,indicating that the generation of reactive oxygen species was NADPHoxidase dependent. We also demonstrated the induction of rice defense-related genes and subsequent resistant enhancement by PA against the rice blast fungus Magnaporthe grisea. Hence,it was concluded that the PA-stimulated defense response likely involves the onset of the hypersensitive response in rice,which also provides a simple eliciting tool for studying apoptosis in the plant cell.展开更多
In plants,recognition between resistance gene(R)and virus induces a local hypersensitive response(HR),which is accompanied by systemic acquired resistance(SAR).The dominant resistance gene N in tobacco confers resista...In plants,recognition between resistance gene(R)and virus induces a local hypersensitive response(HR),which is accompanied by systemic acquired resistance(SAR).The dominant resistance gene N in tobacco confers resistance to tobacco mosaic virus(TMV)at both locally inoculated tissues and systemically infected tissues.However,the mechanisms underlying HR-and SAR-mediated viral inhibition are not fully revealed.In this study,we find that Nicotiana glutinosa RNA-binding protein(NgRBP)is an RNA silencing suppressor which enhances TMV-triggered HR.Stronger HR could result in stronger local and systemic RNA silencing as well as SAR.Enhanced RNA silencing in the systemically infected leaves induced by the NgRBP gene is compromised by transient expression of NahG.These results indicate that RNA silencing is activated by HR and plays a crucial role in local and systemic virus resistance.Our results reveal a crosstalk between N gene-mediated virus resistance and RNA silencing which would deepen our understanding of the established HR and SAR models.展开更多
The sugar beet cyst nematode(Heterodera schachtii) is one of the most destructive pathogens in sugar beet production, which causes serious economic losses every year. Few molecular details of effectors of H. schachtii...The sugar beet cyst nematode(Heterodera schachtii) is one of the most destructive pathogens in sugar beet production, which causes serious economic losses every year. Few molecular details of effectors of H. schachtii parasitism are known. We analyzed the genome and transcriptome data of H. schachtii and identified multiple potential predicted proteins. After filtering out predicted proteins with high homology to other plant-parasitic nematodes, we performed functional validation of the remaining effector proteins. 37 putative effectors of H. schachtii were screened based on the Nicotiana benthamiana system for identifying the effectors that inhibit plant immune response, eventually determines 13 candidate effectors could inhibit cell death caused by Bax. Among the 13 effectors, nine have the ability to inhibit GPA2/RBP1-induced cell death. All 13 effectortriggered immunity(ETI) suppressor genes were analyzed by qRT-PCR and confirmed to result in a significant downregulation of one or more defense genes during infection compared to empty vector. For in situ hybridization,13 effectors were specifically expressed and located in esophageal gland cells. These data and functional analysis set the stage for further studies on the interaction of H. schachtii with host and H. schachtii parasitic control.展开更多
The basic region/leucine zipper(bZIP)transcription factors play important roles in plant development and responses to abiotic and biotic stresses.OsbZIP53 regulates resistance to Magnaporthe oryzae in rice by analyzin...The basic region/leucine zipper(bZIP)transcription factors play important roles in plant development and responses to abiotic and biotic stresses.OsbZIP53 regulates resistance to Magnaporthe oryzae in rice by analyzing APIP5-RNAi transgenic plants.To further investigate the biological functions of OsbZIP53,we generated osbzip53 mutants using CRISPR/Cas9 editing and also constructed OsbZIP53 over-expression transgenic plants.Comprehensive analysis of phenotypical,physiological,and transcriptional data showed that knocking-out OsbZIP53 not only improved disease resistance by inducing a hypersensitivity response in plants,but also regulated the immune response through the salicylic acid pathway.Specifically,disrupting OsbZIP53 increased H2O2 accumulation by promoting reactive oxygen species generation through up-regulation of several respiratory burst oxidase homologs(Osrboh genes)and weakened H2O2 degradation by directly targeting OsMYBS1.In addition,the growth of osbzip53 mutants was seriously impaired,while OsbZIP53 over-expression lines displayed a similar phenotype to the wild type,suggesting that OsbZIP53 has a balancing effect on rice immune response and growth.展开更多
Monitoring expression at the transcriptional level is the first essential step for the functional analysis of plant genes. Genes-encoding proteins directly involved in early response to elicitor constitute only a smal...Monitoring expression at the transcriptional level is the first essential step for the functional analysis of plant genes. Genes-encoding proteins directly involved in early response to elicitor constitute only a small fraction of all the genes affected by elicitor. Transcriptional responses to various elicitors have been extensively studied in different plants including Nicotiana and Arabidopsis thaliana; however, corresponding data aren＇t available for non-heading Chinese cabbage. To address this problem, we describe a suppression subtractive library-based approach to isolate the plant＇s ESTs up-regulated in the early induction/execution of the HR induced by elicitor PB90 from Phytophthora boehmeriae. According to their putative identification in BLAST searches against the three genome databases, 70 up-regulated genes were classified into 9 parts： some aspect of primary ＇metabolism＇ or ＇energy＇ production; ＇protein synthesis＇ or ＇protein fate＇; cellular communication/signal transduction mechanism; cell fates including Beclin, SPT1, and SPT2; HLA-B and AGO1 which participate in transcription; cellular transport and hypothetical proteins or proteins for which a function has yet to be determined. Seven selected genes such as Beclin, thioredoxin, HLA-B, MAP3K, SPT1, SPT2, and AGO1 were up-regulated induced by PB90, suggesting that the genes may play an important role in PB90-triggered HR.展开更多
Using fluorescence in situ hybridization, the authors investigated the homology between three plant species, maize (Zea mays L.) and tobacco (Nicotiana tabacum L.), maize and Arabidopsis thaliana (L.) Heynh. at cy...Using fluorescence in situ hybridization, the authors investigated the homology between three plant species, maize (Zea mays L.) and tobacco (Nicotiana tabacum L.), maize and Arabidopsis thaliana (L.) Heynh. at cytogenetic level using two probes corresponding to functional disease resistance genes myb1 and NDR1 in Arabidopsis and tobacco respectively. The hybridization signals of the tested probes were detected in maize chromosomes 8 and 5 respectively, and the single location of each of the two probes showed only single copy of them in maize genome. The results provided a valuable insight into searching for genes associated with programmed cell death in plants using heterologous probe with comparative genetic approach. In addition, the improvements of FISH technique using heterologous probes were discussed.展开更多
Products of plant resistance ( R ) genes Pto and Cf contain distinct domains, and have different cellular localization. It is intriguing to compare the development mechanisms of resistance conferred by the t...Products of plant resistance ( R ) genes Pto and Cf contain distinct domains, and have different cellular localization. It is intriguing to compare the development mechanisms of resistance conferred by the two R genes. In the present report, two hypersensitive response (HR) initiation systems were employed to study the time_course expression induced by Avr / Cf interaction of the genes encoding Pti4, Pti5 and Pti6 which interact directly with Pto: (1) Seeds of tomato (Lycopersicon esculentum Mill.) containing complementary gene pairs Avr 4/ Cf _4 and Avr 9/ Cf _9 were obtained through crossing. Their seedlings developed HR under room temperature. (2) Avr / Cf seedlings grew normally at 33 ℃. When the temperature was shifted down to 25 ℃, HR occurred within hours in the seedlings. Results of both experiments showed that expression of Pti4, Pti5 and Pti6 was induced upon development of hypersensitive necrosis in Avr / Cf seedlings. However, the expression levels and patterns of these Pti s differed. This finding indicated that these Pti s function complementarily, and might be involved in regulation of both Pto and Cf _conferred resistance.展开更多
Xanthomonas oryzae pv.oryzicola（Xoc） causes a destructive bacterial leaf streak disease in rice.Some of the gene products annotated as hypothetical proteins in the genome of Xoc may contribute to its virulence in ri...Xanthomonas oryzae pv.oryzicola（Xoc） causes a destructive bacterial leaf streak disease in rice.Some of the gene products annotated as hypothetical proteins in the genome of Xoc may contribute to its virulence in rice.A mutant,Mxoc1679,screened from our previous Tn5-tagged mutant library for Xoc strain RS105,showed reduced virulence in rice.In this mutant,a gene named as Xoryp_08180 was disrupted by Tn5 insertion.Xoryp_08180 encodes a 1 306-aa hypothetical protein which is highly conserved in Xanthomonas spp.Non-polar mutation of Xoryp_08180 in RS105 strain led to a significant reduction in bacterial virulence and growth in rice,a delayed hypersensitive response（HR） in non-host tobacco,and a decrease in extracellular protease activity.The deficiencies above were restored to wild-type level in the complementary strain by expressing Xoryp_08180 in trans.In addition,the expression of Xoryp_08180 was repressed in hrpG and hrpX mutants in planta but not in a nutrient-rich condition.These results suggested that Xoryp_08180 is a virulence factor required for extracellular protease production,HR induction and full virulence of Xoc.展开更多
Cell death is an important physiological phenomenon in life.It can be programmed or unprogrammed.Unprogrammed cell death is usually induced by abiotic or biotic stress.Recent studies have shown that many proteins regu...Cell death is an important physiological phenomenon in life.It can be programmed or unprogrammed.Unprogrammed cell death is usually induced by abiotic or biotic stress.Recent studies have shown that many proteins regulate both cell death and immunity in plants.Here,we provide a review on the advances in plant immunity with cell death,especially the molecular regulation and underlying mechanisms of those proteins involved in both cell death and plant immunity.In addition,we discuss potential approaches toward improving plant immunity without compromising plant growth.展开更多
Blast disease,caused by the hemibiotrophic ascomycete fungus,Magnaporthe oryzae,is a significant threat to sustainable rice production worldwide.Studies have shown that the blast fungus secretes vast arrays of functio...Blast disease,caused by the hemibiotrophic ascomycete fungus,Magnaporthe oryzae,is a significant threat to sustainable rice production worldwide.Studies have shown that the blast fungus secretes vast arrays of functionally diverse proteins into the host cell for a successful disease progression.However,the final destinations of these effector proteins inside the host cell and their role in advancing fungal pathogenesis remain a mystery.Here,we reported that a putative mitochondrial targeting non-classically secreted protein(MoMtp)positively regulates conidiogenesis and appressorium maturation in M.oryzae.Moreover,MoM TP gene deletion mutant strains triggered a hypersensitive response when inoculated on rice leaves displaying that MoMtp is essential for the virulence of M.oryzae.In addition,cell wall and oxidative stress results indicated that MoMtp is likely involved in the maintenance of the structural integrity of the fungus cell.Our study also demonstrates an upregulation in the expression pattern of the MoMTP gene at all stages of infection,indicating its possible regulatory role in host invasion and the infectious development of M.oryzae.Furthermore,Agrobacterium infiltration and sheath inoculation confirmed that MoMtpGFP protein is predominantly localized in the host mitochondria of tobacco leaf and rice cells.Taken together,we conclude that MoMtp protein likely promotes the normal conidiation and pathogenesis of M.oryzae and might have a role in disturbing the proper functioning of the host mitochondria during pathogen invasion.展开更多
Nucleotide-binding site leucine-rich repeat receptors (NBS-LRR/NLRs) are crucial intracellular immune proteins in plants. Previous article reported a novel NLR protein SUT1 (SUPPRESSORS OF TOPP4-1, 1), which is involv...Nucleotide-binding site leucine-rich repeat receptors (NBS-LRR/NLRs) are crucial intracellular immune proteins in plants. Previous article reported a novel NLR protein SUT1 (SUPPRESSORS OF TOPP4-1, 1), which is involved in autoimmunity initiated by type one protein phosphatase 4 mutation (topp4-1) in Arabidopsis, however, its role in planta is still unclear. This study employed Nicotiana benthamiana, a model platform, to conduct an overall structural and functional analysis of SUT1 protein. The transient expression results revealed that SUT1 is a typical CNL (CC-NBS-LRR) receptor, both fluorescence data and biochemical results showed the protein is mainly anchored on the plasma membrane due to its N-terminal acylation site. Further truncation experiments announced that its CC (coiled-coil) domain possessed cell-death-inducing activity. The outcomes of point mutations analysis revealed that not only the CC domain, but also the full-length SUT1 protein, whose function and subcellular localization are influenced by highly conserved hydrophobic residues. These research outcomes provided favorable clues for elucidating the activation mechanism of SUT1.展开更多
Increasing evidence is proving the biological significance of the phytoplasma-secreted proteins.However,besides a few Sec-dependent secretory proteins,no other phytoplasma-secreted proteins have been reported yet.Cand...Increasing evidence is proving the biological significance of the phytoplasma-secreted proteins.However,besides a few Sec-dependent secretory proteins,no other phytoplasma-secreted proteins have been reported yet.Candidatus Phytoplasma ziziphi is a phytoplasma that causes witches’-broom,a devastating jujube disease prevalent in east Asia.In this study,using the SecretomeP server coupled with an Escherichia coli-based alkaline phosphatase assay,we identified 25 non-classically secreted proteins(ncSecPs)from Ca.P.ziziphi,a novel type of secreted protein associated with phytoplasmas.Among them,six were characterized as hypersensitive cell death response(HR)suppressors that significantly attenuated both Bax-and INF1-triggered HR and H_(2)O_(2) accumulation in Nicotiana benthamiana,indicating a so-far unknown role of the phytoplasma-secreted proteins.Further,we demonstrated that despite the diverse subcellular localizations in the N.benthamiana cells,the six HR-suppressing ncSecPs enhanced the gene expression of several known cell death inhibitors,including pathogenesis-related proteins(NbPR-1,NbPR-2,and NbPR-5)and Bax inhibitor-1(NbBI-1 and NbBI-2).Together,our data indicated that Ca.P.ziziphi has evolved an arsenal of ncSecPs that jointly circumvent HR by activating the plant cell death inhibitors,thus providing new insight into understanding the pathogenesis of phytoplasmas.展开更多
Dear editor,Dr. Peter Drummond＇s article noted that peripheral nerve and tissue injury in neuropathic pain syndromes releases cytokines which in turn lead to an increase in alphal-adrenoceptor upreg- ulation, resulti...Dear editor,Dr. Peter Drummond＇s article noted that peripheral nerve and tissue injury in neuropathic pain syndromes releases cytokines which in turn lead to an increase in alphal-adrenoceptor upreg- ulation, resulting in a heightened sensitivity to noradrenaline. In these circumstances, noradrenaline acting on upregulated alpha1 a-adrenoceptors increases the release of cytokine interleukin-6. Hence, nociceptive afferent neurons exposed to injury induced cytokines become more hypersensitive to noradrenaline, which in turn promotes the release of more inflammatory cytokines. Dr. Drummond noted that this mechanism may contribute to the pain of post-herpetic neuralgia or complex regional pain syn- drome （Drummond, 2014）.展开更多
Erythema nodosum (EN) is a delayed hypersensitivity response that may be triggered by a range of conditions, including infections and vaccines. Rare cases of EN caused by COVID-19 were recently reported but none due t...Erythema nodosum (EN) is a delayed hypersensitivity response that may be triggered by a range of conditions, including infections and vaccines. Rare cases of EN caused by COVID-19 were recently reported but none due to COVID-19 vaccines were documented. We report here a case of EN occurring after COVID-19 vaccination. Patient presented with painful nodular lesions of all 4 limbs, evolving for one month. These lesions appeared 48 h after the second dose of COVID-19 vaccination. The patient reported no recent infectious episodes. The physical examination found numerous, erythematous dermohypodermatitis knots with no palpable adenopathy. Some were regressive according to biligenesis shades. Biology and radiology findings eliminated other common causes of this dermatosis. The skin biopsy was done and suggested EN. The final diagnosis was post COVID-19 vaccine EN. Patient received a symptomatic treatment and had a slight improvement of the lesions 10 days after diagnosis. Physicians should be aware of the side effects of the vaccine including skin manifestations, especially since more people are bound to be vaccinated.展开更多
Plants deploy sophisticated immune surveillance systems to safeguard themselves against pathogen infection,including plasma membrane-localized pattern-recognition receptors (PRRs) that initiate Pattern-Triggered Immun...Plants deploy sophisticated immune surveillance systems to safeguard themselves against pathogen infection,including plasma membrane-localized pattern-recognition receptors (PRRs) that initiate Pattern-Triggered Immunity (PTI)upon detecting pathogen-associated molecular patterns(PAMPs), and intracellular nucleotide-binding leucine-rich repeat receptors (NLRs) that induce Effector-Triggered Immunity (ETI) upon direct/indirect pathogen effector recognition. Effector-Triggered Immunity is often accompanied by a hypersensitive response (HR), which is known as rapid localized cell death at infection sites to restrict pathogen growth (Contreras et al., 2023;Jones et al., 2024). Nucleotidebinding leucine-rich repeat receptors are classified by their N-terminal domains:TIR-NLRs (TNLs), CC-NLRs (CNLs), and RPW8-NLRs (RNLs). TNLs and CNLs typically function as sensor NLRs (sNLRs) that detect pathogen effectors, while RNLs serve as helper NLRs (hNLRs) that transmit immune signals from diverse sNLRs to ultimately execute downstream resistance and trigger cell death—though some RNLs can themselves be direct targets of pathogen effectors (Contreras et al., 2023;Gong et al., 2023). The hNLRs mainly include Activated Disease Resistance 1 (ADR1), which is conserved in both dicots and monocots, and N REQUIRED GENE 1 (NRG1),which has not been identified in monocots, as well as Solanaceae-specific NLR required for cell death (NRC)-type NLRs, which are required for HR-related cell death (Contreras et al., 2023;Gong et al., 2023).展开更多
Sorghum relies on its immune system to defend against various pathogens,including Pseudomonas syringae syringae van Hall(Pss van Hall).However,the sorghum immune system is largely unknown.Reports on pathogenic effecto...Sorghum relies on its immune system to defend against various pathogens,including Pseudomonas syringae syringae van Hall(Pss van Hall).However,the sorghum immune system is largely unknown.Reports on pathogenic effectors have provided valuable insights into the plant immune system;thus,we aimed to identify Pss van Hall effectors that can regulate the sorghum defense response in this study.Here,we first established the sorghum-Pss van Hall pathosystem and found that typeⅢeffectors played critical roles in the virulence of Pss van Hall to sorghum.To predict its effectors,the whole genome of Pss van Hall was sequenced,and 18 effector-coding genes were identified.Among them,five effectors belong to the core effectors of Pseudomonas syringae pathovars,and two may be monocot pathogen-specific effectors.Pss van Hall triggered the hypersensitive response(HR)in Nicotiana benthamiana.We found that the effectors of Pss van Hall can be divided into cell death inducers and immune repressors by examining their functions in HR induction and repression of PTI marker gene,ROS production,and pathogen growth.Finally,the roles of core effectors HopAJ2 and HopAN1,and specific effector HopAX1 were further confirmed in the sorghum-Pss van Hall pathosystem.Importantly,the functions of HopAN1 and HopAX1 in regulating plant immunity were reported for the first time.We believe that the identification of these effectors will facilitate the continued exploration of the sorghum immune system.展开更多
Plants provide essential nutrients for human beings.Unfortunately,plants can be infected by a wide variety of pathogens,resulting in more than 30%of crop yield loss(Gai and Wang,2024).To keep pathogens under control,p...Plants provide essential nutrients for human beings.Unfortunately,plants can be infected by a wide variety of pathogens,resulting in more than 30%of crop yield loss(Gai and Wang,2024).To keep pathogens under control,plants have evolved intracel ular nucleotide-binding leucine-rich repeat receptors(NLRs)that detect pathogen effectors,activating effectortriggered immunity(ETI)(Wu et al.,2014).One of the major characteristics of ETI is a rapid localized cel death centered at the infection site,termed the hypersensitive response(HR).展开更多
文摘hrp mutants were produced from strain JXOIII of Xanthomonas oryzae pv. oryzae (Xoo) and strain RS105 of X.o. pv. oryzicola (Xooc), respectively, by using diethyl sulfate (DES) as a mutagenic che mical. All the hrp mutants lost their pathogenicity on a susceptible host plant, rice (Shanyou63), and elicitation of the hypersensitive response (HR) on a nonhost plant, tobacco (NC89). Extracellular enzyme (amy lase, pectate lyase, proteinase, cellulase and lipase) activities of all the hrp mutants were similar to those of the corresponding wild type strains. The response of tobacco to cell sonicated integrations of the wild type strains and the hrp mutants demonstrated that there existed an HR eliciting substance which was heat stable and sensitive to protease. No HR appeared on tobacco after infiltration of the lipopolysaccharide (LPS) of both the wild strains and hrp mutants into tobacco leaves. The ability of the Xooc hrp mutants to induce HR on tobacco and cause streak disease on rice was restored by complementation with pUHRX245 from JXOIII genomic DNA library and by pUHRS138 from RS105 genomic DNA library, respectively. Subcloning of a 38.6 kb hrp fragment insert in pUHRX245 and a 39.3 kb insert in pUHRS138 revealed that a 3.3 kb Sac Ⅰ fragment from pUHRX245 and a 4.5 kb Bam HⅠ Kpn Ⅰ fragment from pUHRS138 were the minimal functional portions required for restoration of the ability of Xooc hrp mutants to induce HR on tobacco and cause disease on rice. The disease symptom caused by the conjugant (M1005 plus 3.3 kb) on rice was similar to that caused by the wild type of Xooc. It suggests that the two fragments contain the same hrp gene(s) and are responsible reciprocally for HR induction on tobacco and pathogenicity on rice.
基金Major Project of Science and Technology of Shandong Province(Grant No.2022CXGC010605)Fruit Industrial Technology System of Shandong Province(Grant No.SDAIT-06-03)+1 种基金Key Research and Development Program of Shandong Province(Grant No.2022LZGCQY019)Agriculture Improved Variety Project of Shandong Province(Grant No.2020 LZGC008).
文摘Harpins play a key role in inducing disease resistance in crops,and identifying their core functional regions and establishing a system for their efficient expression would be very valuable.In this study,large amounts of soluble fusion proteins of harpin HrpZ and its subpeptides were obtained via the optimized induction conditions(28℃ with 0.5 mmol·L^(-1) IPTG for 6 h)in Escherichia coli BL21(DE3).Hypersensitive response(HR)assays demonstrated that the C-terminal 66 aa of HrpZ(HrpZ_C_2_2)elicited a strong HR in tobacco(Nicotiana benthamiana)and grape(Flame Seedless)leaves.Additionally,treatment with HrpZ,and particularly HrpZ_C_2_2,significantly reduced the disease incidence and severity index of field vine leaves and those inoculated with downy mildew.The determination of the physiological parameters indicated that HrpZ,and especially HrpZ_C_2_2,improved the photosynthesis-and chlorophyll fluorescence-related parameters,enhanced the activity of defense-related enzymes,including SOD,POD,CAT and PAL,and increased the H_(2)O_(2) level.Collectively,we efficiently expressed a core peptide of HrpZ and elucidated its strong ability to elicit a HR and resistance to downy mildew.This research provides insight into understanding the structure and function of HrpZ and will advance the application of HrpZ_C_2_2 to increase the resistance of grapevine to downy mildew.
基金financially supported by grants from the National Basic Research Program of China (2009CB119000)the Genetically Modified Organisms Breeding Major Projects (2009ZX08009-044B)+2 种基金the PCSIRT Project (IRT0943)the Fundamental Research Funds for the Central Universities (2011XZZX006)the Program for New Century 151 Talents of Zhejiang Province, China
文摘Nonhost resistance is a phenomenon that enables plants to protect themselves against the majority of potential pathogens, and thus has a great potential for application in plant protection. We recently found that CfHNNI1 （for Cladosporium fulvum host and nonhost plant necrosis inducer 1） is an inducer of plant hypersensitive response （HR） and nonhost resistance. In this study, its functional mechanism was analyzed. CfHNN11 was a single copy gene in C. fulvum genome. The functional ORF of the CfHNN11 cDNA was ATG3-TAG780, which showed homology with genes encoding bZIP transcription factors. The functional ORF included in frame an inner one ATG273-TAG780, which was sufficient to induce HR in plants. CfIINN11 induced plant HR in a dose-dependent manner. CfHNNIl-induced necrosis in NahG transgenic tomato plants was significantly stronger than that in their wild type controls. However, the necrosis in Nr and defl tomato mutants was similar to that in their corresponding wild type plants. These data demonstrate that induction of HR and nonhost resistance by CfHNNI1 is negatively regulated by salicylic acid signalling pathway but independent of ethylene and jasmonic acid signalling pathways.
基金supported by the National Natural Science Foudation of China(30125030)the Chinese Academy of Sciences project(KSCX2-SW-301-02)Z.He is a fellow of the CAS“One-Hundred Talent”program.
文摘Alpha-picolinic acid (PA),a metabolite of tryptophan and an inducer of apoptosis in the animal cell,has been reported to be a toxin produced by some of plant fungal pathogens and used in screening for disease resistant mutants. Here,we report that PA is an efficient apoptosis agent triggering cell death of hypersensitive-like response in planta. Confirmed by Fluorescence Activated Cell Sorter (FACS),rice suspension cells and leaves exhibited programmed cell death induced by PA. The PA-induced cell death was associated with the accumulation of reactive oxygen species that could be blocked by diphenylene iodonium chloride,indicating that the generation of reactive oxygen species was NADPHoxidase dependent. We also demonstrated the induction of rice defense-related genes and subsequent resistant enhancement by PA against the rice blast fungus Magnaporthe grisea. Hence,it was concluded that the PA-stimulated defense response likely involves the onset of the hypersensitive response in rice,which also provides a simple eliciting tool for studying apoptosis in the plant cell.
基金supported by Shandong Provincial Natural Science Foundation(ZR2021MC019)National Natural Science Foundation of China(32372634)+1 种基金National Natural Science Foundation of China(32301777)Shandong Provincial Natural Science Foundation(ZR2023QC102).
文摘In plants,recognition between resistance gene(R)and virus induces a local hypersensitive response(HR),which is accompanied by systemic acquired resistance(SAR).The dominant resistance gene N in tobacco confers resistance to tobacco mosaic virus(TMV)at both locally inoculated tissues and systemically infected tissues.However,the mechanisms underlying HR-and SAR-mediated viral inhibition are not fully revealed.In this study,we find that Nicotiana glutinosa RNA-binding protein(NgRBP)is an RNA silencing suppressor which enhances TMV-triggered HR.Stronger HR could result in stronger local and systemic RNA silencing as well as SAR.Enhanced RNA silencing in the systemically infected leaves induced by the NgRBP gene is compromised by transient expression of NahG.These results indicate that RNA silencing is activated by HR and plays a crucial role in local and systemic virus resistance.Our results reveal a crosstalk between N gene-mediated virus resistance and RNA silencing which would deepen our understanding of the established HR and SAR models.
基金supported by the Open Fund of the Key Laboratory of Integrated Pest Management on Crop in Northwestern Oasis,Ministry of Agriculture and Rural Affairsof China(KFJJ202101)the National KeyR&D Program of China(2021YFD1400100)+1 种基金the National Natural Science Foundation of China(31972247)the Tianchi Talent Introduction Program in Xinjiang Uygur Autonomous Region,China and the Science and Technology Innovation Project of the Chinese Academy of Agricultural Sciences.
文摘The sugar beet cyst nematode(Heterodera schachtii) is one of the most destructive pathogens in sugar beet production, which causes serious economic losses every year. Few molecular details of effectors of H. schachtii parasitism are known. We analyzed the genome and transcriptome data of H. schachtii and identified multiple potential predicted proteins. After filtering out predicted proteins with high homology to other plant-parasitic nematodes, we performed functional validation of the remaining effector proteins. 37 putative effectors of H. schachtii were screened based on the Nicotiana benthamiana system for identifying the effectors that inhibit plant immune response, eventually determines 13 candidate effectors could inhibit cell death caused by Bax. Among the 13 effectors, nine have the ability to inhibit GPA2/RBP1-induced cell death. All 13 effectortriggered immunity(ETI) suppressor genes were analyzed by qRT-PCR and confirmed to result in a significant downregulation of one or more defense genes during infection compared to empty vector. For in situ hybridization,13 effectors were specifically expressed and located in esophageal gland cells. These data and functional analysis set the stage for further studies on the interaction of H. schachtii with host and H. schachtii parasitic control.
基金the Zhejiang Natural Science Foundation,China(Grant No.LY21C130004)the Key Research and Development Program of Zhejiang Province,China(Grant No.2021C02056-3)+1 种基金the Central Public-Interest Scientific Institution Basal Research Fund,China(Grant No.CPSIBRF-CNRRI-202202)the Agricultural Science and Technology Innovation Program,China(Grant No.CAASASTIP-2021-CNRRI).
文摘The basic region/leucine zipper(bZIP)transcription factors play important roles in plant development and responses to abiotic and biotic stresses.OsbZIP53 regulates resistance to Magnaporthe oryzae in rice by analyzing APIP5-RNAi transgenic plants.To further investigate the biological functions of OsbZIP53,we generated osbzip53 mutants using CRISPR/Cas9 editing and also constructed OsbZIP53 over-expression transgenic plants.Comprehensive analysis of phenotypical,physiological,and transcriptional data showed that knocking-out OsbZIP53 not only improved disease resistance by inducing a hypersensitivity response in plants,but also regulated the immune response through the salicylic acid pathway.Specifically,disrupting OsbZIP53 increased H2O2 accumulation by promoting reactive oxygen species generation through up-regulation of several respiratory burst oxidase homologs(Osrboh genes)and weakened H2O2 degradation by directly targeting OsMYBS1.In addition,the growth of osbzip53 mutants was seriously impaired,while OsbZIP53 over-expression lines displayed a similar phenotype to the wild type,suggesting that OsbZIP53 has a balancing effect on rice immune response and growth.
基金supported by the National Natural Science Foundation of China(30471123,30571206)Natural Science Foundation of Jiangsu Province,China(BK2005421)New Century Excellent Scholar Project of Ministry of Education of China(NCET-07-0042).
文摘Monitoring expression at the transcriptional level is the first essential step for the functional analysis of plant genes. Genes-encoding proteins directly involved in early response to elicitor constitute only a small fraction of all the genes affected by elicitor. Transcriptional responses to various elicitors have been extensively studied in different plants including Nicotiana and Arabidopsis thaliana; however, corresponding data aren＇t available for non-heading Chinese cabbage. To address this problem, we describe a suppression subtractive library-based approach to isolate the plant＇s ESTs up-regulated in the early induction/execution of the HR induced by elicitor PB90 from Phytophthora boehmeriae. According to their putative identification in BLAST searches against the three genome databases, 70 up-regulated genes were classified into 9 parts： some aspect of primary ＇metabolism＇ or ＇energy＇ production; ＇protein synthesis＇ or ＇protein fate＇; cellular communication/signal transduction mechanism; cell fates including Beclin, SPT1, and SPT2; HLA-B and AGO1 which participate in transcription; cellular transport and hypothetical proteins or proteins for which a function has yet to be determined. Seven selected genes such as Beclin, thioredoxin, HLA-B, MAP3K, SPT1, SPT2, and AGO1 were up-regulated induced by PB90, suggesting that the genes may play an important role in PB90-triggered HR.
文摘Using fluorescence in situ hybridization, the authors investigated the homology between three plant species, maize (Zea mays L.) and tobacco (Nicotiana tabacum L.), maize and Arabidopsis thaliana (L.) Heynh. at cytogenetic level using two probes corresponding to functional disease resistance genes myb1 and NDR1 in Arabidopsis and tobacco respectively. The hybridization signals of the tested probes were detected in maize chromosomes 8 and 5 respectively, and the single location of each of the two probes showed only single copy of them in maize genome. The results provided a valuable insight into searching for genes associated with programmed cell death in plants using heterologous probe with comparative genetic approach. In addition, the improvements of FISH technique using heterologous probes were discussed.
文摘Products of plant resistance ( R ) genes Pto and Cf contain distinct domains, and have different cellular localization. It is intriguing to compare the development mechanisms of resistance conferred by the two R genes. In the present report, two hypersensitive response (HR) initiation systems were employed to study the time_course expression induced by Avr / Cf interaction of the genes encoding Pti4, Pti5 and Pti6 which interact directly with Pto: (1) Seeds of tomato (Lycopersicon esculentum Mill.) containing complementary gene pairs Avr 4/ Cf _4 and Avr 9/ Cf _9 were obtained through crossing. Their seedlings developed HR under room temperature. (2) Avr / Cf seedlings grew normally at 33 ℃. When the temperature was shifted down to 25 ℃, HR occurred within hours in the seedlings. Results of both experiments showed that expression of Pti4, Pti5 and Pti6 was induced upon development of hypersensitive necrosis in Avr / Cf seedlings. However, the expression levels and patterns of these Pti s differed. This finding indicated that these Pti s function complementarily, and might be involved in regulation of both Pto and Cf _conferred resistance.
基金supported by the National Natural Science Foundation of China(31071656,31000071)the National Transgenic Major Program,China(2008ZX08001-002)the Special Fund for Agro-scientific Research in the Public Interest,China(NYHYZX07-056)
文摘Xanthomonas oryzae pv.oryzicola（Xoc） causes a destructive bacterial leaf streak disease in rice.Some of the gene products annotated as hypothetical proteins in the genome of Xoc may contribute to its virulence in rice.A mutant,Mxoc1679,screened from our previous Tn5-tagged mutant library for Xoc strain RS105,showed reduced virulence in rice.In this mutant,a gene named as Xoryp_08180 was disrupted by Tn5 insertion.Xoryp_08180 encodes a 1 306-aa hypothetical protein which is highly conserved in Xanthomonas spp.Non-polar mutation of Xoryp_08180 in RS105 strain led to a significant reduction in bacterial virulence and growth in rice,a delayed hypersensitive response（HR） in non-host tobacco,and a decrease in extracellular protease activity.The deficiencies above were restored to wild-type level in the complementary strain by expressing Xoryp_08180 in trans.In addition,the expression of Xoryp_08180 was repressed in hrpG and hrpX mutants in planta but not in a nutrient-rich condition.These results suggested that Xoryp_08180 is a virulence factor required for extracellular protease production,HR induction and full virulence of Xoc.
基金supported by the National Natural Science Foundation of China (NSFC, 31972254)the Fok Ying Tung Education Foundation (171021)+5 种基金the Tianfu Tenthousand Talents Program (Tianfu Science and Technology Elite Project), Chinathe Outstanding Young Scientific and Technological Talents Project in Sichuan Province, China (2019JDJQ0045)Outstanding Youth Science Foundation of Sichuan Agricultural University, China (2021SZYQ002) to Li Weitaothe Key R&D Projects of Science & Technology Department of Sichuan Province (2018JZ0072)NSFC (31825022) to Chen Xueweithe NSFC (32072041) to Yin Junjie。
文摘Cell death is an important physiological phenomenon in life.It can be programmed or unprogrammed.Unprogrammed cell death is usually induced by abiotic or biotic stress.Recent studies have shown that many proteins regulate both cell death and immunity in plants.Here,we provide a review on the advances in plant immunity with cell death,especially the molecular regulation and underlying mechanisms of those proteins involved in both cell death and plant immunity.In addition,we discuss potential approaches toward improving plant immunity without compromising plant growth.
基金funded by the National Natural Science Foundation of China(32172364 to Shihong Zhang and 32272513 to Zonghua Wang)Fujian Agriculture and Forestry University scholarship,China for Wajjiha Batool。
文摘Blast disease,caused by the hemibiotrophic ascomycete fungus,Magnaporthe oryzae,is a significant threat to sustainable rice production worldwide.Studies have shown that the blast fungus secretes vast arrays of functionally diverse proteins into the host cell for a successful disease progression.However,the final destinations of these effector proteins inside the host cell and their role in advancing fungal pathogenesis remain a mystery.Here,we reported that a putative mitochondrial targeting non-classically secreted protein(MoMtp)positively regulates conidiogenesis and appressorium maturation in M.oryzae.Moreover,MoM TP gene deletion mutant strains triggered a hypersensitive response when inoculated on rice leaves displaying that MoMtp is essential for the virulence of M.oryzae.In addition,cell wall and oxidative stress results indicated that MoMtp is likely involved in the maintenance of the structural integrity of the fungus cell.Our study also demonstrates an upregulation in the expression pattern of the MoMTP gene at all stages of infection,indicating its possible regulatory role in host invasion and the infectious development of M.oryzae.Furthermore,Agrobacterium infiltration and sheath inoculation confirmed that MoMtpGFP protein is predominantly localized in the host mitochondria of tobacco leaf and rice cells.Taken together,we conclude that MoMtp protein likely promotes the normal conidiation and pathogenesis of M.oryzae and might have a role in disturbing the proper functioning of the host mitochondria during pathogen invasion.
文摘Nucleotide-binding site leucine-rich repeat receptors (NBS-LRR/NLRs) are crucial intracellular immune proteins in plants. Previous article reported a novel NLR protein SUT1 (SUPPRESSORS OF TOPP4-1, 1), which is involved in autoimmunity initiated by type one protein phosphatase 4 mutation (topp4-1) in Arabidopsis, however, its role in planta is still unclear. This study employed Nicotiana benthamiana, a model platform, to conduct an overall structural and functional analysis of SUT1 protein. The transient expression results revealed that SUT1 is a typical CNL (CC-NBS-LRR) receptor, both fluorescence data and biochemical results showed the protein is mainly anchored on the plasma membrane due to its N-terminal acylation site. Further truncation experiments announced that its CC (coiled-coil) domain possessed cell-death-inducing activity. The outcomes of point mutations analysis revealed that not only the CC domain, but also the full-length SUT1 protein, whose function and subcellular localization are influenced by highly conserved hydrophobic residues. These research outcomes provided favorable clues for elucidating the activation mechanism of SUT1.
基金funded by the National Key Research and Development Program(2021YFC2600602)the National Natural Science Foundation of China(31970126)the Science Innovation Program of Beijing University of Agriculture.
文摘Increasing evidence is proving the biological significance of the phytoplasma-secreted proteins.However,besides a few Sec-dependent secretory proteins,no other phytoplasma-secreted proteins have been reported yet.Candidatus Phytoplasma ziziphi is a phytoplasma that causes witches’-broom,a devastating jujube disease prevalent in east Asia.In this study,using the SecretomeP server coupled with an Escherichia coli-based alkaline phosphatase assay,we identified 25 non-classically secreted proteins(ncSecPs)from Ca.P.ziziphi,a novel type of secreted protein associated with phytoplasmas.Among them,six were characterized as hypersensitive cell death response(HR)suppressors that significantly attenuated both Bax-and INF1-triggered HR and H_(2)O_(2) accumulation in Nicotiana benthamiana,indicating a so-far unknown role of the phytoplasma-secreted proteins.Further,we demonstrated that despite the diverse subcellular localizations in the N.benthamiana cells,the six HR-suppressing ncSecPs enhanced the gene expression of several known cell death inhibitors,including pathogenesis-related proteins(NbPR-1,NbPR-2,and NbPR-5)and Bax inhibitor-1(NbBI-1 and NbBI-2).Together,our data indicated that Ca.P.ziziphi has evolved an arsenal of ncSecPs that jointly circumvent HR by activating the plant cell death inhibitors,thus providing new insight into understanding the pathogenesis of phytoplasmas.
文摘Dear editor,Dr. Peter Drummond＇s article noted that peripheral nerve and tissue injury in neuropathic pain syndromes releases cytokines which in turn lead to an increase in alphal-adrenoceptor upreg- ulation, resulting in a heightened sensitivity to noradrenaline. In these circumstances, noradrenaline acting on upregulated alpha1 a-adrenoceptors increases the release of cytokine interleukin-6. Hence, nociceptive afferent neurons exposed to injury induced cytokines become more hypersensitive to noradrenaline, which in turn promotes the release of more inflammatory cytokines. Dr. Drummond noted that this mechanism may contribute to the pain of post-herpetic neuralgia or complex regional pain syn- drome （Drummond, 2014）.
文摘Erythema nodosum (EN) is a delayed hypersensitivity response that may be triggered by a range of conditions, including infections and vaccines. Rare cases of EN caused by COVID-19 were recently reported but none due to COVID-19 vaccines were documented. We report here a case of EN occurring after COVID-19 vaccination. Patient presented with painful nodular lesions of all 4 limbs, evolving for one month. These lesions appeared 48 h after the second dose of COVID-19 vaccination. The patient reported no recent infectious episodes. The physical examination found numerous, erythematous dermohypodermatitis knots with no palpable adenopathy. Some were regressive according to biligenesis shades. Biology and radiology findings eliminated other common causes of this dermatosis. The skin biopsy was done and suggested EN. The final diagnosis was post COVID-19 vaccine EN. Patient received a symptomatic treatment and had a slight improvement of the lesions 10 days after diagnosis. Physicians should be aware of the side effects of the vaccine including skin manifestations, especially since more people are bound to be vaccinated.
基金supported by the National Natural Science Foundation of China(32472527 and 32260653)the Guizhou Provincial General Project of the Science Foundation(ZK[2024]Key 011)+1 种基金the Guizhou Plant Bacteria and Biological Control Science and Technology Innovation Talent Team Development(Qian Ke He Talent-BQW[2025]003)the Research and Innovation Team of Guizhou University([2024]05)。
文摘Plants deploy sophisticated immune surveillance systems to safeguard themselves against pathogen infection,including plasma membrane-localized pattern-recognition receptors (PRRs) that initiate Pattern-Triggered Immunity (PTI)upon detecting pathogen-associated molecular patterns(PAMPs), and intracellular nucleotide-binding leucine-rich repeat receptors (NLRs) that induce Effector-Triggered Immunity (ETI) upon direct/indirect pathogen effector recognition. Effector-Triggered Immunity is often accompanied by a hypersensitive response (HR), which is known as rapid localized cell death at infection sites to restrict pathogen growth (Contreras et al., 2023;Jones et al., 2024). Nucleotidebinding leucine-rich repeat receptors are classified by their N-terminal domains:TIR-NLRs (TNLs), CC-NLRs (CNLs), and RPW8-NLRs (RNLs). TNLs and CNLs typically function as sensor NLRs (sNLRs) that detect pathogen effectors, while RNLs serve as helper NLRs (hNLRs) that transmit immune signals from diverse sNLRs to ultimately execute downstream resistance and trigger cell death—though some RNLs can themselves be direct targets of pathogen effectors (Contreras et al., 2023;Gong et al., 2023). The hNLRs mainly include Activated Disease Resistance 1 (ADR1), which is conserved in both dicots and monocots, and N REQUIRED GENE 1 (NRG1),which has not been identified in monocots, as well as Solanaceae-specific NLR required for cell death (NRC)-type NLRs, which are required for HR-related cell death (Contreras et al., 2023;Gong et al., 2023).
基金supported by the National Natural Science Foundation of China(No.32101685 for Aixia Li and 32000224 for Lijing Liu).
文摘Sorghum relies on its immune system to defend against various pathogens,including Pseudomonas syringae syringae van Hall(Pss van Hall).However,the sorghum immune system is largely unknown.Reports on pathogenic effectors have provided valuable insights into the plant immune system;thus,we aimed to identify Pss van Hall effectors that can regulate the sorghum defense response in this study.Here,we first established the sorghum-Pss van Hall pathosystem and found that typeⅢeffectors played critical roles in the virulence of Pss van Hall to sorghum.To predict its effectors,the whole genome of Pss van Hall was sequenced,and 18 effector-coding genes were identified.Among them,five effectors belong to the core effectors of Pseudomonas syringae pathovars,and two may be monocot pathogen-specific effectors.Pss van Hall triggered the hypersensitive response(HR)in Nicotiana benthamiana.We found that the effectors of Pss van Hall can be divided into cell death inducers and immune repressors by examining their functions in HR induction and repression of PTI marker gene,ROS production,and pathogen growth.Finally,the roles of core effectors HopAJ2 and HopAN1,and specific effector HopAX1 were further confirmed in the sorghum-Pss van Hall pathosystem.Importantly,the functions of HopAN1 and HopAX1 in regulating plant immunity were reported for the first time.We believe that the identification of these effectors will facilitate the continued exploration of the sorghum immune system.
基金supported by the National Science Foundation(IOS-2207677)to Z.Q.F.Project of State Key Laboratory of Tropical Crop Breeding(NKLTCB-HZ04)Central Public-interest Scientific Institution Basal Research Fund(1630052025021)to Y.Q。
文摘Plants provide essential nutrients for human beings.Unfortunately,plants can be infected by a wide variety of pathogens,resulting in more than 30%of crop yield loss(Gai and Wang,2024).To keep pathogens under control,plants have evolved intracel ular nucleotide-binding leucine-rich repeat receptors(NLRs)that detect pathogen effectors,activating effectortriggered immunity(ETI)(Wu et al.,2014).One of the major characteristics of ETI is a rapid localized cel death centered at the infection site,termed the hypersensitive response(HR).
