[Objective] This study aimed to investigate an outbreak of apple valsa canker （Valsa ceratosperma） in Yantai apple producing area in 2011 and analyze the major causes of the disease. [Method] In May 2011, 21 commerc...[Objective] This study aimed to investigate an outbreak of apple valsa canker （Valsa ceratosperma） in Yantai apple producing area in 2011 and analyze the major causes of the disease. [Method] In May 2011, 21 commercial apple or-chards in Qixia, Haiyang and Laiyang were selected to investigate the outbreak of applevalsa canker. [Result]The results showed that apple canker occurred seriously in Yantai apple producing area in 2011. The ratio of diseased plants with new canker scars was 68.20% and the ratio of dead plants infected with Valsa cer-atosperma was 2.76%. The average ratios of diseased branches and one-year-old dead branches were 23.98% and 10.74%, respectively. The percentage of orchards with more than 50% diseased plants accounted for 25%-30% of the total number of orchards investigated, and the overal prevalence situation was more serious than normal years. In the investigation, 967 new canker scars were observed, with an average of 2.32 canker scars per plant. Specifical y, 80.04% canker scars were de-veloped from pruning wounds; 60.29% canker scars were developed from previous scars. [Conclusion] The long-period precipitation in the autumn of 2010, low temper-ature in the winter of 2010 and the severe drought in the spring of 2011 might be the major factors causing the outbreak of apple valsa canker in Yantai apple pro-ducing area in 2011. Pruning wounds were the main infection entrances of V. cer-atosperma, and the recurrence in previous scars was the main reason for the out-break of apple canker in spring.展开更多
新疆阿克苏地区由Valsa mali var.pyri、Valsa sordida引起的腐烂病是制约库尔勒香梨发展的重要病害,为研究库尔勒香梨感染腐烂病后与防御酶活性的变化关系,以库尔勒香梨为试验材料,分别采集同一株树不同发病组织和不同发病程度枝条韧皮...新疆阿克苏地区由Valsa mali var.pyri、Valsa sordida引起的腐烂病是制约库尔勒香梨发展的重要病害,为研究库尔勒香梨感染腐烂病后与防御酶活性的变化关系,以库尔勒香梨为试验材料,分别采集同一株树不同发病组织和不同发病程度枝条韧皮部,研究其抗性相关酶活性变化。结果表明:病害在完全侵入组织后,SOD活性呈下降的趋势,在发病组织,POD、CAT活性最高,PAL在病健交界处活性最高。随着发病程度的增加,SOD活性整体呈先上升后下降的趋势,POD活性呈逐渐上升的趋势,CAT活性先下降后上升,PAL活性先上升后下降,PPO总体呈下降趋势。库尔勒香梨抗性相关酶活性呈现不同变化响应Valsa侵染。在Valsa与库尔勒香梨互作系统中,抗性酶可作为抗病性和检测病害指标,为检测库尔勒香梨腐烂病发病程度提供理论依据。展开更多
【目的】明确甘肃省苹果树腐烂病菌(Valsa mali)致病力分化情况。【方法】采用平板培养法和离体枝条接种法对Valsa mali两变种的培养性状和致病力进行了研究。【结果】Valsa mali在PDA上有褐色类群和乳白色类群,褐色类群为Valsa mali va...【目的】明确甘肃省苹果树腐烂病菌(Valsa mali)致病力分化情况。【方法】采用平板培养法和离体枝条接种法对Valsa mali两变种的培养性状和致病力进行了研究。【结果】Valsa mali在PDA上有褐色类群和乳白色类群,褐色类群为Valsa mali var.mali菌株,乳白色类群为Valsa mali var.pyri菌株。Valsa mali var.mali不同菌株之间存在致病力分化,菌株PL-1致病力最强,第7天病斑面积为9.54 cm2,菌株TS-5致病力最弱,第7天时病斑面积为4.7 6cm2。Valsa mali var.pyri不同菌株之间也存在致病力分化,菌株WW-1致病力最强,第7天病斑面积为2.72 cm2,菌株WW-2致病力最弱,第7天病斑面积为1.40 cm2。Valsa mali在不同品种间致病力不同,在‘新红星’致病力强,在‘富士’致病力弱。Valsa mali不但侵染苹果树还可以侵染梨树和桃树,Valsa mali var.pyri菌株在梨树上的致病力强于Valsa mali var.mali。【结论】Valsa mali两变种间致病力差异显著,褐色类群菌株Valsa mali var.mali致病力强于乳白色类群菌株Valsa mali var.pyri,Valsa mali两变种内各菌株之间也存在致病力差异显著。展开更多
[Objective] Inhibition mechanism of the antifungal substances from Chaetomium globosum ND35 against pathogenic fungi of Valsa canker was investigated.[Method] The inhibitory effect of antifungal substances （AFS） pro...[Objective] Inhibition mechanism of the antifungal substances from Chaetomium globosum ND35 against pathogenic fungi of Valsa canker was investigated.[Method] The inhibitory effect of antifungal substances （AFS） produced by endophytic C. globosum ND35 on pathogenic fungi of Valsa canker was studied by means of dual culture,extraction,thin layer chromatography and bioassay of antifungal activity. [Result] The crude extracts of AFS could strongly inhibit Valsa sordida and V. mali. The suppression percentage of mycelial growth of two pathogenic fungi were 66.4% and 72.6%,respectively. The inhibition percentages of conidia germination of two pathogenic fungi were 92.2% and 80.4%,respectively. Separation of thin layer chromatography and bioassay of antifungal activity indicated that the fraction No.2 of AFS played an important role in the process of inhibition on pathogenic fungi,causal agents of Valsa canker. [Conclusion] The antifungal substances from C. globosum ND35 is potential for biological control on Valsa canker.展开更多
We report a case of Valsalva retinopathy associated with esophagogastroduodenoscopy (EGD) under propofol sedation. A 43-year-old woman who had no previous history of systemic or ocular disease presented with a complai...We report a case of Valsalva retinopathy associated with esophagogastroduodenoscopy (EGD) under propofol sedation. A 43-year-old woman who had no previous history of systemic or ocular disease presented with a complaint of decreased vision in her left eye, which developed one day after EGD under propofol sedation. According to the referring physician, the patient had experienced multiple sustained Valsalva maneuvers during EGD. The fundus examination of the left eye showed a large preretinal hemorrhage surrounded by multiple small retinal hemorrhages in the posterior pole. One month later, fundus examination revealed a floating organized vitreous hemorrhage. The pars plana vitrectomy was performed to treat persistent vitreous hemorrhage. One month after vitrectomy, fundus examination showed normal retina and the patient’s vision recovered to 20/20. Valsalva maneuver can occur during EGD under sedation, and Valsalva retinopathy should be considered as a possible cause. Valsalva retinopathy should be included in the differential diagnosis when a patient complains of blurred vision following EGD.展开更多
The papr has reported a new species of Valsa came from the twigs andbranches of Cryptomeria fortunei Hooibrenk ex Otto et Dietr.It was named as Valsa forunea Zhao,Sheng et N.Li sp.nov.when it is in the perfect stage a...The papr has reported a new species of Valsa came from the twigs andbranches of Cryptomeria fortunei Hooibrenk ex Otto et Dietr.It was named as Valsa forunea Zhao,Sheng et N.Li sp.nov.when it is in the perfect stage and Cytospora fortunea Zhao,Sheng et N.Lisp.nov.in the imperfect stage.The new species has been described both in Latin and in Chinese,aswell as the differences between the new species and other similarities.The type specimen of the newspecies is deposited in the plant pathology Herbarium of Southwest Forestry College,Kunming(HSFC 15206 Type).展开更多
Pear Valsa canker is a fungal trunk disease caused by Valsa pyri. Phenolic compounds are ubiquitous in plants and usually contribute to plant resistance against biotic stress. To investigate the association between ph...Pear Valsa canker is a fungal trunk disease caused by Valsa pyri. Phenolic compounds are ubiquitous in plants and usually contribute to plant resistance against biotic stress. To investigate the association between phenolic compounds and level of resistance to V. pyri, we quantified the contents of individual phenolic compounds in the cortex and phloem of stems from 8 cultivars of Pyrus bretschneideri. Significant variation in the levels of all compounds was found among the cultivars. Correlation analysis revealed an inverse correlation between levels of arbutin and gallic acid with the degree of canker resistance. This suggested that these phenolic compounds are beneficial to V. pyri infection. These data could be valuable for breeding cultivars of P. bretschneideri with greater resistance to V. pyri.展开更多
Apple valsa canker caused by the Ascomycete fungus Valsa mali is one of the most serious diseases of apple,resulting in huge economic losses in the apple-growing area of China.Previous study found that the pathogen co...Apple valsa canker caused by the Ascomycete fungus Valsa mali is one of the most serious diseases of apple,resulting in huge economic losses in the apple-growing area of China.Previous study found that the pathogen could acidify the infected tissues to make lower ambient pH(from 6.0 to 3.5)for their successfully colonization.The pH signaling transcription factor VmPacC is required for acidification of its environment and for full virulence in V.mali.It is known that the functional cooperation of proteins secreted by V.mali plays pivotal role in its successful colonization of host plants.In this study,we used tandem mass tag(TMT)labeling coupled with LC-MS/MS-based quantitative proteomics to analyze the VmPacC-mediated pH regulation in V.mali,focusing on differentially expressed proteins(DEPs).We identified 222 DEPs specific to VmPacC deletion,and 921 DEPs specific to different pH conditions(pH 6.0 and 3.4).Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analyses indicated that these DEPs were mainly involved in pathways associated with carbon metabolism,biosynthesis of antibiotics,citrate cycle(TCA cycle),glycolysis/gluconeogenesis,glutathione metabolism,ribosomes,and pentose phosphate pathways.Additionally,we identified 119 DEPs that were shared among the VmPacC deletion mutant and different pH conditions,which were mainly related to energy metabolism pathways,providing the energy required for the hyphal growth and responses to environmental stresses.A protein-protein interaction(PPI)network analysis indicated that most of the shared proteins were mapped to an interaction network with a medium confidence score of 0.4.Notably,one uncharacterized protein(KUI69106.1),and two known proteins(heat shock protein 60(KUI73579.1),aspartate aminotransferase(KUI73864.1))located in the core of the network were highly connected(with≥38 directed edges)with the other shared DEPs.Our results suggest that VmPacC participates in the pathogen’s regulation to ambient pH through the regulation of energy metabolism pathways such as the glycolysis/gluconeogenesis pathway and TCA cycle.Finally,we proposed a sophisticated molecular regulatory network to explain pH decrease in V.mali.Our study,by providing insights into V.mali regulating pH,helps to elucidate the mechanisms of host acidification during pathogen infection.展开更多
【目的】分析新疆生产建设兵团第一师阿拉尔市库尔勒香梨园梨树腐烂病病原菌的种群分类,通过6对保守基因序列,研究库尔勒香梨腐烂病病原菌序列之间相关性及差异性。【方法】在库尔勒香梨园内采集具有典型症状的腐烂病病样,经科赫氏法则...【目的】分析新疆生产建设兵团第一师阿拉尔市库尔勒香梨园梨树腐烂病病原菌的种群分类,通过6对保守基因序列,研究库尔勒香梨腐烂病病原菌序列之间相关性及差异性。【方法】在库尔勒香梨园内采集具有典型症状的腐烂病病样,经科赫氏法则验证获取腐烂病病原菌纯培养。采用CTAB法提取腐烂病病原菌基因组DNA,通过PCR扩增ITS、β-tubulin、EF-1α、ACT、LSU、RBP2基因并测序,利用分子系统学分析不同基因片段的系统发育关系。【结果】在阿拉尔周边混交园内库尔勒香梨腐烂病菌种为Valsa mali var.pyri(V.ambiens、Valsa mali)。种内差异与地理位置有关,国内与国外梨腐烂病分离株差异较明显。EF-1α、ACT、LSU、RBP2在进化过程中更能够体现种间差异,系统发育树分支多,存在种间差异。【结论】新疆生产建设兵团第一师阿拉尔市库尔勒香梨腐烂病病原菌种群分布和种间差异性,库尔勒香梨园的腐烂病病原菌主要为Valsa mali var.pyri、Valsa sordida。新疆南疆绿洲特色果园种植模式,以杨树等为主防护林最为常见,存在着林果树木腐烂病交叉侵染的可能。展开更多
Conserved effectors produced by phytopathogens play critical roles in plant-microbe interactions.NIS1-like proteins represent a newly identified family of effectors distributed in multiple fungal species.However,their...Conserved effectors produced by phytopathogens play critical roles in plant-microbe interactions.NIS1-like proteins represent a newly identified family of effectors distributed in multiple fungal species.However,their biological functions in a majority of pathogenic fungi remain largely elusive and require further investigation.In this study,we characterized two NIS1-like proteins VmNIS1 and VmNIS2 from Valsa mali,the causal agent of apple Valsa canker.Both of these two proteins were predicted to be secreted.Using agroinfiltration,we found that VmNIS1 induced intense cell death,whereas VmNIS2 suppressed INF1 elicitin-triggered cell death in Nicotiana benthamiana.Treatment of N.benthamiana with VmNIS1 recombinant protein produced by Escherichia coli activated a series of immune responses and enhanced plant disease resistance against Phytophthora capsici.In contrast,VmNIS2 suppressed plant immune responses and promoted P.capsici infection when transiently expressed in N.benthamiana.Both VmNIS1 and VmNIS2 were shown to be highly induced at late stage of V.mali infection.By individually knocking out of these two genes in V.mali,however,only VmNIS2 was shown to be required for pathogen virulence as well as tolerance to oxidative stress.Notably,we further showed that C-terminal extension of VmNIS1 was essential for plant recognition and VmNIS2 may escape plant detection via sequence truncation.Our data collectively indicate that VmNIS1 and VmNIS2 play distinct roles in plant recognition and pathogen virulence,which provided new insights into the function of NIS1-like proteins in plant-microbe interactions.展开更多
基金Supported by National Modern Industrial Technology System of Apple(CARS-28)National Natural Science Foundation of China(31000891)~~
文摘[Objective] This study aimed to investigate an outbreak of apple valsa canker （Valsa ceratosperma） in Yantai apple producing area in 2011 and analyze the major causes of the disease. [Method] In May 2011, 21 commercial apple or-chards in Qixia, Haiyang and Laiyang were selected to investigate the outbreak of applevalsa canker. [Result]The results showed that apple canker occurred seriously in Yantai apple producing area in 2011. The ratio of diseased plants with new canker scars was 68.20% and the ratio of dead plants infected with Valsa cer-atosperma was 2.76%. The average ratios of diseased branches and one-year-old dead branches were 23.98% and 10.74%, respectively. The percentage of orchards with more than 50% diseased plants accounted for 25%-30% of the total number of orchards investigated, and the overal prevalence situation was more serious than normal years. In the investigation, 967 new canker scars were observed, with an average of 2.32 canker scars per plant. Specifical y, 80.04% canker scars were de-veloped from pruning wounds; 60.29% canker scars were developed from previous scars. [Conclusion] The long-period precipitation in the autumn of 2010, low temper-ature in the winter of 2010 and the severe drought in the spring of 2011 might be the major factors causing the outbreak of apple valsa canker in Yantai apple pro-ducing area in 2011. Pruning wounds were the main infection entrances of V. cer-atosperma, and the recurrence in previous scars was the main reason for the out-break of apple canker in spring.
文摘新疆阿克苏地区由Valsa mali var.pyri、Valsa sordida引起的腐烂病是制约库尔勒香梨发展的重要病害,为研究库尔勒香梨感染腐烂病后与防御酶活性的变化关系,以库尔勒香梨为试验材料,分别采集同一株树不同发病组织和不同发病程度枝条韧皮部,研究其抗性相关酶活性变化。结果表明:病害在完全侵入组织后,SOD活性呈下降的趋势,在发病组织,POD、CAT活性最高,PAL在病健交界处活性最高。随着发病程度的增加,SOD活性整体呈先上升后下降的趋势,POD活性呈逐渐上升的趋势,CAT活性先下降后上升,PAL活性先上升后下降,PPO总体呈下降趋势。库尔勒香梨抗性相关酶活性呈现不同变化响应Valsa侵染。在Valsa与库尔勒香梨互作系统中,抗性酶可作为抗病性和检测病害指标,为检测库尔勒香梨腐烂病发病程度提供理论依据。
文摘【目的】明确甘肃省苹果树腐烂病菌(Valsa mali)致病力分化情况。【方法】采用平板培养法和离体枝条接种法对Valsa mali两变种的培养性状和致病力进行了研究。【结果】Valsa mali在PDA上有褐色类群和乳白色类群,褐色类群为Valsa mali var.mali菌株,乳白色类群为Valsa mali var.pyri菌株。Valsa mali var.mali不同菌株之间存在致病力分化,菌株PL-1致病力最强,第7天病斑面积为9.54 cm2,菌株TS-5致病力最弱,第7天时病斑面积为4.7 6cm2。Valsa mali var.pyri不同菌株之间也存在致病力分化,菌株WW-1致病力最强,第7天病斑面积为2.72 cm2,菌株WW-2致病力最弱,第7天病斑面积为1.40 cm2。Valsa mali在不同品种间致病力不同,在‘新红星’致病力强,在‘富士’致病力弱。Valsa mali不但侵染苹果树还可以侵染梨树和桃树,Valsa mali var.pyri菌株在梨树上的致病力强于Valsa mali var.mali。【结论】Valsa mali两变种间致病力差异显著,褐色类群菌株Valsa mali var.mali致病力强于乳白色类群菌株Valsa mali var.pyri,Valsa mali两变种内各菌株之间也存在致病力差异显著。
基金Supported by National Natural Science Foundation of China(30571489)Shandong Agricultural University Youth Science and Technology Innovation Fund Projects(23406)~~
文摘[Objective] Inhibition mechanism of the antifungal substances from Chaetomium globosum ND35 against pathogenic fungi of Valsa canker was investigated.[Method] The inhibitory effect of antifungal substances （AFS） produced by endophytic C. globosum ND35 on pathogenic fungi of Valsa canker was studied by means of dual culture,extraction,thin layer chromatography and bioassay of antifungal activity. [Result] The crude extracts of AFS could strongly inhibit Valsa sordida and V. mali. The suppression percentage of mycelial growth of two pathogenic fungi were 66.4% and 72.6%,respectively. The inhibition percentages of conidia germination of two pathogenic fungi were 92.2% and 80.4%,respectively. Separation of thin layer chromatography and bioassay of antifungal activity indicated that the fraction No.2 of AFS played an important role in the process of inhibition on pathogenic fungi,causal agents of Valsa canker. [Conclusion] The antifungal substances from C. globosum ND35 is potential for biological control on Valsa canker.
基金Supported by The 2012 Yeungnam University Research Grant
文摘We report a case of Valsalva retinopathy associated with esophagogastroduodenoscopy (EGD) under propofol sedation. A 43-year-old woman who had no previous history of systemic or ocular disease presented with a complaint of decreased vision in her left eye, which developed one day after EGD under propofol sedation. According to the referring physician, the patient had experienced multiple sustained Valsalva maneuvers during EGD. The fundus examination of the left eye showed a large preretinal hemorrhage surrounded by multiple small retinal hemorrhages in the posterior pole. One month later, fundus examination revealed a floating organized vitreous hemorrhage. The pars plana vitrectomy was performed to treat persistent vitreous hemorrhage. One month after vitrectomy, fundus examination showed normal retina and the patient’s vision recovered to 20/20. Valsalva maneuver can occur during EGD under sedation, and Valsalva retinopathy should be considered as a possible cause. Valsalva retinopathy should be included in the differential diagnosis when a patient complains of blurred vision following EGD.
文摘The papr has reported a new species of Valsa came from the twigs andbranches of Cryptomeria fortunei Hooibrenk ex Otto et Dietr.It was named as Valsa forunea Zhao,Sheng et N.Li sp.nov.when it is in the perfect stage and Cytospora fortunea Zhao,Sheng et N.Lisp.nov.in the imperfect stage.The new species has been described both in Latin and in Chinese,aswell as the differences between the new species and other similarities.The type specimen of the newspecies is deposited in the plant pathology Herbarium of Southwest Forestry College,Kunming(HSFC 15206 Type).
基金supported by the Special Fund for AgroScientific Research in the Public Interest(201203034)the Agriculture Research System of China(CARS-29-14)+1 种基金the National Natural Science Foundation of China(31401831)the Foundation of Discipline Capacity Promotion at AHAU(XKTS 2013010)
文摘Pear Valsa canker is a fungal trunk disease caused by Valsa pyri. Phenolic compounds are ubiquitous in plants and usually contribute to plant resistance against biotic stress. To investigate the association between phenolic compounds and level of resistance to V. pyri, we quantified the contents of individual phenolic compounds in the cortex and phloem of stems from 8 cultivars of Pyrus bretschneideri. Significant variation in the levels of all compounds was found among the cultivars. Correlation analysis revealed an inverse correlation between levels of arbutin and gallic acid with the degree of canker resistance. This suggested that these phenolic compounds are beneficial to V. pyri infection. These data could be valuable for breeding cultivars of P. bretschneideri with greater resistance to V. pyri.
基金supported by grants from the National Natural Science Foundation of China(Grant No.31772115 and U1903206).
文摘Apple valsa canker caused by the Ascomycete fungus Valsa mali is one of the most serious diseases of apple,resulting in huge economic losses in the apple-growing area of China.Previous study found that the pathogen could acidify the infected tissues to make lower ambient pH(from 6.0 to 3.5)for their successfully colonization.The pH signaling transcription factor VmPacC is required for acidification of its environment and for full virulence in V.mali.It is known that the functional cooperation of proteins secreted by V.mali plays pivotal role in its successful colonization of host plants.In this study,we used tandem mass tag(TMT)labeling coupled with LC-MS/MS-based quantitative proteomics to analyze the VmPacC-mediated pH regulation in V.mali,focusing on differentially expressed proteins(DEPs).We identified 222 DEPs specific to VmPacC deletion,and 921 DEPs specific to different pH conditions(pH 6.0 and 3.4).Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analyses indicated that these DEPs were mainly involved in pathways associated with carbon metabolism,biosynthesis of antibiotics,citrate cycle(TCA cycle),glycolysis/gluconeogenesis,glutathione metabolism,ribosomes,and pentose phosphate pathways.Additionally,we identified 119 DEPs that were shared among the VmPacC deletion mutant and different pH conditions,which were mainly related to energy metabolism pathways,providing the energy required for the hyphal growth and responses to environmental stresses.A protein-protein interaction(PPI)network analysis indicated that most of the shared proteins were mapped to an interaction network with a medium confidence score of 0.4.Notably,one uncharacterized protein(KUI69106.1),and two known proteins(heat shock protein 60(KUI73579.1),aspartate aminotransferase(KUI73864.1))located in the core of the network were highly connected(with≥38 directed edges)with the other shared DEPs.Our results suggest that VmPacC participates in the pathogen’s regulation to ambient pH through the regulation of energy metabolism pathways such as the glycolysis/gluconeogenesis pathway and TCA cycle.Finally,we proposed a sophisticated molecular regulatory network to explain pH decrease in V.mali.Our study,by providing insights into V.mali regulating pH,helps to elucidate the mechanisms of host acidification during pathogen infection.
文摘【目的】分析新疆生产建设兵团第一师阿拉尔市库尔勒香梨园梨树腐烂病病原菌的种群分类,通过6对保守基因序列,研究库尔勒香梨腐烂病病原菌序列之间相关性及差异性。【方法】在库尔勒香梨园内采集具有典型症状的腐烂病病样,经科赫氏法则验证获取腐烂病病原菌纯培养。采用CTAB法提取腐烂病病原菌基因组DNA,通过PCR扩增ITS、β-tubulin、EF-1α、ACT、LSU、RBP2基因并测序,利用分子系统学分析不同基因片段的系统发育关系。【结果】在阿拉尔周边混交园内库尔勒香梨腐烂病菌种为Valsa mali var.pyri(V.ambiens、Valsa mali)。种内差异与地理位置有关,国内与国外梨腐烂病分离株差异较明显。EF-1α、ACT、LSU、RBP2在进化过程中更能够体现种间差异,系统发育树分支多,存在种间差异。【结论】新疆生产建设兵团第一师阿拉尔市库尔勒香梨腐烂病病原菌种群分布和种间差异性,库尔勒香梨园的腐烂病病原菌主要为Valsa mali var.pyri、Valsa sordida。新疆南疆绿洲特色果园种植模式,以杨树等为主防护林最为常见,存在着林果树木腐烂病交叉侵染的可能。
基金supported by China Postdoctoral Science Foundation(2021 M690128)the Open Project Program of State Key Laboratory of Crop Stress Biology for Arid Areas(CSBAA2020011)+1 种基金National Natural Science Foundation-Xinjiang Joint Foundation of China(U1903206)Major Scientific and Technological Projects of Shaanxi Province(2020zdzx03-03-01).
文摘Conserved effectors produced by phytopathogens play critical roles in plant-microbe interactions.NIS1-like proteins represent a newly identified family of effectors distributed in multiple fungal species.However,their biological functions in a majority of pathogenic fungi remain largely elusive and require further investigation.In this study,we characterized two NIS1-like proteins VmNIS1 and VmNIS2 from Valsa mali,the causal agent of apple Valsa canker.Both of these two proteins were predicted to be secreted.Using agroinfiltration,we found that VmNIS1 induced intense cell death,whereas VmNIS2 suppressed INF1 elicitin-triggered cell death in Nicotiana benthamiana.Treatment of N.benthamiana with VmNIS1 recombinant protein produced by Escherichia coli activated a series of immune responses and enhanced plant disease resistance against Phytophthora capsici.In contrast,VmNIS2 suppressed plant immune responses and promoted P.capsici infection when transiently expressed in N.benthamiana.Both VmNIS1 and VmNIS2 were shown to be highly induced at late stage of V.mali infection.By individually knocking out of these two genes in V.mali,however,only VmNIS2 was shown to be required for pathogen virulence as well as tolerance to oxidative stress.Notably,we further showed that C-terminal extension of VmNIS1 was essential for plant recognition and VmNIS2 may escape plant detection via sequence truncation.Our data collectively indicate that VmNIS1 and VmNIS2 play distinct roles in plant recognition and pathogen virulence,which provided new insights into the function of NIS1-like proteins in plant-microbe interactions.
