Apple replant disease is a complex soil syndrome that occurs when the same fields are repeatedly utilized for apple orchard cultivation.It can be caused by various pathogens,and Fusarium solani is the main pathogen.Fu...Apple replant disease is a complex soil syndrome that occurs when the same fields are repeatedly utilized for apple orchard cultivation.It can be caused by various pathogens,and Fusarium solani is the main pathogen.Fusarium solani disrupts the structure and function of the orchard soil ecosystem and inhibits the growth and development of apple trees,significantly impacting the quality and yield of apples.In this study,we conducted a transcriptome comparison between uninoculated apple saplings and those inoculated with F:solani.The differentially expressed genes were mainly enriched in processes such as response to symbiotic fungus.Plant defensins are antimicrobial peptides,but their roles during F.solani infection remain unclear.We performed a genome-wide identification of apple defensin genes and identified 25 genes with the conserved motif of eight cysteine residues.In wildtype apple rootstock inoculated with F.solani,the root surface cells experienced severe damage,and showed significant differences in the total root length,total root projection area,root tips,root forks,and total root surface area compared to the control group.qRT-PCR analysis revealed that MdDEF3 and MdDEF25 were triggered in response to F.solani infection in apples.Subcellular localization showed specific expression of the MdDEF3-YFP and MdDEF25-YFP proteins on the cell membrane.Overexpressing theMdDEF25-YFP fusiongene enhanced resistance against F.solani in apple,providing a new strategy for the future prevention and biological control of apple replantdisease.展开更多
In recent years,the prevalence of rice sheath blight caused by Rhizoctonia solani has significantly increased in Heilongjiang Province.Chemical control has become the primary control method.To cope with this,a novel m...In recent years,the prevalence of rice sheath blight caused by Rhizoctonia solani has significantly increased in Heilongjiang Province.Chemical control has become the primary control method.To cope with this,a novel mycelium growth rate method was employed to assess the toxicity of 13 fungicides,including a combination of 45%prochloraz and 125 g·mL^(-1)epoxiconazole,against R.solani.Additionally,the resistance of 99 R.solani strains to thifluzamide across various regions was also evaluated.The findings indicated that 75%trifloxystrobin-tebuconazole exhibited the most effective inhibitory effect,with an effective inhibitory medium concentration(EC50)value of 0.0101μg·mL^(-1).The EC50 values for 20%prothioconazole,125 g·mL^(-1)epoxiconazole,24%thifluzamide,and 50%hexaconazole were all less than 10μg·mL^(-1),indicating a better inhibitory effect on R.solani.The strongest synergistic effect was noted in the mixture of prochloraz and epoxiconazole at a 1:2 ratio,resulting in an EC50 value of 2.9917μg·mL^(-1),and a co-toxicity coefficient of 213.38.Among the 34 strains from Harbin City,the average EC50 value was 196.9341μg·mL^(-1)indicating the highest susceptiblility to thifluzamide.Conversely,15 strains from Shuangyashan City exhibited an average EC50 value of 364.7323μg·mL^(-1),reflecting the lowest sensitivity to thifluzamide.The sensitivity baseline EC50 value for R.solani was 253.8854μg·mL^(-1),with an overall resistance level between 0.1567 and 3.3292,indicating that the resistance level of R.solani in Heilongjiang Province remained low.Therefore,R.solani was still sensitive to thifluzamide in most areas of Heilongjiang Province,but there was a certain risk of resistance in Qitaihe City,which needed to be continuously monitored.At the same time,this study might provide a theoretical foundation for enhancing the prevention and management of the rice sheath blight.展开更多
Rice sheath blight, caused by Rhizoctonia solani AG1-IA, is a major disease in rice-growing areas worldwide. Effectors of phytopathogenic fungi play important roles during the infection process of fungal pathogens ont...Rice sheath blight, caused by Rhizoctonia solani AG1-IA, is a major disease in rice-growing areas worldwide. Effectors of phytopathogenic fungi play important roles during the infection process of fungal pathogens onto their host plants. However, the molecular mechanisms by which R. solani effectors regulate rice immunity are not well understood. Through prediction, 78 candidate effector molecules were identified. Using the tobacco rattle virus-host induced gene silencing(TRV-HIGS) system, 45 RNAi constructs of effector genes were infiltrated into Nicotiana benthamiana leaves. The results revealed that eight of these constructs resulted in a significant reduction in necrosis caused by infection with the AG1-IA strain GD-118. Additionally, stable rice transformants carrying the double-stranded RNA construct for one of the effector genes, AGLIP1, were generated to further verify the function of this gene. The suppression of the AGLIP1 gene increased the resistance of both N. benthamiana and rice against GD-118, and also affected the growth rate of GD-118, indicating that AGLIP1 is a key pathogenic factor. Small RNA sequencing showed that the HIGS vectors were processed into si RNAs within the plants and then translocated to the fungi, leading to the silencing of the target genes. As a result, AGLIP1 might be an excellent candidate for HIGS, thereby enhancing crop resistance against the pathogen and contributing to the control of R. solani infection.展开更多
Apple replant disease(ARD)has led to severe yield and quality reduction in the apple industry.Fusarium solani(F.solani)has been identified as one of the main microbial pathogens responsible for ARD.Auxin(indole-3-acet...Apple replant disease(ARD)has led to severe yield and quality reduction in the apple industry.Fusarium solani(F.solani)has been identified as one of the main microbial pathogens responsible for ARD.Auxin(indole-3-acetic acid,IAA),an endogenous hormone in plants,is involved in almost all plant growth and development processes and plays a role in plant immunity against pathogens.Gretchen Hagen3(GH3)is one of the early/primary auxin response genes.The aim of this study was to evaluate the function of MdGH3-2 and MdGH3-12 in the defense response of F.solani by treating MdGH3-2/12 RNAi plants with F.solani.The results show that under F.solani infection,RNAi of MdGH3-2/12 inhibited plant biomass accumulation and exacerbated root damage.After inoculation with F.solani,MdGH3-2/12 RNAi inhibited the biosynthesis of acid-amido synthetase.This led to the inhibition of free IAA combining with amino acids,resulting in excessive free IAA accumulation.This excessive free IAA altered plant tissue structure,accelerated fungal hyphal invasion,reduced the activity of antioxidant enzymes(SOD,POD and CAT),increased the reactive oxygen species(ROS)level,and reduced total chlorophyll content and photosynthetic ability,while regulating the expression of PR-related genes including PR1,PR4,PR5 and PR8.It also changed the contents of plant hormones and amino acids,and ultimately reduced the resistance to F.solani.In conclusion,these results demonstrate that MdGH3-2 and MdGH3-12 play an important role in apple tolerance to F.solani and ARD.展开更多
[Objective] The aim was to clone the up-regulated expression gene of rice induced by Rhizoctonia solani.[Method] The EST fragment K16 obtained by suppression subtraction hybridization（SSH）was cloned and confirmed by...[Objective] The aim was to clone the up-regulated expression gene of rice induced by Rhizoctonia solani.[Method] The EST fragment K16 obtained by suppression subtraction hybridization（SSH）was cloned and confirmed by reverse transcription-polymerase chain reaction（RT-PCR）.Then RT-PCR products were cloned into the PMD18-T vector and sequenced.The functions of the sequence were predicted with bioinformatics method.[Result] A 1 079 bp gene was obtained.The gene encoded a protein with 236 amino acids.The protein contains many motif sites,two WRKY domains and a C2H2 zinc finger motif.The gene showed high identities with WRKY8,WRKY24 and WRKY30 gene of rice.[Conclusion] The up-regulated expression gene induced by R.solani was representative WRKY family gene.The gene could play an important role on rice sheath blight resistance.展开更多
The aim of this study was to investigate the in vitro antifungal effects of antifungal monomer component DZP8 isolated from Streptomyces 702 on the mycelium growth, sclerotium formation and germination of Rhizoctonia ...The aim of this study was to investigate the in vitro antifungal effects of antifungal monomer component DZP8 isolated from Streptomyces 702 on the mycelium growth, sclerotium formation and germination of Rhizoctonia solani and on the mycelium growth, conidial formation, germination, appressorium formation of Magnaporthe grisea. The results showed that the antifungal monomer component DZP8 has strong antifungal effect on both the R. solani and M. grisea. The EC50 and EC90 of DZP8 were 1.81 and 3.35 μg/ml on Ft. solani respectively, and 37.01 and 136.21 μg/ml on M. grisea respectively. Under the treatment of 48.01 μg/ml DZP8, the sclerotium formation rate of R. solani was just 39.21%, the formation time delayed by 216 h and the dry weight decreased by 81.37% in comparison the con- trol; and 33.51 μg/ml DZP8 significantly inhibited the sclerotium germination. In the presence of 160.08 μg/ml DZP8, the sporulation of M. grisea was just 9.29% of control sample; 20.14 μg/ml DZP8 inhibited the conidial germination suppression rate by 95.16%, and the appressorium formation by 100%.展开更多
[Objective] The study was to provide the theoretical guidance for the control of rice sheath blight using the mixture of endophytic Bacillus megaterium strain B196 and fungicide. [Method] The toxicity of the mixture o...[Objective] The study was to provide the theoretical guidance for the control of rice sheath blight using the mixture of endophytic Bacillus megaterium strain B196 and fungicide. [Method] The toxicity of the mixture of endophytic strain B196 and jinggangmycin against Rhizoctonia solani was determined by inhibition rate method,and the effect of the mixture on R. solani was also tested. [Result] The mixture of B196 strain and 5% Jinggangmycin water agent with the mass ratio of 1∶68.47 had synergy effect,co-toxicity coefficient （CTC） was 209,the control effect of 200 μg/ml mixture against R. solani was 75.57% in field,which was 17.68% higher than that of single endogenous bacillus strain B196 treatments. [Conclusion] The mixture of endophytic strain B196 and Jinggangmycin had good control effect against R. solani.展开更多
[Objective] The aim of the study was to provide the basis for researching the pathogenicity mechanism of Rhizoctonia solani.[Method] The extracellular protease was purified after ammonium sulfate precipitation through...[Objective] The aim of the study was to provide the basis for researching the pathogenicity mechanism of Rhizoctonia solani.[Method] The extracellular protease was purified after ammonium sulfate precipitation through DEAE-Sephrase Fast Flow,Phenyl-Sepharose Fast Flow and Sephadex G-75 ch rom atography. [Result] The extracellular protease with molecular weight of 49.5 ku was obtained from fermentation liquid of R. solani. The optimal temperature and pH value for its activity were 6.4 and 30 ℃ respectively. Zn^2＋,Fe^3＋,Cu^2＋had inhibition on enzyme activity,while Mg^2＋,Mn^2＋had no effect on enzyme activity,and Ca^2＋ could activate enzymatic activity in low concentration.[Conclusion] R. solani could secrete extracellular protease,but the relationship between the extracellular protease and the pathogenicity of R. solani required further study.展开更多
[Objective] The antifungal activity of the extracts from,Atractylodes macracephal Koidz and Pulsatilla chinensis Bunge Regel,against Botrytis cinerea and Alternaria solani were studied under the condition of laborator...[Objective] The antifungal activity of the extracts from,Atractylodes macracephal Koidz and Pulsatilla chinensis Bunge Regel,against Botrytis cinerea and Alternaria solani were studied under the condition of laboratory,in order to develop and utilize these two plants.[Method] The mycelium growth rate test was applied to measure the antifungal activities of extracts against fungi.[Result] the extracts of all the two plants showed strong antifungal activity against the target pathogenic fungi,especially the antifungal activity of the extract from Pulsatilla chinensis Bunge Regel was stronger and more stable.The inhibition rate to the mycelium growth of Botrytis cinerea was 80.25%.At the same concentration,the extract from Atractylodes macracephal Koidz showed little inhibition to Botrytis cinerea and Alternaria solani.The petrolelum ether extract of Atractylodes macracephal Koidz showed stronger antifungal activities and the EC50 was 5.31 mg/ml,and the n-butanol extract of Pulsatilla chinensis Bunge Regel showed stronger antifungal activities and the EC50 was 2.93 mg/ml.[Conclusion] The extracts from Pulsatilla chinensis Bunge Regel showed the stronger antifungal activity against Botrytis cinerea and Alternaria solani.展开更多
基金supported by a project grant from the Key Research and Development and Promotion Projects of Henan Province,China(212102110113)the Special Fund for Henan Agriculture Research System,China(HARS-22-09-Z2).
文摘Apple replant disease is a complex soil syndrome that occurs when the same fields are repeatedly utilized for apple orchard cultivation.It can be caused by various pathogens,and Fusarium solani is the main pathogen.Fusarium solani disrupts the structure and function of the orchard soil ecosystem and inhibits the growth and development of apple trees,significantly impacting the quality and yield of apples.In this study,we conducted a transcriptome comparison between uninoculated apple saplings and those inoculated with F:solani.The differentially expressed genes were mainly enriched in processes such as response to symbiotic fungus.Plant defensins are antimicrobial peptides,but their roles during F.solani infection remain unclear.We performed a genome-wide identification of apple defensin genes and identified 25 genes with the conserved motif of eight cysteine residues.In wildtype apple rootstock inoculated with F.solani,the root surface cells experienced severe damage,and showed significant differences in the total root length,total root projection area,root tips,root forks,and total root surface area compared to the control group.qRT-PCR analysis revealed that MdDEF3 and MdDEF25 were triggered in response to F.solani infection in apples.Subcellular localization showed specific expression of the MdDEF3-YFP and MdDEF25-YFP proteins on the cell membrane.Overexpressing theMdDEF25-YFP fusiongene enhanced resistance against F.solani in apple,providing a new strategy for the future prevention and biological control of apple replantdisease.
基金Supported by the Green Plant Protection Project(213010801)the Heilongjiang Province Key Research and Development Plan Project(20232X02 B0502)the Natural Science Foundation of Heilongjiang Province(LH2022C022)。
文摘In recent years,the prevalence of rice sheath blight caused by Rhizoctonia solani has significantly increased in Heilongjiang Province.Chemical control has become the primary control method.To cope with this,a novel mycelium growth rate method was employed to assess the toxicity of 13 fungicides,including a combination of 45%prochloraz and 125 g·mL^(-1)epoxiconazole,against R.solani.Additionally,the resistance of 99 R.solani strains to thifluzamide across various regions was also evaluated.The findings indicated that 75%trifloxystrobin-tebuconazole exhibited the most effective inhibitory effect,with an effective inhibitory medium concentration(EC50)value of 0.0101μg·mL^(-1).The EC50 values for 20%prothioconazole,125 g·mL^(-1)epoxiconazole,24%thifluzamide,and 50%hexaconazole were all less than 10μg·mL^(-1),indicating a better inhibitory effect on R.solani.The strongest synergistic effect was noted in the mixture of prochloraz and epoxiconazole at a 1:2 ratio,resulting in an EC50 value of 2.9917μg·mL^(-1),and a co-toxicity coefficient of 213.38.Among the 34 strains from Harbin City,the average EC50 value was 196.9341μg·mL^(-1)indicating the highest susceptiblility to thifluzamide.Conversely,15 strains from Shuangyashan City exhibited an average EC50 value of 364.7323μg·mL^(-1),reflecting the lowest sensitivity to thifluzamide.The sensitivity baseline EC50 value for R.solani was 253.8854μg·mL^(-1),with an overall resistance level between 0.1567 and 3.3292,indicating that the resistance level of R.solani in Heilongjiang Province remained low.Therefore,R.solani was still sensitive to thifluzamide in most areas of Heilongjiang Province,but there was a certain risk of resistance in Qitaihe City,which needed to be continuously monitored.At the same time,this study might provide a theoretical foundation for enhancing the prevention and management of the rice sheath blight.
基金supported by the Henan Province Science and Technology Research Project, China (Grant No. 242102110232)the National Natural Science Foundation of China (Grant No. 31801677)the Major Program of Guangdong Basic and Applied Basic Research, China (Grant No. 2019B030302006)。
文摘Rice sheath blight, caused by Rhizoctonia solani AG1-IA, is a major disease in rice-growing areas worldwide. Effectors of phytopathogenic fungi play important roles during the infection process of fungal pathogens onto their host plants. However, the molecular mechanisms by which R. solani effectors regulate rice immunity are not well understood. Through prediction, 78 candidate effector molecules were identified. Using the tobacco rattle virus-host induced gene silencing(TRV-HIGS) system, 45 RNAi constructs of effector genes were infiltrated into Nicotiana benthamiana leaves. The results revealed that eight of these constructs resulted in a significant reduction in necrosis caused by infection with the AG1-IA strain GD-118. Additionally, stable rice transformants carrying the double-stranded RNA construct for one of the effector genes, AGLIP1, were generated to further verify the function of this gene. The suppression of the AGLIP1 gene increased the resistance of both N. benthamiana and rice against GD-118, and also affected the growth rate of GD-118, indicating that AGLIP1 is a key pathogenic factor. Small RNA sequencing showed that the HIGS vectors were processed into si RNAs within the plants and then translocated to the fungi, leading to the silencing of the target genes. As a result, AGLIP1 might be an excellent candidate for HIGS, thereby enhancing crop resistance against the pathogen and contributing to the control of R. solani infection.
基金supported by the Earmarked Fund for the China Agriculture Research System(CARS-27)the Key Science and Technology Special Projects of Shaanxi Province,China(2020zdzx03-01-02).
文摘Apple replant disease(ARD)has led to severe yield and quality reduction in the apple industry.Fusarium solani(F.solani)has been identified as one of the main microbial pathogens responsible for ARD.Auxin(indole-3-acetic acid,IAA),an endogenous hormone in plants,is involved in almost all plant growth and development processes and plays a role in plant immunity against pathogens.Gretchen Hagen3(GH3)is one of the early/primary auxin response genes.The aim of this study was to evaluate the function of MdGH3-2 and MdGH3-12 in the defense response of F.solani by treating MdGH3-2/12 RNAi plants with F.solani.The results show that under F.solani infection,RNAi of MdGH3-2/12 inhibited plant biomass accumulation and exacerbated root damage.After inoculation with F.solani,MdGH3-2/12 RNAi inhibited the biosynthesis of acid-amido synthetase.This led to the inhibition of free IAA combining with amino acids,resulting in excessive free IAA accumulation.This excessive free IAA altered plant tissue structure,accelerated fungal hyphal invasion,reduced the activity of antioxidant enzymes(SOD,POD and CAT),increased the reactive oxygen species(ROS)level,and reduced total chlorophyll content and photosynthetic ability,while regulating the expression of PR-related genes including PR1,PR4,PR5 and PR8.It also changed the contents of plant hormones and amino acids,and ultimately reduced the resistance to F.solani.In conclusion,these results demonstrate that MdGH3-2 and MdGH3-12 play an important role in apple tolerance to F.solani and ARD.
基金Supported by Young Academic Backbone Support Program of Heilongjiang Province(1152G022)~~
文摘[Objective] The aim was to clone the up-regulated expression gene of rice induced by Rhizoctonia solani.[Method] The EST fragment K16 obtained by suppression subtraction hybridization（SSH）was cloned and confirmed by reverse transcription-polymerase chain reaction（RT-PCR）.Then RT-PCR products were cloned into the PMD18-T vector and sequenced.The functions of the sequence were predicted with bioinformatics method.[Result] A 1 079 bp gene was obtained.The gene encoded a protein with 236 amino acids.The protein contains many motif sites,two WRKY domains and a C2H2 zinc finger motif.The gene showed high identities with WRKY8,WRKY24 and WRKY30 gene of rice.[Conclusion] The up-regulated expression gene induced by R.solani was representative WRKY family gene.The gene could play an important role on rice sheath blight resistance.
基金Supported by National Natural Science Foundation of China(31071724)Natural Science Foundation of Jiangxi Province(2010GZN0037)~~
文摘The aim of this study was to investigate the in vitro antifungal effects of antifungal monomer component DZP8 isolated from Streptomyces 702 on the mycelium growth, sclerotium formation and germination of Rhizoctonia solani and on the mycelium growth, conidial formation, germination, appressorium formation of Magnaporthe grisea. The results showed that the antifungal monomer component DZP8 has strong antifungal effect on both the R. solani and M. grisea. The EC50 and EC90 of DZP8 were 1.81 and 3.35 μg/ml on Ft. solani respectively, and 37.01 and 136.21 μg/ml on M. grisea respectively. Under the treatment of 48.01 μg/ml DZP8, the sclerotium formation rate of R. solani was just 39.21%, the formation time delayed by 216 h and the dry weight decreased by 81.37% in comparison the con- trol; and 33.51 μg/ml DZP8 significantly inhibited the sclerotium germination. In the presence of 160.08 μg/ml DZP8, the sporulation of M. grisea was just 9.29% of control sample; 20.14 μg/ml DZP8 inhibited the conidial germination suppression rate by 95.16%, and the appressorium formation by 100%.
基金Supported by Guangxi Natural Science Foundation(GSN0728012)Graduate Education Innovation Project in Guangxi University(2008105930904M023)~~
文摘[Objective] The study was to provide the theoretical guidance for the control of rice sheath blight using the mixture of endophytic Bacillus megaterium strain B196 and fungicide. [Method] The toxicity of the mixture of endophytic strain B196 and jinggangmycin against Rhizoctonia solani was determined by inhibition rate method,and the effect of the mixture on R. solani was also tested. [Result] The mixture of B196 strain and 5% Jinggangmycin water agent with the mass ratio of 1∶68.47 had synergy effect,co-toxicity coefficient （CTC） was 209,the control effect of 200 μg/ml mixture against R. solani was 75.57% in field,which was 17.68% higher than that of single endogenous bacillus strain B196 treatments. [Conclusion] The mixture of endophytic strain B196 and Jinggangmycin had good control effect against R. solani.
基金Supported by High Academic Youth Backbone Support Projects in Heilongjiang Province(1152G022)Scientific Research Foundation for Doctor in Heilongjiang August First Land Reclamation University~~
文摘[Objective] The aim of the study was to provide the basis for researching the pathogenicity mechanism of Rhizoctonia solani.[Method] The extracellular protease was purified after ammonium sulfate precipitation through DEAE-Sephrase Fast Flow,Phenyl-Sepharose Fast Flow and Sephadex G-75 ch rom atography. [Result] The extracellular protease with molecular weight of 49.5 ku was obtained from fermentation liquid of R. solani. The optimal temperature and pH value for its activity were 6.4 and 30 ℃ respectively. Zn^2＋,Fe^3＋,Cu^2＋had inhibition on enzyme activity,while Mg^2＋,Mn^2＋had no effect on enzyme activity,and Ca^2＋ could activate enzymatic activity in low concentration.[Conclusion] R. solani could secrete extracellular protease,but the relationship between the extracellular protease and the pathogenicity of R. solani required further study.
基金Supported by Talent Introduction Grantin Anhui Science and Technology University(ZRC2007102)Outstanding Young Talets Project of Anhui Provincal Universities(2009SQRZ11)~~
文摘[Objective] The antifungal activity of the extracts from,Atractylodes macracephal Koidz and Pulsatilla chinensis Bunge Regel,against Botrytis cinerea and Alternaria solani were studied under the condition of laboratory,in order to develop and utilize these two plants.[Method] The mycelium growth rate test was applied to measure the antifungal activities of extracts against fungi.[Result] the extracts of all the two plants showed strong antifungal activity against the target pathogenic fungi,especially the antifungal activity of the extract from Pulsatilla chinensis Bunge Regel was stronger and more stable.The inhibition rate to the mycelium growth of Botrytis cinerea was 80.25%.At the same concentration,the extract from Atractylodes macracephal Koidz showed little inhibition to Botrytis cinerea and Alternaria solani.The petrolelum ether extract of Atractylodes macracephal Koidz showed stronger antifungal activities and the EC50 was 5.31 mg/ml,and the n-butanol extract of Pulsatilla chinensis Bunge Regel showed stronger antifungal activities and the EC50 was 2.93 mg/ml.[Conclusion] The extracts from Pulsatilla chinensis Bunge Regel showed the stronger antifungal activity against Botrytis cinerea and Alternaria solani.
