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
Pear is a fruit crop of worldwide importance and cold storage is an integral part of the production and distribution of pears.An uncharacterized fungal disease has been observed on‘Huangguan’pear fruit during cold s...Pear is a fruit crop of worldwide importance and cold storage is an integral part of the production and distribution of pears.An uncharacterized fungal disease has been observed on‘Huangguan’pear fruit during cold storage in Hebei Province.The fungus was consistently isolated from diseased fruit by routine tissue separation method,and shown to be the causal agent according to Koch postulates.Based on its morphology,molecular characteristics,pathogenicity and ITS sequence,the fungus was identified as Rhizoctonia solani.This study recorded postharvest fruit rot caused by Rhizoctonia solani on pear fruit in China.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
分别基于7个烟草靶斑病菌株基因组中ITS-5.8S r DNA序列设计引物和探针;并对引物及探针特异性进行验证;建立检测体系并对接种烟草靶斑病菌的叶片和土壤中的烟草靶斑病菌进行检测。结果表明:所设计的引物及探针对R.solani AG-3具有特异性...分别基于7个烟草靶斑病菌株基因组中ITS-5.8S r DNA序列设计引物和探针;并对引物及探针特异性进行验证;建立检测体系并对接种烟草靶斑病菌的叶片和土壤中的烟草靶斑病菌进行检测。结果表明:所设计的引物及探针对R.solani AG-3具有特异性,检测体系可以检测出烟草叶片及土壤样品中的烟草靶斑病菌。接种烟草叶片的检测表明,接种后6h就可检测到强致病力菌株YC-9,12h后能检测到弱致病力菌株LF-2;获得了烟草靶斑病菌DNA质量的对数与添加菌丝量的对数之间的回归曲线方程,对不同月份土壤样品的测定结果表明烟草靶斑病菌在土壤中呈周年动态变化趋势。展开更多
Rice sheath blight disease （ShB）, caused by Rhizoctonia solani, gives rise to significant grain yield losses. The present study evaluated the efficacy of Integral, the commercial liquid formulation of Bacillus subti...Rice sheath blight disease （ShB）, caused by Rhizoctonia solani, gives rise to significant grain yield losses. The present study evaluated the efficacy of Integral, the commercial liquid formulation of Bacillus subtilis strain MBI 600, against rice ShB and for plant growth promotion. In greenhouse studies, four log concentrations of Integral （from 2.2×10^6 to 2.2×10^9 cfu/mL） were used as seed treatment （ST）. After 25 d, seedlings were dipped （SD） into Integral prior to transplanting. At 30 d after transplanting （DAT）, leaf sheaths were inoculated with immature sclerotia of the pathogen. At 45 DAT, a foliar spray （FS） with Integral was applied to some treatments. The fungicide control was 50% carbendazim at 1.0 g/L, and a nontreated control was also included. Overall, there were 10 treatments, each with five replications. ShB severity was rated at 52 DAT, and seedling height and number of tillers per plant were rated at 60 DAT. In 2009, two field trials evaluated Integral at 2.2×10^8 and 2.2×10^9 cfu/mL. Integral was applied as ST, and seedlings were produced in a nursery bed. After 32 d, seedlings were treated with Integral as SD and transplanted into 10 m^2 blocks. Foliar sprays were given at 45 and 60 DAT. There were seven treatments, each with eight replications arranged as a factorial randomized complete block design. At 20 DAT, the plots were broadcast inoculated with R. solani produced on rice grains. Seedling height before transplanting, ShB severity at 90 DAT, and grain yield at harvest were recorded. Integral at 2.2×10^9 cfu/mL provided significant increase of seedling heights over other treatments under greenhouse conditions. The Integral treatments of ST ＋ SD ＋ FS at 2.2×10^9 cfu/mL significantly suppressed ShB over other treatments. In field studies, Integral provided significant increase of seedling height in nursery, and number of tillers per plant, compared with the control. ShB severity was significantly suppressed with higher concentrations of Integral compared to lower concentrations. Grain yield were the highest at an Integral concentration of 2.2×10^9 cfu/mL. Overall, Integral significantly reduced ShB severity, enhanced seedling growth, number of tillers per plant and grain yield as ST ＋ SD ＋ FS at the concentration of 2.2×10^9 cfu/mL under the conditions evaluated.展开更多
The inhibition of lanthanum (La) to mycelial growth and three disease-related enzymes of Rhizoctonia solani were studied. The results showed that lanthanum inhibits the growth of Rhizoctonia solani strongly. EC_(50) a...The inhibition of lanthanum (La) to mycelial growth and three disease-related enzymes of Rhizoctonia solani were studied. The results showed that lanthanum inhibits the growth of Rhizoctonia solani strongly. EC_(50) and EC_(95) of La were 171.9 and 667.7 mg·L^(-1) measured in solid culture media respectively, while 111.4 and 500.7 mg·L^(-1) measured in liquid culture media respectively. Lanthanum also has activating effects on disease-related enzymes of the fungus such as pectinase, protease and cellulase. However, the quantity or the activity of the total enzymes decreases significantly because of the strong blockage of mycelial growth when the La_2O_3 concentration is over 50 mg·L^(-1), and the virulence of pathogen decreases as well.展开更多
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 National Key R&D Program of China(Grant No.2016YFD0400903–06)the earmarked fund for China Agriculture Research System(Grant No.CARS-29–19)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences。
文摘Pear is a fruit crop of worldwide importance and cold storage is an integral part of the production and distribution of pears.An uncharacterized fungal disease has been observed on‘Huangguan’pear fruit during cold storage in Hebei Province.The fungus was consistently isolated from diseased fruit by routine tissue separation method,and shown to be the causal agent according to Koch postulates.Based on its morphology,molecular characteristics,pathogenicity and ITS sequence,the fungus was identified as Rhizoctonia solani.This study recorded postharvest fruit rot caused by Rhizoctonia solani on pear fruit in China.
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.
文摘分别基于7个烟草靶斑病菌株基因组中ITS-5.8S r DNA序列设计引物和探针;并对引物及探针特异性进行验证;建立检测体系并对接种烟草靶斑病菌的叶片和土壤中的烟草靶斑病菌进行检测。结果表明:所设计的引物及探针对R.solani AG-3具有特异性,检测体系可以检测出烟草叶片及土壤样品中的烟草靶斑病菌。接种烟草叶片的检测表明,接种后6h就可检测到强致病力菌株YC-9,12h后能检测到弱致病力菌株LF-2;获得了烟草靶斑病菌DNA质量的对数与添加菌丝量的对数之间的回归曲线方程,对不同月份土壤样品的测定结果表明烟草靶斑病菌在土壤中呈周年动态变化趋势。
文摘Rice sheath blight disease （ShB）, caused by Rhizoctonia solani, gives rise to significant grain yield losses. The present study evaluated the efficacy of Integral, the commercial liquid formulation of Bacillus subtilis strain MBI 600, against rice ShB and for plant growth promotion. In greenhouse studies, four log concentrations of Integral （from 2.2×10^6 to 2.2×10^9 cfu/mL） were used as seed treatment （ST）. After 25 d, seedlings were dipped （SD） into Integral prior to transplanting. At 30 d after transplanting （DAT）, leaf sheaths were inoculated with immature sclerotia of the pathogen. At 45 DAT, a foliar spray （FS） with Integral was applied to some treatments. The fungicide control was 50% carbendazim at 1.0 g/L, and a nontreated control was also included. Overall, there were 10 treatments, each with five replications. ShB severity was rated at 52 DAT, and seedling height and number of tillers per plant were rated at 60 DAT. In 2009, two field trials evaluated Integral at 2.2×10^8 and 2.2×10^9 cfu/mL. Integral was applied as ST, and seedlings were produced in a nursery bed. After 32 d, seedlings were treated with Integral as SD and transplanted into 10 m^2 blocks. Foliar sprays were given at 45 and 60 DAT. There were seven treatments, each with eight replications arranged as a factorial randomized complete block design. At 20 DAT, the plots were broadcast inoculated with R. solani produced on rice grains. Seedling height before transplanting, ShB severity at 90 DAT, and grain yield at harvest were recorded. Integral at 2.2×10^9 cfu/mL provided significant increase of seedling heights over other treatments under greenhouse conditions. The Integral treatments of ST ＋ SD ＋ FS at 2.2×10^9 cfu/mL significantly suppressed ShB over other treatments. In field studies, Integral provided significant increase of seedling height in nursery, and number of tillers per plant, compared with the control. ShB severity was significantly suppressed with higher concentrations of Integral compared to lower concentrations. Grain yield were the highest at an Integral concentration of 2.2×10^9 cfu/mL. Overall, Integral significantly reduced ShB severity, enhanced seedling growth, number of tillers per plant and grain yield as ST ＋ SD ＋ FS at the concentration of 2.2×10^9 cfu/mL under the conditions evaluated.
文摘The inhibition of lanthanum (La) to mycelial growth and three disease-related enzymes of Rhizoctonia solani were studied. The results showed that lanthanum inhibits the growth of Rhizoctonia solani strongly. EC_(50) and EC_(95) of La were 171.9 and 667.7 mg·L^(-1) measured in solid culture media respectively, while 111.4 and 500.7 mg·L^(-1) measured in liquid culture media respectively. Lanthanum also has activating effects on disease-related enzymes of the fungus such as pectinase, protease and cellulase. However, the quantity or the activity of the total enzymes decreases significantly because of the strong blockage of mycelial growth when the La_2O_3 concentration is over 50 mg·L^(-1), and the virulence of pathogen decreases as well.
