[Objective]The research aimed to investigate the biological diversity of nematode-trapping fungi in the sediment of Erhai Lake.[Method]616 pieces of sediments were collected from Erhai Lake.The traditional classificat...[Objective]The research aimed to investigate the biological diversity of nematode-trapping fungi in the sediment of Erhai Lake.[Method]616 pieces of sediments were collected from Erhai Lake.The traditional classification and identification methods were used to isolate,purify and identify.[Result]3 genera and 22 species of nematode-trapping fungi were isolated.Arthrobotrys oligospora,A.musiformis and Dactylella leptospora were the dominant species,and their detection rates were 28.05%,16.04% and 8.92% respectively.By analyzing the diversity of nematode-trapping fungi in four seasons,it was found that the biological diversity was richer in summer,spring and autumn,and the diversity indexes were 2.59,2.47 and 2.34 respectively.The diversity index in winter was 1.48 and was lower.Species forming the adhesive nets were predominant;positive rate was 41.00%.[Conclusion]The rich nematode-trapping fungi resource existed in Erhai Lake,and its biological diversity had the seasonal variation characteristic.The nematode-trapping fungi which formed the viscous net were the dominant species in Erhai Lake.展开更多
Monacrosporium ellipsosporum, a nematode-trapping fungus, was isolated by baiting with sclerotiaof Sclerotinia sclerotiorum in soil from a tobacco field in Yuxi, Yunnan Province. Colonizationfrequency of the scleroti...Monacrosporium ellipsosporum, a nematode-trapping fungus, was isolated by baiting with sclerotiaof Sclerotinia sclerotiorum in soil from a tobacco field in Yuxi, Yunnan Province. Colonizationfrequency of the sclerotia by the fungus was 18% in natural soil. Reinoculation tests byplacing surface-sterilized sclerotia on fungal cultures for two weeks and then surface-sterilized again led to 32% sclerotia be infected. Dual culture tests in PDA plates did notgive rise to a suppression zone between the colonies of M. ellipsosporum and its counterpartfungi S. sclerotiorum and Rhizoctonia solani, suggesting there was little or no nutritionalcompetition and absent of antifungal compounds. However, M. ellipsosporum could grow overabsent of S. sclerotiorum and R. solani, and significantly inhibited their growth on agarplates. Scanning electron and light microscopic observations showed that hyphae of M. ellipsosporumgrew along and appressed on hypha of S. sclerotiorum and coiled around hyphae of R. solani.Assays of cell wall-degrading enzymes showed that M. ellipsosporum grew well in chitin agarmedia, with clear transparent hydrolysis zones. Activities of total chitinase, exo-chitinase,β-1, 3-glucanase and protease were 140.2±11.9, 82.9±4.1, 111.2±7.6 and 76.1±4.3 U respect-ively, after incubation for 4 days at 30 ℃ in liquid media containing ground sclerotia of S.sclerotiorum as sole nutrient source. These enzymes might be important in the mycoparasiticactivity of M. ellipsosporum.展开更多
Pine wilt disease,caused by Bursaphelenchus xylophilus and Bursaphelenchus mucnatus,is a serious quarantined disease.Arboreal nematode-trapping fungi of P inus spp.are effective predators on nematodes and have strong ...Pine wilt disease,caused by Bursaphelenchus xylophilus and Bursaphelenchus mucnatus,is a serious quarantined disease.Arboreal nematode-trapping fungi of P inus spp.are effective predators on nematodes and have strong host adaptability.The development of these fungal resources may be an effective way to control pine wood nematodes.We collected 515 samples of pine wilt disease from the areas of Ninghai City(Zhejiang province),Shuangbai County(Yunnan province),and Daxing'anling(Heilongjiang province),China.Through isolation,culture and identification,6 species of nematode-trapping fungi(A rthrobotrys cladodesr,A.oligospora,A.musiformis,A.dendroides,Dactylellina ellipsospora,Monacrosporium thaumasium)were identified for predation against B.xylophilus,and 9 species(Arthrobotrys dactyloides,A.cladodes r A.oligospora A.dendroides,Dactylellina ellipsospora,Dactylella asthenopaga,D.leptospora,Arthrobotrys superba,Monacrosporium drechseri)were identified for predation against B.mucnatus.This study provides information in the classification of arboreal predator nematodes and provides an important basis for future biological control of pine wood nematodes.展开更多
In order to apply the nematode-trapping fungi biocontrol of animal parasitic nematode, prove that mutagenesis strain of the Arthrobotrys Oligospora N spores can be passed to experimental animal digestive tract. Ion be...In order to apply the nematode-trapping fungi biocontrol of animal parasitic nematode, prove that mutagenesis strain of the Arthrobotrys Oligospora N spores can be passed to experimental animal digestive tract. Ion beam injected into the spores of Arthrobotrys oligospora of nematode-trapping.Experimental animals are hurled Arthrobotrys Oligospora N spores, collect the feces of experimental animals, test fungal germination, growth, reproduction and predation livestock parasitic nematode larvae in laboratory. Mutant strains of Arthrobotrys Oligospora N can be through the digestive tract in experimental animals. Such biotechnology could be explored for improving the effectiveness of the use of funsal infections to control livestock parasitic nematodes.展开更多
The lifestyle transition of fungi,defined as switching from taking organic material as nutrients to pathogens,is a fundamental phenomenon in nature.However,the mechanisms of such transition remain largely unknown.Here...The lifestyle transition of fungi,defined as switching from taking organic material as nutrients to pathogens,is a fundamental phenomenon in nature.However,the mechanisms of such transition remain largely unknown.Here we show microRNA-like RNAs(milRNAs)play a key role in fungal lifestyle transition for the first time.We identified milRNAs by small RNA sequencing in Arthrobotrys oligospora,a known nematode-trapping fungus.Among them,7 highly expressed milRNAs were confirmed by northern-blot analysis.Knocking out two milRNAs significantly decreased A.oligospora’s ability to switch lifestyles.We further identified that two of these milRNAs were associated with argonaute protein QDE-2 by RNA-immunoprecipitation(RIP)analysis.Three of the predicted target genes of milRNAs were found in immunoprecipitation(IP)products of QDE-2.Disruption of argonaute gene qde-2 also led to serious defects in lifestyle transition.Interestingly,knocking out individual milRNAs or qde-2 lead to diverse responses under different conditions,and qde-2 itself may be targeted by the milRNAs.Collectively,it indicates the lifestyle transition of fungi is mediated by milRNAs through RNA interference(RNAi)machinery,revealing the wide existence of miRNAs in fungi kingdom and providing new insights into understanding the adaptation of fungi from scavengers to predators and the mechanisms underlying fungal infections.展开更多
基金Supported by National Natural Science Foundation of China(30960017)Fund Project of Yunnan Education Department(09Y0360)Start Fund ofDali University(KY421140)~~
文摘[Objective]The research aimed to investigate the biological diversity of nematode-trapping fungi in the sediment of Erhai Lake.[Method]616 pieces of sediments were collected from Erhai Lake.The traditional classification and identification methods were used to isolate,purify and identify.[Result]3 genera and 22 species of nematode-trapping fungi were isolated.Arthrobotrys oligospora,A.musiformis and Dactylella leptospora were the dominant species,and their detection rates were 28.05%,16.04% and 8.92% respectively.By analyzing the diversity of nematode-trapping fungi in four seasons,it was found that the biological diversity was richer in summer,spring and autumn,and the diversity indexes were 2.59,2.47 and 2.34 respectively.The diversity index in winter was 1.48 and was lower.Species forming the adhesive nets were predominant;positive rate was 41.00%.[Conclusion]The rich nematode-trapping fungi resource existed in Erhai Lake,and its biological diversity had the seasonal variation characteristic.The nematode-trapping fungi which formed the viscous net were the dominant species in Erhai Lake.
基金supported by the National High-Tech R&D Proqram(863)of China(2001AA246011).
文摘Monacrosporium ellipsosporum, a nematode-trapping fungus, was isolated by baiting with sclerotiaof Sclerotinia sclerotiorum in soil from a tobacco field in Yuxi, Yunnan Province. Colonizationfrequency of the sclerotia by the fungus was 18% in natural soil. Reinoculation tests byplacing surface-sterilized sclerotia on fungal cultures for two weeks and then surface-sterilized again led to 32% sclerotia be infected. Dual culture tests in PDA plates did notgive rise to a suppression zone between the colonies of M. ellipsosporum and its counterpartfungi S. sclerotiorum and Rhizoctonia solani, suggesting there was little or no nutritionalcompetition and absent of antifungal compounds. However, M. ellipsosporum could grow overabsent of S. sclerotiorum and R. solani, and significantly inhibited their growth on agarplates. Scanning electron and light microscopic observations showed that hyphae of M. ellipsosporumgrew along and appressed on hypha of S. sclerotiorum and coiled around hyphae of R. solani.Assays of cell wall-degrading enzymes showed that M. ellipsosporum grew well in chitin agarmedia, with clear transparent hydrolysis zones. Activities of total chitinase, exo-chitinase,β-1, 3-glucanase and protease were 140.2±11.9, 82.9±4.1, 111.2±7.6 and 76.1±4.3 U respect-ively, after incubation for 4 days at 30 ℃ in liquid media containing ground sclerotia of S.sclerotiorum as sole nutrient source. These enzymes might be important in the mycoparasiticactivity of M. ellipsosporum.
基金supported by the National Natural Science Foundation of China(No.30571495)。
文摘Pine wilt disease,caused by Bursaphelenchus xylophilus and Bursaphelenchus mucnatus,is a serious quarantined disease.Arboreal nematode-trapping fungi of P inus spp.are effective predators on nematodes and have strong host adaptability.The development of these fungal resources may be an effective way to control pine wood nematodes.We collected 515 samples of pine wilt disease from the areas of Ninghai City(Zhejiang province),Shuangbai County(Yunnan province),and Daxing'anling(Heilongjiang province),China.Through isolation,culture and identification,6 species of nematode-trapping fungi(A rthrobotrys cladodesr,A.oligospora,A.musiformis,A.dendroides,Dactylellina ellipsospora,Monacrosporium thaumasium)were identified for predation against B.xylophilus,and 9 species(Arthrobotrys dactyloides,A.cladodes r A.oligospora A.dendroides,Dactylellina ellipsospora,Dactylella asthenopaga,D.leptospora,Arthrobotrys superba,Monacrosporium drechseri)were identified for predation against B.mucnatus.This study provides information in the classification of arboreal predator nematodes and provides an important basis for future biological control of pine wood nematodes.
基金Acknowledgements This work was funded by the the National Natural Science Foundation of China （grant number30260081）.Inner Mongolia Natural Science Foundation（grant number 2009MS0411 ）.
文摘In order to apply the nematode-trapping fungi biocontrol of animal parasitic nematode, prove that mutagenesis strain of the Arthrobotrys Oligospora N spores can be passed to experimental animal digestive tract. Ion beam injected into the spores of Arthrobotrys oligospora of nematode-trapping.Experimental animals are hurled Arthrobotrys Oligospora N spores, collect the feces of experimental animals, test fungal germination, growth, reproduction and predation livestock parasitic nematode larvae in laboratory. Mutant strains of Arthrobotrys Oligospora N can be through the digestive tract in experimental animals. Such biotechnology could be explored for improving the effectiveness of the use of funsal infections to control livestock parasitic nematodes.
基金This work was supported by the National Basic Research Program of China(2013CB127500)the National Natural Science Foundation of China(31160021,31270131 and U1502262)+1 种基金sponsored by the Nanjing University of Posts and Telecommunications Scientific Foundation(NUPTSF)(NY218140)a grant(2018KF003)from YNCUB.We thank BGI-Shenzhen who contributed to the small RNA sequencing projects.We thank H.Yin for comments and discussion.
文摘The lifestyle transition of fungi,defined as switching from taking organic material as nutrients to pathogens,is a fundamental phenomenon in nature.However,the mechanisms of such transition remain largely unknown.Here we show microRNA-like RNAs(milRNAs)play a key role in fungal lifestyle transition for the first time.We identified milRNAs by small RNA sequencing in Arthrobotrys oligospora,a known nematode-trapping fungus.Among them,7 highly expressed milRNAs were confirmed by northern-blot analysis.Knocking out two milRNAs significantly decreased A.oligospora’s ability to switch lifestyles.We further identified that two of these milRNAs were associated with argonaute protein QDE-2 by RNA-immunoprecipitation(RIP)analysis.Three of the predicted target genes of milRNAs were found in immunoprecipitation(IP)products of QDE-2.Disruption of argonaute gene qde-2 also led to serious defects in lifestyle transition.Interestingly,knocking out individual milRNAs or qde-2 lead to diverse responses under different conditions,and qde-2 itself may be targeted by the milRNAs.Collectively,it indicates the lifestyle transition of fungi is mediated by milRNAs through RNA interference(RNAi)machinery,revealing the wide existence of miRNAs in fungi kingdom and providing new insights into understanding the adaptation of fungi from scavengers to predators and the mechanisms underlying fungal infections.
