Characterization Of VdMyo11 During The Development And Pathogenicity On Plant In Verticillium Dahliae

Verticillium wilt of vegetable is a soil-borne vascular fungal disease caused by Verticillium dahliae.The fungus has a rapid genetic variation,a wide host,and is difficult to control.The fungal cytoskeleton has a very significant function in life activities such as cytokinesis,mycelial morphogenesis,mycelial growth and colonization.However,the interaction mechanism between the cytoskeleton and host is not well clear in V.dahliae.In this research,we obtained the V.dahliae type ? myosin deletion mutant ?Vdmyo11 and the complemented strain ?Vdmyo11/Vd Myo11-GFP by Agrobacterium genetic transformation method,and the function of Vd Myo11 during the development and the pathogenesis of V.dahliae was analyzed.The research results are as follows:1.Vd Myo11 has high homology with the model filamentous fungus Myosin ? proteins,and contains many conserved functional domain of common class ? myosin.The deletion mutant ?Vdmyo11 rarely formed branched conidiophores,and the spores were three-dimensionally skewed.The sporulation and germination rate of the conidia were reduced.The mycelium grew slowly and the morphology of septum was deformed.It indicates that Vd Myo11 plays the critical role in the conidiation,conidial germination and hyphal septum formation during the course of growth,development and reproduction in V.dahliae.2.The pathogenicity of ?Vdmyo11 to cotton is reduced significantly,and it can hardly colonize the vascular tissues of host.The virulence of ?Vdmyo11 to Arabidopsis thaliana also decreased markedly,indicating that the pathogenicity of deletion mutant strains did not have significant host specificity.Therefore,Vd Myo11 is necessary for the pathogenicity of V.dahliae.3.The localization of Vd Myo11-GFP at the septum of the hyphae specifically suggests that Vd Myo11 may affect the vegetative growth and the pathogenic process of pathogenic fungus by regulating actomyosin contraction ring system during cytokinesis and septum formation.In addition,there was no significant difference in the localization of the Septin5-GFP septin proteins,GFP-TUBA1 tubulin and Lifeact-m Cherry actin protein between deletion mutant ?Vdmyo11 and wild type.In summary,the Vd Myo11 gene has an irreplaceable role in the development and pathogenicity on palnt in V.dahliae.Targeting silencing of this gene by using host-induced gene silencing technology(HIGS)is expected to provide an effective way for the efficient control of vegetable Verticillium wilt.