| In recent years,Verticillium wilt of Cotinus coggygria occurred in many places of north China,causing leaf wilting and plant death in some cases.The pathogen of Verticillium wilt of Cotinus coggygria is Verticillium dahliae Kleb.,which is a soil-borne plant pathogenic fungus.Microsclerotia formed by V.dahliae is a kind of highly resistant dormancy structure,which plays an important role in the infection cycle.Therefore,it is important to elucidate the regulatory mechanism of microsclerotia formation for the prevention and treatment of smoke tree wilt.The components Vd Ste11 and Vd Ste7 in the Kss1-MAPK signaling pathway have been proved to be involved in the regulation of microsclerotium formation and pathogenicity,while the specific regulation function of VdKss1 is not clear.In this study,functional analysis was carried out on the component VdKss1 of the Kss1-MAPK signal pathway of V.dahliae.The main results are as follows:1.V.dahliae VdKss1 regulates conidiation: The deletion of VdKss1 does not affect the biomass,but leads to an increase in the production of conidia and a decrease in the formation of aerial hyphae.2.V.dahliae VdKss1 regulates microsclerotia formation: Knockout of VdKss1 would lead to defects in the structure of microsclerotium.The volume of microsclerotium formed by the knockout mutant of VdKss1 would be decreased,and the accumulation of melanin would be significantly reduced.3.V.dahliae VdKss1 regulates pathogenicity: Knockout of VdKss1 could lead to the mutant unable to form infection structure,unable to penetrate the cellulophane film and onion epidermal tissue,and lost the pathogenicity to the host plants,indicating that VdKss1 could regulate the invasive growth of mycelia and pathogenicity.In this study,VdKss1 is defined to regulate the fungus growth,microsclerotia formation and pathogenic process of V.dahliae,which perfects the function reaserch of each component of V.dahliae Kss1-MAPK signal pathway.This study provides data and the genetic material for further research,and it laid a foundation for parsing the signal transduction and pathogenic mechanism of V.dahliae. |
