Diversity Of Fungal Viruses From Bipolaris Maydis And Interaction Between BmPV1 Coat Protein And Host Factors

Maize is the main food crop in China.Its high and stable yield is related to the national economy and people ’ s livelihood.In production,corn disease is an important reason for maize yield reduction,the most common corn leaf disease,such as corn leaf spot,corn leaf spot,corn rust and so on.In order to explore the green prevention and control technology of maize diseases,the diversity of fungal viruses in Bipolaris maydis was detected by ds RNA extraction and high-throughput sequencing in this paper,and it was verified that the ds RNA2 genomic nucleic acid of BmPV1(Bipolaris maydis partitivirus1)encoded the coat protein of the virus in the fungal virus population of Bipolaris maydis.On this basis,the interaction between the viral coat protein and the host factors was further explored by yeast two-hybrid technique,which laid the foundation for analyzing the mechanism of hypovirulence caused by viruses.The specific research results are as follows :The leaf samples of maize leaf spot disease in Hannan District of Wuhan City were collected.and 293 strains of Bipolaris maydis were isolated by cell separation.The results of ds RNA extraction showed that there were rich diversity of ds RNA bands in the population of Bipolaris maydis in this area,indicating that there may be a variety of fungal viruses.25 representative strains with ds RNA bands were selected for high-throughput sequencing.Sequencing results showed that these 25 strains contained35 viruses,including 9 ds RNA viruses and 19 single-stranded RNA viruses.These 19 viruses belonged to 8 families,and 7 new strains of unclassified viruses.In addition,12 of the 35 viruses may be new viruses.Prepared the polyclonal antibody of BmPV1 ds RNA2 that may encode protein P2,and the biological functions of P2 protein were detected by virus particle extraction,SDS-PAGE and Western Blot.The results showed that P2 protein could be detected in both virus particles and strains that containing BmPV1,but not in control strains(strains which without BmPV1)and virus-free strains,indicating that P2 protein is the Coat protein of the virus.The coat protein of BmPV1 was used as bait protein to screen the c DNA library of Bipolaris maydis by yeast two-hybrid technique,and then,and 150 positive clones were obtained.The positive clone sequencing results showed that 46 host factors might interact with the coat protein of BmPV1.Ten genes of interest were selected for full-length cloning and further yeast two-hybrid verification.The results showed that two of the 10 host factors interacted with the coat protein of BmPV1,and the two host factors were enolase and precursor m RNA processing factors,respectively.In addition,the interaction between nine key factors of host fungal melanin pathway and the coat protein of BmPV1 was analyzed by yeast two-hybrid technology,since BmPV1 can reduce melanin synthesis in host fungi.The results showed that Bz Mco1 could interact with the coat protein of BmPV1 in nine key factors of melanin pathway.The analysis showed that the host factor was polycopper oxidase,which was helpful for the infection and diffusion of pathogens in the host.These interactions indicate that the coat protein of BmPV1 not only acts as the function of viral structural protein,but also plays a key role in viral infection and reduced melanin synthesis in host.