A Novel RNA Virus Related to Sobemoviruses Confers Hypovirulence on the Phytopathogenic Fungus Sclerotinia sclerotiorum

Viruses

Yanping Fu¹  Jiatao Xie²  MuhammadRizwan Hamid²  Huang Huang²  Ayesha Azhar²  Daohong Jiang²  Fan Mu²  Jiasen Cheng² 

[1] Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China;State Key Laboratory of Agricultural Microbiology, Hubei Key Laboratory of Plant Pathology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, China;

关键词: Sclerotinia sclerotiorum;    mycovirus;    plant virus;    Sobemovirus;   

DOI  :  10.3390/v11080759

来源: DOAJ

【 摘 要 】

Infection by diverse mycoviruses is a common phenomenon in Sclerotinia sclerotiorum. In this study, the full genome of a single-stranded RNA mycovirus, tentatively named Hubei sclerotinia RNA virus 1 (HuSRV1), was determined in the hypovirulent strain 277 of S. sclerotiorum. The HuSRV1 genome is 4492 nucleotides (nt) long and lacks a poly (A) tail at the 3ˊ- terminus. Sequence analyses showed that the HuSRV1 genome contains four putative open reading frames (ORFs). ORF1a was presumed to encode a protein with a conserved protease domain and a transmembrane domain. This protein is 27% identical to the P2a protein encoded by the subterranean clover mottle virus. ORF1b encodes a protein containing a conserved RNA-dependent RNA polymerase (RdRp) domain, which may be translated into a fusion protein by a -1 ribosome frameshift. This protein is 45.9% identical to P2b encoded by the sowbane mosaic virus. ORF2 was found to encode a putative coat protein, which shares 23% identical to the coat protein encoded by the olive mild mosaic virus. ORF3 was presumed to encode a putative protein with an unknown function. Evolutionary relation analyses indicated that HuSRV1 is related to members within Sobemovirus, but forms a unique phylogenetic branch, suggesting that HuSRV1 represents a new member within Solemoviridae. HuSRV1 virions, approximately 30 nm in diameter, were purified from strain 277. The purified virions were successfully introduced into virulent strain Ep-1PNA367, resulting in a new hypovirulent strain, which confirmed that HuSRV1 confers hypovirulence on S. sclerotiorum.

【 授权许可】

Unknown