Characterization of a Botybirnavirus Conferring Hypovirulence in the Phytopathogenic Fungus Botryosphaeria dothidea

Viruses

Meixin Zhang¹  Guoping Wang²  Mengmeng Yang²  Ni Hong²  Lifeng Zhai² 

[1] College of Life Science and Technology, Yangtze Normal University, Chongqing 400000, China;College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430000, China;

关键词: Botryosphaeria dothidea;    hypovirulence;    Botybirnavirus;    genome;    double-stranded RNA virus;   

DOI  :  10.3390/v11030266

来源: DOAJ

【 摘 要 】

A double-stranded RNA (dsRNA) virus was isolated and characterized from strain EW220 of the phytopathogenic fungus Botryosphaeria dothidea. The full-length cDNAs of the dsRNAs were 6434 bp and 5986 bp in size, respectively. The largest dsRNA encodes a cap-pol fusion protein that contains a coat protein gene and an RNA-dependent RNA polymerase (RdRp) domain, and the second dsRNA encodes a hypothetical protein. Genome sequence analysis revealed that the sequences of the dsRNA virus shared 99% identity with Bipolaris maydis botybirnavirus 1(BmBRV1) isolated from the causal agent of corn southern leaf blight, Bipolaris maydis. Hence, the dsRNA virus constitutes a new strain of BmBRV1 and was named Bipolaris maydis botybirnavirus 1 strain BdEW220 (BmBRV1-BdEW220). BmBRV1-BdEW220 contains spherical virions that are 37 nm in diameter and consist of two dsRNA segments. The structural proteins of the BmBRV1-BdEW220 virus particles were 110 kDa, 90 kDa, and 80 kDa and were encoded by dsRNA1 and 2-ORFs. Phylogenetic reconstruction indicated that BmBRV1 and BmBRV1-BdEW220 are phylogenetically related to the genus Botybirnavirus. Importantly, BmBRV1-BdEW220 influences the growth of B. dothidea and confers hypovirulence to the fungal host. To our knowledge, this is the first report of a botybirnavirus in B. dothidea.

【 授权许可】

Unknown