Abstract
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.
Highlights
Mycoviruses have been reported from a wide range of fungal species [1,2,3,4]
11, 266 mm/day), (23.0 mm/day), EW220-64T2 (19.4 mm/day), and EW220-64T3 (20.7 mm/day) were significantly lower than that of EW220-64 (32.6 mm/day), which was the single-conidium strain from EW220 (Figure 7C). These results revealed that Bipolaris maydis botybirnavirus 1 (BmBRV1)-BdEW220 exerted greater influence single-conidium strain from EW220 (Figure 7C). These results revealed that BmBRV1-BdEW220 exerted on the growth rate of B. dothidea
The largest lesion was observed in JNT1111 (44.4 mm) (Figure 7B,C). Combination, these findings indicate that BmBRV1-BdEW220 confers hypovirulence to the fungal. These findings indicate that BmBRV1-BdEW220 confers hypovirulence to the fungal host B. dothidea
Summary
The majority of mycoviruses reported to date consist of double-stranded RNA (dsRNA) and positive-sense single-stranded RNA (+ssRNA), whereas the rest possess negative-sense single-stranded RNA (-ssRNA) and single-stranded DNA (ssDNA) as their genetic material [1,4,5,6,7,8,9,10]. A proposed dsRNA virus family Botybirnaviridae has been described, which includes the newly reported bipartite dsRNA virus Botrytis porri botybirnavirus. The family Botybirnaviridae includes six members, namely, BpRV1, Sclerotinia sclerotiorum botybirnavirus 1 (SsBRV1), SsBRV2, Alternaria botybirnavirus 1 (ABRV1), Bipolaris maydis botybirnavirus 1 (BmBRV1), and Soybean leaf-associated botybirnavirus 1 (SlaBRV1) [11,12,13,14,15,16]. Viruses of the family Botybirnaviridae consist of two dsRNAs. A satellite-RNA associated SsBRV1
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call