Genomic characterization of a novel dsRNA virus detected in the phytopathogenic fungus Verticillium dahliae Kleb.

Abstract

Four novel double-stranded RNA segments were detected in a Verticillium dahliae Kleb. strain (V. dahliae isolate 0-21), a causal fungal agent of Verticillium wilt disease of cotton. Each dsRNA genome segment contains a single large open reading frame (ORF) that encodes a distinctive protein with modest levels of sequence similarities to the corresponding putative proteins in the genus Chrysovirus. These include an RNA-dependent RNA polymerase (RdRp), a coat protein, an undefined replication-related protein and an ovarian tumor domain peptidase. Phylogenetic analysis of the four putative proteins unanimously indicated that they are evolutionarily related to viruses in Chrysovirus. The 5'- and 3'-untranslated regions of the four dsRNAs share highly similar internal sequence and contain conserved sequence stretches of UGAUAAAAAA(/U)UG(/U)AAAAA- (in the 5'-UTR) and -UUUACUACU (in the 3'-UTR), indicating that they have a common virus origin. Indeed, isometric virus-like particles (VLPs) with a diameter of approximately 34nm were extracted from the fungal mycelia, and the four dsRNA segments were also detected in the virus-like particle (VLP) fraction. These results suggest that the mycovirus with four different dsRNA genome segments from the fungal isolate 0-21 is a new member of the genus Chrysovirus. We named the virus Verticillium dahliae chrysovirus 1 (VdCV1).

• Authors: Yue-Fen Cao, Xi-Wu Zhu, Yu Xiang, De-Qiang Li, Jia-Rong Yang, Qian-Zhuo Mao, Ji-Shuang Chen
• Journal: Virus research (Virus Res) Vol. 159 Issue 1 Pg. 73-8 (Jul 2011) ISSN: 1872-7492 [Electronic] Netherlands
• PMID: 21571013 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2011 Elsevier B.V. All rights reserved.

Chemical References

• RNA, Double-Stranded
• RNA, Viral
• Viral Proteins

Topics

• Cluster Analysis
• Genome, Viral
• Gossypium (microbiology)
• Molecular Sequence Data
• Mycelium (virology)
• Open Reading Frames
• Phylogeny
• Plant Diseases (microbiology)
• RNA Viruses (genetics, isolation & purification)
• RNA, Double-Stranded (genetics)
• RNA, Viral (genetics)
• Sequence Analysis, DNA
• Sequence Homology, Amino Acid
• Verticillium (isolation & purification, virology)
• Viral Proteins (genetics)
• Virion (isolation & purification, ultrastructure)