title: Characterization of a novel Sclerotinia sclerotiorum RNA virus as the prototype of a new proposed family within the order Tymovirales.
abstract: Recent studies have shown that Sclerotinia sclerotiorum, an important plant pathogen fungus, harbors diverse mycoviruses. A new mycovirus, tentatively named as Sclerotinia sclerotiorum deltaflexivirus 1 (SsDFV1), was isolated from a S. sclerotiorum strain AX19 containing multiple dsRNA elements. The complete genome of SsDFV1 was shown to be 8178 nucleotides long excluding the poly (A) tail. SsDFV1 has a large putative open reading frame (ORF1) and three smaller ORFs (2-4). ORF1 encodes a putative methyltransferase-helicase-RdRp polyprotein of 2075 amino acids. ORFs (2-4) encode three putative small hypothetical proteins (<40kDa) with unknown biological functions. No evidence for a coat protein encoded by SsDFV1 was obtained. Multiple alignment suggested that three conserved domains, RdRp, methyltransferase, and helicase, from SsDFV1 have lower identity (approximately 25%) with all the reported viruses of four approved families, Alphaflexiviridae, Betaflexiviridae, Gammaflexiviridae and Tymoviridae in the order Tymovirales. Moreover, a phylogenetic tree also suggested that the SsDFV1 could not be phylogenetically placed in any of the approved families, and forms a separated cluster distinct from other known viruses. Therefore, these combined results suggest that SsDFV1 could represent a new positive-sense single-stranded RNA virus with some unique molecular features, and we propose to create a tentative family Deltaflexiviridae that accommodates SsDFV1.
authors.affiliation: State Key Laboratory of Agriculture Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, People's Republic of China; Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, People's Republic of China.
authors.forename: Kunfei
authors.initials: K
authors.lastname: Li
authors.affiliation: State Key Laboratory of Agriculture Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, People's Republic of China; Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, People's Republic of China.
authors.forename: Dan
authors.initials: D
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Agriculture Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, People's Republic of China; Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, People's Republic of China.
authors.forename: Jiasen
authors.initials: J
authors.lastname: Cheng
authors.affiliation: State Key Laboratory of Agriculture Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, People's Republic of China; Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, People's Republic of China.
authors.forename: Tao
authors.initials: T
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Agriculture Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, People's Republic of China; Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, People's Republic of China.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Fu
authors.affiliation: State Key Laboratory of Agriculture Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, People's Republic of China; Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, People's Republic of China.
authors.forename: Daohong
authors.initials: D
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Agriculture Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, People's Republic of China; Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, People's Republic of China. Electronic address: jiataoxie@mail.hzau.edu.cn.
authors.forename: Jiatao
authors.initials: J
authors.lastname: Xie
mesh_terms: D000595:Amino Acid Sequence; D001203:Ascomycota / Q000821:virology*; D000067148:Fungal Viruses / Q000145:classification* / Q000235:genetics*; D023061:Gene Order; D016679:Genome, Viral; D010802:Phylogeny; D012328:RNA Viruses / Q000145:classification* / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics
chemical_list: D012367:RNA, Viral; D014764:Viral Proteins
keywords: (+)ssRNA virus; Mixture infection; Mycovirus; Sclerotinia sclerotiorum; Tymovirales