ABSTRACT
A putative endornavirus was detected in Carolina geranium (Geranium carolinianum) in Louisiana, USA. The virus was provisionally named Geranium carolinianum endornavirus 1 (GcEV1). The viral RNA was sequenced, and it consisted of 14,625 nt containing a single ORF coding a putative polyprotein of 4815 aa with conserved domains for a helicase 1, peptidase C97, glycosyl transferase GTB-type, and RNA-dependent RNA polymerase 2. The 5'end consisted of 130 nt while the 3'end consisted of 54 nt ending in nine cytosine residues. The closest relative to GcEV1 was Phaseolus vulgaris endornavirus 3. In phylogenetic analyses, GcEV1 clustered with members of the genus Alphaendornavirus. GcEV1 was detected in 57 of 60 G. carolinianum plants collected from three distinct agroecosystems. The virus was not detected in eight other species of the genus Geranium. There was no association of a particular phenotypic trait of the host with the presence or absence of the virus. GcEV1 was transmitted at a rate of 100% in seeds of a self-pollinated G. carolinianum plant.
Subject(s)
Ecosystem , Genome, Viral , Geranium/virology , Plant Diseases/virology , RNA Viruses/classification , RNA Viruses/genetics , Agriculture , Open Reading Frames , Phylogeny , RNA Viruses/isolation & purification , RNA, Viral/genetics , Sequence Analysis, DNA , Viral Proteins/geneticsABSTRACT
Extraction and electrophoretic analysis of viral dsRNA from plants has been used successfully to detect infections by RNA viruses. We used this approach as an initial tool to test non-cultivated plant species for the presence of endornaviruses. Foliar samples were collected from symptomless plants in various locations within East Baton Rouge Parish, Louisiana, USA, and tested for viral dsRNA. After testing 208 plant species belonging to 74 families, five (Geranium carolinianum, Hydrocotyle umbellata, H. prolifera, Sorghum halepense, and Sisyrinchium atlanticum) yielded dsRNAs similar in size to the dsRNAs of members of the family Endornaviridae. The endornavirus nature of the dsRNAs was confirmed by reverse-transcription PCR (RT-PCR) and sequencing the RT-PCR products. Sequence data were used to determine relationships of the putative endornaviruses to members of the family Endornaviridae. The putative endornaviruses were detected in both native and introduced plants species. This is the first survey on the occurrence of endornaviruses in non-cultivated plant species.
Subject(s)
Plant Viruses/classification , Plant Viruses/isolation & purification , RNA Viruses/classification , RNA Viruses/isolation & purification , RNA, Double-Stranded/genetics , RNA, Viral/genetics , Centella/virology , Genome, Viral/genetics , Geranium/virology , Iridaceae/virology , Louisiana , Plant Viruses/genetics , RNA Viruses/genetics , Reverse Transcriptase Polymerase Chain Reaction , Sorghum/virologyABSTRACT
Since the first report in Costa Rica in 1971, bean rugose mosaic virus (BRMV) has been found in Colombia, El Salvador, Guatemala and Brazil. In this study, the complete genome sequence of a soybean isolate of BRMV from Paraná State, Brazil, was determined. The BRMV genome consists of two polyadenylated RNAs. RNA1 is 5909 nucleotides long and encodes a single polypeptide of 1856 amino acids (aa), with an estimated molecular weight of 210 kDa. The RNA1 polyprotein contains the polypeptides for viral replication and proteolytic processing. RNA2 is 3644 nucleotides long and codes for a single polypeptide of 1097 aa, containing the movement and coat proteins. This is the first complete genome sequence of BRMV. When compared with available aa sequences of comoviruses, the highest identities of BRMV coat proteins and proteinase polymerase were 57.5 and 58 %, respectively. These were below the 75 and 80 % identity limits, respectively, established for species demarcation in the genus. This confirms that BRMV is a member of a distinct species in the genus Comovirus.
