Characterization of three new viruses of the family Betaflexiviridae associated with camellia ringspot disease.

In this study, flexuous, filamentous virions of approximately 680-780 nm long were observed by electron microscopy in sap of camellia trees with chlorotic ringspots. Five large viral contigs were identified by high-throughput sequencing technology, and complete genome sequences of them were determined. Sequence analyses show that these five isolates represent three novel viruses, two in the genus Prunevirus, one in the genus Capillovirus. The genome organization of the two camellia pruneviruses resembles that of pruneviruses but does not contain the nucleic acid-binding protein (NABP) at the 3'-terminal region. They share 66.5-66.8% with each other and 51.9-58.6% with the known pruneviruses at the genome sequence level. The genome of the camellia capillovirus contains an additional NABP at the 3'-terminus when compared to those of Capillovirus. The genomes of the two capillovirus variants are 72.7% identical to each other and 42.1-48.4% to the known capilloviruses. Phylogenetic analyses support these viruses are new members of either Prunevirus or Capillovirus. The two pruneviruses are tentatively named as camellia ringspot associated virus 1 (CRSaV-1) and CRSaV-2, and the capillovirus is named as CRSaV-3. Infections of these viruses were common in camellia species, cultivars and hybrids. The viruses were also detected in seedlings from seeds collected from two camellia trees, indicating that they are seed transmissible.
PMID: 31445958 [PubMed - as supplied by publi...

Source: Virus Research - August 21, 2019 Category: Virology Authors: Liu H, Wu L, Zheng L, Cao M, Li R Tags: Virus Res Source Type: research