ABSTRACT
We have sequenced 1873 nucleotides from the 3'-end region of a sunflower potyvirus genome including the 3'-NIb protein coding region (813 nucleotides), the entire coat protein coding region (807 nucleotides) and 3'-NCR (253 nucleotides), excluding the poly (A) tail. Amino acids identity of the whole CP between the sunflower virus and Potyvirus members ranged from 49.5% (SCMV) to 81.5% (PVY-NsNr), and the core ranged from 55% (TVMV) to 87% (PVY-NsNr; PepMoV). The 3'-NCR nucleotides showed 38.7% homology to PeSMV and 61% to PepMoV-C. The sequence of 3' end region and analysis of phylogenetic relationships suggest this sunflower virus could belong to PVY subgroup and the name of "sunflower chlorotic mottle virus" (SuCMoV) is proposed. This is the first report on the partial nucleotide sequence of a potyvirus infecting sunflower.
Subject(s)
Helianthus/virology , Plant Diseases/virology , Potyvirus/genetics , 3' Untranslated Regions/genetics , Amino Acid Sequence , Base Sequence , Capsid/genetics , Cloning, Organism , Molecular Sequence Data , Phylogeny , Potyvirus/classification , Potyvirus/isolation & purification , Sequence Analysis, DNAABSTRACT
A virus causing chlorotic mottling symptoms on sunflower was found in various locations in Argentina. Symptoms were small chlorotic spots, yellow blotches on leaves, and plant stunting. Virus transmission efficiency by mechanical inoculation was 73 to 100%, and by Myzus persicae was 31 to 49%. The host range included members of the Amaranthaceae, Asteraceae, Chenopodiaceae, and Solanaceae families. Electron microscopy of leaf dips from infected plants revealed flexuous particles 17 nm wide and 770 nm long. Cytoplasmic laminar aggregates and pinwheel inclusions were observed in ultrathin sections. Purified virus preparations analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis resolved a capsid protein of 33 kDa. A monoclonal antibody to aphid-transmitted potyviruses reacted with the capsid protein of this virus. In dot blot immunoassays, a polyclonal antiserum (early bleeding) reacted with infected sunflowers and weakly with Bidens mottle potyvirus, but not with either maize dwarf mosaic potyvirus or potato virus Y. The evidence suggests that a potyvirus is infecting sunflower, and a partial characterization of the causal agent is reported.
