During a survey, 148 wheat, 70 barley and 24 wild grass samples of plants showing symptoms of yellowing or reddening of leaves and general stunting were collected in central and southern provinces of Iran and tested for Barley yellow dwarf virus (BYDV) and Cereal yellow dwarf virus (CYDV) infection by enzymelinked immunosorbent assay (ELISA) and tissue print immunoassay (TPIA). The results showed the presence of the viruses in most regions. Positive reactions to BYDV-PAV, BYDV-MAV, CYDV-RPV and BYDV-SGV antisera were recorded. BYDV-PAV was the most prevalent virus. The genetic diversity of BYDV-PAV isolates in central and southern provinces was studied by analysing ORF1 (903 nt) and read through domain (RTD) (575 nt) of 13 and nine isolates respectively. Sequence analysis of RTD at nucleotide and amino acid levels revealed a high identity (91.8-97.2% and 91.4-100% respectively) between Iranian and other available isolates in the GenBank. However, in regards to ORF1, a high genetic diversity among Iranian and other known PAV isolates at both amino acid (2-16.9%) and nucleotide (4.1-16.5%) levels were detected. Based on phylogenetic analysis of ORF1, two major groups of BYDV-PAV isolates were distinguished. The Iranian isolates were divided between the two clusters. Our results suggest that the occurrence of two genetically distinct groups of PAV isolates in central and southern Iran, from which according to the ICTV criteria for species demarcation in the family Luteoviridae, four isolates from central parts of the country, qualify for designation as new species.
The complete nucleotide sequence of an Iranian isolate of Barley yellow striate mosaic virus (BYSMV) L gene comprising 6171 nucleotides was determined using the random polymerase chain reaction followed by filling of gaps by the use of specific primers. The deduced L protein sequence of BYSMV showed similarities with the L proteins of other plant rhabdoviruses and contained polymerase module motifs characteristic of RNA-dependent RNA polymerases of negative-strand RNA viruses. Pairwise and multiple alignments and phylogenetic analysis of BYSMV L protein revealed that it was more closely related to cytorhabdoviruses. These results revealed that, on the basis of polymerase gene, the Iranian isolate of BYSMV and Northern cereal mosaic virus (NCMV) appeared to be the most closely related plant rhabdoviruses sequenced to date. Interestingly, the amino acid sequence identity of BYSMV ⁄ NCMV (61.3%), shared more than twice the amino acid sequence identity compared with the next two most similar cytorabdoviruses, Lettuce necrotic yellows virus (28.8%) and Lettuce yellow mottle virus (28.2%). In this paper, we discuss the similarities and differences of BYSMV with other rhabdoviruses which support the classification of BYSMV as a distinct Cytorhabdovirus. This is the first report of BYSMV genome sequences.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.