Complete genome sequence of a novel wheat-infecting polerovirus associated with yellowing dwarf disease in China.

A novel wheat-infecting polerovirus, tentatively named "wheat yellow dwarf virus" (WYDV), was identified from winter wheat in China using transcriptome sequencing (RNA-seq) combined with RT-PCR and RACE amplification. WYDV has a single-stranded RNA genome of 5,650 nucleotides (nt) and contains seven putative open reading frames (ORFs). WYDV was found to share the highest sequence identity with cereal yellow dwarf virus RPV (CYDV-RPV, genus Polerovirus), 71.1% for the nucleotide sequence of the whole genome, and 77.3% and 70.0% for the amino acid sequences of the coat protein (CP) and RNA-dependent RNA polymerase protein (RdRp), respectively. Phylogenetic analysis based on the complete genome and CP and RdRp amino acid sequences showed that WYDV is most closely related to the cereal-infecting poleroviruses CYDV-RPV, CYDV-RPS, and barley yellow dwarf virus-GPV. These data suggest that WYDV, which is associated with a newly emerging yellow dwarf disease in wheat fields in central China, should be classified as a new member of the genus Polerovirus.