Molecular characterization of the movement and coat proteins of a new Elm mottle virus isolate infecting European white elm (Ulmus laevis Pall.)

Abstract

European white elms (Ulmus laevis Pall.) growing in a park in Caputh near Berlin (Germany) were regularly monitored over a period of 18 years showing virus infection-like symptoms such as chloroses, chlorotic ringspots, mottling and dieback. To obtain the evidence for viral infection, RNA-seq using an Illumina Hi Seq2500 was conducted and three contigs were obtained. They match with the three EMoV genomic RNAs and cover the open reading frames for the viral replicase, the polymerase and the movement and coat proteins (MP, CP). The contigs show identities of 95.3–96.4%, 91.9–93.3% and 89.0–92.5% at the nucleotide level with RNA 1, RNA 2 and RNA 3 of reference sequences, respectively. The analyses of the MP and CP showed significant differences in amino acid sequence compositions compared to those of reference EMoV sequences. These results demonstrate the presence of a so far unknown isolate of EMoV. This is the first report of sequence data of EMoV infecting U. laevis.