Molecular characterization of a novel emaravrius infecting Actinidia spp. in China

Viruses in the genus Emaravirus contain 5-8 negative genomic RNAs and cause severe diseases of plants. In this study, a novel emaravirus, provisionally named Actinidia emaravirus 2 (AcEV-2), was identified from a kiwifruit tree showing leaf mottle and chlorosis symptoms. The genome of AcEV-2 consisted of at least six RNAs (RNAs 1-6) with sizes of 7079, 2252, 1387, 1514, 1744 and 1233 nucleotides (nts), respectively. Proteins encoded by RNAs1-4 of AcEV-2 shared the highest amino acid (aa) sequence identities of 62.2%-77.3% with the corresponding proteins of fig mosaic emaravirues (FMV) and pigeonpea sterility mosaic emaravirus 2 (PPSMV-2). Whilst, the P5 and P6 encoded by AcEV-2 exhibited the highest identities of 44.2% and 39.2% with the corresponding proteins of PPSMV-2. It was the second emaravirus infecting Actinidia trees in China. Preliminary virus detection disclosed the presence of AcEV-2 in three Actinidia species grown in three provinces in the central and southern China.