Sequence variability between Plantago asiatica mosaic virus isolates
Plantago asiatica mosaic virus (PlAMV) was described four decades ago from the weedy species Plantago asiatica in the Russian Far East, but has also been reported from lilies (Lilium spp.) and primrose (Primula seiboldii) in Japan. More recently PlAMV has been reported in the Netherlands and elsewhere in Europe, in Taiwan, and in the United States in bulbs imported from the Netherlands. An isolate from heavenly bamboo (Nandina domestica) was initially described from California (USA) as Nandina mosaic virus at about the same time as PlAMV was described from Russia, and was recognized as a strain of PlAMV (PlAMV-NMV) only when the full sequence of a Nandina mosaic isolate (PlAMV-PLH) was determined; however, Nandina is the only reported natural host of PlAMV-NMV. Lily isolates of PlAMV cause significant economic damage in lilies, especially Asiatic and Oriental hybrid types grown for cut-flower production. We have therefore determined the 3'-terminal sequence including the coat protein (CP) gene of multiple isolates from different imported lily cultivars, and compared these sequences to those of isolates from lilies and other hosts from different countries. To date the CP sequences of all isolates from imported lilies fall within the same 'European' clade as isolates from Europe, with minimal variation in amino acid sequence, whereas lily and primrose isolates from Japan form a separate 'Japanese' clade; PlAMV-Type and PlAMV-Gunwi (from P. asiatica) and PlAMV-PLH form a third, 'Russian' clade. Isolates of the 'Russian' clade share multiple N-terminal CP-residues that distinguish them from all other available PlAMV isolates; several variant N-terminal residues are uniquely conserved within the 'European' clade, and others within the 'Japanese' clade. These results support the serological differentiation of 'European' lily isolates from PlAMV-NMV, and suggest that 'Japanese' isolates may also be serologically distinct.
Hammond, J. and Reinsel, M.D. (2018). Sequence variability between Plantago asiatica mosaic virus isolates. Acta Hortic. 1193, 1-8
Lilium hybrids, lilies, virus detection, virus characterization, RT-PCR