The p19.7 RNA silencing suppressor from Grapevine leafroll-associated virus 3 shows different levels of activity across phylogenetic groups.
At least five phylogenetic groups have been reported for Grapevine leafroll-associated virus 3 (GLRaV-3). The p19.7 protein encoded by the GLRaV-3 was previously identified as an RNA silencing suppressor. In this study, five constructs of p19.7 belonging to different groups were compared for their suppressing activity. For each p19.7 variant, the accumulation level of green fluorescent protein mRNA and specific siRNAs were determined using co-infiltration assays in transgenic 16C Nicotiana benthamiana. Differences in the suppressing activity were found among the variants assayed. Some constructs originated viral-like mosaic symptoms that evolved to necrosis. The intensity of these symptoms appeared to be related to the strength of the suppressor activity. A comparison of the protein sequences revealed a few amino acid substitutions that may be associated with the observed differences in the suppressing activity.
Center for Biodiversity, Functional and Integrative Genomics, Faculdade de Ciências e Tecnologia, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
Paulo
P
Gouveia
Gustavo
G
Nolasco
D029381:Closteroviridae / Q000235:genetics / Q000472:pathogenicity*; D015967:Gene Expression Regulation, Viral; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D020125:Mutation, Missense; D010935:Plant Diseases / Q000821:virology; D030821:Plants, Genetically Modified / Q000235:genetics; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014026:Nicotiana / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
D012333:RNA, Messenger; D034741:RNA, Small Interfering; D014764:Viral Proteins; D037521:Virulence Factors; D049452:Green Fluorescent Proteins