Variability in the level of RNA silencing suppression caused by triple gene block protein 1 (TGBp1) from various potexviruses during infection.
RNA silencing is an important defence mechanism against virus infection, and many plant viruses encode RNA silencing suppressors as a counter defence. In this study, we analysed the RNA silencing suppression ability of multiple virus species of the genus Potexvirus. Nicotiana benthamiana plants exhibiting RNA silencing of a green fluorescent protein (GFP) transgene showed reversal of GFP fluorescence when systemically infected with potexviruses. However, the degree of GFP fluorescence varied among potexviruses. Agrobacterium-mediated transient expression assay in N. benthamiana leaves demonstrated that the triple gene block protein 1 (TGBp1) encoded by these potexviruses has drastically different levels of silencing suppressor activity, and these differences were directly related to variations in the silencing suppression ability during virus infection. These results suggest that suppressor activities differ even among homologous proteins encoded by viruses of the same genus, and that TGBp1 contributes to the variation in the level of RNA silencing suppression by potexviruses. Moreover, we investigated the effect of TGBp1 encoded by Plantago asiatica mosaic virus (PlAMV), which exhibited a strong suppressor activity, on the accumulation of microRNA, virus genomic RNA and virus-derived small interfering RNAs.
Senshu
Hiroko
H
Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Ozeki
Johji
J
Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Komatsu
Ken
K
Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Hashimoto
Masayoshi
M
Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Hatada
Kouji
K
Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Aoyama
Michiko
M
Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Kagiwada
Satoshi
S
Department of Clinical Plant Science, Faculty of Bioscience and Applied Chemistry, Hosei University, Tokyo, Japan.
Yamaji
Yasuyuki
Y
Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Namba
Shigetou
S
Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
D005786:Gene Expression Regulation; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D010935:Plant Diseases / Q000821:virology*; D018515:Plant Leaves / Q000821:virology; D017863:Potexvirus / Q000145:classification / Q000235:genetics / Q000472:pathogenicity*; D034622:RNA Interference / Q000187:drug effects*; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism; D012231:Rhizobium / Q000821:virology*; D014026:Nicotiana / Q000821:virology*; D019076:Transgenes; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*
D035683:MicroRNAs; D034741:RNA, Small Interfering; D012367:RNA, Viral; D014764:Viral Proteins; D049452:Green Fluorescent Proteins