Rice grassy stunt virus nonstructural protein p5 serves as a viral suppressor of RNA silencing and interacts with nonstructural protein p3

Abstract

Rice grassy stunt virus (RGSV), a member of the genus Tenuivirus, causes serious rice disease in Southeast Asian countries. In this study, a green fluorescent protein (GFP)-based transient expression assay was conducted to show that p5, encoded on RNA5 in the viral sense, is a viral suppressor of RNA silencing (VSR). Protein-protein interactions (PPIs) between p5 and all RGSV proteins except pC1 and pC2 were investigated using Gal4-based yeast two-hybrid (Y2H) experiments. The results demonstrated that p5 interacts with itself and with p3 encoded on RNA3 in the viral sense. p5-p5 and p5-p3 interactions were detected by bimolecular fluorescence complementation (BiFC) assay, and the p5-p3 interaction was confirmed by subcellular co-localization and co-immunoprecipitation (Co-IP) assays. Using the Y2H system, we demonstrated that the p5-p3 interaction requires both the N-terminal (amino acid residues 1 to 99) and C-terminal (amino acid residues 94 to 191) domains of p5. In addition, either p5 or p3 could enhance the pathogenicity of potato virus X (PVX) in Nicotiana benthamiana plants. A much more significant enhancement of PVX pathogenicity and accumulation was observed when p5 and p3 were expressed together. Our data also showed that RGSV p3 does not function as a VSR, and it had no effect on the VSR activity of p5 or the subcellular localization pattern of p5 in plant cells from Nicotiana benthamiana.

Suppression of Jasmonic Acid-Mediated Defense by Viral-Inducible MicroRNA319 Facilitates Virus Infection in Rice

“…Zhang et al, 2015). Northern blot analyses were performed as 421 previously described(Qi et al, 2005).…”

The Bunyavirales: The Plant-Infecting Counterparts

“…In RGSV, NS5 (p5) protein, similar to RSV p3, functions as an RNA-silencing suppressor [ 174 ] ( Figure 4 ). RGSV p2 also shows (weak) RNA silencing suppressor activity [ 175 ].…”

Application of Virus-Derived Small Interfering RNAs (vsiRNAs) in Rice Viruses with Insect Vectors, Especially <em>Rice Grassy Stunt Virus</em>

“…Interestingly, when p5 and p3 were expressed together, then PVX accumulation and pathogenicity was found [120].…”

“…Characterization and identification of PPIs could provide important insights into protein functions helpful at the cellular level [121]. The mapping of viral protein interaction network will significantly help in understanding the cycle of virus infection, viral pathogenicity mechanism, and host-virus interactions.…”

“…It is supposed that the RGSV protein functions are going to be deduced by RSV counterparts, but its functional authentication is very important which is given by the sequence of the low amount of amino acid characterization between these two proteins [121].…”