Suppressor of RNA silencing encoded by Rice gall dwarf virus genome segment 11

Abstract

Rice gall dwarf virus (RGDV) is an important rice pathogen in China and Southeast Asia. However, little is known about the molecular mechanisms of RGDV interactions with plant cells. Here, we have identified an RGDV protein, Pns11, which acts as a suppressor of RNA silencing in coinfiltration assays with the reporter, green fluorescent protein (GFP) in transgenic Nicotiana benthamiana line 16c carrying GFP. Pns11 suppressed local and systemic silencing induced by sense RNA. The spread of mobile RNA silencing signals was blocked or inactivated by Pns11. Expression of Pns11 also enhanced Potato virus X pathogenicity in N. benthamiana. This suppressor could reduce, but not eliminate, siRNA in the local and systemic RNA silencing suppression assays, suggesting that Pns11 functions by interfering with initial stages of RNA silencing.