Pinczés Dóra, Sáray Réka, Nemes Katalin, Palkovics László, Salánki Katalin
Department of Plant Pathology, Plant Protection Institute, Centre for Agricultural Research, HUN-REN, Budapest, Hungary.
Doctoral School of Horticultural Sciences, Hungarian University of Agriculture and Life Sciences (MATE), Budapest, Hungary.
Sci Rep. 2024 Dec 28;14(1):31008. doi: 10.1038/s41598-024-81998-4.
Plant viruses have evolved different viral suppressors of RNA silencing (VSRs) to counteract RNA silencing which is a small RNA-mediated sequence-specific RNA degradation mechanism. Previous studies have already shown that the coat protein (CP) of cucumber mosaic virus (CMV) reduced RNA silencing suppression (RSS) activity of the VSR of CMV, the 2b protein. To demonstrate the universality of this CP-VSR interference, our study included three different viruses: CMV and peanut stunt virus (PSV) from the Bromoviridae, and plum pox virus (PPV) from the Potyviridae family. The RSS activity of the three VSRs (CMV 2b, PSV 2b, and PPV HC-Pro) was compared using Agrobacterium-mediated transient expression in Nicotiana benthamiana and the effect of CMV CP, PSV CP and PPV CP was validated on the RSS activity of their cognate and heterologous VSRs as well. Furthermore, the VSRs were also evaluated in PTGS suppressor-deficient CMV mutant (CMV NVE/10-12/AAA) virus-infected plants. The joint presence of CPs and VSRs resulted in decreased RSS activity in each combination, regardless of the origin of the two proteins, suggesting a universal role of the viral CPs in fine tuning of RSS. Interestingly the PSV CP elicited the strongest negative effect on the RSS activity of all three VSRs.
植物病毒已经进化出不同的RNA沉默病毒抑制子（VSR）来对抗RNA沉默，RNA沉默是一种由小RNA介导的序列特异性RNA降解机制。先前的研究已经表明，黄瓜花叶病毒（CMV）的外壳蛋白（CP）降低了CMV的VSR即2b蛋白的RNA沉默抑制（RSS）活性。为了证明这种CP-VSR干扰的普遍性，我们的研究纳入了三种不同的病毒：来自雀麦花叶病毒科的CMV和花生矮化病毒（PSV），以及来自马铃薯Y病毒科的李痘病毒（PPV）。利用农杆菌介导的瞬时表达在本氏烟草中比较了三种VSR（CMV 2b、PSV 2b和PPV HC-Pro）的RSS活性，并且验证了CMV CP、PSV CP和PPV CP对其同源和异源VSR的RSS活性的影响。此外，还在PTGS抑制子缺陷型CMV突变体（CMV NVE/10-12/AAA）病毒感染的植物中评估了VSR。CP和VSR的共同存在导致每种组合中的RSS活性降低，无论这两种蛋白的来源如何，这表明病毒CP在微调RSS中具有普遍作用。有趣的是，PSV CP对所有三种VSR的RSS活性产生了最强的负面影响。
