Cis-acting element (SL1) of Potato virus X controls viral movement by interacting with the NbMPB2Cb and viral proteins

Abstract

A number of candidate tobacco proteins that bind to cis-acting elements (SL1 RNAs) of Potato virus X (PVX) have been identified in previous studies. We further characterized TMV-MP30 binding protein 2C (MPB2C) homologous protein. We isolated NbMPB2Cb from Nicotiana benthamiana and confirmed the interaction of NbMPB2Cb with SL1 RNAs in vitro. The mRNA level of NbMPB2Cb was increased upon infection by PVX and Tobacco mosaic virus. The movement of PVX was reduced by overexpression of NbMPB2Cb and increased by silenced of NbMPB2Cb. In contrast, PVX RNA accumulation was not significantly altered in protoplasts. Protein-protein interaction assays showed that NbMPB2Cb interacts with PVX movement-associated proteins. PVX infection altered the subcellular localization of NbMPB2Cb from microtubules to endoplasmic reticulum. These data suggest that the NbMPB2Cb negatively affects PVX movement by interacting with SL1 RNAs and movement-associated proteins of PVX and by re-localizing in response to PVX infection.

Plant virus replication and movement

“…Another example is PMTV, whose TGB1 protein interacts with microtubules (Shemyakina et al, 2011;Wright et al, 2010) and thus may provide anchorage to support VRC formation at the ER. Microtubule association was also reported for the coat protein of PVX (Serazev et al, 2003) and the observation that PVX movement is inhibited by expression of a microtubule-associated protein seems to support a microtubule-associated movement mechanism (Cho et al, 2012). Grapevine fanleaf virus (GFLV) is a "tubule-forming" virus, which moves cell-to-cell in the form of encapsidated virions through tubules that are assembled by MP within the plasmodesmal pore.…”

The Plant Cellular Systems for Plant Virus Movement

“…They observed that MPB2C is not essential for the movement of MP, but subcellular localization of MP clearly changed toward PDs. MPB2C also acts as a modulator for intercellular trafficking of PVX (Cho et al, 2012). …”

Salicylic acid mitigates physiological and proteomic changes induced by the SPCP1 strain of Potato virus X in tomato plants

“…PVX is one of the most common plant viruses and causes great economic losses to solanaceous crops around the world [1]. This virus induces mild to no symptoms, but increased symptom expression has been observed in mixed infections with other plant viruses [11,47].…”