Silencing of Putative Plasmodesmata-Associated Genes and Reveals Their Differential Involvement during Plant Infection with Cucumber Mosaic Virus.

Plant viruses utilize a subset of host plasmodesmata-associated proteins to establish infection in plants. In the present study, we aimed to understand the role of two plant genes, one encoding a putative plasmodesma located protein (PDLP) and a homolog of soybean gene regulated by cold 2 protein (SRC2) during Cucumber mosaic virus (CMV) infection. Virus-induced gene silencing (VIGS) was used to silence and genes in and in two related solanaceous plants, and Jacq. (Bhut Jolokia). Up to 50% downregulation in the expression of the gene using the TRV2- VIGS construct was observed in and while, using the same gene construct, 30% downregulation of the target mRNA was observed in . Similarly, using the TRV2- VIGS construct, a 60% downregulation of the mRNA was observed in , , and a 40% downregulation in as confirmed by qRT-PCR analysis. Downregulation of the gene in resulted in delayed symptom appearance up to 7-12 days post inoculation with reduced CMV accumulation compared to the control plants expressing TRV2-. In contrast, -silenced plants showed enhanced susceptibility to CMV infection compared to the control plants. Our data suggest that the gene might facilitate infection of CMV, thus being a susceptibility factor, while the gene could play a role in resistance to CMV infection in .