Effects of PVX-mediated expression of begomovirus genes on the levels of miR166, 167, 168, 169 and 170. The bar graphs show the average of two independent experiments (with standard error). The accumulation of each miRNA upon the expression of begomovirus genes from PVX was calculated relative to plants infected with PVX, which was taken as 1. The genes used were those encoding the replication associated protein (Rep), the transcriptional activator protein (TrAP), the C2 protein (C2), the replication enhancer protein (REn), the (A)C4 protein [(A)C4], the coat protein (CP), the (A)V2 protein [(A)V2], the nuclear shuttle protein (NSP) and the movement protein (MP). Additionally the gene encoding the hypothetical protein C5 (C5*) of Cotton leaf curl Kokhran virus and the green fluorescence protein (GFP) were expressed from the PVX vector.