Fig. 1.

TMV.GFP accumulation in upper, non-inoculated leaves in N. benthamiana plants is not prevented by expression of an MtRDR1-transgene or by treatment with salicylic acid. Five-week-old MtRDR1-transgenic plants (MtRDR1), or plants transformed with an ‘empty vector’ transformation vector (EV-control), were pre-treated with a solution of 1 mM SA or a control solution [water amended with 0.05 % (v/v) ethanol] prior to inoculation with GFP-tagged TMV. a The movement of TMV.GFP from directly-inoculated leaves into non-inoculated leaves was monitored daily using a hand-held UV lamp and the first appearance of GFP fluorescence in non-inoculated leaves recorded. There was no apparent difference in the timing of appearance of TMV.GFP in non-inoculated leaves between the two groups of plants although systemic infection with TMV.GFP was delayed by SA treatment in both types of plant. There were 23 plants in each treatment group. b Western blot analysis of TMV.GFP accumulation in systemically-infected leaf tissue of water- (top) and SA- (bottom) treated plants using anti-TMV coat protein (CP). In each case leaf tissue samples were harvested at 14 days post-inoculation from the uppermost three leaves above the inoculated leaf. Three samples were taken from each treatment group (one sample = one plant). Equal loading of gel lanes with protein is shown by accumulation of ribulose-1, 5-bisphosphate carboxylase/oxygenase large subunit (LSU) revealed by Ponceau S staining of the western blot membrane. c The extent of GFP fluorescence in the upper leaves of water-treated TMV.GFP-infected empty vector control (control) and MtRDR1-transgenic plants (MtRDR1-transgenic) appeared similar when visualised using a hand-held UV lamp and photographed at 14 days post-inoculation. GFP fluorescence was less extensive in SA-treated plants of both groups. The data and photographs above are from one experiment, out of a total of four independent experiments. Scale bar = 8 cm