Fig. 1: TuMV NIb interacts with Arabidopsis NPR1.

a Growth of serially diluted yeast cells that were transformed with the indicated plasmids on selective medium. b Confocal microscopic photographs of N. benthamiana epidermal cells that were infiltrated by agrobacteria harboring the indicated plasmids at 2 dpi. Scale bar, 50 μm. The experiment was independently repeated three times with similar results. c Co-IP assay to test the interaction between NIb and NPR1 or SUMO3. FLAG-4×Myc or YFP-tagged proteins were expressed in N. benthamiana leaves by agroinfiltration, immunoprecipitated with GFP-trap agarose at 2 dpi, and detected with anti-GFP N-terminal (anti-GFP-N) or anti-Myc antibodies, respectively. Asterisks indicate nonspecific bands. The experiment was independently repeated twice with similar results. d In vitro binding assay with purified proteins from E. coli. GST or GST-NIb was used as matrix-bound bait to bind TrxA-6×His or TrxA-6×His-NPR1. The asterisk indicates degraded NPR1. The experiment was independently repeated twice with similar results. e Schematic representation of NPR1. Numbers represent amino acid positions of domain boundaries. Ser11/Ser15, Cys82, Cys156, Cys216, His334, and SIM3 are also indicated. f Confocal microscopic photographs of N. benthamiana epidermal cells expressing NIb-YN and YC-tagged NPR1-truncated mutants or sim3 at 2 dpi. Scale bar, 50 μm. The experiment was independently repeated three times with similar results. g Growth of serially diluted yeast cells that were transformed with BD-NIb and AD-tagged NPR1-truncated mutants or sim3 on selective medium.