Fig. 4: NIb attenuates the phosphorylation of NPR1 at Ser11/Ser15.

a Evaluation of the interaction between NIb and NPR1 mutants by Y2H. The experiment was performed as shown in Fig. 1a except that the incubation time was reduced due to the fast growth rate of yeast cells transformed with BD-NIb and S11/15D-AD. b Box and whisker plot with individual data points showing the nuclear YFP intensity in N. benthamiana epidermal cells expressing NIb-YC and YN-tagged NPR1 or its mutants. The data are the mean of the nuclear signal intensity of 5 micrographs. The whisker indicates minimum and maximum, and the box indicates the 25th and 75th percentiles (edges of the box), and median (center line). The original figures are available in the Figshare repository under [https://doi.org/10.6084/m9.figshare.23243918]. c Phenotypes of 3-week-old WT, 35S::sim3|S11/15A-GFP(35S::sim3|S11/15A), 35S::sim3|S11/15D-GFP (35S::sim3|S11/15D), and 35S::S11/15D-GFP (35S::S11/15D) seedlings under steady-state conditions. d Phenotypes of mock or TuMV-infected WT and transgenic plants at 18 dpi. e Bar plot showing the ratio of virus-infected to total leaf area of WT and transgenic plants at 18 dpi (n = 5). f Immunoblot analysis of the phosphorylation of transiently expressed NPR1 or its mutants in the presence of GUS, NIb or NIb_sim2 by Phos-tag. Equal amounts of GFP-Trap agarose-enriched NPR1 or its mutants were analyzed by anti-NPR1 antibodies or treated with Phos-tag. Numbers represent relative Phos-tag intensities that are corrected according to the total protein amount. FLAG-4×Myc-SUMO3 and RFP-tagged GUS, NIb or NIb_sim2 were detected with anti-Myc and anti-mRFP antibodies, respectively. The experiment was independently repeated twice with similar results. Data are presented as mean values ± SD. Statistical analyses were performed using two-tailed Student’s t test. Source data are provided as a Source Data file.