Fig. 3

Exogenous NAD(P)⁺-induced systemic responses in lecrk-VI.2 and several SAR mutants. a, b NAD(P)⁺-induced systemic PR1 expression a and systemic resistance b in the wild-type (WT), lecrk-VI.2, and dorn1-3 plants. Three lower leaves on each 4-week-old soil-grown plant were infiltrated with H₂O, 0.4 mm NAD⁺, or 0.8 mm NADP⁺ every 12 hr for a total of four times. About 5 hr after the last infiltration, two systemic leaves were either collected for PR1 analysis a or challenge-inoculated with a Psm suspension (OD₆₀₀ = 0.001) b. Three d later, eight leaves were collected to examine the growth of the pathogen. Expression levels of PR1 a were normalized against the constitutively expressed UBQ5. Data represent the mean ± SD of three a or eight biological replicates b. Asterisks denote significant differences between the induction in the mutants and that in the wild type (**p < 0.01, ***p < 0.001; two-way ANOVA with Sidak’s test). Upper line: induction by NADP⁺; lower line: induction by NAD⁺. c NAD(P)⁺-induced systemic resistance in the wild-type, sid2, ald1, fmo1, nho1, npr1, azi1, and pepr1 pepr2 plants. The experiment was conducted as in b. Data represent the mean ± SD of eight biological replicates. Asterisks denote significant differences between the induction in the mutants and that in the wild type (***p < 0.001; two-way ANOVA with Sidak’s test). Upper line: induction by NADP⁺; lower line: induction by NAD⁺