Figure 2
Involvement of the SA signalling pathway in F. graminearum-infiltrated Arabidopsis leaves with and without NMN pretreatment. (a,b) RT-qPCR analysis of PR1 and PDF1.2a mRNA expression in F. graminearum-inoculated WT plants with and without NMN pretreatment. Six hours after NMN pretreatment (time point 0), leaves were injected with F. graminearum (n = 18). Plants were incubated under high humidity conditions and harvested at 0, 6, 24, 48 and 72 h. ACTIN2/8 (Act2/8) was used as the reference gene. The data represent the average of all samples, and error bars represent the standard deviation (n = 3). ACTIN2/8 (Act2/8) was used as the reference gene. Each value is shown as fold change (each sample vs 0 h of water treatment). Error bars represent the standard deviation (n = 3). (c) Accumulation of salicylic acid (SA). (Student’s t-test *P < 0.05) (d,e) NMN induces disease resistance against F. graminearum via the salicylic acid (SA)-independent signalling pathway. NMN (0.3 mM) was sprayed onto the surface of sid2-2 rosette leaves prior to incubation for 6 h. Six hours after NMN treatment, conidia solutions (1 × 105 conidia/ml) of F. graminearum were injected into leaves. (d) The disease severity was evaluated by the disease symptoms of inoculated leaves 3 days after inoculation (n = 18). Open box: normal, cross-hatched box: colour change, dot box: partial aerial mycelium, closed box: expanded aerial mycelium. (e) F. graminearum DNA was measured by qPCR. Error bars represent the standard deviation (n = 3) (Student’s t-test **P < 0.01).
