Expression profiles for sporamin, Ib NAC 1 and Ib WRKY 1 in sweet potato leaves. The third leaves of sweet potato plants were sampled at 0.25, 0.5 and 6 h after treatment with MeJA (0.5 μM) (A-C), DIECA (50 mM) (D-F), or SA (2 mM) (G-I) independently. Total RNA was extracted at the indicated time points from untreated (cK) and treated leaf samples. (A-I) Relative expression of sporamin, IbNAC1 and IbWRKY1 transcripts were measured by qRT-PCR. Asterisks indicate statistically significant differences (Dunnett’s multiple comparison test, *represents P < 0.05; ** represents P < 0.01; *** represents P < 0.001; ‘ns’ not significant represents P > 0.05). The results are representative of three replicates.