Fig. 4

The effect of salicylic acid (SA) on the growth of Cmm and expression of WRKY genes in tomato plant. a Disease symptom of the SA-treated tomato cotyledons at 6 dpi. b The effect of exogenous applied SA on the growth of Cmm in tomato cotyledons. Tomato seedlings were transplanted to soil with or without 1 mM of SA 24 h before inoculation. The amount of Cmm ptssk DNA relative to tomato COX DNA was determined by quantitative polymerase chain reaction analysis. Values are represented as the means ± standard deviation for six seedlings. Significantly lower values compared with water control are denoted by asterisk (*p-value < 0.05; **p-value < 0.01, t-test). c The effect of SA on the expression of WRKY genes in tomato cotyledons. Tomato seedlings were transplanted to soil with or without 1 mM of SA and incubated for 6 h. Transcript levels were quantified by quantitative reverse transcription-polymerase chain reaction and expressed relative to the transcript level in SA-treated cotyledons, which was assumed to be 100. Data are represented as the mean values ± standard deviation for three replicates