Fig. 4

Enzyme activities in tomato levels. The activities of protease inhibitor (PI, A), peroxidase (POD, B) and polyphenol oxidase (PPO, C) were determined using the leaves from tomato plants grown in sterilized soil inoculated with Stenotrophomonas sp. T6–4 and 24 h after S. litura larvae inoculation. Values are means ± SE from three replicates. The asterisk indicates statistically significant differences according to independent t-test between the bacterium-treated group and control-treated group (*P < 0.05,**P < 0.01,***P < 0.001)