Fig. 2 Tomato plants grown in competition (A) and tomato plants grown with mycorrhizae had higher C/N ratios compared to tomato plants grown without competition (B), or without mycorrhizae. Tomato plants grown with competition and mycorrhizae induced an increase in carbon nitrogen ratio and thus a decrease in nutritional quality for herbivores. A higher C/N ratio means a lower plant nutritional quality. Symbols represent mean +/- SE.
Overall, plants treated with jasmonic acid had almost double the level of protease inhibitor activity (Fig. 3, F1,148=9.55, p=0.002), confirming that the treatment was effective at inducing the plants. Mycorrhizae decreased protease inhibitor levels by 30% regardless of whether the plant was treated with jasmonic acid (Fig. 3, F1,148=4.35, p=0.039). Neither competition (F1,148=0.057, p=0.451) nor interaction between competition and mycorrhizae (F1,148=0.986, p=0. 0.323) impacted protease inhibitors.