Tomato Plants’ Chemical Weapons

Backyard garden tomato patches may seem like spots of peace and tranquility. But researchers in Japan report that these pastoral plots are actually sites of complex chemical warfare (Proc. Natl. Acad. Sci. USA 2014, DOI: 10.1073/pnas.1320660111). A team led by Kenji Matsui of Yamaguchi University found that when hungry cutworms begin to chomp away on tomato plants, the plants’ leaves release the volatile compound (Z)-3-hexenol. Neighboring plants detect this chemical cry for help and pull (Z)-3-hexenol from the air. The plants convert the alcohol to the glycoside (Z)-3-hexenylvicianoside, a compound that Matsui’s team found negatively affects the cutworms’ maturation and survival rate and therefore protects the neighboring plants. Now that’s one smart tomato. Although this is the first time this type of defensive strategy has been reported in plants, the researchers believe that because (Z)-3-hexenol is common in leaves, it might be a general defense for many kinds of plants. The research could also lead to new methods of pest control.