Benefits and costs of tomato seed treatment with plant defense elicitors for insect resistance

Seeds may be receptive to plant defense activators such as β-amino butyric acid and jasmonic acid, conferring protection to the subsequent plant against a wide spectrum of plant pathogens and insects. We examined the independent and interactive effects of methyl jasmonate (MeJA) seed treatment on tomato fruit worm (Helicoverpa zea) larval growth and the activity of the defensive protein, polyphenol oxidase (PPO), in leaves of tomato plants at three different plant stages. Additionally, we measured the dosage effects of MeJA seed treatment on several plant vegetative and reproductive traits. Results suggest that seed treatment with MeJA will induce defenses in plants, which is correlated with increased PPO activity in leaves and reduction in larval growth. However, fitness costs in plants were observed with higher dosage of MeJA. Thus, if successfully integrated with other facets of an integrated pest management program, the use of MeJA as elicitors of plant defense could be an important tool in managing insect pests and contribute to a reduction in applications of chemical pesticides.