Methyl jasmonate

Methyl jasmonate (MeJA) is a substance used in plant defense. Plants produce jasmonic acid and methyl jasmonate in response to many biotic and abiotic stresses (particularly herbivory and wounding), which build up in the damaged parts of the plant. Jasmonates act as signalling compounds for the production of phytoalexins. Phytoalexins, once ingested by the attacker (e.g., insect), can be toxic or interfere with its digestion and may deter the attacker from further feeding. The jasmonate signal often spreads systemically throughout the plant and is a major component of systemic acquired resistance.

MeJA is also a plant hormone involved in tendril (root) coiling and seed maturation.