Regulation of protease inhibitors and plant defense

Protease inhibitors are an important element of the plant defense response to insect predation, and may also act to restrict infection by some nematodes. Production of these inhibitors is highly regulated by a signal transduction pathway that is initiated by predation and transduced as a wound response. Local and systemic extracellular inducers of the signal pathway are released by injury. Current evidence suggests that the production of the inhibitors occurs via the octadecanoid pathway, which catalyzes the breakdown of linolenic acid and the formation of jasmonic acid to induce protease inhibitor gene expression.