INDUCTION OF WOUND RESPONSE GENES IN TOMATO LEAVES BY BESTATIN, AN INHIBITOR OF AMINOPEPTIDASES

Bestatin, an inhibitor of some aminopeptidases in plants and animals, is a powerful inducer of defense genes in tomato leaves; these genes a re also induced by herbivore attacks, mechanical wounding, systemin, a nd methyl jasmonate. Unlike wounding and systemin, bestatin does not c ause an increase in intracellular jasmonic acid concentrations, and in hibitors of the octadecanoid pathway do not inhibit induction by besta tin. Furthermore, defense genes were induced by bestatin in a mutant t omato line (JL-5) with a defect in the octadecanoid pathway. Bestatin therefore appears to be exerting its effects close to the level of tra nscriptional control of these genes, where it may be inhibiting a regu latory protease.