Induction of antimicrobial 3-deoxyflavonoids in pome fruit trees controls fire blight.

, 765Ð770 (2003); received August 1, 2003Fire blight, a devastating bacterial disease in pome fruits, causes severe economic lossesworldwide. Hitherto, an effective control could only be achieved by using antibiotics, but thisimplies potential risks for human health, livestock and environment. A new approach allowstransient inhibition of a step in the flavonoid pathway, thereby inducing the formation of anovel antimicrobial 3-deoxyflavonoid controlling fire blight in apple and pear leaves. Thiscompound is closely related to natural phytoalexins in sorghum. The approach does not onlyprovide a safe method to control fire blight: Resistance against different pathogens is alsoinduced in other crop plants.