VIEW ARTICLE

Physiology and Biochemistry

Involvement of Ethylene in Herbicide-Induced Resistance to Fusarium oxysporum f. sp. melonis. R. Cohen, Department of Plant Pathology and Microbiology, The Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot 76100; J. Riov(2), N. Lisker(3), and J. Katan(4). (2)Department of Horticulture, The Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot 76100; (3)Department of Stored Products, Agricultural Research Organization, The Volcani Center, P.O.B. 6 Bet Dagan 50250, Israel; (4)Department of Plant Pathology and Microbiology, The Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot 76100. Phytopathology 76:1281-1285. Accepted for publication 28 April 1986. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/Phyto-76-1281.

Pretreatment of melon seedlings with the herbicide dinitramine induced resistance to subsequent inoculation with Fusarium oxysporum f. sp. melonis. Ethylene production in leaves and stems of the herbicide-treated plants or in genetically resistant ones was much suppressed compared with nontreated diseased seedlings. Ethylene production in diseased seedlings reached its peak shortly after the appearance of symptoms. Similarly, dinitramine increased resistance to Fusarium wilt and suppressed ethylene production in tomato seedlings. Suppression of ethylene production was positively correlated with levels of induced resistance in melon seedlings treated with various herbicides or with various concentrations of dinitramine. Aminoethoxyvinylglycine and aminooxyacetic acid, which inhibit ethylene biosynthesis, induced resistance to Fusarium wilt and suppressed ethylene production. Silver thiosulfate, an inhibitor of ethylene action, also increased resistance to Fusarium wilt.