Induction of an acidic isozyme of peroxidase and acquired resistance to wilt disease in response to treatment of tomato roots with 2-furoic acid, 4-hydroxybenzoic hydrazide or salicylic hydrazide

Abstract

Thirty nine derivatives of salicylic acid, nicotinic acid or furoic acid were tested for their ability to induce cell wall bound peroxidase activity in an attempt to identify inducers of acquired resistance. The activity of cell wall bound peroxidase in tomato hypocotyls was enhanced by treatment of roots with 4-hydroxybenzoic hydrazide (4HBHZ), salicylic hydrazide (SHZ), or 2-furoic acid (2FA). Isoelectric focusing revealed that an acidic isozyme (pI 4.6) of peroxidase was induced specifically by treatment with these compounds. The isozyme was induced independently to wounding or pathogen infection. Dipping roots in solutions of these compounds at concentrations of 0.1 μm4HBHZ, 1.0 μmSHZ and 10 μm2FA also induced resistance against the tomato wilt disease caused byFusarium oxysporumf.sp.lycopersici.