This work deals with the effect of aqueous extracts from the mushrooms Lentinula edodes and Agaricus blazei and the inducer of resistance acibenzolar-S-methyl (ASM) on the control of bacterial wilt in tomato (Lycopersicon esculentum Mill.), as well as investigating changes in enzyme activities. Aqueous extracts of the mushrooms and ASM were tested for inhibition of bacterial growth in vitro. Plants were treated with different concentrations of the extracts and with ASM two days before inoculation in greenhouse conditions. The evaluations were based upon disease severity and activity of some enzymes. In general, the isolates of A. blazei and L. edodes, as well as ASM, did not inhibit in vitro bacterial growth. In treated plants, the isolate Le-96/17 10 % (v/v) of L. edodes and ASM significantly reduced bacterial wilt. Chitinase, phenylalanine ammonia-lyase and polyphenoloxidase activities were not changed for most of the treatments; however, increased chitinase activity was verified in plants treated with ASM. The ASM, Abl-26 and Le-96/17 treatments increased peroxidase activity in plants and, based upon the results, L. edodes mushroom and ASM both exhibit potential to reduce bacterial wilt in tomato plants, probably by inducing resistance.
bacterial wilt; PR-proteins; induced resistance
