Induction of disease resistance by acibenzolar-S-methyl and o-hydroxyethylorutin against Botrytis cinerea in tomato plants

This study reports the comparison of effectiveness of o-hydroxyethylorutin (HER) and known plant defence activator acibenzolar-S-methyl (ASM) in limiting Botrytis cinerea infection development on tomato plants. Pretreatment of plants with ASM as well as with HER 24 h before pathogen challenge reduced B. cinerea infection development. Limited infection development was correlated with increasing generation of reactive oxygen species (ROS): superoxide anion (O2−) and hydrogen peroxide (H2O2) as well as with rising peroxidase (PO) activity. O2− and H2O2 generation was weakly enhanced with ASM and HER treatment alone or pathogen inoculation alone and highly enhanced in ASM and HER pretreated plants upon challenge inoculation shortly after challenge, suggesting the occurrence of priming during the interaction tomato–ASM- and tomato–HER–B. cinerea. Early and enhanced ROS generation as well as the increase in PO activity seems to be an important element of induced tomato resistance mechanism against B. cinerea.