[Effect of hydrogen peroxide on morphological characteristics and resistance of wheat calluses to the stinking smut fungus].

We studied the effect of hydrogen peroxide on morphological characteristics and resistance of common wheat calluses (Triticum aestivum L.) to Tilletia caries Till. The induction of the defense response and morphogenesis in calluses depended on H2O2 concentration. A correlation was revealed between the elevated concentration of hydrogen peroxide in wheat calluses and high activity of oxalate oxidase in the cell wall. Administration of H2O2 into the callus culture medium was followed by rhizogenesis, induced the formation of dense regions, and inhibited fungal growth on calluses. Hydrogen peroxide at high concentrations was less potent in inhibiting the growth of fungi. A relationship was found between oxalate oxidase activity, H2O2 concentration, and morphogenetic and defense responses of calluses induced by exogenous hydrogen peroxide. These data suggest that the induction of H2O2 generation is one of the approaches to increase callus resistance.