Induction of heat resistance of wheat coleoptiles by salicylic and succinic acids: Connection of the effect with the generation and neutralization of reactive oxygen species

The influence of salicylic (SaA) and succinic (SuA) acids on the generation of reactive oxygen species (ROS) and the heat resistance of wheat (Triticum aestivum L.) coleoptiles has been studied. The treatment of coleoptiles with 10 μM SaA or SuA results in the accumulation of hydrogen peroxide and enhanced formation of a superoxide anion radical. This effect was partially suppressed by both α-naphthol (the NADPH oxidase inhibitor) and salicylhydroxamic acid (peroxidase inhibitor). SaA and SuA cause an increase in the activity of antioxidant enzymes, such as superoxide dismutase, catalase, and soluble peroxidase, and improve the heat resistance of coleoptiles. Antioxidant ionol and inhibitors of the NADPH oxidase and peroxidase significantly reduce the positive influence of SaA and SuA on the heat resistance of wheat coleoptiles. ROS are considered to be intermediates for heat resistance induction in coleoptiles, treated with SaA and SuA; enhanced ROS generation can be caused by an increased activity of the NADPH oxidase and peroxidase.