[The role of reactive oxygen species and calcium ions in the implementation of the stress-protective effect of brassinosteroids on plant cells].

The effect of the brassinosteroids (BS) 24-epibrassiniolide and 24-epicastasterone on the thermoresistance of wheat coleoptile (Triticum aestivum L.) and their generation of the superoxide anion radical and antioxidant enzymes activity were investigated. The treatment of coleoptiles with 10 nM solutions of BS caused a transient increase in O2·- generation and a subsequent increase in the activity of superoxide dismutase and catalase and an improvement in heat resistance.

[Reactive oxygen forms and Ca ions as possible intermediaries under the induction of heat resistance of plant cells by jasmonic acid].

The participation of reactive oxygen species (ROS) and calcium ions in realization of influence of exogenous jasmonic acid (JA) on the heat resistance of wheat coleoptiles has been investigated. Influence of 1 microM JA caused the transitional intensifying of generation of superoxide anion-radical (O2*-) and hydrogen peroxide in coleoptiles with the maximum within 15-30 minutes after the treatment beginning. Within the first hour after the beginning of coleoptiles treatment with JA the increase of superoxide dismutase (SOD) activity was noted.

[Possible pathways of heat resistance induction in plant cells by exogenous nitrogen oxide].

The mechanisms of influence of exogenous nitrogen oxide (NO) on heat resistance of wheat coleoptiles have been studied. The treatment of plant cells with nitrogen oxide donor (sodium nitroprusside) resulted in the increase of superoxide anion-radical (O2*-) generation already after 10 minutes. The inhibitor of protein biosynthesis cycloheximide did not inhibit the O2*- generation by coleoptiles caused with the NO donor whereas the inhibitor of phosphatidic acid formation (butanol-1) partially inhibited it.

[Induction of heat resistance in wheat coleoptiles by salicylic and succinic acids: connection of the effect with the generation and neutralization of active oxygen forms].

The influence of salicylic (SaA) and succinic (SuA) acids on the generation of active oxygen forms (AOFs) and the heat resistance of wheat (Triticum aestivum L.) coleoptiles has been studied. The treatment of coleoptiles with 10 microM SaA or SuA results in the accumulation of hydrogen peroxide and enhanced formation of a superoxide anion radical.

[Influence of salicylic and succinic acids on formation of active oxygen forms in wheat coleoptiles].

The comparative study of influence of exogenous salicylic (SaA) and succinic (SuA) acids on the production of reactive oxygen species by isolated wheat coleoptiles has been provided. Under the action of both acids the increase of generation of superoxide anion-radical (O2(.-)) was observed.