Stress-protective effect of jasmonic and succinic acids on barley plants under soil drought conditions
The effect of the preplant treatment of seeds with solutions of jasmonic (JA, 10 <sup>-7</sup> M) and succinic (SA, 10 <sup>-3</sup> M) acids and their combination on the resistance of barley ( Hordeum vulgare L.) plants to the drought at early phases of development has been investigated in soil culture. A higher content of water in plant leaves was recorded under the action of JA and SA in the drought conditions in comparison with the plants grown from untreated seeds. The treatment of seeds with JA and SA also reduced the inhibition of plant growth caused by drought. In the leaves of plants grown from the seeds treated with JA and (to a lesser degree) SA, a higher activity of superoxide dismutase was observed under drought conditions. The pretreatment with JA and SA invoked a decrease of catalase activity in plant leaves under normal wetting conditions; at the same time, at the drought, the enzyme activity most significantly increased in the treatment with JA. An increase of peroxidase activity in leaves under the effect of JA and SA was recorded, which was more appreciable in the drought conditions. At the combined treatment of seeds with JA and SA, antagonism of effects on all studied parameters has been revealed. The mechanisms of the stress-protective effect of JA and SA on barley plants in the drought conditions and possible reasons of antagonism of their physiological effects have been discussed.