Exogenous hydrogen peroxide enhanced corn (Zea mays L.) plants response to drought stress

Drought stress is one of the most important factors limiting the growth and production of crops. Exogenous application of some biological or chemical agents can mitigate the negative effects of drought stress. In this experiment, the effect of hydrogen peroxide application on water-stressed corn plants was investigated through various biochemical and molecular methods. Corn seedlings grown in hydroponic culture were treated with hydrogen peroxide (2 mM) and then exposed to water stress using polyethylene glycol 6000 at 3 levels of 0, -2 bar and -4 bar. The results showed that drought stress altered all of the studied traits significantly. With increase in stress level, the activity of catalase enzyme was decreased and the highest drop was of 50% was on the eighth day post stress. It was revealed that catalase activity was increased up to 18% on the second day after the stress and it decreased significantly with the time. The indigenous accumulation of hydrogen peroxide increased significantly in -4 treatment and four days after stress while it was reduced by 50% on the eighth day after stress. It was revealed that hydrogen peroxide application increased PAO gene expression 1.7 times compared to the control plants. Its expression was decreased by 35% at -4 bar in control plants while hydrogen peroxide treatment increased its expression by 2.8 times. These results increase the plant's resistance to drought stress and reduce the negative effects of drought stress. In this way, it reduces the negative effects of drought stress.