Molecular Responses of Exogenous Polyamines under Drought Stress in the Barley Plants

The effects of exogenous polyamines were investigated in Hordeum vulgare L. Btilbtil-89 exposed to drought stress about mitotic activity, chromosome behaviors, cell cycle, and total protein content. In this study, drought stress had a reducing effect on the mitotic index and caused chromosomal abnormalities. All of the polyamines applied under drought stress had reducing effects on them. Due to the cell cycle analysis, although the Spd application increased in the S phase compared to the control group, other polyamine groups had reducing effect. As a result of drought application alone, the G(1) and G(2) stages increased numerically compared to the control group, while after the PEG+polyamine applications, the G(1) stage decreased compared to its control. In PEG application alone, a 2-fold increase in total protein amount compared to the control group was observed, while PEG+polyamine applications showed a remarkable increase compared to its control. Consequently, the application of polyamines at the appropriate time and dose can greatly alleviate the negative effects of drought stress on plant growth and development.