Gibberellic acid improves water deficit tolerance in maize plants
The combination effects of water stress and gibberellic acid (GA3) on physiological attributes and nutritional status of maize (Zea mays L. cv., DK 647 F1) were studied in a pot experiment. Maize plants were grown in the control (well watered WW) and water stress subjected to treated both water stress and two concentrations of gibberellic acid (GA3 25 mg L-1, 50 mg L-1). WS was imposed by maintaining the moisture level equivalent to 50 % pot capacity whereas the WW pots were maintained at full pot capacity. Water stress reduced the total dry weight, chlorophyll concentration, and leaf relative water content (RWC), but it increased proline accumulation and electrolyte leakage in maize plants and appears to affect shoots more than roots. Both concentrations of GA3 (25 and 50 mg L-1) largely enhanced the above physiological parameters to levels similar to control. WS reduced leaf Ca2+ and K+ concentrations, but exogenous application of GA3 increased those nutrient levels similar or close to control. Exogenous application of GA3 improved the water stress tolerance in maize plants by maintaining membrane permeability, enhancing chlorophyll concentration, leaf relative water content (LRWC) and some macro-nutrient concentrations in leaves.