Gibberellic Acid Enhances the Germination and Growth of Maize under Salinity Stress

Soil salinity is the major limiting factor restricting plant growth and development. Little is known about the comparative and combined effects of gibberellic acid (GA3) seed priming and foliar application on maize under salt stress. The current study determined the impact of different concentrations of GA3 on morpho-physiological and photosynthetic attributes of maize seedlings under salinity stress treatments (no salinity and severe salinity-15 dSm-1). The GA3 treatments consisted of 1mM, 2mM, 3mM, 4mM and 5mM GA3 seed priming and exogenous application in salt condition. Salt stress particularly at 15 dSm-1 reduced the length of shoots and roots, fresh and dry weights, chlorophyll, lycopene, beta-carotine and carotenoid contents in maize plants. Nevertheless, the application of GA3 improved maize growth under salt stress. Compared with salt, the 2mM GA3 treatment (T4) recorded the highest increase in roots and shoots length, roots fresh and dry weights, shoots fresh and dry weights, chlorophyll content under salt stress compared to other concentrations. These results indicated that 2mM GA3 priming and exogenous application could be used as an effective tool for improving the maize growth and development in salt contaminated soils.