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

Abstract

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.

Mitigation of Salinity-Induced Growth Inhibition of Maize by Seed Priming and Exogenous Application of Salicylic Acid

“…These outcomes are consistent with past studies [47], which shown that applying GA3 increased the chlorophyll content of leaves. When maize was exposed to salt stress, foliar SA treatment significantly improved the amount of chlorophyll in the plant [20].…”

“…Maintaining a sufficient water level is an essential physiological step for keeping normal development progression in plants under salt stress [20]. RWC is a well-known indicator of water status in plants since it is a water-related feature [23].…”

“…RWC is a well-known indicator of water status in plants since it is a water-related feature [23]. Salinity reduces the soil's water potential, which has been linked to a drop in photosynthesis and a decline in the RWC of leaves [23,20]. Exogenous chemical supplementation has been found to improve the water status of many plant families [41].…”

“…"The capacity of seeds to germinate in soil with high salt concentrations is critical for the survival of many plant species. Seed priming accelerates many metabolic processes involved in the early stages of germination, and seedlings from primed seeds have been shown to develop more vigorously and perform better under adverse environmental conditions than non-primed seeds" [19,20]. "Salicylic acid (SA) improves crop performance under abiotic and biotic conditions by acting as both a plant growth regulator and an antioxidant" [21,22].…”

Spraying exogenous hormones alleviate impact of weak-light on yield by improving leaf carbon and nitrogen metabolism in fresh waxy maize

“…The application of IAA and CTK increased grain yield, 1000-grain weight and filled-grain percentage of rice under salt stress ( Javid et al., 2011 ). The application of GA 3 improved maize growth under salt stress ( Rauf et al., 2022 ). It was well established and known that 6-BA could promote plant cell division, inhibit and scavenge free radicals, delay leaf senescence, increase DM and N accumulation ( Roitsch and Ehneß, 2000 ).…”