The Effect of Hormonal Priming on Morphological Characteristics and Antioxidant Enzyme Activities in Silage Maize Under Salt Stress

Abstract

Salinity is one of the major problems limiting plant growth, development, survival, yield, and quality. Climate change and increasing salinity levels force a concentration on sustainable production systems. Therefore, this study aimed to determine the effects of different doses of gibberellic acid (GA3) (0, 150, and 300 mg/L) and salicylic acid (SA) (0, 0.25, and 0.50 mM) priming on some morphological and antioxidant enzyme activities of silage maize (Zea mays L.) seedlings exposed to salinity stress. Four different NaCl (0, 75, 150, and 225 mM) concentrations as salt stress and three different doses of both SA and GA3 were investigated. The data obtained were subjected to analysis of variance according to a randomized complete block design using a factorial experimental design with four replications per treatment in 3 L pots. The results showed that GA3 and SA priming had statistically significant effects on all investigated traits under different salt concentrations (except water content). Findings revealed that shoot, root, and leaf development, as well as antioxidant enzymes, were suppressed by salinity stress. The silage maize plant was statistically significantly affected starting from the lowest dose of 75 mM, depending on salt concentrations. Increasing salt concentrations negatively affected above-ground and below-ground parameters. However, SA and GA3 treatments had positive impacts on all examined traits. SA and GA3 priming treatments emerged as important strategies supporting root and shoot growth under saline conditions, thereby strengthening plant adaptation. The best results were obtained in groups exposed to 75 mM salt stress, where 300 mg/L GA3 was applied, and in groups without salt stress, where the same GA3 dose was applied. It was concluded that GA3 priming treatments, in particular, were more effective than SA treatments, alleviating salt stress and positively contributing to plant development.