Combined Physiological and Transcriptomic Analyses of the Effects of Exogenous Trehalose on Salt Tolerance in Maize (Zea mays L.)

Soil salinization severely affects the quality and yield of maize. As a C4 plant with high efficiency in utilizing light and carbon dioxide, maize (<i>Zea mays</i> L.) is one of the most important crops worldwide. This study aims to investigate the pathways and mechanisms by which trehalose mediates the improvement of salt tolerance in maize through a combined analysis of physiology and transcriptomics. The results indicate that foliar application of trehalose treatment significantly increased maize biomass and antioxidant enzyme activity while reducing the H₂O₂ and Na⁺/K⁺ ratios in both the aerial and underground parts of the plant. Additionally, trehalose enhanced the total secretion of organic acids from maize roots, improving the soil microenvironment for maize growth under salt stress and alleviating Na⁺ toxicity. Transcriptomic data revealed that under salt stress, most differentially expressed genes (DEGs) were enriched in pathways related to photosynthesis, abscisic acid signaling, and sugar metabolism, and trehalose application increased the expression levels of these pathways, thereby mitigating the growth inhibition caused by salinity. This study elucidates mechanisms for enhancing salt tolerance in maize, providing theoretical support for improving its resilience and offering innovative strategies for utilizing a wide range of saline-alkali land.