Sortin2: a chemical compound to enhance tolerance against salinity stress in Arabidopsis thaliana

Due to climate change, drought-prone areas have increased, and soil salinity is progressively increasing, leading to a greater number of regions with highly saline soils. Salt stress represents one of the most detrimental factors in modern agriculture, prompting the scientific community to seek effective solutions. Among the proposed alternatives, the use of bioactive chemical compounds to enhance plant tolerance and counteract saline stress has emerged as a promising approach. Since salt stress tolerance could be conferred by increasing the endocytic trafficking, the use of the synthetic compound Sortin2 (5-[[5-(3-Chlorophenyl)-2-furanyl] methylene]-4-oxo-2-thioxo-3-thiazolidineethanesulfonic acid) that induces endocytic transport toward the vacuole in root cells could be a tool of particular interest to overcome the detrimental effects of salt stress in plants. This study analyzed the use of Sortin2 to mitigate salinity stress in the model plant Arabidopsis thaliana. Indeed, Sortin2 conferred tolerance to salt stress in seedlings, improving water retention capacity and preventing loss of photosynthetic pigments. The effect of Sortin2 counteracted the toxicity of sodium ions, thereby diminishing ROS levels produced by salt stress. Sortin2 promoted sodium sequestration into the vacuole, explaining the improved performance of A. thaliana under salt stress. In addition, Sortin2 modulated stress-related hormonal responses in roots, enhancing abscisic acid and brassinosteroid signaling while suppressing the jasmonate response under salt stress. In contrast, in aerial tissues, Sortin2 inhibited brassinosteroid- and ABA-mediated signaling. Based on our results, Sortin2 enhances salt stress tolerance in A. thaliana by reducing oxidative stress and promoting hormone-mediated stress responses. Therefore, Sortin2 could be considered a beneficial compound for improving stress tolerance in agriculturally relevant species. These findings highlight the potential of targeting endomembrane trafficking as a strategy to improve salt tolerance in plants and lead to further investigation of Sortin2 in crop systems.