Bacterial osmoprotectants-a way to survive in saline conditions and potential crop allies

Soil salinization, affecting 6.5% of arable land, deteriorates soil properties, reduces microbiota activity, hinders plant growth, and accelerates soil erosion. Excessive salt induces physiological drought and toxicity stress in plants, causing chlorosis, ion imbalances, and enzyme disruptions. This paper discusses microorganisms' resistance mechanisms, plant responses to salt stress, and summarizes current knowledge on bacterial osmoprotectants and their functions. It also reviews emerging agrobiotechnological strategies using microbial osmoprotectants to remediate salinized soils and enhance plant growth and productivity under salt stress. Osmoprotectants stabilize proteins, buffer redox potential, and retain water, thus alleviating osmotic stress and promoting bacteria and plants growth. Their application improves soil properties by enhancing aggregate formation, water permeability, moisture content, cation exchange capacity, and ion availability. Despite extensive literature on the function of osmoprotectants, the knowledge about their role in soil environments and agrobiotechnology applications remains limited. This paper indicates proposed research perspectives, including discovering new osmoprotectants, their correlation with soil fertilization, interactions with the soil microbiome, and plant responses. It also identifies significant knowledge gaps in these areas, highlighting the need for further studies to consolidate existing data and assess the potential of this approach to enhance soil health and crop productivity in saline environments.