Enhancing Plant Stress Resilience with Osmolytes and Nanoparticles

Osmolytes are small organic compounds produced by plants in response to abiotic stresses such as salinity, drought, heavy metals, and high temperature. They play a vital role in mitigating the detrimental effects of these stresses on plant growth and productivity. While past reviews have discussed the biosynthesis of various osmolytes, there remains a lack of critical evaluation and consolidation of recent advances in understanding the functional mechanisms of osmolytes in conferring stress tolerance across plant species. Furthermore, the emerging use of osmolytes in conjugation with nanoparticles (NPs) to enhance abiotic stress alleviation has not been reviewed thus far. This paper comprehensively examines the state-of-the-art on the protective roles of diverse osmolytes against major abiotic stresses including salinity, drought, heavy metals and heat stress. The multifaceted exogenous protective effects of osmolytes arising from oxidative damage prevention, protein/membrane stabilization and toxic ion detoxification leading to improved ion homeostasis are discussed. Additionally, this review provides the very first insight into the use of osmolyte-coated NPs in improving abiotic stress amelioration, evaluating current research on synergy between plant osmolytes and NPs. Recent biotechnological interventions in developing transgenic plants with improved osmolyte production are also assessed. This timely review comprehensively evaluates recent progress in osmolytes-based abiotic stress mitigation research, while underlining key challenges in this domain that need to be addressed to leverage the full potential of osmolytes. Thereby, it provides important perspectives for researchers working on plant adaptation under changing climatic conditions.