MECHANISMS OF ENHANCING PLANT STRESS TOLERANCE UNDER DROUGHT AND SALINITY CONDITIONS USING COBALT(II) COMPLEXES AND HYDROGEL CAPSULES

Abstract

This study investigates the role of cobalt(II) complexes incorporated into hydrogel capsules in enhancing plant tolerance to abiotic stresses such as drought and salinity. Cobalt(II) ions, when coordinated with biologically active ligands such as quinazolin-4-one and 6-aminopurine, form stable complexes that demonstrate biostimulatory effects on seed germination, root elongation, and photosynthetic activity. The encapsulation of these complexes into hydrogels ensures their controlled and prolonged release into the rhizosphere, creating a microenvironment that maintains soil moisture and nutrient availability under stress conditions. Experimental results revealed that plants treated with cobalt(II) complex-loaded hydrogels exhibited significantly higher germination rates, increased root and shoot growth, larger leaf area, and enhanced photosynthetic intensity compared to untreated controls. Moreover, stress indices indicated improved drought and salinity resistance, suggesting that cobalt(II) hydrogel formulations mitigate oxidative damage and improve water use efficiency. These findings highlight the potential application of cobalt(II) complex-based hydrogel systems as environmentally safe, cost-effective, and sustainable biostimulants for modern agriculture. Their use can contribute to stable crop productivity under adverse environmental conditions, supporting food security in regions prone to water scarcity and soil salinization.