Nanoparticles and their crosstalk with stress mitigators: A novel approach towards abiotic stress tolerance in agricultural systems

Plants are exposed to adverse environmental conditions, including cold, drought, heat, salinity, and heavy metals, which negatively impact plant growth and productivity of edible crops worldwide. Although the previous literature summarized the nanoparticle’s involvement in abiotic stress mitigation, the interaction of nanoparticles with other stress mitigators to overcome abiotic stress from plants remains unclear. Currently, nanotechnology is considered a growing new field in agriculture for understanding plants’ adapted stress tolerance mechanisms. Recent research has shown that nanoparticles can effectively mitigate abiotic stress by interacting synergistically with plant growth regulators. To address this, we comprehensively demonstrated the combined positive potential of nanoparticles in combination with plant growth regulators (signaling molecules, phytohormones, nanoparticles-nanoparticles interaction, fungi, plant growth promoting rhizobacteria and other metal salts) to improve plant growth and mitigate abiotic stresses. Their co-applications augment the plant’s growth, nutrient uptake, antioxidant defense system, water absorption, cell viability, water use efficiency, and photosynthetic and biochemical attributes by reducing oxidative stressors under various abiotic stresses in different plant species. This review provides a comprehensive overview of the combined applications of nanoparticles and plant growth regulators, a novel strategy to reduce the harmful effects of abiotic stress on plants. It identifies research gaps and recommends future studies to overcome their phytotoxicity worldwide.