ABSTRACT
Anthropic climate change factors lock the global agri-food sector into a ‘vicious cycle’ of crop yield penalty, food insecurity, increased crop production, environmental deterioration, and intensifying public health issues. Drought, submergence, temperature extremes, salinity, and heavy metal toxicity are major abiotic stresses that are detrimental to the growth and productivity of economically important crop plants. Contextually, integrating nanotechnology with agricultural practices offers an immediate, climate-smart solution for sustainable agriculture and breaking the crop yield barrier. The present chapter reviews how engineered and biosynthesized metal/metal oxide nanoparticles (NPs) have been employed as nanobiosensors, foliar sprays, nutritional supplements, or stimulants and in seed priming, to ameliorate diverse abiotic stresses. Contrary to their bulk counterparts, the unique physiochemical attributes of NPs like size, shape, surface properties, and solubility, augment their bioavailability, bioactivity, and, particularly, radical scavenging potential, which is crucial for containing stress-induced oxidative damage. NP application positively impacts plant biomass, photosynthetic performance, and nutrient acquisition, enhances antioxidant potential, affects sugar and amino acid metabolism, and orchestrates hormonal signalling. Owing to the versatile multilevel and multimodal control over stress signalling responses, coupled with the prospects of developing into a durable technology, metal-based NPs can be exploited as agrochemical alternatives for ensuring multistress tolerance in plants.
