Plant-based green synthesis of silver nanoparticles and its effective role in abiotic stress tolerance in crop plants

The development of effective and environmentally friendly methods for the green synthesis of nanoparticles (NPs) is a critical stage in the field of nanotechnology. Silver nanoparticles (AgNPs) are significant due to their unique physical, chemical, and biological properties, as well as their numerous applications. Physical, chemical, and green synthesis approaches can all be used to produce AgNPs; however, synthesis using biological precursors, particularly plant-based green synthesis, has shown outstanding results. In recent years, owing to a combination of frequent droughts, unusual rainfall, salt-affected areas, and high temperatures, climate change has changed several ecosystems. Crop yields have decreased globally as a result of these changes in the environment. Green synthesized AgNPs role in boosting antioxidant defense mechanisms, methylglyoxal (MG) detoxification, and developing tolerance for abiotic stress-induced oxidative damage has been thoroughly described in plant species over the last decade. Although various studies on abiotic stress tolerance and metallic nanoparticles (NPs) in plants have been conducted, but the details of AgNPs mediated abiotic stress tolerance have not been well summarized. Therefore, the plant responses to abiotic stress need to be well understood and to apply the gained knowledge to increase stress tolerance by using AgNPs for crop plants. In this review, we outlined the green synthesis of AgNPs extracted from plant extract. We also have updates on the most important accomplishments through exogenous application of AgNPs to improve plant tolerance to drought, salinity, low and high-temperature stresses.