Nanoparticles and their potential role in plant adaptation to abiotic stress in horticultural crops: A review

Abiotic stresses such as salinity, drought, heavy metals, and extreme temperatures are a major constraint that negatively affect growth and productivity of horticultural plants. In order to mitigate the negative consequences of abiotic stresses, various approaches have been utilized to enhance plant resistance through genetic improvements, demanding extensive breeding programmes and substantial financial investments. In this regard, various nanoparticles (NPs) such as zinc oxide, silicon oxide, magnesium oxide, iron oxide, aluminum oxide, copper oxide and silver nanoparticles have exhibited their potential in boosting the performance of horticultural plants amidst challenging conditions. In general, NPs enhance plant resistance to stress factors by strengthening the physical barrier, facilitating the uptake and transport of essential minerals and nutrients, improving photosynthetic efficiency, increasing the synthesis of anti-stress compounds and modulating hormone balance, particularly auxins and gibberellins confirms their effectiveness in promoting plant tolerance to various abiotic stresses. Additionally, NPs can potentially mitigate oxidative damage induced by abiotic stresses by scavenging reactive oxygen species (ROS) and activating antioxidant defense mechanisms. This review aims to highlight the valuable insights regarding the application of NPs as a promising approach for enhancing the resilience of horticultural plants and ensuring food security in a changing environment. Despite the positive outcomes observed in improving plant performance under abiotic stresses, the molecular mechanisms responsible for the positive effects of NPs are still being unraveled. More research is needed to investigate the long-term consequences, safety concerns, and optimal application methods of NPs in horticultural plants.