Recent advances in nano-enabled plant salt tolerance: Methods of application, risk assessment, opportunities and future perspectives

Abstract

Salinity is a big issue threatening global food security. Among the different strategies, nanotechnology has shown tremendous potential for crop production under abiotic stresses, such as salinity. In this review, we discussed the environmental challenges associated with the different methods of nanomaterials application, including seed nanopriming, foliar, and soil/root application. Based on the previous research, nanopriming uses less nanomaterials and has minimum concerns about environmental safety and the food chain. We discussed in detail the preventive measures based on the application methods for the safe and sustainable use of nanomaterials in agriculture. Furthermore, we summarized the role of antioxidant enzyme-triggering nanomaterials and direct reactive oxygen species (ROS) scavenging nanomaterials (nanozymes) in plant salt tolerance. Nanomaterials improve sodium (Na+) and potassium (K+) homeostasis through various anatomical, physiological, and molecular mechanisms while improving plant salt tolerance. The role of nanomaterials in modulating plant photosynthesis and hormonal balance is largely overlooked. We also identified research gaps, providing guidelines for future research work. This review aimed to provide guidelines for the researchers to understand better the proper designing of NPs and different plant-related factors while using NPs for plant stress tolerance. It will help to improve the delivery efficiency of NPs into plants. Furthermore, after gaining sufficient scientific knowledge and better understanding, NPs can be integral to sustainable agriculture, saving costs and reducing biosafety concerns and environmental pollution.