Nano-Priming for Inducing Salinity Tolerance, Disease Resistance, Yield Attributes, and Alleviating Heavy Metal Toxicity in Plants

Abstract

In today’s time, agricultural productivity is severely affected by climate change and increasing pollution. Hence, several biotechnological approaches, including genetic and non-genetic strategies, have been developed and adapted to increase agricultural productivity. One of them is nano-priming, i.e., seed priming with nanomaterials. Thus far, nano-priming methods have been successfully used to mount desired physiological responses and productivity attributes in crops. In this review, the literature about the utility of nano-priming methods for increasing seed vigor, germination, photosynthetic output, biomass, early growth, and crop yield has been summarized. Moreover, the available knowledge about the use of nano-priming methods in modulating plant antioxidant defenses and hormonal networks, inducing salinity tolerance and disease resistance, as well as alleviating heavy metal toxicity in plants, is reviewed. The significance of nano-priming methods in the context of phytotoxicity and environmental safety has also been discussed. For future perspectives, knowledge gaps in the present literature are highlighted, and the need for optimization and validation of nano-priming methods and their plant physiological outcomes, from lab to field, is emphasized.

Assessment of Various Nanoprimings for Boosting Pea Germination and Early Growth in Both Optimal and Drought-Stressed Environments

“…The potentially adverse effects of NPs on biogeochemical cycles, such as nitrogen turnover and carbon emissions, have also been discussed [ 90 ]. However, seed nanopriming minimizes the exposure of the environment to NPs and is thus less harmful than the foliar use of NPs [ 91 ].…”

“…Additionally, it has been demonstrated that NPs that are accumulated in plant roots tend to translocate to other tissues, such as newly developed seeds and plant shoots, and that NP translocation is significantly influenced by the properties of both plants and the characteristics of NPs [ 92 , 93 ]. In this regard, it is reported that the accumulation of Fe and Zn could be increased in wheat and maize grains due to nanopriming [ 91 , 94 , 95 ]. However, the chemical mechanisms behind the uptake, absorption, and transport of nanoparticles in plants remain unclear [ 96 , 97 ].…”

The Impact of ZnO and Fe2O3 Nanoparticles on Sunflower Seed Germination, Phenolic Content and Antiglycation Potential

“…The nano-priming of seeds has emerged as a novel and highly effective technique that favorably modifies the metabolism and signaling pathways of seeds [25], thereby impacting various stages of a plant's lifecycle, such as germination and overall plant growth [26]. Among the multitude of advantages associated with seed nano-priming, the most notable are improved plant growth and development [27], as well as increased nutritional value [28] and increased tolerance to stress [29].…”

Defense Pathways of Wheat Plants Inoculated with Zymoseptoria tritici under NaCl Stress Conditions: An Overview

“…Ion transport should be regulated via the exclusion or storage of ions in vacuoles to maintain cellular homeostasis in the crucial parts of plant cells to minimize ionic toxicity [25]. In addition to these responses, the production of ROS and RNS is triggered [26]. The production of free radicals such as superoxide ions (O 2 − ), hydroxyl radicals (OH), singlet oxygen ( 1 O 2 ), and hydrogen peroxide (H 2 O 2 ) destroys metabolic activities during growth and development [27].…”

“…When plant cells are exposed to low levels of salinity stress, signaling mechanisms, through specific proteins, the Ca 2+ transduction pathway, and ROS (at very low concentrations), induce gene expression [24,47]. Under salinity stress, mitochondria and chloroplasts work hard to improve the conditions of plants; however, as a side effect, the ROS levels increase rapidly because these sites are characterized by ROS production [3,26,38]. Osmotic stress and ion imbalance also lead to ROS production.…”