The effects of metallic engineered nanoparticles upon plant systems: An analytic examination of scientific evidence

Abstract

Recent evidence for the effects of metallic engineered nanoparticles (ENPs) on plants and plant systems was examined together with its implications for other constituents of the Society-Environment-Economy (SEE) system. In this study, we were particularly interested to determine whether or not metallic ENPs have both stimulatory and inhibitory effects upon plant performance. An emphasis was made to analyze the scientific evidence on investigations examining both types of effects in the same studies. Analysis of evidence demonstrated that metallic ENPs have both stimulatory and inhibitory effects mostly in well-controlled environments and soilless media. Nano zero-valent iron (nZVI) and Cu ENPs have potential for use as micronutrients for plant systems, keeping in mind the proper formulation at the right dose for each type of ENP. The concentration levels for the stimulatory effects of Cu ENPs are lower than for those for nZVI. Newer findings showed that extremely smaller concentrations of Au ENPs (smaller than those for nZVI and Cu ENPs) induce positive effects for plant growth, which is attributed to effects on secondary metabolites. Ag ENPs have demonstrated their usage as antimicrobial/pesticidal agents for plant protection; however, precautions should be taken to avoid higher concentrations not only for plant systems, but also, other constituents in the SEE. Further research is warranted to investigate the stimulatory and inhibitory effects of metallic ENPs in soil media in order to broaden the horizon of sustainable agriculture production in terms of higher and safer yields so as to meet the food requirements of human population.

Green-synthesized copper nanoparticles as a potential antifungal against plant pathogens

“…It has been reported that nanotechnology may improve the production of the crop with the development of nano-fertilizers and nano-treatments for plant diseases. [6][7][8] Different nanoparticles (NPs) have been studied for the treatment of plant diseases. 9 Particularly, it has been claimed that copper (Cu) NPs can be a potent fungicide.…”

Effects of Manganese Nanoparticle Exposure on Nutrient Acquisition in Wheat (Triticum aestivum L.)

“…The advent of nanotechnology and increased inclusion of nanoscale (1-100 nanometer in size) components in various products have included the use of nanoparticles of micronutrients as fertilizers and agropesticides. Recent reviews in this area describe both the negative and positive aspects of nanoparticle nutrients on plant growth and productivity [8][9][10][11][12]. Notably, because nanoparticles are more reactive than their bulk-scale equivalents, these materials may cause greater toxicity or beneficial effects on agricultural crops.…”

“…However, the literature contains very few studies that are focused on nano-Mn behavior in plant systems, particularly when compared to the number of reports on nano-ZnO, nano-CuO, or nano FeO [9][10][11]14]. The few published studies show that nano Mn treatment resulted in an increase in mung bean growth, 52% and 38%, for root and shoot [3]; a 22% increase in eggplant yield [15]; non-significant effects on root elongation of White Mustard [16]; no effect on lettuce germination, but a dose-dependent increase in plant root length [17]; and, suppression of disease progression over time in watermelon that was not accompanied by significant yield increase [18].…”

An Assessment of the Effect of Green Synthesized Silver Nanoparticles Using Sage Leaves (Salvia officinalis L.) on Germinated Plants of Maize (Zea mays L.)

“…With increasing interest in nanotechnology and nanotechnology applications, the relationships and behaviour of nanoparticles in the environment and their relationship to plant organisms have been summarized by various authors [33,69,70,71]. Nanoparticles enter the environment naturally or through an engineering approach [72].…”

“…Plants can absorb nanoparticles by all exposure routes including soil, water, and air [32]. An important aspect is the risk assessment of nanoparticles and the understanding of nanoparticle interactions with plants as essential components of all ecosystems [33,34]. Application of nanoparticles to a plant can result in the modification of gene expression and alteration of genetic pathways, which ultimately affects the growth and development of that plant [35].…”