Author: PARIMAL RAMESH UDGAVE
In present status, Nanotechnology is the Miracle of science which is in the initial stage of development. Undoubtedly, it can solve a variety of problems from chemistry to biology. Nanotechnology can be applied to Agriculture, Food technology, Pharmaceutical industry, biomedicine, and even other fields. There is the reason why we focus on Nanotechnology in Agriculture. Agriculture is the backbone of more than half of world and it directly affects living and daily life. Shortage of food could be lethal if there will be a shortage of food.
There will be two situations which will be the result of nanotechnology use. Firstly, it will be used. Secondly, it will destroy the purity of biological molecules by forming a complex or acting upon them. The soil is very important and the basic need of human population for survival on the planet. We cannot replace it. Soil formation process takes millions of years. Identified forms of soil destruction are soil erosion, physical, chemical and biological destruction, salinization and pollution. Soil erosion is the primary reason for its destruction. In the present world, the most important factor to affect soil quality is toxicity. Toxicity from chemicals, heavy metals, and specifically nanoparticles. There are some agrochemical and pesticide companies which are trying to spread Nano-based fertilizers and nutrients. Farmers and commercial growers should clarify the process for nanoparticle synthesis. A nanoparticle can be synthesized by different processes. Conventionally, Chemical synthesis is a popular one. Use of chemicals like DMSO can burn out the soil nutrients and soil microbiota. In initial days of nanoparticles, there will be no problems. Biomagnification process will take place years after years and will make soil with chemicals and toxic materials. On another side, green synthesis of nanoparticles is an eco-friendly method. However, bio-constituents in plant extracts can act against (Antibiotic, Anti-bacterial, Anti-fungal) soil microbiota and change or decrease the soil fertility and might result in a barren land.
There are some results of experiment which indicates how plant system absorbs nanoparticles from soil-
Table No. 1 Showing silver ion content in Barley grown in petri dish at 2 hours, 6 hours and 24 hours’ treatment (ICP-OES Analysis)
| Treatment | 2 hours | 6 hours | 24 hours | ||||||
| Root (μg/ml) | Shoot (μg/ml) | Leaves (μg/ml) | Root (μg/ml) | Shoot (μg/ml) | Leaves (μg/ml) | Root (μg/ml) | Shoot (μg/ml) | Leaves (μg/ml) | |
| Control | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Silver Nanoparticles 20nm | 1.66 | 1.66 | 0 | 1.66 | 0 | 0 | 6.66 | 5 | 1.66 |
| Silver nanoparticles 40 nm | 1.66 | 1.66 | 1.66 | 5 | 1.66 | 1.66 | 1.66 | 0 | 0 |
The data obtained from ICP-OES also matched with the hypothesis suggested by Khodakovskaya et al. 2009 indicated in Figure No. 1 According to the report, nanoparticles firstly observed by root tip, root hair and then it will be transported to stem aerial branches and leaves. All the concentrations divided under Table No. 1, indicate that the higher silver on concentration was found in roots, and lower was observed in shoot and leaves. The seeds indicated silver content in seeds with the highest concentration in roots, low in the shoot and lowest in leaves (roots> shoots >leaves). In Figure 1, the route of nanoparticles is indicated.
Figure No. 1 Route of nanoparticles in Plant system
This table indicates a number of silver nanoparticles absorbed by plant systems in the controlled environment. This clearly depicts travel of silver nanoparticles from soil to plant leaves.
Some evidence how it can lead toxicity in food chain and environment-
- Stegemeier et al. 2015 investigated the effect of silver nanoparticles, silver sulfide nanoparticles and silver nitrate on seeds of alfalfa. This suggests that nanoparticle in original condition and modified behaves in a different manner with the seeds. However, the silver nitrate resulted in inhibition of germination and growth of seeds. In addition to that, the roots indicated highest silver content as compared to shoots. Surface effects (showing smooth properties and regular behavior) and Quantum effects (Showing discontinuous properties) affect the behavior of the material which decides the fate of original condition/bulk material and modified/nanomaterial with respect to their mechanical, optical, electric and magnetic properties.
- Silver ions also indicated to inhibit the ethylene plant hormone and mitochondrial function (Knee 1992).
- The inhibition or stunted growth parameters such as germination, shoot, root, and biomass could be explained as disruption of the cell to cell signaling in plant root cells. In the plant root cells, the aggregation of silver ions was found in plasmodesmata and rarely in the cell wall. Because of the blockage in the cell wall, it cannot perform the cell to cell signaling which delays or stops the intercellular transport of plant hormones and nutrients which subsequently destroy the cell to signaling which puts end to the integrity of root apical meristem (RAM) (Zhu et al. 2008). This results in improper hormone and nutrient transport and in the stunted growth of plants.
- Governmental agencies should take interest to control Nano-technology based materials regulatory authority.
- Forging link between research institutes and govt. organizations can lead safe future.
- Knowledge gap of nanoparticles should be addressed to consumers.
References:
1. Khodakovskaya M, Dervishi E, Mahmood M, Xu Y, Li Z, Watanabe F, (2009). Carbon nanotubes are able to penetrate plant seed coat and dramatically affect seed germination and plant growth. ACS Nano, 3 (10), 3221-7.
2. Stegemeier, J., P. Schwab, F., Colman, B., P. , Webb, S., M., Newville, M., Lanzirotti, A., Winkler,C., Wiesner, M., R., and Lowry, G., V. (2015). Speciation Matters: Bioavailability of Silver and Silver Sulfide Nanoparticles to Alfalfa (Medicago sativa). Environmental science and technology, 49 (14), 8451-8460.
3. Knee, M., (1992). Sensitivity of ATPases to silver ions suggests that silver acts outside the plasama membrane to block ethylene action. Phytochemisty , 31, 1093-1096.
4. Zhu, H., Han, J., Xiao, J.Q., Jin, Y. (2008). Uptake, translocation, and accumulation of manufactured iron oxide nanoparticles by pumpkin plants. Journal of Environmental Monitoring, 10, 713-717.
About Author / Additional Info:
I am working as Asst. professor. My scientific interests include Nano-biotechnology, Soil toxicology, Eco-toxicology and Environmental science.