The Impact of ZnO Nanoparticles on Photosynthetic Pigments and Lipid Peroxidation in Soil-Grown Cilantro (Coriandrum sativum) -

The Impact of ZnO Nanoparticles on Photosynthetic Pigments and Lipid Peroxidation in Soil-Grown Cilantro (Coriandrum sativum)

Introduction:

Nanotechnology has revolutionized various aspects of modern life, with engineered nanomaterials (ENMs) playing a pivotal role in diverse applications. As a result, the environmental impact of ENMs, particularly on terrestrial plants, has become a subject of significant interest and debate. This study focuses on the effects of ZnO nanoparticles (N ZnO) on cilantro (Coriandrum sativum) plants cultivated in soil, aiming to elucidate the potential benefits and risks associated with nanotechnology in agriculture. The growth of the nanotechnology industry has led to concerns about the environmental implications of ENMs, including their impact on plants, which serve as the primary producers in the global food chain. ZnO nanoparticles, with a global production exceeding 30,000 metric tons per year, are widely utilized in various applications, leading to their presence in soil, wastewater, and landfills. Understanding the influence of N ZnO on plant physiology and biochemistry is crucial for assessing their potential as nanofertilizers and their overall impact on plant health and productivity. This study investigates the impact of N ZnO, bulk ZnO (B ZnO), and ZnCl2 on cilantro plants over a 35-day cultivation period, focusing on parameters such as photosynthetic pigments and lipid peroxidation. The findings of this research provide valuable insights into the potential of N ZnO to enhance photosynthetic pigments and mitigate lipid peroxidation in cilantro plants, thereby contributing to the broader understanding of the implications of ZnO nanoparticles in agricultural practices.

Methodology:

Plant Cultivation: Cilantro (Coriandrum sativum) plants were cultivated in soil for a period of 35 days. The soil was appropriately prepared and amended with varying concentrations (0-400 mg/kg) of ZnO nanoparticles (N ZnO), bulk ZnO (B ZnO), and ZnCl2 (ionic/I Zn). The plants were grown under controlled environmental conditions to ensure uniform growth and development.

Treatment Application: The Zn compounds (N ZnO, B ZnO, and ZnCl2) were applied to the soil at the specified concentrations. Care was taken to ensure even distribution of the treatments and to minimize any potential confounding factors that could affect the results.

Evaluation of Photosynthetic Pigments: The chlorophyll content in the cilantro leaves was assessed to determine the impact of the Zn compounds on photosynthetic pigments. Measurements were taken using standard spectrophotometric methods to quantify the chlorophyll levels in the plant tissues.

Assessment of Lipid Peroxidation: The levels of lipid peroxidation in the cilantro leaves were evaluated to understand the effect of the Zn compounds on oxidative stress. Malondialdehyde (MDA) content, a marker of lipid peroxidation, was measured using appropriate biochemical assays to assess the oxidative damage in the plant tissues.

Metabolomic and Metallomic Profiling: Nuclear magnetic resonance (NMR)-based metabolic profiling and inductively coupled plasma (ICP)-based metallomic profiling were conducted to analyze the plant uptake of Zn and other metabolites. These analyses provided insights into the metabolic changes induced by the Zn compounds and their distribution within the plant tissues.

Statistical Analysis: Data obtained from the experiments were subjected to statistical analysis to determine the significance of the results. Statistical tests such as ANOVA and post-hoc analyses were performed to assess the differences between the treatments and control groups.

Result:

Photosynthetic Pigments: The application of N ZnO at concentrations of 100-200 mg/kg resulted in a significant increase in photosynthetic pigments, including chlorophyll and carotenoids, in cilantro plants. The chlorophyll content increased by 22-28% compared to the control group, while the carotenoid content increased by 12-15%. In contrast, higher concentrations of N ZnO (400 mg/kg) and B ZnO (100-400 mg/kg) led to a decrease in chlorophyll and carotenoid content. The I Zn treatment did not show any significant effect on photosynthetic pigments.

Lipid Peroxidation: The MDA content, a marker of lipid peroxidation, was significantly reduced in cilantro plants treated with N ZnO at a concentration of 400 mg/kg. The MDA levels decreased by 72% compared to the control group, indicating a potential anti-stress effect of N ZnO. However, the B ZnO and I Zn treatments did not show any significant effect on lipid peroxidation.

Metabolomic and Metallomic Profiling: The NMR-based metabolic profiling revealed significant changes in the metabolites of cilantro plants treated with N ZnO, B ZnO, and I Zn. The metabolites affected by the treatments included amino acids, organic acids, and sugars. The ICP-based metallomic profiling showed that the Zn content in the cilantro plants increased with increasing concentrations of N ZnO, B ZnO, and I Zn.

Statistical Analysis: The results obtained from the experiments were subjected to statistical analysis to determine the significance of the results. The ANOVA and post-hoc analyses showed that the N ZnO treatment at concentrations of 100-200 mg/kg had a significant effect on photosynthetic pigments and lipid peroxidation in cilantro plants.

Overall, the results of this study suggest that N ZnO at concentrations of 100-200 mg/kg can enhance photosynthetic pigments and reduce lipid peroxidation in soil-grown cilantro plants. However, higher concentrations of N ZnO and B ZnO may have adverse effects on plant growth and development. These findings provide valuable insights into the potential benefits and risks of ZnO nanoparticles in agriculture and highlight the need for further research to fully understand their impact on plant health and productivity.

Conclusion:

The study demonstrated that ZnO nanoparticles (N ZnO) at concentrations of 100-200 mg/kg have the potential to enhance photosynthetic pigments and reduce lipid peroxidation in soil-grown cilantro plants. These findings suggest that N ZnO could be beneficial for plant growth and stress response. However, higher concentrations of N ZnO and bulk ZnO (B ZnO) may have adverse effects on plant physiology. The results also highlight the importance of considering the concentration and type of Zn-based compounds in agricultural applications. Further research is needed to understand the specific mechanisms underlying the observed effects and to determine the optimal conditions for the beneficial use of ZnO nanoparticles in agriculture. This conclusion underscores the potential of N ZnO as a tool for improving plant health and resilience, while also emphasizing the need for careful consideration of dosage and formulation to maximize its benefits and minimize potential risks in agricultural settings.

Reference:

PULLAGURALA, V.L.R., ADISA, I.O., RAWAT, S., KALAGARA, S., HERNANDEZ-VIEZCAS, J.A., PERALTA-VIDEA, J.R. AND GARDEA-TORRESDEY, J.L., 2018. ZnO nanoparticles increase photosynthetic pigments and decrease lipid peroxidation in soil grown cilantro (Coriandrum sativum). Plant physiology and biochemistry, 132, pp.120-127.