The size of the nanoparticles is between 1 and 100 nm. Nanoparticles are widely used in consumer and medical products, as well as in agricultural and industrial applications. The excessive use nanoparticles increases its release into the environment. Plants are an important part of the environment that is affected by nanoparticles. Studies have examined the effect of nanoparticles on plants. The results showed that high concentrations of nanoparticles showed a negative effect. Reactive oxygen species generation is a toxicological mechanism of nanoparticles in plants. When the production of radicals is greater than its removal, oxidative stress occurs. The key indicator of oxidative stress is lipid peroxidation. The unsaturated fatty acids in the cell membrane are a major target for radicals. Radical absorbs hydrogen from unsaturated fatty acids to form water. Therefore, the fatty acid has a non-coupled electron, which is then able to capture oxygen and form a peroxyl radical. Lipid peroxyl radical can lead to a chain of radical production. Enzymatic and nonenzymatic systems exist for the removal of radicals in plants. Enzymatic systems include catalase, guaiacol peroxidase, ascorbate peroxidase, superoxide dismutase, glutathione reductase, and dehydroascorbate reductase. Nonenzymatic systems include ascorbate and carotenoids, glutathione, tocopherol, and phenolic compounds.
Part of the book: Advances in Lipid Metabolism