Influence of Fe₃ O₄ Nanoparticles on Oxidative Processes and Photosynthetic Pigments of Brassica Napus L., Under Drought

Iron oxide nanoparticles $\left(\mathrm{Fe}_{3} \mathrm{O}_{4}\right)$ are an important class of nanomaterials that have several unique properties. In this work, we investigated the effect of Fe<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> nanoparticles in different concentrations (0,50, and $100 \mathrm{mg} / \mathrm{L}$) on oxidative processes and production of chlorophyll a, chlorophyll b, and carotenoids under drought as well as adaptation/recovery capabilities in rape Brassica napus L. The nanoparticles were synthesized using the coprecipitation (Massart) method. For the detection of oxidative process in plants the electrochemical measurements of $\mathbf{H}_{\mathbf{2}} \mathrm{O}_{\mathbf{2}}$ by CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> Nanostructured Electrode were used. The concentrations of chlorophylls ($\mathrm{Chl} a, \mathrm{Chl} b$), and total carotenoids were determined spectrophotometrically in acetone extracts of fresh plant material.Our results show that Fe<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> nanoparticles at a concentration of $100 \mathrm{mg} / \mathrm{L}$ have a stimulating effect on the production of chlorophylls in rapeseed leaves, but a slight decrease in the production of carotenoids, which indicates their positive effect on the processes of photosynthesis in cell chloroplasts. However, a slight addition of Fe<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> nanoparticles to the soil at $50 \mathrm{mg} / \mathrm{L}$ did not have a pronounced effect on the plant and was observed a slight decrease in chlorophyll a and chlorophyll b, which could be caused by the natural processes of plant aging. These results highlight the potential application of Fe<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> nanoparticles in agriculture to potentially increase yields and improve product quality by stimulating photochemical processes in plants.