Magnetite nanoparticles coated with citric acid are not phytotoxic and stimulate soybean and alfalfa growth

In this work, the internalization and distribution of citric acid-coated magnetite nanoparticles (here, Fe3O4-NPs) in soybean alfalfa tissues their effects on plant growth were studied. Both legumes germinated pots containing an inert growing matrix (vermiculite) to which Hoagland solution without (control, C), with Fe3O4-NPs (50 100 mg iron L?1, NP50 NP100), or same amount soluble supplied as Fe-EDTA (Fe50, Fe100) was added once before sowing. Then, plants watered standard nutrient solution. The observation superparamagnetic signals root at harvest (26 days after emergence) indicated uptake by both legumes. A weak signal also present stems leaves plants. These findings suggest that are readily absorbed but not translocated (soybean) scarcely (alfalfa) from roots shoots. addition sources resulted increased weight; however, only significantly higher surface; shoot weight significantly. As a general trend, chlorophyll content enhanced grown vermiculite supplemented extra pre-sowing; greatest increase observed NP50. antioxidant enzyme affected our treatments catalase, whose activity shoots species exposed Fe3O4-NPs. However, no symptoms oxidative stress, such lipid peroxidation reactive oxygen accumulation, evidenced any these Besides, evidence cell membrane damage death found. Our results toxic alfalfa; instead, they behave stimulators.