Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, 1113 Buenos Aires, Argentina; Instituto de Química y Fisicoquímica Biológicas (IQUIFIB-CONICET), Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, 1113 Buenos Aires, Argentina.
Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, 1113 Buenos Aires, Argentina; Instituto de Química y Fisicoquímica Biológicas (IQUIFIB-CONICET), Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, 1113 Buenos Aires, Argentina.
Ecotoxicol Environ Saf. 2021 Mar 15;211:111942. doi: 10.1016/j.ecoenv.2021.111942. Epub 2021 Jan 19.
In this work, the internalization and distribution of citric acid-coated magnetite nanoparticles (here, FeO-NPs) in soybean and alfalfa tissues and their effects on plant growth were studied. Both legumes were germinated in pots containing an inert growing matrix (vermiculite) to which Hoagland solution without (control, C), with FeO-NPs (50 and 100 mgironL, NP50 and NP100), or with the same amount of soluble iron supplied as Fe-EDTA (Fe50, Fe100) was added once before sowing. Then, plants were watered with the standard nutrient solution. The observation of superparamagnetic signals in root tissues at harvest (26 days after emergence) indicated FeO-NPs uptake by both legumes. A weak superparamagnetic signal was also present in the stems and leaves of alfalfa plants. These findings suggest that FeO-NPs are readily absorbed but not translocated (soybean) or scarcely translocated (alfalfa) from the roots to the shoots. The addition of both iron sources resulted in increased root weight; however, only the addition of FeO-NPs resulted in significantly higher root surface; shoot weight also increased significantly. As a general trend, chlorophyll content enhanced in plants grown in vermiculite supplemented with extra iron at pre-sowing; the greatest increase was observed with NP50. The only antioxidant enzyme significantly affected by our treatments was catalase, whose activity increased in the roots and shoots of both species exposed to FeO-NPs. However, no symptoms of oxidative stress, such as increased lipid peroxidation or reactive oxygen species accumulation, were evidenced in any of these legumes. Besides, no evidence of cell membrane damage or cell death was found. Our results suggest that citric acid-coated FeO-NPs are not toxic to soybean and alfalfa; instead, they behave as plant growth stimulators.
在这项工作中，研究了柠檬酸包覆的磁铁矿纳米粒子（此处为 FeO-NPs）在大豆和紫花苜蓿组织中的内化和分布及其对植物生长的影响。这两种豆科植物都在含有惰性生长基质（蛭石）的花盆中发芽，向其中添加不含铁（对照，C）、含有 FeO-NPs（50 和 100 mg 铁 L-1，NP50 和 NP100）或相同量的以 Fe-EDTA 形式提供的可溶铁（Fe50、Fe100）的 Hoagland 溶液，播种前添加一次。然后，用标准营养液给植物浇水。收获时（出苗后 26 天）观察到根系组织中的超顺磁信号表明两种豆科植物都吸收了 FeO-NPs。紫花苜蓿植物的茎和叶中也存在微弱的超顺磁信号。这些发现表明，FeO-NPs 很容易被吸收，但不会从根部转运（大豆）或很少转运（紫花苜蓿）到地上部分。添加两种铁源均导致根重增加；然而，只有添加 FeO-NPs 才会导致根表面积显著增加，地上部分重量也显著增加。总的来说，在播种前添加额外铁源的蛭石中生长的植物中，叶绿素含量增加；NP50 处理的增加幅度最大。只有过氧化氢酶这一种抗氧化酶受到我们处理的显著影响，其活性在暴露于 FeO-NPs 的两种植物的根和地上部分均增加。然而，在这些豆科植物中，没有证据表明存在氧化应激症状，例如脂质过氧化或活性氧积累增加。此外，没有发现细胞膜损伤或细胞死亡的证据。我们的结果表明，柠檬酸包覆的 FeO-NPs 对大豆和紫花苜蓿没有毒性，而是作为植物生长的刺激物。
