Dipartimento di Scienze Teoriche e Applicate, Università degli Studi dell'Insubria, via J. H. Dunant 3, 21100, Varese, Italy.
Environ Sci Pollut Res Int. 2015 May;22(10):7600-11. doi: 10.1007/s11356-015-4132-4. Epub 2015 Feb 3.
Environmental palladium levels are increasing because of anthropogenic activities. The considerable mobility of the metal, due to solubilisation phenomena, and its known bioavailability may indicate interactions with higher organisms. The aim of the study was to determine the Pd uptake and distribution in the various organs of the higher plant Pisum sativum and the metal-induced effects on its growth and reproduction. P. sativum was grown in vermiculite with a modified Hoagland's solution of nutrients in the presence of Pd at concentrations ranging 0.10-25 mg/L. After 8-10 weeks in a controlled environment room, plants were harvested and dissected to isolate the roots, stems, leaves, pods and peas. The samples were analysed for Pd content using AAS and SEM-EDX. P. sativum absorbed Pd, supplied as K₂PdCl₄, beginning at seed germination and continuing throughout its life. Minimal doses (0.10-1.0 mg Pd/L) severely inhibited pea reproductive processes while showing a peculiar hormetic effect on root development. Pd concentrations ≥1 mg/L induced developmental delay, with late growth resumption, increased leaf biomass (up to 25%) and a 15-20% reduction of root mass. Unsuccessful repeated blossoming efforts led to misshapen pods and no seed production. Photosynthesis was also disrupted. The absorbed Pd (ca. 0.5 % of the supplied metal) was primarily fixed in the root, specifically in the cortex, reaching concentrations up to 200 μg/g. The metal moved through the stem (up to 1 μg/g) to the leaves (2 μg/g) and pods (0.3 μg/g). The presence of Pd in the pea fruits, together with established evidence of environmental Pd accumulation and bioavailability, suggests possible contamination of food plants and propagation in the food chain and must be the cause for concern.
由于人为活动，环境中的钯含量正在增加。由于溶解现象，该金属具有相当大的迁移性，并且其已知的生物利用度可能表明它与高等生物相互作用。本研究的目的是确定高等植物豌豆（Pisum sativum）对钯的吸收和分布及其对生长和繁殖的金属诱导效应。将豌豆种植在含有改良 Hoagland 营养液的蛭石中，钯的浓度范围为 0.10-25 mg/L。在控制环境室中培养 8-10 周后，收获植物并进行解剖，以分离根、茎、叶、豆荚和豌豆。使用 AAS 和 SEM-EDX 分析样品中的钯含量。豌豆吸收了作为 K₂PdCl₄提供的钯，从种子发芽开始，一直持续到生命结束。最小剂量（0.10-1.0 mg Pd/L）严重抑制了豌豆生殖过程，而对根发育表现出奇特的激素效应。Pd 浓度≥1 mg/L 会导致发育延迟，随后恢复生长，叶片生物量增加（高达 25%），根质量减少 15-20%。反复开花失败导致豆荚畸形且无法产籽。光合作用也受到干扰。吸收的钯（约占供应金属的 0.5%）主要固定在根中，特别是在皮层中，浓度高达 200 μg/g。金属通过茎（高达 1 μg/g）移动到叶子（2 μg/g）和豆荚（0.3 μg/g）。豌豆果实中存在钯，以及环境钯积累和生物利用度的既定证据，表明可能对食用植物造成污染，并在食物链中传播，这必须引起关注。
