Instituto Multidisciplinario de Biología Vegetal, Área Contaminación y Bioindicadores, FCEFyN, Universidad Nacional de Córdoba, CONICET, Av. Vélez Sársfield 1611, X5016CGA, Córdoba, Argentina.
Unidad de Estudios Agropecuarios (UDEA), Centro de Investigaciones Agropecuarias (CIAP), Instituto Nacional de Tecnología Agropecuaria (INTA), Camino 60 cuadras km 5.5, 5119, Córdoba, Argentina.
Environ Sci Pollut Res Int. 2021 Apr;28(16):20624-20636. doi: 10.1007/s11356-020-11901-x. Epub 2021 Jan 6.
Glycine max (L.) Merr. (soybean) crop plants have been found to have high lead (Pb) levels in aerial organs; however, knowledge about the processes involved in the incorporation, and subsequent translocation and accumulation of the metal in the plants is scarce. Considering the toxicity of this heavy metal, the aim of the present study was to evaluate Pb uptake and translocation, and their toxic effects on soybean seedlings via experiments of ionic competition with Ca (2.5 mM, Ca:Pb 1:1) and alteration of the transpiration flow [0.25 mM Pb(NO)]. The following variables were analyzed: biomass, leaf area (morphological parameters), photosynthetic efficiency, biochemical response (considered physiological stress markers: antioxidant power, chlorophylls, carotenoids, starch, proteins, sugars, and malondialdehyde), and Pb content. Results showed that soybean seedlings can accumulate high Pb concentration in its organs; however, in general, no morpho-physiological Pb stress symptoms were observed, except for lipid peroxidation and antioxidant power. The treatment with Ca ions was not effective in reducing Pb entry into root over time when both Ca and Pb where present in the grow solution. Alteration of the transpiration rate in soybean showed that the air flow increased the consumption of solutions, regardless of the treatments. However, Pb accumulation was lower in seedlings exposed to air flow, indicating a selective exclusion of the metal in the solution. In both experiments, soybean seedlings showed to be tolerant to high Pb concentrations.
大豆（ Glycine max （L.）Merr.）作物地上器官中发现含有高浓度的铅（Pb）；然而，关于植物吸收、随后转运和积累金属的过程的知识却很少。考虑到这种重金属的毒性，本研究旨在通过与 Ca（2.5 mM，Ca：Pb 1：1）的离子竞争实验和改变蒸腾流[0.25 mM Pb（NO）]来评估 Pb 的吸收和转运及其对大豆幼苗的毒性效应。分析了以下变量：生物量、叶面积（形态学参数）、光合作用效率、生化反应（考虑生理胁迫标志物：抗氧化能力、叶绿素、类胡萝卜素、淀粉、蛋白质、糖和丙二醛）和 Pb 含量。结果表明，大豆幼苗可以在其器官中积累高浓度的 Pb；然而，一般来说，除了脂质过氧化和抗氧化能力外，没有观察到形态生理 Pb 胁迫症状。当生长溶液中同时存在 Ca 和 Pb 时，用 Ca 离子处理不能有效地减少根中 Pb 的进入。改变大豆的蒸腾速率表明，气流增加了溶液的消耗，而不管处理方式如何。然而，暴露于气流中的幼苗中 Pb 的积累较低，表明该金属在溶液中被选择性排斥。在这两个实验中，大豆幼苗对高浓度 Pb 表现出耐受性。
