Nickel (Ni) element is strongly phytotoxic at high concentrations for several plants, but due to its dual behavior and complicated chemistry, it has received little attention in plant nutrition and relevant experimental data are limited. The current research was carried out to study the effect of Ni on maize (Zea mays L.) growth and phytoextraction potential with EDTA assistance, a process termed as chemical assisted phytoremediation. Treatments included two levels of EDTA (0 and 0.5 mM), two levels of Ni (0 and 40 µM) and their combination (EDTA+Ni) that were applied to maize plants grown in a pot experiment. Application of Ni alone or in combination with EDTA reduced maize root and shoot length by 7.8% to 13.3% and by 15.6% to 21.1%, respectively, compared with control, as well as root and shoot dry weight by 42.0% to 60.0% and by 29.8% to 46.6%, respectively. A similar declining trend was observed also for the content of photosynthetic pigments (chl-a, chl-b, total chlorophyll, and carotenoids) as well as total proteins. However, proline, total soluble sugars, and free amino acids showed an increasing trend with application of Ni and EDTA alone or in combination. These treatments significantly decreased P and Na content in maize roots, stems, leaves, and grains, while increased K content compared with control. Application of EDTA with Ni was the most effective treatment to enhance Ni accumulation in maize (50.23 mg per plant) compared with Ni alone (40.62 mg per plant), EDTA alone (27.75 mg per plant), and control (15.51 mg per plant). Application of EDTA in combination with Ni enhanced Ni accumulation by 4.9 folds in maize shoots and by 2.6 folds in roots over control. In conclusion, application of EDTA in suitable concentrations may enhance Ni uptake by maize providing an effective and economic phytoremediation method of Ni-contaminated soils.

中文翻译：

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玉米 (Zea mays L.) 在镍污染土壤中的生长和生理学以及使用 EDTA 的植物修复效率

镍 (Ni) 元素在高浓度时对多种植物具有强烈的植物毒性，但由于其双重行为和复杂的化学性质，在植物营养方面很少受到关注，相关实验数据有限。目前的研究是在 EDTA 辅助下研究 Ni 对玉米 (Zea mays L.) 生长和植物提取潜力的影响，这一过程称为化学辅助植物修复。处理包括两种水平的 EDTA（0 和 0.5 mM）、两种水平的 Ni（0 和 40 µM）及其组合（EDTA+Ni），它们被应用于盆栽试验中种植的玉米植物。与对照相比，单独或与 EDTA 联合施用 Ni 分别使玉米根和枝条长度减少 7.8% 至 13.3% 和 15.6% 至 21.1%，根和枝条干重减少 42.0% 至 60.0% 和从 29.8% 到 46.6%，分别。光合色素（chl-a、chl-b、总叶绿素和类胡萝卜素）以及总蛋白质的含量也观察到类似的下降趋势。然而，脯氨酸、总可溶性糖和游离氨基酸随着 Ni 和 EDTA 单独或联合应用显示出增加的趋势。与对照相比，这些处理显着降低了玉米根、茎、叶和籽粒中 P 和 Na 的含量，同时增加了 K 的含量。与单独使用 Ni（每株植物 40.62 mg）、单独使用 EDTA（每株植物 27.75 mg）和对照（每株植物 15.51 mg）相比，使用 EDTA 和 Ni 是提高玉米中 Ni 积累的最有效处理（每株植物 50.23 mg） . 与对照相比，EDTA 与 Ni 结合使用使玉米枝条中的 Ni 积累增加了 4.9 倍，在根中增加了 2.6 倍。综上所述，