Wang Yu, Wang Shengli, Nan Zhongren, Ma Jianmin, Zang Fei, Chen Yazhou, Li Yepu, Zhang Qian
Gansu Key Laboratory for Environmental Pollution Prediction and Control, College of Earth and Environmental Sciences, Lanzhou University, Tianshui South Road 222, Lanzhou, 730000, Gansu, China.
Environ Sci Pollut Res Int. 2015 Dec;22(24):19756-63. doi: 10.1007/s11356-015-5153-8. Epub 2015 Aug 18.
Effects of heavy metal on uptake of mineral nutrition elements in plants have attracted widespread interest and been widely explored. This paper reports the translocation and accumulation behaviors of Ni in the organs of mature wheat plants by means of pot experiment using the sierozem collected from northwestern China as experimental soil. Effect of Ni on accumulation of Cu, Mn, Ca, and Mg is also demonstrated. It was found that influence of Ni on wheat plants differed greatly at different Ni levels. Ni content in the organs of wheat plants increased with the increase in Ni level, and the increasing rate decreased when the Ni level was higher than 400 mg/kg. Ni was mainly accumulated in the roots and less distributed in the shoots, shells, and grains. When the Ni level was lower than 400 mg/kg, the bioconcentration factor (BCF) of the roots was higher than 1, suggesting that Ni was taken in against a concentration gradient. The average translocation factor (TF) of wheat plants was 0.221, indicating the weak ability of wheat plants in translocating Ni toward the aboveground parts. Since Ni is readily accumulated in the grains of wheat plants at lower Ni level, concerns in health risks might be raised. Excess Ni in wheat plants could inhibit the transfer of Cu, Mn, and Mg to grains, leading to the accumulation of Ca, Mg, and Mn in the shoots and shells of wheat plants. The increase in Ni content can disturb the uptake and distribution of mineral nutrition elements in the organs of plants, resulting in the toxic effect of Ni on wheat plants. Results from this study provide a scientific support to prevent or control heavy metal pollution in an arid region.
重金属对植物矿质营养元素吸收的影响已引起广泛关注并得到深入研究。本文通过盆栽试验，以取自中国西北的灰钙土为试验土壤，研究了成熟小麦植株各器官中镍的转运和积累行为。同时也探讨了镍对铜、锰、钙和镁积累的影响。研究发现，不同镍水平下镍对小麦植株的影响差异很大。小麦植株各器官中的镍含量随镍水平的升高而增加，当镍水平高于400mg/kg时，增加速率降低。镍主要积累在根部，在地上部、颖壳和籽粒中的分布较少。当镍水平低于400mg/kg时，根部的生物富集系数（BCF）高于1，表明镍是逆浓度梯度吸收的。小麦植株的平均转运系数（TF）为0.221，表明小麦植株将镍向地上部转运的能力较弱。由于在较低镍水平下镍容易在小麦籽粒中积累，可能会引发对健康风险的担忧。小麦植株中过量的镍会抑制铜、锰和镁向籽粒的转运，导致钙、镁和锰在小麦植株的地上部和颖壳中积累。镍含量的增加会扰乱植物各器官中矿质营养元素的吸收和分布，从而导致镍对小麦植株产生毒害作用。本研究结果为干旱地区预防或控制重金属污染提供了科学依据。
