Innovation Team of Remediation for Heavy Metal Contaminated Farmlands, Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, People's Republic of China; Key Laboratory of Original Environmental Pollution Control, Ministry of Agriculture, Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, People's Republic of China.
Innovation Team of Remediation for Heavy Metal Contaminated Farmlands, Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, People's Republic of China; Key Laboratory of Original Environmental Pollution Control, Ministry of Agriculture, Agro-Environmental Protection Institute, Ministry of Agriculture, Tianjin 300191, People's Republic of China.
Sci Total Environ. 2021 May 20;770:145328. doi: 10.1016/j.scitotenv.2021.145328. Epub 2021 Jan 22.
Wheat is one of the main sources of dietary Cd in northern China, and the reduction of Cd accumulation in wheat is of great significance for human health. This study explored and highlighted the effects of soil application of manganese sulfate (MnSO) on the distribution and transport of Cd in two wheat cultivars, and identified the key tissues and elements during the Cd translocation in wheat by measuring the concentrations of eight elements in 17 parts of wheat under MnSO treatment. The bioaccumulation factor of Cd in the roots and the translocation factor of Cd in node1 (connected to the panicle) of the high-Cd wheat cultivar were found to be higher than that of the low-Cd wheat cultivar. Soil application of MnSO (0.05-0.2%) significantly reduced the Cd concentration in high- and low-Cd wheat grains by 24.16-57.52% and 25.90-63.44%, respectively, and decreased the Cd concentrations in all wheat tissues. MnSO application had no effect on wheat growth, and the inhibition effects on wheat Cd accumulation were more pronounced at wheat-seeding stage. MnSO application inhibited Cd uptake by the ion antagonism between Mn/Zn/Fe and Cd in the wheat roots and reduced Cd upward transport by reducing the Cd transport from node1 to internode1 and from panicle to wheat grain. Nodes 2-4 can restrict the transport of both Cd and Mn, whereas node1 and the panicle can inhibit Cd transport but have no effect on Mn transport. The ionomic results show that the overall spatial distribution of different tissues is consistent with the growth morphology of wheat plants. MnSO application significantly changed the ionomes of the roots, nodes, glumes, and wheat grains; meanwhile, the differences in the ionomic responses among the roots are the most remarkable. The results of this study show that soil application of MnSO is efficient for reducing the Cd accumulation in wheat grown in Cd-contaminated soil, demonstrating wide application potential.
小麦是中国北方地区膳食镉的主要来源之一，减少小麦中镉的积累对人类健康具有重要意义。本研究通过测量施锰处理后 17 个小麦部位的 8 种元素浓度，探讨并强调了硫酸锰（MnSO）在两种小麦品种中镉分布和迁移的影响，并确定了小麦镉转运过程中的关键组织和元素。发现高镉小麦品种的根镉生物积累系数和节 1（与穗连接）镉迁移系数高于低镉小麦品种。土壤施锰（0.05-0.2%）显著降低了高、低镉小麦籽粒中 Cd 浓度，分别降低了 24.16-57.52%和 25.90-63.44%，同时降低了所有小麦组织中的 Cd 浓度。MnSO 处理对小麦生长没有影响，且在小麦播种期对小麦 Cd 积累的抑制作用更为明显。MnSO 处理通过 Mn/Zn/Fe 与 Cd 之间的离子拮抗作用抑制了小麦根系对 Cd 的吸收，并通过减少 Cd 从节 1 向节 1 内、从穗向麦粒的转运来降低 Cd 的向上转运。节 2-4 可以限制 Cd 和 Mn 的转运，而节 1 和穗可以抑制 Cd 的转运，但对 Mn 的转运没有影响。离子组学结果表明，不同组织的整体空间分布与小麦植株的生长形态一致。MnSO 处理显著改变了根系、节、颖片和麦粒的离子组；同时，根系的离子组响应差异最为显著。本研究结果表明，土壤施锰对于降低 Cd 污染土壤中生长的小麦 Cd 积累是有效的，具有广泛的应用潜力。
