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Arsenic (As) and cadmium (Cd) are known to be toxic to humans, and elevated concentrations have been documented in food crops worldwide. However, little is known regarding their uptake, translocation, and distribution in wheat plants during plant development. A series of experiments were conducted to investigate the spatial distribution and dynamics of As and Cd in two wheat cultivars (cv. JN12 and JM85; the latter is a low grain Cd accumulator) at different developmental stages. Root concentrations of As decreased by 84%, and those of Cd by 67%, from tillering to maturity. In contrast, As concentrations in the stems increased 3.1-fold. A significant decrease in root As accumulation was observed at the mature stage, whereas root Cd accumulation decreased largely at the elongation stage. The concentrations of Cd in all leaves and As in new leaves increased as plant growth advanced. However, As concentrations in old leaves decreased significantly from grain filling to maturity. In both cultivars, the upward transfer toward younger parts of shoots was greater in the case of Cd than of As. The remobilization of As and Cd from stems and roots differed between the two cultivars. Arsenic concentrations in rachis, glumes, and grain in JM85 were significantly higher than those in JN12, whereas As concentrations in roots and stems did not differ between the cultivars. Grain Cd was significantly higher in JN12 than in JM85, but Cd concentrations in rachis and glumes were similar between the cultivars. The difference in grain Cd concentration between the two cultivars depended on root and stem Cd remobilization and redistribution from rachis to glumes and grain; in contrast, accumulation of As in grain was influenced by As remobilization from the leaves and stem to the spike., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Pot experiments were conducted to investigate the difference in arsenic (As), cadmium (Cd), and phosphorus (P) uptake, accumulation, and translocation among 12 wheat cultivars and their relationships with each other in soil "naturally" contaminated with both As and Cd. As, Cd, and P concentrations in wheat grain, straw, and root differed significantly (p<0.05) among the 12 wheat cultivars. The grain As concentration was not correlated with straw and root As, or the total As content in plants, but was significantly (p<0.05) correlated with As translocation factors (TFs), i.e., TFs(Grain/Root) and TFs(Grain/Straw). The grain Cd concentration was positively correlated with the total Cd content and TFs(Grain/Straw). The grain P concentration was positively correlated with straw and root P. Both As and Cd concentrations in wheat grains were correlated with P in wheat straw and grain. Compared with As, Cd was more easily transported to the wheat grain, and the rachis played a key role in ensuring this difference. A significant positive correlation was observed between root As and Cd, but no significant relationship was detected between grain As and Cd concentrations. The lack of a relationship between grain As and Cd suggests the possibility of selecting cultivars in which little As and Cd accumulation occurs in the wheat grain., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Field studies were conducted to investigate arsenic (As), copper (Cu), and zinc (Zn) contamination in agricultural soils and wheat crops at two areas in Huaibei, China. Area A is in the proximity of Shuoli coal mine. In area B, three coal mines and a coal cleaning plant were distributed. The potential health risk of As, Cu, and Zn exposure to the local inhabitants through consumption of wheat grains was also estimated. The results showed that significantly higher (p<0.05) concentrations of As, Cu, and Zn were found in soils collected from area B than in those from area A. Arsenic concentrations in wheat sampled from area A were negatively correlated with the distance from the coal mine (p<0.001). Concentrations of Cu and Zn in wheat seedlings and grains collected from area B were significantly higher (p<0.05) than in those collected from area A, with the exception of Zn in wheat seedlings. Concentrations of Cu and Zn in most wheat grain samples were above the permissible limits of Cu and Zn in edible plants set by the Food and Agriculture Organization/World Health Organization. The hazard index of aggregate risk through consumption of wheat grains was 2.3-2.4 for rural inhabitants and 1.4-1.5 for urban inhabitants. The average intake of inorganic As for rural inhabitants in Huaibei was above 10 μg day(-1). These findings indicated that the inhabitants around the coal mine are experiencing a significant potential health risk due to the consumption of locally grown wheat.