Gradual Accumulation of Heavy Metals in an Industrial Wheat Crop from Uranium Mine Soil and the Potential Use of the Herbage

Testing the quality of heavy-metal (HM) excluder plants from non-remediable metalliferous soils could help to meet the growing demands for food, forage, and industrial crops. Field cultures of the winter wheat cv. JB Asano were therefore established on re-cultivated uranium mine soil (A) and the adjacent non-contaminated soil (C). Twenty elements were determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) from soils and plant sections of post-winter seedlings, anthesis-state, and mature plants to record within-plant levels of essential and toxic minerals during ripening and to estimate the (re)use of the soil-A herbage in husbandry and in HM-sensitive fermentations. Non-permissible HM loads (mg·kg−1·DW) of soil A in Cd, Cu, and Zn of 40.4, 261, and 2890, respectively, initiated the corresponding phytotoxic concentrations in roots and of Zn in shoots from the seedling state to maturity as well as of Cd in the foliage of seedlings. At anthesis, shoot concentrations in Ca, Cd, Fe, Mg, Mn, and Zn and in As, Cr, Pb, and U had fallen to a mean of 20% to increase to 46% during maturation. The respective shoot concentrations in C-grown plants diminished from anthesis (50%) to maturity (27%). They were drastically up/down-regulated at the rachis-grain interface to compose the genetically determined metallome of the grain during mineral relocations from adjacent sink tissues. Soil A caused yield losses of straw and grain down to 47.7% and 39.5%, respectively. Nevertheless, pronounced HM excluder properties made Cd concentrations of 1.6–3.08 in straw and 1.2 in grains the only factors that violated hygiene guidelines of forage (1). It is estimated that grains and the less-contaminated green herbage from soil A may serve as forage supplement. Applying soil A grains up to 3 and 12 in Cd and Cu, respectively, and the mature straw as bioenergy feedstock could impair the efficacy of ethanol fermentation by Saccharomyces cerevisiae.