Molybdenum mitigates cadmium stress for bread wheat (Triticum aestivum L.) seedlings

Abstract

Pollution with heavy metals has become a serious problem that threatens all living organisms. Cadmium (Cd) pollution has become focus of the environmental studies and can negatively affect human health and plant growth. Molybdenum has been highlighted as a stress-resistant micronutrient that supports the defense system against environmental stresses. In this context, this study highlighted the role of molybdenum in the mitigation of the toxic effect of cadmium in wheat seedlings. The study included four concentrations of cadmium (0, 75, 150, and 225 mg L-1), three concentrations of molybdenum (0, 15, and 30 mg L-1), and two wheat genotypes (G-31 and IRAQ). These factors were laid as a factorial experiment according to a completely randomized design (CRD) with three replications. The results of this study indicated the negative impact of cadmium on wheat seedlings' growth in terms of physiological and anatomical traits. It also highlighted the positive role of molybdenum in the mitigation of the toxic effect of cadmium. Molybdenum at a concentration of 15 mg L-1 enhanced the structure of the root and leaf of cadmium-treated wheat. The two wheat genotypes did not vary in terms of anatomy when they were treated with molybdenum. Further studies are required on a wide range of wheat genotypes to investigate their ability to withstand heavy metal stress. Therefore, heavy metal-tolerant genotypes could be utilized in heavy metal-contaminated soils.