Zinc Biofortified Wheat Cultivar Lessens Grain Cadmium Accumulation under Cadmium Contaminated Conditions

摘要

Zinc (Zn) efficient wheat genotypes have been developed to enhance grain Zn concentration to combat the Zn malnutrition in humans. However, such biofortified genotypes/cultivars may also take up the toxic metals from heavy-metals contaminated soils due to similarities with Zn uptake and transport mechanisms in plants. This study was designed to explore uptake of a ubiquitous toxic metal i.e., cadmium (Cd) by a Zn-efficient (Zincol-2016) and was compared with Zn-inefficient (Faisalabad- 2008) wheat cultivar. Both wheat cultivars were sown in pots till maturity in Zn and Cd amended soil. Growth and yield response, and distribution of Cd and Zn, in roots, shoot and grains were observed. Significant differences in Zn and Cd concentration in root, shoot and grain were found among both cultivars in response of Zn and Cd application. Zincol 2016 was more efficient cultivar for Zn uptake compared to the Faisalabad-2008. Cd uptake was increased by both cultivars and suppressed plant growth in Cd contaminated soil. However, Zn application in Cd contaminated soil significantly diminished the Cd uptake and vice versa. Interestingly, Cd concentration was higher in root of Zincol-2016 as compared to Faisalabad 2008; similar was the case in shoot of both cultivars, while it was lower in grain of Zincol-2016. In conclusion, Zn efficient cultivar not only produces high Zn grains but also has ability to contain Cd in root and shoot reducing its accumulation in grains. Furthermore, Zn fertilization in Cd contaminated soils can decrease Cd uptake by plants and may be used as an ameliorating strategy to grow wheat in Cd contaminated soils.