The uptake and translocation of hexavalent chromium and effects on growth and enzyme activity of Zea mays L.

The present study was carried out to determine the uptake and translocation of hexavalent chromium (Cr (VI)) by Zea mays L. and its subsequent effects on plant growth parameters and enzyme activity. A pot experiment was performed using Zea mays L. seedlings irrigated with water contaminated by different concentrations of Cr (VI) ranging from 0.25 to 1.25 mmol for 51 days. Cr concentrations measured were greater in roots than in other parts of the plants. The concentration of Cr in roots increased significantly with increasing Cr (VI) concentration of irrigation water and harvest time. The relatively small amounts of Cr accumulated in the roots were transferred to the aerial parts. The accumulation and distribution pattern of Cr in different parts of the plants was observed as roots > leaf > stem > corn and cob. At the end of the experiment, plant height was by around 65% lower than that in control plants with the highest Cr (VI) level (1.25 mmol) in irrigation water. The GR and APX activities increased in leaf and root tissues with increasing Cr (VI) concentration of irrigation water. However, the activity of CAT showed sharp increase in the highest concentration of Cr (IV) following gradual decrease.