Assessment of Phytoremediation Capacity and the Tolerance of Sorghum (Sorghum bicolor (L.) Moench) Seedlings to Hexavalent Chromium
摘要
Hexavalent chromium (Cr (VI)), resulting from several industrial activities, has become a significant environmental concern due to its high levels in water, soil, and plant tissues. This study aimed to assess the ability of white sorghum (Poaceae) to tolerate and remediate Cr (VI)-contaminated soil. Plants were cultivated in plastic pots containing a mixture of (1:1:1) agricultural sand, soil, and compost, and were treated with different concentrations of chromium (0 PPM, 20 PPM, and 60 PPM). The main results revealed that chromium predominantly accumulated in the roots, with an accumulation rate of 184 mg/kg of dry matter. The bioaccumulation factor (BF) exceeded 1, accompanied by a high biomass production (12 g within 30 days). This indicates the capacity of sorghum seedlings to absorb and retain significant amounts of Cr (VI), likely through SO42− and HPO42− membrane transporters. Increased Cr concentrations induced a significant rise in cell electrolyte leakage, indicating the loss of cell membrane integrity. Additionally, exposure to chromium resulted in a significant increase in total soluble sugars and proline, as well as heightened activities of catalase (CAT) and peroxidase (POD) which serve to protect cellular components and mitigate damage from reactive oxygen species. The results from the correlation analysis and principal component analysis revealed a high degree of alignment with the analyses of individual traits, thereby validating the interrelationships among the parameters studied. These findings indicate that the tested sorghum variety can thrive in Cr (VI)-contaminated environments, effectively accumulate chromium in its roots, and convert it to its trivalent form, emphasizing its potential for phytoremediation. However, it is essential to ascertain the concentration of heavy metals in plants remains within recommended safe thresholds, particularly for plants that may enter the food chain.