PHYSIOLOGICAL AND BIOCHEMICAL RESPONSES RESULTING FROM CADMIUM AND ZINC ACCUMULATION IN CARROT PLANTS

Abstract

The interactive effect of cadmium (Cd) and zinc (Zn) bioaccumulation on physiological and biochemical characteristics of carrot (Daucus carota L. var Pusa Kesar) plants grown with different levels of Cd and Zn was examined. The combined application of Cd and Zn (Cd+Zn) had synergistic and antagonistic effects at low and high concentrations, respectively, on Cd accumulations in plants, chlorophyll b, and photosynthesis and transpiration rates. Whereas both low and high Cd+Zn concentrations had synergistic effects on Zn accumulation, ascorbic acid, protein content, total phenols, peroxidase activity, chlorophyll a, total, carotenoids and stomatal conductance. Bioaccumulation of Cd had strong and negative relationships with measured physiological and biochemical parameters. The study further showed that Cd and Zn in combination have more toxic effects on carrot plants as compared to their individual treatments. This study concludes that interactive effects of Cd and Zn on test plant depend on their ratios present in plants.

Keywords:

• bioaccumulation
• cadmium
• carrot
• physiological
• biochemical
• zinc

ACKNOWLEDGMENTS

The staff of the Department of Botany and Farm Incharge, Institute of Agricultural Science BHU, Varanasi, India are gratefully acknowledged for providing the laboratory facilities and field for conducting the experiment. Rajesh Kumar Sharma is also thankful to the Department for International Development, United Kingdom and Council of Scientific and Industrial Research, New Delhi, India for providing financial support.

Notes

∗∗Correlation is significant at the 0.01 level.

∗Correlation is significant at the 0.05 level.

^NSCorrelation is not significant.