Functional and Structural Changes associated with Cadmium in Mustard Plant: Effect of Applied Sulphur

Abstract

The effect of cadmium (Cd) and sulphur (S) on dry weight, biochemical parameters and anatomical features of mustard (Brassica campestris L. cv. Pusa Bold) plant was investigated in a pot culture experiment using Cd (25, 50, and 100 mg kg⁻¹ of soil), S (40 mg kg⁻¹ of soil), and the combination of Cd+S (25+40 mg kg⁻¹ of soil, 50+40 mg kg⁻¹ of soil, and 100+40 mg kg⁻¹ of soil). Sulphur treatment was given at sowing and Cd treatment was given when seedlings were fully established. Observations were recorded at the flowering stage. A significant and antagonistic interaction of Cd and S was observed. Compared to the control, leaf dry weight, total chlorophyll content, sugar content, nitrate reductase activity, and protein content decreased significantly with each Cd treatment, whereas the reverse was observed with S treatment. Combined treatments of Cd+S also reduced these parameters, but this reduction was less than the one observed with Cd treatments alone. However, nitrate accumulation in the leaves was 2.35 times higher with treatment of 100 mg Cd+40 mg S kg⁻¹ of soil than in the controls, whereas it was 3.5 times higher with Cd (100 mg kg⁻¹ of soil) alone. The relative proportion of vasculature in the stem, stoma length and width, and stomata length and width were inhibited with Cd treatments, whereas the combined treatments mitigated the adverse effect caused by Cd. Thus, S could alleviate the Cd induced impairment of biochemical and anatomical features of the plant and the enhancement of nitrate accumulation in the leaves.

Keywords:

• Alleviation
• cadmium
• nutrition
• sulphur
• toxicity

Acknowledgments

The authors are thankful to Y.P. Kalra, soil chemist, Canadian Forest Service, Edmonton, Alberta, Canada, for helpful comments on manuscript.