Arsenic and Cadmium Phytoextraction Potential of Crambe Compared with Indian Mustard

ABSTRACT

The ability to tolerate and accumulate arsenic (As) and cadmium (Cd) was compared between Brassica juncea (Indian mustard) and Crambe abyssinica (Hochst.) (Crambe or Abyssinian mustard). Plants were grown hydroponically and treated with 70 μM sodium arsenate or 50 μ M cadmium chloride for two weeks. When nutrients were omitted during the As treatment, leaves of C. abyssinica accumulated an average of 140 mg As kg⁻¹, compared with 34 mg kg⁻¹ for B. juncea. When quarter-strength Hoagland's nutrient solution was provided during As treatment, leaves of C. abyssinica accumulated an average of 270 mg As kg⁻¹, compared with 13 mg kg⁻¹ for B. juncea. Cadmium accumulation on a dry-weight basis was approximately two times greater in shoots of B. juncea. Shoot biomass production in the presence or absence of metals was greatest for C. abyssinica. Because of its larger biomass and more efficient accumulation of As, C. abyssinica should be considered for use in phytoremediation research.

Keywords:

• arsenic
• Brassica juncea
• cadmium
• Crambe abyssinica
• phytoextraction
• phytoremediation

ACKNOWLEDGMENTS

The author thanks Dr. Carol Bessel at Villanova University for the use of the hydride-generating atomic absorption spectrometer, and the students who have participated in this work, particularly R. Baxter, J. Leasa, C. Neal, and C. Ferguson. The work was supported in part by a DuPont educational aid grant to the Biology Department at West Chester University, and by funds from the S. Umlauf White Botany Fund at West Chester University.

Notes

^a Plants were provided with complete nutrition before the As treatment (phosphate concentration = 500 μ M) and then deprived of nutrients during a two-week treatment with 70 μ M sodium arsenate. Values are means, ± SD, n = 4.

^b Phosphate was not provided for the week prior to treatment with 70 μ M sodium arsenate or throughout treatment. Values are means ± SD, n = 20.

^c Because each root sample consisted of the combined roots of two plants grown in the same pot, standard deviations are not given.

^a A phosphate concentration of 250 μ M was provided during the 70 μ M sodium arsenate treatment. Cadmium was provided as 50 μ M cadmium chloride.

^b Values are mean ± SD (n = 6).

**Interspecies differences very significant at p < .01.

***Interspecies differences extremely significant at p < .0001.