biologia plantarum

Biologia plantarum 51:116-120, 2007 | DOI: 10.1007/s10535-007-0023-y

Accumulation and detoxification of cadmium in Brassica pekinensis and B. chinensis

C. P. Liu^1,2, Z. G. Shen^1,*, X. D. Li³

¹ College of Life Sciences, Nanjing Agricultural University, Nanjing, China

² Guangdong Institute of Eco-Environment and Soil Sciences, Guangzhou, China

³ Dept. Civil Struct. Engn., The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong

The effect of excessive Cd on the growth and metal uptake by leafy vegetables Brassica chinensis L. (cv. Wuyueman) and Brassica pekinensis (Lour.) Rupr. (cv. Qingyan 87-114) were studied in hydroponic solution culture. The Cd concentration higher than 10 µM significantly decreased the root elongation and leaf chlorophyll contents of both plant species. The shoots of B. pekinensis had significantly higher concentrations of total and water-soluble Cd than B. chinensis. The roots of both species accumulated more Cd than the shoots in all the Cd treatments. Most of the Cd in the roots was found in the cell walls. The shoot/root ratio of Cd concentrations in B. pekinensis was always greater than that in B. chinensis. But, the concentration and proportion of Cd in the cell walls in B. chinensis were higher than that in B. pekinensis. Cadmium treatments also increased the concentrations of total non-protein thiols (NPT) in the shoots of the both species. A significant correlation was found between the concentrations of soluble Cd and NPT in plant shoots.

Keywords: Cd tolerance; cell wall; non-protein thiols; toxicity

Subjects: Brassica chinensis; Brassica pekinensis; cadmium; chlorophyll a,b; glutamic acid, glutathione; heavy metals; metals; phytochelatins

Received: March 2, 2005; Accepted: October 20, 2005; Published: March 1, 2007  Show citation