Lead tolerance and detoxification mechanism of Chlorophytum comosum

Abstract

Chlorophytum comosum seedlings were grown in soils containing different lead (Pb) concentrations (CK, 200, 400, 600, 800, 1000, 1250, 1500 and 2000 mg/kg-dry soil) for three months and the effects on the growth, physiological indexes and the accumulation of C. comosum were examined. The results show that the tolerance index (TI) of C. comosum were all above 100 in soils containing 500 mg/kg or lower Pb. Malondialdehyde (MDA) level and electrical conductivity (EC) of C. comosum differed insignificantly with rising Pb concentration. The activities of catalase (CAT) and peroxidase (POD) increased significantly in lower Pb concentration and reached their maximum at 1000 and 250 mg/kg, respectively. In addition, C. comosum plant could maintain a lower Pb level in vivo in soils containing higher Pb concentration. These data indicate that C. comosum is surprisingly tolerant to Pb stress.

Key words: Chlorophytum comosum, lead, accumulation, tolerance, physiological index.