Bot. Bull. Acad. Sin. (1995) 36: 89-93

Wu et al. Proline accumulation due to Cu & Cd

Intracellular proline accumulation in some algae exposed to copper and cadmium

Jiunn-Tzong Wu1,2,3, Su-Jee Chang2 and Tsuan-Lin Chou1

1Institute of Botany, Academia Sinica, Taipei, Taiwan 115, Republic of China

2Department of Botany, National Taiwan University, Taipei, Taiwan 107, Republic of China

(Received December 2, 1994; Accepted March 10, 1995)

Abstract. The intracellular proline level in four species of algae: Anacystis nidulans, Chlorella sp., Pediastrum duplex, and Nitzschia palea, was enhanced when they were treated with deleterious concentrations of Cu2+ or Cd2+. The maximum enhancement of proline level followed the order: Chlorella > Pediastrum > Anacystis > Nitzschia for either metal ion, but copper caused a greater accumulation of proline than did cadmium. Proline accumulation appears to be a general response of algal cells to copper and cadmium. The present study characterizes the time course of praline accumulation. In addition, experiments conducted with Chlorella sp. and A. nidulans showed that when incubated under illumination, metal-treated cells accumulated more proline than they did in the dark. The possible role of proline accumulation is discussed.

Keywords: Anacystis; Cadmium; Chlorella; Copper; Light dependence; Nitzschia; Pediastrum; Proline accumulation.

3Corresponding authors.