Physiological responses of Hizikia fusiformis to copper and cadmium exposure

✍ Scribed by Zhu, Xifeng; Zou, Dinghui; Du, Hong

• Book ID: 121656813
• Publisher: Walter de Gruyter GmbH & Co. KG
• Year: 2011
• Tongue: English
• Weight: 741 KB
• Volume: 54
• Category: Article
• ISSN: 0006-8055
• DOI: 10.1515/BOT.2011.054

✦ Synopsis

Abstract

The brown macroalga Hizikia fusiformis was cultured in media with different copper (Cu) or cadmium (Cd) concentrations for 7 days; physiological indicators were measured to establish the toxic effects of Cu and Cd on this economically important seaweed. Relative growth rate of H. fusiformis was significantly reduced at Cu concentrations of ≥0.05 mg l^-1^ or Cd ≥4 mg l^-1^. Chlorophyll a and carotenoid contents increased at low Cu or Cd concentrations, but significantly decreased at 0.25 and 0.50 mg l^-1^ Cu. Optimal quantum yield, maximum net photosynthetic rate and apparent photosynthetic efficiency were reduced with increasing Cu or Cd concentrations. Malondialdehyde content and the superoxide dismutase activity increased under Cu or Cd stress. Catalase activity also increased at low Cu or Cd concentrations, but significantly decreased at high concentrations. Nitrate reductase activity significantly increased at 0.05 mg l^-1^ Cu and 4 mg l^-1^ Cd, but was inhibited at high Cu or Cd concentrations. Thus, both Cu and Cd were physiological stressors for H. fusiformis, with Cu being more toxic than Cd.