Phytotoxic effects of cyanobacteria extract on the aquatic plant Lemna gibba: Microcystin accumulation, detoxication and oxidative stress induction

• Type: Article in International Scientific Journal
• Date: 2007

Authors

Sana Saqrane (Author) Other; Issam El ghazali (Author) Other; Youness Ouahid (Author) Other; Majida El Hassnib (Author) Other; Ismail El Hadrami (Author) Other; Lahcen Bouarab (Author) Other; Franscica F del Campo (Author) Other; Brahim Oudra (Author) Other; Vitor Vasconcelos (Author) FCUP

Journal

Title: Aquatic Toxicology

Vol. 83

Pages: 284-294

ISSN: 0166-445X

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 91 Citations

Scopus - 99 Citations

Scientific classification

FOS: Medical and Health sciences > Basic medicine

Other information

Authenticus ID: P-004-89A

DOI: 10.1016/j.aquatox.2007.05.004

Abstract (EN): The occurrence of toxic cyanobacteria in the aquatic environment constitutes a serious risk for the ecological balance and the functioning of ecosystems. The presence of cyanotoxins in ecosystems could have eventual adverse effects on aquatic plants, which play an important biological role as primary producers. The original aim of this study was to investigate microcystin (MC) accumulation, detoxication and oxidative stress induction in the free-floating aquatic vascular plant Lemna gibba (Duckweed, Lemnaceae). Experiments were carried out with a range of MC levels, obtained from toxic Microcystis culture extracts (0.075, 0.15, 0.22 and 0.3 mu g equiv. MC-LR mL(-1)). During chronic exposure of the plant to MC, we examined the growth, photosynthetic pigment contents and also the physiological behavior related to toxin accumulation, possible biodegradation and stress oxidative processes of L. gibba. For the last reason, changes in peroxidase activity and phenol compound content were determined. This is a first report using phenol compounds as indicators of biotic stress induced by MC contamination in aquatic plants. Following MC exposure, a significant decrease of plant growth and chlorophyll content was observed. Also, it was demonstrated that L. gibba could take up and bio-transform microcystins. A suspected MC degradation metabolite was detected in treated Lemna cells. In response to chronic contamination with MCs, changes in the peroxidase activity and qualitative and quantitative changes in phenolic compounds were observed after 24 h of plant exposure. The physiological effects induced by chronic exposure to microcystins confirm that in aquatic ecosystems plants coexisting with toxic cyanobacterial blooms may suffer an important negative ecological impact. This may represent a sanitary risk due to toxin bioaccumulation and biotransfer through the food chain.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11