Effect assessment of the herbicide paraquat on a green alga using differential gene expression and biochemical biomarkers

Environmental Toxicology and Chemistry - Tập 29 Số 4 - Trang 893-901 - 2010
An Jamers1, Wim De Coen1
1Laboratory for Ecophysiology, Biochemistry and Toxicology, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium

Tóm tắt

AbstractEffects of the herbicide paraquat were assessed on the green freshwater alga Chlamydomonas reinhardtii using different endpoints of toxicity. Cell concentration and growth rate were monitored, whereas flow cytometry was applied to determine changes in chlorophyll content, viability and presence of reactive oxygen species. Furthermore, a transcriptomics approach using microarray hybridizations was applied to elucidate the mechanisms of toxicity. The results reveal that paraquat concentrations above 0.25 µM induce toxic effects in C. reinhardtii, reflected in a significantly reduced growth rate and cell concentration with a corresponding median effective concentration (EC50) value of 0.26 µM. With increasing paraquat concentrations, an increase in cell volume was registered with a particle counter as well as in the forward scattering signal of flow cytometric measurements, which is a measure of cell size. Flow cytometry, moreover, showed an increase in reactive oxygen species with increasing exposure concentration, corroborating the general knowledge that this herbicide exerts its toxicity through the generation of oxidative stress. At the same time, several genes involved in oxidative stress defense mechanisms, such as L‐ascorbate peroxidase, glutaredoxin, and a possible glutathione‐S‐transferase were differentially expressed, demonstrating the value of microarrays for elucidating possible mechanisms of toxicity. The fact that several genes were differentially expressed at paraquat concentrations that caused no adverse effects on higher levels of biological organization indicates that a transcriptomics approach allows for the detection of early effects, even before they become manifest at higher levels. Environ. Toxicol. Chem. 2010;29:893–901. © 2009 SETAC

Từ khóa


Tài liệu tham khảo

10.1016/0021-9673(95)01101-3

10.1007/BF00211506

10.1016/S0045-6535(99)00408-7

10.1006/eesa.2001.2113

10.1007/s002449900470

10.1016/j.envint.2008.06.012

10.1016/S0300-483X(02)00382-7

Harris EH, 1989, The Chlamydomonas Sourcebook: A Comprehensive Guide

Organization for Economic Cooperation and Development.2002.Alga growth inhibition test. Guideline 201. Paris France.

Jamers A, 2009, Flow cytometric analysis of the cadmium exposed green alga Chlamydomonas reinhardtii, Eur J Psychol (forthcoming).

10.1016/j.aquatox.2006.09.002

10.1093/nar/29.9.e45

10.1007/s001289900422

10.1016/j.ecoenv.2006.11.010

10.1139/b93-020

10.1016/S0166-445X(01)00255-7

Reiriz S, 1994, Different responses of the marine diatom Phaeodactylum tricornutum to copper toxicity, Microbiologia, 10, 263

10.1073/pnas.152337999

10.1104/pp.127.1.159

10.1002/cyto.990100518

10.1016/S0166-445X(01)00254-5

10.1016/j.pestbp.2007.11.009

10.1016/S1532-0456(02)00253-3

10.1111/j.1420-9101.2005.00921.x

10.1104/pp.116.1.173

10.1016/0009-2797(95)03651-2

10.1016/j.tiv.2006.09.003

10.1006/pest.1999.2405

Thông tin
Thông tin xuất bản

Environmental Toxicology and Chemistry

Tập 29 Số 4

893-901

Thông tin tác giả