Hsp70 expression in Enteromorpha intestinalis (Chlorophyta) exposed to environmental stressors

Numerous studies have indicated that stress proteins have potential as biom arkers of exposure to environmental contaminants. Analysis of stress protei ns in animals, especially Hsp70, has dominated this research area despite i ncreasing interest in the use of plants as pollution monitors. In the prese nt study Hsp70 expression in Enteromorpha intestinalis has been investigate d under exposure to a variety of stressors, to evaluate the potential use o f Hsp70 as a biomarker of contaminant exposure in this seaweed. E. intestin alis was exposed to thermal stress, copper under differing conditions of nu trient availability and the triazine herbicide Irgarol 1051. Measurements w ere also taken to compare Hsp70 with conventional sublethal endpoints of to xicity such as growth and fluorescence induction parameters such as Fv/Fm. E. intestinalis exhibited a typical heat shock response. Hsp70 expression w as increased with copper exposure, but proved to be a relatively insensitiv e biomarker of copper exposure compared to growth measurements. Nutrient li mitation enhanced copper toxicity and significantly impaired growth, Fv/Fm and Hsp70 production. Fv/Fm and growth were strongly affected by Irgarol 10 51 exposure, but Hsp70 levels were unaltered following exposure to the herb icide. The implications of using Hsp70 expression in E. intestinalis as a b iomarker are discussed. (C) 2001 Elsevier Science B.V. All rights reserved.