engleski

The impact of cadmium on photosynthetic performance and secondary metabolites in the lichens Parmelia sulcata, Flavoparmelia caperata and Evernia prunastri

Lichens are one of the most common air quality bioindicators. Airborne heavy metal pollution causes various physiological changes in lichens, but sensitivity to metal pollution is species specifi c. In this research, three lichen species (Parmelia sulcata, Flavoparmelia caperata and Evernia prunastri) were exposed to cadmium (50 mg L–1) in laboratory conditions. Photosynthetic effi ciency of photosystem II and content of secondary metabolites were determined after one, three and eight days of exposure. In all investigated species treatment of lichen thalli with cadmium signifi cantly changed Fv/Fm and RFd only after eight days of exposure. Quantifi cation of metabolites showed a decreased content of the medullary depsidones salazinic acid (in P. sulcata) and protocetraric acid (in F. caperata) but increased content of cortical depside atranorin (in P. sulcata) and dibenzofurane usnic acid (in F. caperata) after cadmium exposure. However, no changes in secondary metabolites were found in E. prunastri. Results show that investigated species are relatively resistant to short-term cadmium-exposure and that secondary metabolites could have an important role in the protection of primary metabolism from negative cadmium impacts, at least in some species.

air pollution; heavy metal; HPLC; photosynthesis

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