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Keywords:

  • Fucus serratus (Phaeophyta);
  • Cu2+;
  • tolerance;
  • photosynthesis;
  • chlorophyll fluorescence;
  • hyper-accumulation;
  • algae;
  • heavy metal

Summary

  • • 
    A comparative study of copper (Cu) toxicity and tolerance in three populations of Fucus serratus was conducted by examining Cu2+ effects on various physiological parameters.
  • • 
    Chlorophyll fluorescence, oxygen evolution, copper content, and relative growth rate of embryos and adults were measured on Cu2+-exposed material.
  • • 
    Algae naturally exposed to elevated total Cu concentration (CuT), were more Cu2+ resistant than those from clean sites, as indicated by higher embryo and adult growth rates and lower copper contents. The Cu2+ tolerance of F. serratus is at least partly inherited and relies partly on metal exclusion.
  • • 
    There were inhibitory effects of Cu2+ on oxygen exchange rates in both tolerant and non-tolerant algae. By contrast to sensitive algae, the maximum efficiency of photosystem II (Fv/Fm), maximum fluorescence (Fm) and zero fluorescence (Fo) of resistant algae were unaffected by Cu2+, whereas decreased quantum yield (ΦPSII) and increased nonphotochemical quenching (NPQ) were most pronounced in resistant algae. Inhibitory effects of Cu2+ on ΦPSII may result in the excitation energy being dissipated through xanthophyll-dependent quenching mechanisms in tolerant algae. In nontolerant algae, lower energy dissipation may result in chlorophyll degradation.