2008 Volume 73 Issue 4 Pages 437-443
The unicellular red alga Cyanidioschyzon merolae is tolerant of high levels of several different metal ions. Cells of the alga cultured with divalent or trivalent metal ions at 10 mM contained elevated concentrations of each metal. The highest tolerance was shown for Al followed by Fe, Cu>Ni>Zn>Mn. The viability and morphology of the cells were investigated for different periods of time after metal addition. In contrast to land plants, C. merolae exhibited a very high tolerance to metal ions, but the response varied according to the metal ion added. In particular, Mn, Zn and Ni ions affected the structure and function of the chloroplast, and markedly reduced the cell viability. Nevertheless, the tolerance of C. merolae to metal ions is the highest among reported eukaryotic cells. Cellular mechanisms for detoxification or defense against metal ions must be well developed in this alga.
