Pigment mutants of the green microalga Chlamydomonas reinhardtii: Morphological properties and photosynthetic performance

Pigment mutants CC-124y-1, СС-124у-2, and СС-124р-2 of the green microalga Chlamydomonas reinhardtii Dangeard were obtained by means of UV-induced mutagenesis. Morphological properties and photosynthetic activity of these mutants were examined. The mutants displayed a lowered content of chlorophyll b and carotenoids. Analysis of fluorescence induction curves revealed the decreased rates of electron transport in photosystem II (PSII), the increase in the fraction of QB-nonreducing centers, and the enhancement of nonphotochemical fluorescence quenching. The mutations had no direct impact on oxidation of pigment P700 in PSI and on the decline of delayed fluorescence. The parameters of induction curves of prompt and delayed fluorescence are proposed for use in early diagnostics of UV-induced mutagenesis. The pigment mutants obtained can be applied in biomonitoring studies.