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

Abstract

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 Q_B-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.