Role of anthocyanin and carotenoids in the adaptation of the photosynthetic apparatus of purple- and green-leaved cultivars of sweet basil (Ocimum basilicum) to high-intensity light

Abstract

Comparative studies of the adaptation of green- and purple-leaved Ocimum basilicum varieties, which differ in carotenoid and anthocyanin contents, to high-intensity light have been carried out. The plants were grown for 21 d under white light-emitting diode providing different light intensities [300, 550, and 1,350 µmol(photon) m-2 s-1]. During the experiment, fresh mass and relative water content, photosynthetic pigment and anthocyanin content, amount of total free phenolic compounds, and the contents of thiobarbituric acid reactive substances and H2O2 were analysed. The fluorescent parameters, which characterized the PSII activity in the leaves (Fv/Fm, Y(II)), as well as the efficiency of dissipation of absorbed energy into heat (Y(NPQ),Y(NO)) and the fraction of the PSII open centres (qL), were determined. The obtained results are consistent with the concept of the important role of not only anthocyanin but also carotenoids in plant adaptation to high-intensity light.