Lighting intensity affects the fatty acid composition of total lipids of basil leaves and roots (Ocimum basilicum L.)

Abstract

The vegetative organs of common basil (Ocimum basilicum L.) grown in water culture at different levels of illumination (50, 100, and 150 μmol PAR quanta/(m2 s)) for 21 days were studied. In the work, the Purple Velvet basil variety, which is popular in agriculture and has intensely colored leaves was used. The biomass, water content, and composition of fatty acids (FA) of total lipids in the leaves and roots of plants and the content of malondialdehyde and chlorophylls (a, b) in the aerial parts of plants were determined. The sensitivity of the FA composition and morphophysiological parameters (biomass and chlorophyll content in leaves) of O. basilicum plants to the intensity of illumination was shown. The greatest effect was caused by the illumination intensity mode of 150 μmol/(m2 s). Species composition of O. basilicum FA under all lighting conditions was wider in root lipids; however, more pronounced changes in the qualitative composition of Fas were observed in leaves. Photodependent regulation of FA component composition of O. basilicum manifested itself in an increase in the proportion of unsaturated FAs, especially polyene ones, which led to an increase in the unsaturation index (UI) of esterified lipid FAs. The highest UI values were obtained with illumination of 150 μmol/(m2 s). At the same time, with an increase in the illumination intensity, a significant increase in the activity of ω-3 and ω-9-desaturases occurred, which indicates in favor of their lightdependent activation. Thus, increasing the intensity of lighting to certain values directly proportionally affects the physiological parameters of O. basilicum. The maximum indicators of productive growth and the implementation of adaptive mechanisms of green and underground parts of basil plants correspond to illumination of 150 μmol/(m2 s).