Lipid Content Variation in Plantago media Leaves in Response to Light Conditions

Abstract

The aim of the present work was to study the variation of lipid and fatty acids (FA) composition as well as morphometric characteristics of Plantago media leaves from the different light conditions in northeastern Russia. The content of lipids in the leaves was measured for several years during the blooming period, and the level of lipid peroxidation was estimated. For lipid analysis, the mid leaf part from 12-15 typical plants was cut in small parts and three samples of 1-2 g were chosen from the total biomass. Lipids were extracted three times using three times chloroform/methanol. The quantification of phospholipids (РL) was performed by the content of inorganic phosphorus. Glycolipids (GL) and non-polar lipids (NL) were quantified using a densitometer. The leaves of the plants grown under lower light had lower leaf mass/area ratio (LMA) but larger areas of lamina. They accumulated lower levels of lipid peroxide products. Daily content of malondialdehyde changed more significantly during periods with clear and warm weather. It was found that as the duration of sunshine increased, the content of total lipids (TL) increased (r=0.78), but an increase in temperature resulted in a decrease of their content (r=-0.70), especially for plants in high-sunshine habitats. Concentration of GL in leaves of shaded plants increased with increasing precipitation but decreased with increasing temperature and the duration of sunshine. The same effect is exerted by rainfall on PL content. Amount of saturation FA (SFA) increased with increasing temperature and the duration of sunshine. Precipitation contributed to the accumulation of unsaturation FA (USFA). Thus, the content of lipids in the leaves depended on weather and microclimate conditions.