Effect of Evernic Acid on Structure of Spinach Chloroplasts

Detached leaves of Spinacia oleracea were incubated with evernic acid, the main phenolic substance present in Evernia prunastri thalli. This lichen substance produced a decrease in the amount of total chlorophyll and chlorophyll a in treated spinach leaves. Chloroplast structure suffered a decrease in several parameters, i.e. chloroplast area, number of grana, granal width, number of thylakoids per granum and starch content. The submicroscopic structure of the chloroplast membranes revealed smaller particle diameters in several of the fracture faces in the evernic acid treated samples and even a decrease in the density of particles in the EF, fracture face. The alterations observed may be related to changes in photosynthetic activity, probably by modification of both photosystem I and photosystem II activities.