Study of the Spectral Characteristics of the Plant Cell Surface: Occurrence of Azulenes and Biogenic Amines

The spectral characteristics of plant surface cells of different evolutionary levels, from unicellular (diatom algae and spores of horsetails and ferns) to multicellular (woody and herbaceous species) organisms, have been studied. It was shown that the surface layers of the cuticle and cell wall of some analyzed plants included antioxidants – blue pigments azulenes. Using histochemical methods, it has been discovered that here neurotransmitter compounds (biogenic amines) are present in the excretions on the entire surface or are released from specialized secretory structures of leaves. Under conditions of high salt concentration, dopamine and histamine are secreted, which is blocked by the addition of exogenous azulene and proazulene grosshemine. We suggest that the azulene-containing surface protects from the formed reactive oxygen species and toxic biogenic amines in high concentrations.