ABSTRACT
W hat are the main signs that the visible fluorescence of secretory cells actually belongs to a secretion? First of all, the evacuation of the secretion from the secretory cells leads to the quenching of the luminescence within the secretory cell, as can be seen for leaf secretory hair of the common nettle of Urtica dioica (Fig. 1.6), tomato Lycopersicon esculentum, and calendula Calendula officinalis (Roshchina and Melnikova, 1995; 1999). The empty space within the secretory hair (Fig. 1.6 ) is observed as a dark space. Often drops of lipophilic secretion may stay at the end of the secreting hair and can fluoresce, appearing as lightening against the dark background of the empty hair (Roshchina and Melnikova, 1995). Only cell walls, when they include phenols, have a weak emission, which is non measured or measured maximally as less than 7 -1 0 % of the total emission of the fluorescing secretory cell (Roshchina et al., 1998a). Therefore, about 90% of the emission of the secretory cell is due to its secretion. The second evidence of the main contribution of the secretion to light emission of the secretory cell is an analogous fluorescence of the secretion released on the surface such as liquids or crystals of some alkaloids, terpenes and phenols (Roshchina et al., 1997a, b; 1998a; Roshchina and Melnikova, 1999).
