ABSTRACT
Some allelochemicals (phenols, alkaloids, terpenoids) and other biologi cally active compounds, can fluoresce at the excitation of ultra-violet or violet light (Roshchina, 2002; 2003; 2004, 2005a,b). The fluorescence in duced by ultra-violet or violet light has also been observed both in intact secretory plant cells enriched in the substances and excretions from the cells. The substance fluorescence may serve as a marker for the cytodiagnostics of the secretory structures in luminescent microscope (they are not seen in usual microscope without special histochemical staining). The compounds may be also used as fluorescent probes in the studies both for the wider laboratory practice or specially for the analysis of the mechanisms of the allelochemical action (Roshchina, 2004). The effects of allelochemicals on the chlorophyll fluorescence in leaves have already been described (Reigosa Roger and Weis, 2001; Weis and Reigosa Roger, 2001)
The visible fluorescence of intact living cells is called autofluorescence. If the cells treated with special fluorescent dyes, the cellular common fluorescence also includes the additional light emission. Autofluorescence could be used: (i) in express-microanalysis of the accumulation of the secondary metabolites in secretory cells without long biochemical procedures; (ii) in diagnostics of cellular damage and (iii) in analysis of cell cell interactions (Roshchina, 2003). During the plant development, secretory
cells may change both the composition of the fluorescing secretions and their amount, that could be measured by estimating their characteristic fluorescence spectra and the fluorescence intensity (Roshchina, 2003). Most medicinal plants have secretory cells, where, pharmacologically-valuable secondary metabolites are accumulated (Roshchina and Roshchina, 1993).
