ABSTRACT
Secretions play an essential role as chemical signals or/and as medium for the reception of the signals (Roshchina, 1999a, b; 2001a, b). The celldonor for chemosignal (fluorescent signalling substance in its excretion) and the cell-acceptor of the same chemosignal (recognizing systems in its excretion) interact via their excretions. The secretory products are located in surface (0.01 -0.02 \Xm in diameter) channels of the cell wall, for example in the cuticle of nectary cells (Koteeva, 2005), or in pollen exine (Rowley et al., 1959; Roshchina et al., 1998d) as well in the secretory ducts of pistil stigma (Fahn, 1978). The changes in the fluorescence of the cell-donor and
cell-acceptor may be observed under a luminescence microscope or with a help of microspectrofluorimetry (Roshchina et a l, 1996; Roshchina and Melnikova, 1996; 1998a, b; 1999; Roshchina, 2003; 2005a). M icrospectrofluorimetry and the new Laser Scanning Confocal Microscopes from Leica can be used for recording the fluorescence spectra in several ways: 1) the diagnostics of secretory cells containing allelochemicals; and 2) dynamics of chemical interaction between secreting cells.
