Abstract: Our recent work has uncovered that a direct communication is established between the developing wheat proembryo and the surrounding medium at the parietal area of the basal region, in which a few cells were undergoing structural deformation and disintegration. With fluorescence microscopy and electron microscopy a series of experiments were conducted by using cationized ferritin and lucifer yellow CH as tracers to investigate the above mentioned “direct communication” in relation to the absorption of external materials. Evidences obtained show that either the macromolecule, ferritin, or the fluorescent dye, lucifer yellow actually can enter into the proembryo cells through non-transmenbrane pathway. Ultrastructural studies confirm that the incorporation of these external chemicals is realized by traversing a special route (ectodesma-like plasmodesmata and open channels) at the boundary wall of the local area of the basal region.

Key words: Triticum aestivum, Proembryo, Absorption, Cationized ferritin, Lucifer yellow CH