[Electron microscopic localization of acid phosphatase in the extrafloral nectary of vicia faba L].

In the extrafloral nectary of broad bean and in the companion cells of its subjacent conducting bundle, there is evidence of the presence of acid phosphatase around and in the plasmalemma. This evidence suggests an active transport of sugars during their translocation from cell to cell and their excretion. Endoplasmic reticulum and Golgi apparatus are often stained by the lead phosphate reaction, a result showing the presence of acid phosphatase in these organelles. From the intensity and localization of this reaction three types of nectary cells can be distinguished.