Structure and Function in the Grass Ligule: the Endomembrane System of the Adaxial Epidermis of the Membranous Ligule of Lolium temulentum L. (Poaceae)

The endomembrane system of the adaxial epidermal cells of themembranous ligule of the grass Lolium temulentum L. has beenstudied by conventional transmission electron microscopy, andby using zinc iodide-osmium tetroxide impregnation with examinationof thick sections at 100 kV. The components of the endomembranesystem are the nuclear membranes, rough endoplasmic reticulum(present in both cisternal and tubular forms), dictyosomes,dictyosome-derived vesicles, coated vesicles, plasma membraneand tonoplast. Direct continuity between tubular endoplasmicreticulum and the cis face of dictyosomes is demonstrated andthe applicability of the endomembrane concept to this putativesecretory tissue is discussed. The presence of vesicle-likeprofiles apparently within the outer tangential walls is reported.Copyright1995, 1999 Academic Press Ligule, Lolium temulentum L., darnel, grasses, Poaceae, Gramineae, endomembrane concept, ultrastructure, zinc-iodide-osmium tetroxide impregnation