01439nas a2200133   4500008004100000245009200041210006900133260001200202300001200214490000700226520094000233100001601173856011601189       1980                        eng d00aEndoplasmic reticulum-dictyosome interconnections in ligula cells of Isoetes lacustris.0 aEndoplasmic reticulumdictyosome interconnections in ligula cells  c1980///  a16 - 210 v233 aThe sub-marginal ligula cels of the water fern, Isoetes lacustris, were investigated with the electron microscope. Their most conspicuous ultrastructural elements, a well developed tubular ER and a cisternal rER, as well as numerous active dictyosomes, indicate a high activity of protein synthesis and intracellular transport. Several dictyosomes show interassociations and partly direct interconnections with each other and with the tubular ER, the latter occurring at the fenestrated regions of the Golgi cisternae. These details, demonstrated by sections parallel and perpendicular to the cisternal planes of the dictyosomes, point to the existence of a functionally homogeneous endomembrane system. The results are discussed with regard to the question whether the endomembrane concept (Morré and Mollenhauer [32]) be of general validity, or whether it needs to be restricted to the intracellular transport of secretion proteins.1 aKristen, U.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-0019271550&partnerID=40&md5=2ef1a83ac2ced91f0284bc93240cf9c4