Dilatiertes ER in Kalluszellen und in Zellen vonin vitro kultivierten Pfl�nzchen vonArmoracia rusticana

Abstract

Callus tissue, plants grown in the Botanical gardens, andin vitro cultivated plants ofArmoracia rusticana, were investigated. Dilated rough cisternae of ER characteristic ofBrassicaceae andCapparaceae occur in both the leaf and the root callus. They are spindle shaped and contain granula and filaments the latter are often oriented longitudinally. A tubular pattern could never be observed in the cisternae of the callus. This pattern is considered as typical of the dilated cisternae of the leaves and shoots ofArmoracia plants grown in the garden and of plants cultivatedin vitro. Few cells of the shoot apex containing filamentous material, however, were additionally found. In parenchyma cells of aseptically cultivated plants cisternae often fuse into shapeless formations which seem to persist. Phloem parenchyma cells of plants cultivatedin vitro contain tubules and areas of filaments in the very same cisternae, we suppose a close connexion between the two structures. Adjacent tubules appear to be linked by fine filaments. In the transverse section they form a hexagonal pattern with a centre-to-centre spacing of about 60 nm. The tubules have an external diameter of 20–24 nm and seem to be formed by 5 or 6 subunits in the transection. In differentiating sieve elements P protein tubules and cisternae containing tubules occur together. Relationship between the two tubules cannot be found.