Arrangement and Structure of Plastids in Dormant and Cultured Tissue from Artichoke Tubers

The plastids in the tubers of the Jerusalem artichoke are foundboth scattered in the peripheral cytoplasm of the cells andalso in compact clusters usually near the nucleus. The clustersmay be a stage in the formation of plastids. The membrane-boundstructures within the plastids themselves can be assigned toone or other of two systems: a peripheral system of irregulartubules and cisternae some of which connect with the inner membraneof the plastid envelope; and a central system of highly variablemorphology which appears not to connect with the peripheralsystem. It is, apparently, from the central system that thethylakoids of stroma lamellae and grana develop during the greeningof illuminated cultures.