Little is known about possible interactions between chloroplasts and the Golgi apparatus, although there is increasing evidence for a direct Golgi to chloroplast transport pathway targeting proteins to their destinations within the membranes and stroma of plastids. Here data are presented showing that a blockage of secretion results in a significant increase of starch within plastids. Golgi dis...

Yes! It is now time to consider mitochondria as bacteria, as recently explored in this journal [1], and this highly heuristic viewpoint should also be extended to plastids [2]. Clearly, Eubacteria would be paraphyletic, as defined in [1], without mitochondria and plastids. In his thought-provoking paper, Dr Pallen raises the apparent opposition between the views of mitochondria as either bacter...

We have developed a reliable procedure for the purification of envelope membranes from cauliflower (Brassica oleracea L.) bud plastids and sycamore (Acer pseudoplatanus L.) cell amyloplasts. After disruption of purified intact plastids, separation of envelope membranes was achieved by centrifugation on a linear sucrose gradient. A membrane fraction, having a density of 1.122 grams per cubic cen...

Plastids in the leaf epidermal cells of plants are regarded as immature chloroplasts that, like mesophyll chloroplasts, undergo binary fission. While mesophyll chloroplasts have generally been used to study plastid division, recent studies have suggested the presence of tissue- or plastid type-dependent regulation of plastid division. Here, we report the detailed morphology of plastids and thei...

The function of plastid ribosomes in pea (Pisum sativum L.) was investigated by characterizing the products of protein synthesis in vitro in plastids isolated at different stages during the transition from etioplast to chloroplast. Etioplasts and plastids isolated after 24, 48 and 96h of greening in continuous white light, use added ATP to incorporate labelled amino acids into protein. Plastids...

Hans Ris proposed in 1961 that chloroplasts might be highly derived endosymbiotic microorganisms, originally related to blue-green algae. Evidence from 1966 and earlier is reviewed to test this proposal. Elegant experiments using the unique genetic system offered by Oenothera (the evening primroses) clearly show that plastids carry heritable characters not under nuclear control. Two or even thr...

Plastids are able to relay information to the nucleus to regulate stress responses. A new genetic screen has identified an isoprenoid intermediate that accumulates in stressed plastids and acts as a novel retrograde signal.