In Vitro Protein Synthesis by Plastids of Phaseolus vulgaris

Abstract

Etioplasts are converted to chloroplasts when etiolated leaves of higher plants are placed in the light. Chlorophyll is formed during this conversion, the ability to photosynthesize develops (2,8,19,26,31), and the plastids increase in size and form their characteristic lamellar structures (9,24). Development of the ability to photosynthesize depends both on the formation of chlorophyll and on the formation of protein (11,20,21 tine were used throughout. They were grown in darkness for 6 to 8 days, or they were grown in darkness for 6 days and then illuminated for up to 48 hr. The temperature in darkness was 25 C and in light 28 C. Plants were illuminated with 1000 ft-c of white fluorescent light. Otherwise conditions of growth were the same as described previously (25).Preparation of Plastids. Chloroplasts and etioplasts were prepared from plants that were 6.5 days old, except where mentioned otherwise. Preparation of etioplasts was carried out in dim green light (5). Otherwise, both etioplasts and chloroplasts were prepared in the same way. Leaves were picked and stored and plastids were isolated as described previously (25)

Light regulation of the synthesis of the large subunit of ribulose-1,5-bisphosphate carboxylase in peas: Evidence for translational control

“…It is also possible that protein synthesis is very low in organelles from dark-grown plants, so that translation of all etioplast mRNAs, including LS mRNA, is markedly reduced. However, other studies (26,32) have shown that in the first 48 hr of greening, there appears to be an increase of only 3-fold in the proteinsynthesizing capacity of isolated plastids. A change of this magnitude may reflect the increase in total plastid RNA resulting from gene amplification and not be related to increased translational efficiency.…”

Pre‐existence of chloroplast lamellar proteins in wheat etioplasts. Functional and protein changes during greening under continuous or intermittent light

“…For some investigators working on etiolated Euglena [5] as well as on higher plants [6,7], the etiolated material exposed to light leads necessarily to a de novo synthesis of new proteins. For others, etiolated plastids contain all or at least a large part of the proteins necessary for the building of lamellae and grana [8] and consequently, it has been proposed that structural changes might be due to a reorganization of the existing protein molecules rather than to a de novo protein synthesis.…”

Protein Synthesis by Isolated Etioplasts and Chloroplasts from Pea and Wheat and the Effects of Chloramphenicol and Cycloheximide

“…There have been several studies made of protein synthesis in chloroplasts isolated from higher plants, most notably from bean (9,23), pea (29), spinach (35), tobacco (4,5,11,14), tomato (20), and wheat (2). Little is known, however, about the development of the capacity for protein synthesis during chloroplast biogenesis, and with one exception (9) studies comparable to those cited above have not been carried out using isolated etioplasts or immature chloroplasts.…”

“…Little is known, however, about the development of the capacity for protein synthesis during chloroplast biogenesis, and with one exception (9) studies comparable to those cited above have not been carried out using isolated etioplasts or immature chloroplasts. Indeed, the development of an extraction medium for isolating structurally intact etioplasts (from maize) has only recently been reported (21).…”