Intact protoplasts and chloroplasts have been isolated from mature flag leaves of wheat (Triticum aestivum L.). Both showed high rates of photosynthesis, the best of which equaled those observed in the parent tissue (greater than 150 micromoles O(2) per milligram chlorophyll per hour). The presence of ethylenediaminetetraacetate and an alkaline medium (pH 8.4) were required in the isolation and...

The photochemical reduction of triphosphopyridine nucleotide by isolated chloroplasts has been known since 1951 (see “Discussion”). The discovery of this photochemical reaction marked a significant advance in the biochemical analysis of the energy conversion process of photosynthesis because it established the first link between photon capture by chloroplast pigments and the reduction of a phys...

Chloroplasts import post-translationally most of their constituent polypeptides via two distinct translocon units located in the outer and inner envelope. The protein import channel of the translocon of the outer envelope of chloroplasts, Toc75, is the most abundant protein in that membrane. We identify a novel Toc75 homologous protein, atToc75-V, a prominent protein that is clearly localized i...

The localization of carbamoylphosphate synthetase (CPSase) and aspartate carbamoyltransferase (ACTase), the first two enzymes of the pyrimidine biosynthetic pathway, in chloroplasts was investigated. In dark-grown radish (Raphanus sativus) seedlings, light induced a prominent increase in CPSase activity, but had little effect on ACTase activity. Both enzymes were found in chloroplasts isolated ...

The photoreduction of cytochrome c by spinach chloroplasts has been noted by several investigators (12, 20, 25). In a preliminary report, we have presented evidence that aqueous digitonin extracts of spinach chloroplasts contain a cytochrome c photooxidase (22) which appears to be similar to the photooxidase present in extracts of photosynthetic bacteria studied by Kamen and Vernon (13, 14, 32)...