By use of a micro technique for producing extracts of spinach mesophyll cells, chloroplasts were isolated in a state wherein they displayed microscopically visible, reversible osmotic properties. Swollen spherical chloroplasts treated with hypertonic sucrose or mannitol media, but not NaCl, could be shrunken to a state resembling their disk appearance in living cells. Reversible osmotic behavio...

The methanol-ether extract of chloroplasts contains an ether-insoluble part which after purification was classified as a glycolipopeptide. This fraction can be precipitated by the antisera to the lamellar system of chloroplasts. By immunisation of rabbits with this compound, a glycolipopeptideantiserum was obtained. This antiserum precipitates the glycolipopeptide. There was only one precipitat...

Triazine-resistant chloroplasts o f the Canadian spring oilseed rape variety OAC Triton were transferred into four German winter oilseed rape lines and two cultivars o f double-low quality by means o f protoplast fusion. X-irradiation has been used to reduce the amount o f nuclear D N A o f the spring type cultivar and to promote cybrid formation. RFLP-analysis showed that some regenerants and ...

Chloroplasts are known to maintain specific intracellular distribution patterns under specific environmental conditions, enabling the optimal performance of photosynthesis. To this end, chloroplasts are anchored in the cortical cytoplasm. In leaf epidermal cells of aquatic monocot Vallisneria, we recently demonstrated that the anchored chloroplasts are rapidly de-anchored upon irradiation with ...

The rate of nonphosphorylating electron transport (in the absence of ADP and inorganic phosphate) in well-coupled (ATP/2e(-) = 0.9-1.1) maize mesophyll chloroplasts is not modulated by external pH (6.5-8.5), low levels of ADP or ATP, or energy transfer inhibitors, e.g. triphenyltin and Hg(2+) ions. In contrast nonphosphorylating electron flow in pea chloroplasts is sensitive to alterations in m...

Plastoquinone-9 (PQ-9) was isolated from the chloroplasts of Euglena gracilis Strain Z and spinach. The functional involvement and the structural specificity of PQ-9 in photochemical reactions was investigated in the isolated chloroplasts of Euglena gracilis. It was found that PQ-9 was required for both photoreduction of ferricyanide and photosynthetic phosphorylation in Euglena chloroplasts. T...

The lipids of photosystem II particles, of chloroplasts and leaves are compared in the variegated tobacco mutant N C 95. The mutant differs from other N. tabacum mutants by the phenomenon that it has variegated leaves with green and with yellow-green leaf patches. Chloroplasts from the green leaf areas exhibit photosystem II and photosystem I reactions and have a normal lamellar system with gra...

Photosynthesis is one of the most important biological processes in biosphere, which provides production of organic substances from atmospheric CO2 and water at expense of solar energy. In this review, we contemplate computer models of oxygenic photosynthesis in the context of feedback regulation of photosynthetic electron transport in chloroplasts, the energy-transducing organelles of the plan...

Immunoelectron microscopy and a quantitative analysis of immunogold labeling of a glutamine synthetase (GS; EC 6.3.1.2) revealed that, in mesophyll cells of mature leaves of Azolla filiculoides, almost all GS was present in chloroplasts. By contrast, in hair cells, abundant labeling of GS was observed both in chloroplasts and in the cytoplasm. In hair cells of cyanobiont-free plants, the labeli...

Chloroplasts have been considered primarily as the site of light-catalyzed CO2 fixation and photosynthetic phosphorylation. The present investigation was initiated in order to obtain further information on the question of protein synthesis as an integral function of chloroplasts. Towards this end a study was made of the activation of amino acids, a reaction generally regarded as the first step ...