In chloroplasts, several water-soluble carbohydrates have been suggested to act as stress protectants. The trisaccharide raffinose (alpha-1,6-galactosyl sucrose) is such a carbohydrate but has received little attention. We here demonstrate by compartmentation analysis of leaf mesophyll protoplasts that raffinose is clearly (to about 20%) present in chloroplasts of cold-treated common bugle (Aju...

Chloroplasts were isolated from triazine-sensitive and triazine-resistant biotypes of common groundsel (Senecio vulgaris L.), common lambsquarter (Chenopodium album L.), and redroot pigweed (Amaranthus retroflexus L.). Chloroplast lipids were extracted and analyzed for differences among sensitive and resistant biotypes. The distribution of lipid between major lipid classes differed in chloropla...

Non-contact intracellular binding and controllable manipulation of chloroplasts in vivo was demonstrated using an optical fiber probe. Launching a 980-nm laser beam into a fiber, which was placed about 3 μm above the surface of a living plant (Hydrilla verticillata) leaf, enabled stable binding of different numbers of chloroplasts, as well as their arrangement into one-dimensional chains and tw...

The role of chloride in photosynthetic oxygen evolution was reinvestigated by determining the effect of this ion on photochemical reactions of chloroplasts in which oxygen either is or is not produced. The chloroplasts used were isolated from normal spinach leaves. The level of chloride in the reaction mixture was controlled by washing the isolated chloroplasts and by avoiding a chloride contam...

A nuinber of detergenits have beeni used to convert chloroplasts inlto smaller complexes for miiore intensive study of the properties of the photosynithetic apparatus (16). In all early series of experiments, Smiiith treated chloroplasts with digitonin, bile salts, sodium deoxycholate and sodium dodecyl sulfate (2325). The first 3 detergents removed and solubilized the chlorophyll wlhile the la...

Protoplasts, protoplast extracts (intact chloroplasts plus extrachloroplastic material), and chloroplasts isolated from protoplasts of wheat (Triticum aestivum) have rates of photosynthesis as measured by light-dependent O(2) evolution of about 100 to 150 micromoles of O(2) per milligram of chlorophyll per hour at 20 C and saturating bicarbonate. The assay conditions sufficient for this activit...

Intact chloroplasts and cell walls were prepared from horse-chestnut leaves that had previously metabolized [2-(14)C]mevalonate. The bulk of the castaprenols and plastoquinone-9 was found within the chloroplasts. The remaining portion of the castaprenols was associated with the cell-wall preparation whereas that of the plastoquinone-9 was probably localized in the soluble fraction of the plant ...

Photosynthetic reactions of whole leaves and isolated chloroplasts from various mutants of Nicotiana tabacum have been correlated to the lamellar structure seen in electron micrographs of the chloroplasts. In this way it could be established that a fully active photosystem I can be associated with single unfolded thylakoids. The complete photosynthetic electron transport system including the ox...

The chloroplasts of internodal cells of Nitella are fixed to a stationary layer of cytoplasm whereas the nuclei and most of the cytoplasm stream along the longitudinal axis. Isolated internodal cells were maintained for several days with half the cell kept in the dark, the other half kept under continuous light. Photosynthetic activity of the cells was checked by placing the cell evenly illumin...

Granum-containing chloroplasts from mesophyll cells of maize (Zea mays L. var. MV 861) leaves exhibited circular dichroism spectra with a large double signal; peaks at 696 nm (+) and 680 nm (-). In the circular dichroism spectra obtained with agranal chloroplasts of bundle sheath cells, this large double signal is absent. Separation of grana lamellae, in a medium of low salt concentration and i...