| | 1 | Author
| G. K. Ulandaivelu An, D.0 H All | Requires cookie* | | | Title
| Ultrastructural Changes in in vitro Ageing Spinach Chloroplasts  | | | | Abstract
| Ultrastructural changes in in vitro ageing spinach chloroplasts have been studied in detail. Prolonged storage caused swelling of the chloroplasts due to the increase in the thickness and spacing of the thylakoid membranes. The increase in the thickness of the membrane is partly ac companied by the release of lipids. Addition of crystalline bovine serum albumin was found to stabilize the membrane structures. Storage of the chloroplasts at 77 °K even though it resulted in complete breakage of the whole chloroplasts, maintained the thylakoid structures in a highly intact form. | | | |
Reference
| (Z. Naturforsch. 31c, 82 [1976]; received August 8 1975) | | | |
Published
| 1976 | | | |
Keywords
| Ultrastructure, Thylakoid Membrane, Ageing, Storage Conditions, Spinach | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_C/31/ZNC-1976-31c-0082.pdf | | | | Identifier
| ZNC-1976-31c-0082 | | | | Volume
| 31 | |
| 3 | Author
| H. Gimmler, B. Heilmann, B. Demmig, W. Hartung | Requires cookie* | | | Title
| The Permeability Coefficients of the Plasmalemma and the Chloroplast Envelope of Spinach Mesophyll Cells for Phytohormones | | | | Abstract
| The uptake of auxin (LAA), abscisic acid (ABA) the synthetic cytokinin benzylaminopurine (BA), gibberellic acid (GA3) and mevalonic acid (lactone) (MVA) into intact chloroplasts and protoplasts from spinach mesophyll cells was measured and the permeability coefficients Ps of the chloroplast envelope and the plasmalemma were calculated. With all solutes tested uptake and P s values were considerably higher in the chloroplast system than in the protoplast system. At an external pH of 7.0, rates of uptake exhibited the order BA > LAA > MVA > ABA > GA3 in both systems. However, the P s values (corrected for the undissociated species of the solutes) exhibited the order LAA > GA3 > (ABA or BA) > MVA. This corrected sequence indicates the theoretical capacity of penetration under the assumption that preferentially the protonated species of phytohormones are capable of readily penetrating membranes. P s values for phytohormones appeared largely to be determined by the distribution coefficient K d and to a lesser extent by the molecular weight (Mr). In the Collander-plot the relation between the logarithm of Ps values for phytohormones and some other solutes such as acetate, glycerol, glucose, sorbitol and sucrose and the logarithm of K J M T 1.5 approached linearity. | | | |
Reference
| Z. Naturforsch. 36c, 672—678 (1981); received March 9 1981 | | | |
Published
| 1981 | | | |
Keywords
| Chloroplast Envelope, Permeability Coefficients, Phytohormones, Plasmalemma, Spinach | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_C/36/ZNC-1981-36c-0672.pdf | | | | Identifier
| ZNC-1981-36c-0672 | | | | Volume
| 36 | |
| 4 | Author
| Kirsten Heim, G. Eorg, Kreim Er, M. Ichael, M. Elkonian, Erwin Latzko | Requires cookie* | | | Title
| Light-Induced Ca2+ Influx into Spinach Protoplasts | | | | Abstract
| Protoplasts from spinach leaves exhibit a light-induced Ca2+ influx. The half maximum rate of C a2+ influx is achieved at ~ 5 W m"2. The action spectrum o f this influx is similar to that of photosynthesis. Furtherm ore, light-induced Ca2+ influx is abolished by D C M U (2* 0.5 ^ im) and is sensitive to the uncoupler FCCP. Vanadate up to 3 enhances light-induced Ca2+ influx. These data indicate that photosynthetic electron transport is involved in light-induced Ca2+ influx into spinach protoplasts. | | | |
Reference
| Z. Naturforsch. 42c, 283 (1987); received O ctober 24 1986 | | | |
Published
| 1987 | | | |
Keywords
| Calcium-Influx, Protoplasts, Spinach, Light-Induced | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_C/42/ZNC-1987-42c-0283.pdf | | | | Identifier
| ZNC-1987-42c-0283 | | | | Volume
| 42 | |
| 6 | Author
| Wolfgang Schmidt, Ulrich Schreiber, Wolfgang Urbach | Requires cookie* | | | Title
| | | | | Abstract
| The effects of short-time fumigation (0-60 min) of intact spinach leaves with S0 2 (2 ppm) on the photosynthetic apparatus were investigated. A rather high S0 2 concentration was applied to monitor immediate effects on the fluorescence behaviour with the influence of repair processes or secondary types of damage being minimized. Three different types of in vivo chlorophyll fluores-cence measurements were used: Rapid induction kinetics (Kautsky effect), slow induction kinetics with repetitive application of saturation pulses (saturation pulse method), and decay kinetics following a single turnover saturating flash. The slow induction kinetics with repetitive application of saturation pulses reacts in the most sensitive way indicating a primary damage at the level of the enzymatic reactions of the Calvin cycle. It is suggested that stromal acidification upon S0 2 uptake interferes with light activation of Calvin cycle enzymes. With longer fumigation times also damage at the level of photosystem II becomes apparent: A decrease in variable fluorescence yield reflects a lowering of photosystem II quantum yield, and the slowing down of fluorescence relaxation kinetics reveals an effect on the secondary electron transport from Q A to Q B . The detrimental effects of S0 2 depend to a great extent on the application of light during fumigation. Besides a light requirement for S0 2 uptake by stomata opening also the possibility of photoinhibitory damage is discussed. The susceptibility of leaves to photoinhibition may increase with a lowering of Calvin cycle activity by S0 2 . | | | |
Reference
| Z. Naturforsch. 43c, 269—274 (1988); received December 7 1987 | | | |
Published
| 1988 | | | |
Keywords
| Chlorophyll Fluorescence, S0 2, Spinach, Intact Leaves, Calvin Cycle | | | |
Similar Items
| Find | | | DEBUG INFO
| | | | | TEI-XML for
| default:Reihe_C/43/ZNC-1988-43c-0269.pdf | | | | Identifier
| ZNC-1988-43c-0269 | | | | Volume
| 43 | |
|
