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'Carotenoid' in keywords Facet   Publication Year 1984  [X]
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1984[X]
1Author    ArminR. Gemmrich, Hartmut KayserRequires cookie*
 Title    Hormone Induced Changes in Carotenoid Composition in Ricinus Cell Cultures. II. Accumulation of Rhodoxanthin during Auxin-Controlled Chromoplast Differentiation  
 Abstract    The effects of auxin and cytokinin on light dependent carotenoid synthesis were studied in callus cultures derived from Ricinus endosperm tissue. Chloroplasts differentiate when calli are grown in the light in the presence of cytokinin and auxin. When cultures are transferred to an auxin-free medium, chromoplast differentiation is initiated, i.e. rhodoxanthin accumulates whereas lutein and chlorophyll content decrease and the plastid morphology changes from that of a typical chloroplast to that of a globular-type chromoplast. These changes are fully reverted by readdition of auxin. Plastid differentiation into either chloroplasts or chromoplasts in Ricinus endosperm cultures therefore appears to be controlled by auxin and cytokinin. 
  Reference    Z. Naturforsch. 39c, 753—757 (1984); received May 11 1984 
  Published    1984 
  Keywords    Plant Cell Cultures, Cytokinin, Auxin, Plastid Differentiation, Carotenoids 
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 TEI-XML for    default:Reihe_C/39/ZNC-1984-39c-0753.pdf 
 Identifier    ZNC-1984-39c-0753 
 Volume    39 
2Author    SeymourSteven BrodyRequires cookie*
 Title    Flash Photolysis of Liposomes Containing Chlorophyll and Zeaxanthin, as a Function of Temperature (2 °—34 °C)  
 Abstract    The transfer o f triplet excitation from chlorophyll to zeaxanthin in lip osom es is a function o f temperature and pigment concentration. At 525 nm both chlorophyll and zeaxanthin triplet states are observed. The result is a biphasic increase in absorption. The rise time o f absorption by the chlorophyll triplet is much faster, than by the zeaxanthin triplet. With increasing temperature the contribution o f absorption by zea­ xanthin (relative to that o f chlorophyll) at 525 nm increases, and its rise tim e gets faster. At high ratios o f zeaxanthin to chlorophyll, temperature has less effect on both the rise tim e and absorption by the zeaxanthin triplet state. The chlorophyll triplet is measured at 780 nm. It decays faster with increasing temperature and or increasing ratio o f zeaxanthin to chlorophyll. The results are interpreted in terms of: increasing fluidity o f the lipid lip osom e with tem per­ ature, formation o f zeaxanthin-chlorophyll com plexes at high ratios o f zeaxanthin and chloro­ phyll, presence o f different lipid phases in the lip osom e bilayer. 
  Reference    Z. Naturforsch. 39c, 1108—1111 (1984); received June 15 1984 
  Published    1984 
  Keywords    Chlorophyll, Carotenoid, Liposomes, Triplet States, Excitation Energy Transfer 
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 TEI-XML for    default:Reihe_C/39/ZNC-1984-39c-1108.pdf 
 Identifier    ZNC-1984-39c-1108 
 Volume    39 
3Author    Jürgen FeierabendRequires cookie*
 Title    Comparison of the Action of Bleaching Herbicides  
 Abstract    Among chlorosis-inducing herbicides that interfere with carotenoid synthesis two groups o f different potency can be discriminated (group 1; aminotriazole amd haloxidine; group 2 with more extensive photodestructions: pyridazinone herbicides and difunon). After application o f herbicides o f group 2 colored carotenoids were com pletely absent and preexisting chlorophyll was degraded by photochem ical reactions requiring high light intensity and 0 2, that occurred also at 0 °C . In treatments with group 1 herbicides direct photodegradation o f chlorophyll was not sufficient to generate the chlorosis. Light-induced interference with constituents o f the chloroplast protein synthesis apparatus being more sensitive to ph otooxidative dam age than chlorophyll, appeared to indirectly m ediate the chlorosis. In the absence o f chloroplast protein synthesis further chlorophyll accum ulation is prevented. Photodegradation o f chlorophyll in the presence o f group 2 herbicides involved the participation o f 0 2~ radicals and was accom panied by lipid peroxidation. In all herbicide treatments the catalase activity o f the leaves was very low. Only in the presence o f group 2 herbicides chloroplast enzym es o f cytoplasm ic origin (e.g. NADP-glyceraldehyde-3-phosphate dehydrogenase) were also inactivated. Rapid inactivation o f catalase as well as o f N A D P-glyceraldehyde-3-phosphate dehydrogenase was induced by exposure o f dim-light-grown herbicide-treated leaves to bright light, also at 0 ° C . In treatments with herbicides o f group 2 also other peroxisom al enzymes (e.g. glycolate oxidate, hydroxy-pyruvate reductase) were affected. The elim ination o f these peroxisom al enzym es also appeared to depend on photooxidative processes o f the chloroplast. 
  Reference    Z. Naturforsch. 39c, 450 (1984); received N ovem ber 4 1983 
  Published    1984 
  Keywords    Bleaching Herbicides, Carotenoids, Catalase, Chlorosis, Leaf Peroxisom es, Photooxidation 
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 TEI-XML for    default:Reihe_C/39/ZNC-1984-39c-0450.pdf 
 Identifier    ZNC-1984-39c-0450 
 Volume    39 
4Author    K. H. GrumbachRequires cookie*
 Title    Herbicides which Interfere with the Biosynthesis of Carotenoids and Their Effect on Pigment Excitation, Chlorophyll Fluorescence and Pigment Composition of the Thylakoid Membrane  
 Abstract    Plants grown in the presence o f the herbicides assayed synthesized chlorophylls during growth at low fluence rates. Subsequent irradiation with higher fluence rates o f red light induced a strong chlorosis with SAN 6706 being a much stronger herbicide than J 852 or am ino-triazole. All herbicides assayed also changed the content and com position o f chlorophylls, carotenoids and pigment-protein-complexes o f the thylakoid m em brane and therefore the pigm ent excitation and chlorophyll fluorescence em ission spectra o f the plastid. W ith increasing herbicide toxicity the main characteristic em ission bands at 690 and 730 nm disappeared and new em ission bands at 715 (J 852) and 700 nm (SA N 6706) appeared. Such "artificial" m em branes with a changed pigment composition were very susceptible to light. Presented data m ay be taken as evidence, that the lack o f photoprotective cyclic carotenoids caused by the specific action o f a bleaching herbicide is the primary event that m ay lead to a disturbed form ation o f the thylakoid membrane and its destruction by light and oxygen. 
  Reference    Z. Naturforsch. 39c, 455—458 (1984); received N ovem ber 29 1983 
  Published    1984 
  Keywords    Bleaching Herbicides, Carotenoids, Chlorophylls, F luorescence, Pigm ent Excitation 
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 TEI-XML for    default:Reihe_C/39/ZNC-1984-39c-0455.pdf 
 Identifier    ZNC-1984-39c-0455 
 Volume    39