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'Prenyllipids' in keywords
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1979 (2)
1Author    H. K. KleudgenRequires cookie*
 Title    Veränderungen der Pigment-und Prenylchinongehalte in Chloroplasten von Gerstenkeimlingen nach Applikation des Wuchsstoffherbizids MCPA (4-Chlor-2-methylphenoxyessigsäure) Changes of the Amounts of Pigments and Prenylquinones in Chloroplasts of H ordeum vulgare — Seedlings Treated with the Growth Regulating Herbicide MCPA (4-Chloro-2-methylphenoxyacetic Acid)  
 Abstract    MCPA (4-chloro-2-methylphenoxyacetic acid) was applied (1, 10, 100 ^ m/ 1) via the roots to 4 day old etiolated barley seedlings, which were subjected to continuous white light at the same time. The prenyllipids of chloroplasts (chlorophylls, carotenoids, prenylquinones) were determined 7 and 10 days after sowing. Chlorophyll accumulation was reduced by up to 40% compared to the control depending on the herbicide concentration. The formation of carotenoids was inhibited to a lower degree, the ratio xanthophylls/carotenes being increased. There were decreasing ratios of chlorophyll a/benzoquinones and a higher inhibition of the oxidized benzoquinones plastoquinone-9 and a-tocoquinone compared to the reduced forms plastohydroquinone-9 and a-tocopherol. Very similar changes had been observed in earlier works on barley seedlings undergoing an artificial degeneration of their chloroplasts in the dark. It is suggested that MCPA induces a state of senescence in the prenyllipid metabolism of the photosynthetic apparatus, which is cor­ related with respect to structure, to a reduction of the pigment antennae. 
  Reference    Z. Naturforsch. 34c, 106 (1979); eingegangen am 13. November 1978 
  Published    1979 
  Keywords    Growth-Regulator, Prenyllipids, Chloroplasts, Senescence 
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 TEI-XML for    default:Reihe_C/34/ZNC-1979-34c-0106.pdf 
 Identifier    ZNC-1979-34c-0106 
 Volume    34 
2Author    H. K. KleudgenRequires cookie*
 Title    Die Wirkung von Simazin auf die Bildung der plastidären Prenyllipide in Keimlingen von Hordeum vulgare L. Effect of Simazine on Formation of Chloroplasts Prenyllipids in Seedlings of H ordeum vulgare L  
 Abstract    Barley seedlings were grown for 7, 10 or 13 days under continuous white light (Fluora lamps) on a nutrient solution containing simazine (2-chloro-4,6-bis-(ethylamino)-s-triazine, 10, 100 j u m) . Accumulation of chlorophylls and in part of carotenoids was increasingly enhanced depending on age and concentrations applied. The ratio chlorophyll a/b decreased on this line in 10 and 13 day old plants, the ratio xanthophylls//?-carotene and the ratio chlorophyll a/prenylquinones (plasto-quinone-90x. + red. , a-tocopherol, a-tocoquinone) increased. The way how these prenyllipid ratios are changed in 10 and 13 day old plants is characteristic of a shade type adaptation, as it was shown earlier for other herbicides inhibiting photosystem II. In 7 day old plants the ratio chlorophyll a/prenylquinones decreased. Photosynthetic activity (Hill-reaction) was enhanced in the simazine plants. The ratio chlorophyll a/b was higher, the ratio xanthophylls//?-carotene was lower than in the older seedlings. Similar changes of prenyllipid ratios like in 7 day seedlings and a higher Hill activity were also found in plants grown under blue light (sun type adaptation) as compared to red light (shade type adaptation). This points to similar metabolic changes in the chloroplasts which could be related to a common site of regulation, perhaps the endogenuous cytokinins. The Hill activity, increasing with age in the 10 and 13 day plants, indicates that the mode of action of simazine may be a multiple process resulting to a parallel formation of shade type and sun type characteristics. 
  Reference    Z. Naturforsch. 34c, 110 (1979); eingegangen am 13. November 1978 
  Published    1979 
  Keywords    Herbicide, Simazine, Prenyllipids, Chloroplasts, Regulation 
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 TEI-XML for    default:Reihe_C/34/ZNC-1979-34c-0110.pdf 
 Identifier    ZNC-1979-34c-0110 
 Volume    34