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1981 (1)
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1977 (1)
1Author    G. Renger, D. Difiore, B. Luuring, P. GräberRequires cookie*
 Title    The Variation of the Electrochromic Difference Spectrum at Various Stages of the Chloroplast Developm ent+  
 Abstract    The flash-induced difference spectrum in the range of 450 — 550 nm of protochloroplasts isolated from pea-leaves greened under intermittent illumination (2 min light, 98 min dark) was measured and compared with that of fully developed chloroplasts from pea leaves. Because of the sensitivity of the decay o fthe absorption changes to the ionophore valinomycin they were shown to mainly be due to an electrochromic bandshift of the membrane pigments (chlorophylls-a, -b and caro-tenoids). The differences in the shape and the amplitude between both spectra are consistently explained within the framework of a recent hypothesis supposed by Sewe and Reich (Z. Natur-forsch. 33 c, 161 — 171 (1978)) by the lack of chlorophyll-b in the protochloroplasts. It is con­ cluded, that the transformation of the protochloroplasts into chloroplasts which is accompanied by the incorporation of the light harvesting complex and the formation of grana stacks does not seriously change the orientation of the field indicating pigments within the membrane with respect of the polarity of the light induced vectorial electron transport. 
  Reference    Z. Naturforsch. 34c, 120 (1979); received October 23 1978 
  Published    1979 
  Keywords    Chloroplast Development, Electric Field, Electrochromism, Pigment Orientation 
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 TEI-XML for    default:Reihe_C/34/ZNC-1979-34c-0120.pdf 
 Identifier    ZNC-1979-34c-0120 
 Volume    34 
2Author    Claus Buschmann, H. Artm, K. LichtenthalerRequires cookie*
 Title    Hill-Activity and P700 Concentration of Chloroplasts Isolated from Radish Seedlings Treated with -Indoleacetic Acid, Kinetin or Gibberellic Acid  
 Abstract    The Hill-activity (reduction of DCPIP or methylviologen) and the concentration of P700 were studied in chloroplasts isolated from cotyledons of radish seedlings (R aphanus sativu s L. Saxa Treib), which had been grown with the addition of ^-indoleacetic acid (IA A), kinetin, or gib­ berellic acid. 1) The photosynthetic activity of young chloroplasts from 3 day old R aphanus seedlings is very high (c. 180 /*mol 0 2/mol chlorophyll X h) and decreases continuously thereafter with increasing age. The steady state Hill-activity is readied after 8 to 10 days (values of 55 to 50 wmol 0 2/mg chlorophyll X h). 2) Chloroplasts from plants treated with IAA or kinetin not only exhibit higher plastoquinone levels *> 2, but also a higher P700-content and a higher Hill-activity. The promotion effect is more pronounced with kinetin (+ 36 to 40%) than with IAA (+ 1 2 to 17%). 3) Gibberellic acid has a different effect on composition and activity of chloroplasts. In younger seedlings the Hill-activity appears to be somewhat stimulated, without promotion effect on plasto­ quinone 2 or P700 concentration. After 10 days GA3-treated plants show signs of chlorosis combined with a strong decrease in photosynthetic activity. 4) The data clearly demonstrate that the composition and activity of the photosynthetic ap­ paratus are under phytohormone control. IAA and even better kinetin promote the light induced formation of pigment systems and electrontransport chains. GA3 seems to block the rebuilding of the photosynthetic apparatus under steady state conditions. 
  Reference    (Z. Naturforsch. 32c, 798 [1977]; received March 22/ July 4 1977) 
  Published    1977 
  Keywords    Hill-Activity, Indoleacetic Acid, Kinetin, Gibberellic Acid, Chloroplast Development 
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 TEI-XML for    default:Reihe_C/32/ZNC-1977-32c-0798.pdf 
 Identifier    ZNC-1977-32c-0798 
 Volume    32 
3Author    H. K. Lichtenthaler, G. Burkard, G. Kuhn, U. PrenzelRequires cookie*
 Title    Light-Induced Accumulation and Stability of Chlorophylls and Chlorophyll-Proteins during Chloroplast Development in Radish Seedlings  
 Abstract    Illumination of 3 day old etiolated radish seedlings with continuous white light results in a progressive accumulation o f chlorophyll a and b. Both pigments are bound in a different way to the thylakoid chlorophyll-proteins, which appear parallel to the formation of chlorophylls. By applying the SDS-PAGE method to SDS-digested chloroplasts, it was possible to show that the chloroplasts of radish cotyledons contain the typical chlorophyll proteins LHCPi_ 3, CPa, CPI and CPIa which have been found in other plants. Between LHCPj and CPI an additional chlorophyll protein is detected with the spectral properties of a LHCP; it is termed here LHCPy. When the green plants are transferred to continuous darkness, chlorophylls and the chloro-phyll-proteins are progressively degraded. At an early stage of greening chlorophyll b is destroyed at a much higher rate in darkness than chlorophyll a, which yields high chlorophyll a/b ratios. This is paralleled by a faster decrease in the level of the corresponding chloro­ phyll a/b-protein LHCP3 than of CPI. At a later stage of greening, after the end o f the logarithmic chlorophyll accumulation, the chlorophylls a and b and also the LHCP3 and CPI are destroyed in continuous darkness at equal rates; the a/b ratios and the LHCP3/CPI ratios are then little different from the light control. The data indicate that at an early stage o f greening the light-harvesting chlorophyll a/b-protein LHCPj is less stable than the other chlorophyll-proteins (CPI, CPIa, CPa), which contain pre­ dominantly chlorophyll a. The ratio chlorophyll a to /?-carotene (a/c ratio) of CPIa, CPI and CPa is about 10, while that of the LHCPj_ 3 is found to be between 150 to 300. We therefore propose using the a/c ratio to define the chlorophyll-proteins which, besides the absorption spectra, is the most suitable parameter. 
  Reference    Z. Naturforsch. 36c, 421 (1981); received March 17 1981 
  Published    1981 
  Keywords    Chlorophyll a/b ratio, Chlorophyll Degradation, Chlorophyll-Proteins, Chloroplast Development, Stability of Chlorophylls 
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 TEI-XML for    default:Reihe_C/36/ZNC-1981-36c-0421.pdf 
 Identifier    ZNC-1981-36c-0421 
 Volume    36