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'Chloroplast Ultrastructure' in keywords
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1999 (1)
1982 (1)
1980 (1)
1Author    Agnieszka MostowskaRequires cookie*
 Title    Response of Chloroplast Structure to Photodynamic Herbicides and High Oxygen  
 Abstract    Response of chloroplast on the structural level to photodynamic herbicides and high oxy­ gen concentration was compared with symptoms of chloroplast senescence. Based on the present results and those known from the literature a general pattern of response was pro­ posed: the action of most of environmental factors induces the oxidative stress and often gives similar symptoms of structural damage and dysfunctions independent of the primary stressing factor. These alterations consist mostly in swelling of thylakoids, disruption of chlo­ roplast membranes, intensive plastoglobuli accumulation, photodestruction of pigments and inhibition of photosynthesis. 
  Reference    Z. Naturforsch. 54c, 621 (1999); received November 4 1998/February 18 1999 
  Published    1999 
  Keywords    Chloroplast Ultrastructure, Environmental Factors, Oxidative Stress Photodynamic Herbi­ cides, Senescence 
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 TEI-XML for    default:Reihe_C/54/ZNC-1999-54c-0621.pdf 
 Identifier    ZNC-1999-54c-0621 
 Volume    54 
2Author    D. Meier, H. K. Lichtenthaler, G. BurkardRequires cookie*
 Title    Change of Chloroplast Ultrastructure in Radish Seedlings under the Influence of the Photosystem II-Herbicide Bentazon  
 Abstract    The influence of the photosystem II-herbicide bentazon on the ultrastructure o f chloroplasts o f radish seedlings (Raphanus sativus L.) was investigated with special emphasis on thylakoid developm ent and grana formation. Bentazon application (10-3 m) induces the formation of broader and higher grana stacks (grana width: 0 .5 -0 .6 n m ; greatest frequency: 3 -8 thylakoids per granum) than in the control plants (grana width: 0.3 |im; greatest frequency: 2 -4 thylakoids per granum). Furtherm ore, the am ount of chloroplast lamellae is enhanced, as are the stacking degree of thylakoids and the grana area. The chloroplasts of bentazon-treated plants appear to be shorter and thicker than in the controls and show all signs of a shade-type adaptation of the photosynthetic apparatus. 
  Reference    Z. Naturforsch. 35c, 656 (1980); received March 17 1980 
  Published    1980 
  Keywords    Bentazon, Chloroplast-Ultrastructure, G rana Form ation, Photosystem II-Herbicide, Shade-type Chloroplasts 
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 TEI-XML for    default:Reihe_C/35/ZNC-1980-35c-0656.pdf 
 Identifier    ZNC-1980-35c-0656 
 Volume    35 
3Author    H. K. Lichtenthaler, G. Kuhn, U. Prenzel, C. Buschmann, D. MeierRequires cookie*
 Title    Adaptation of Chloroplast-Ultrastructure and of Chlorophyll- Protein Levels to High-Light and Low-Light Growth Conditions  
 Abstract    Adaptation In saturating light radish seedlings grown in high-light growth conditions (90 W • n r 2) possess a much higher photosynthetic capacity on a chlorophyll and leaf area basis than the low-light grown plants (10 W • m-2). The higher C 0 2-fixation rate o f HL-plants is due to the presence of HL-chloroplasts which possess a different ultrastructure and also different levels o f the individual chlorophyll-carotenoid-proteins than the LL-chloroplasts of LL-seedlings. 1. Ultrastructure: The high-light adapted chloroplasts are characterized by fewer photo­ synthetic membranes per chloroplast section, by low grana stacks (only few thylakoids per granum), a lower stacking degree o f thylakoids, a higher proportion o f non-appressed mem­ branes (stroma thylakoids + end grana membranes) and a high starch content. The LL-chloro­ plasts possess no starch, their grana stacks are higher (up to 17 thylakoids per granum) and also significantly broader than that o f HL-chloroplasts. 2. Chlorophyll-proteins: The photosynthetic apparatus o f HL-chloroplasts contains a larger proportion of chlorophyll a-proteins of photosystem I (CPIa + CPI) and of photosystem II (CPa, the presumable reaction center o f PS II) than the LL-chloroplasts which possess a higher propor­ tion of light-harvesting chlorophyll a/fc-proteins (LHCP,, LHCP2, LHCP3, LHCPy). The higher levels of LHCPs in LL-plants are associated with a higher ground fluorescence fo and maximum fluorescence fp of the in vivo chlorophyll. 3. Chlorophyll and carotenoid ratios: The chloroplasts o f HL-plants possess a higher proportion of chlorophyll a and /2-carotene (higher values for the ratios chlorophyll a /b and lower values for a/c and x /c) which reflect the increased level o f the chlorophyll a//?-carotene-proteins CPIa, CPI and CPa. The higher level o f light-harvesting chlorophyll a/6-xanthophyll-proteins (LHCPs) in LL-plants is also indicated by an increased content o f xanthophylls and chlorophyll b as seen from lower a /b and higher x /c and a /c ratios. 4. The results indicate that plants possess the capacity for an ontogenetic adaptation o f their photosynthetic apparatus to the incident light intensity. The HL-chloroplasts o f HL-plants which contain less antenna chlorophyll, are adapted for a more efficient photosynthetic quantum conversion at light saturation than the LL-chloroplasts with high grana stacks. The correlation between higher levels o f light-harvesting chlorophyll ö/6-proteins (LHCPs) and a higher stacking degree of thylakoids, and the involvement o f LHCPs in stacking is discussed. Abbreviations: a/b, ratio chlorophyll a/b', a /c, weight ratio chlorophyll a to /^-carotene, CPI and CPIa, the two P700 containing chlorophyll a /?-carotene-proteins o f photosys­ tem I; CPa, chlorophyll a /?-carotene-protein o f photosys­ tem II, c/x, ratio /?-carotene/xanthophylls; fo, ground fluo­ rescence of the in vivo chlorophyll fluorescence; fp, maxi­ mum level of the in vivo chlorophyll fluorescence; FP, free pigments; HL, high-light growth condition; LHCPs, sum of the 4 light-harvesting-chlorophyll a/6-proteins L H C P,, LHCP2, LHCP3 and LHCPy; LL, low light growth condi­ tion; PAGE, polyacrylamide-gel electrophoresis; PS I and PS II photosynthetic photosystem I and II; SDS, sodium dodecylsulphate; Tris, tris (hydroxymethyl)-aminomethan; v/v, volume per volume; w/v, weight per volume; x/c, weight ratio xanthophylls to /7-carotene. * The work described here, was presented on the European Symposium Light Mediated Plant Development in April 1981 in Bischofsmais, Bavaria. 
  Reference    Z. Naturforsch. 37c, 464 (1982); received March 2 1982 
  Published    1982 
  Keywords    of Chloroplasts, Chlorophyll Fluorescence, Chlorophyll a-Proteins, Chloroplast Ultrastructure, High-Light Chloroplasts 
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 TEI-XML for    default:Reihe_C/37/ZNC-1982-37c-0464.pdf 
 Identifier    ZNC-1982-37c-0464 
 Volume    37