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1988 (1)
1Author    W. Bilger, U. Heber, U. SchreiberRequires cookie*
 Title    Kinetic Relationship between Energy-Dependent Fluorescence Quenching, Light Scattering, Chlorophyll Luminescence and Proton Pumping in Intact Leaves  
 Abstract    A measuring system was designed for simultaneous recording of modulated chlorophyll fluorescence and light scattering changes. The kinetic relationship was investigated between light-induced changes in non-photochemical fluorescence quenching, as determined by the saturation pulse method, and in light scattering, as measured via the apparent absorbance change at 543 nm. Very similar, but not identical kinetics were observed, reflecting a close non-linear relationship between these two indicators of thylakoid membrane energization. Fluorescence was found more sensitive at low levels of energization, while scattering continued indicating further increases in energization when quenching already was saturated. A general relationship between quenching and scattering is demonstrated which holds irrespective of whether energization is varied during induction or via changes in light intensity or C02 concentration. In the light-off responses, only part of fluorescence quenching was found to relax with the same kinetics as scattering. It is suggested that at high levels of energization slowly reversible membrane changes may be induced which have the potential of non-photochemical quenching at a low level of energization, and which are not accompanied by scattering changes. Neither quenching nor scattering changes displayed kinetics sufficiently fast to be taken as a direct expression of internal thylakoid acidifica-tion in intact leaves. This conclusion is drawn from comparative measurements of proton-uptake, as reflected by C02-solubilization upon light-induced stroma alkalization, and of chlorophyll luminescence. Both, the initial C02-gulp and the pH-dependent luminescence rise were found to clearly precede the development of energy-dependent quenching. 
  Reference    Z. Naturforsch. 43c, 877—887 (1988); received July 18 1988 
  Published    1988 
  Keywords    Chlorophyll Fluorescence, Light Scattering, Chlorophyll Luminescence, Thylakoid Membrane, Proton Pumping 
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 TEI-XML for    default:Reihe_C/43/ZNC-1988-43c-0877.pdf 
 Identifier    ZNC-1988-43c-0877 
 Volume    43