The relationship between light scattering and chlorophyll a fluorescence during oscillations in photosynthetic carbon assimilation.
Light scattering, which can be taken as an indicator of the transthylakoid proton gradient, and the 518-nm rise, which can be regarded as a measure of the transthylakoid membrane potential, have been followed during oscillations in chlorophyll a fluorescence, which are known to be associated with corresponding changes in photosynthetic carbon assimilation. Both components oscillated in a manner which was broadly reciprocal to chlorophyll a fluorescence. However, there was a phase shift such that the light-scattering change usually anticipated fluorescence and often also the 518-nm shift. It is concluded that the proton motive force rises and falls slightly in advance of rises and falls in carbon assimilation. The relationship of these changes to a possible underlying mechanism is discussed.
D002244:Carbon / Q000378:metabolism*; D002245:Carbon Dioxide; D002734:Chlorophyll / Q000378:metabolism*; D000077194:Chlorophyll A; D002736:Chloroplasts / Q000378:metabolism*; D004563:Electrochemistry; D008027:Light; D010100:Oxygen; D010788:Photosynthesis; D010944:Plants / Q000378:metabolism; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence
D002734:Chlorophyll; D002245:Carbon Dioxide; D002244:Carbon; D010100:Oxygen; D000077194:Chlorophyll A