Indications for chlororespiration in relation to light regime in the marine diatom Thalassiosira weissflogii.
The marine diatom Thalassiosira weissflogii was cultured under a light regime simulating the daily rise and fall of the sun. The light regime caused a daily cycle in non-photochemical quenching. Remarkable were the changes in fluorescence directly after a light-to-dark transition that occurred in addition to the changes induced by non-photochemical quenching. A transient non-photochemical reduction of PQ and of Q(A) was indicated by a transient increase in apparent F(o) and by changes in the shape of the fluorescence induction curve. The observed changes developed approximately the first 100-120 s after a light-to-dark transition and could be reversed by the application of far-red illumination. Chlororespiration is thought to cause the reduction of PQ and, as the PQ-pool is in equilibrium with Q(A), also a reduction of Q(A). The function and ecological relevance of chlororespiration are discussed.
Dijkman
Nicole A
NA
Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany. dijkman@cemo.nioo.knaw.nl
Kroon
Bernd M A
BM
D000204:Activity Cycles; D002734:Chlorophyll / Q000378:metabolism*; D000077194:Chlorophyll A; D003624:Darkness; D017377:Diatoms / Q000378:metabolism*; D008027:Light; D012119:Respiration; D012623:Seawater; D013050:Spectrometry, Fluorescence; D013472:Sunlight
D002734:Chlorophyll; D000077194:Chlorophyll A