Temperature inducible protochlorophyllide reduction in darkness in a pigment mutant of Scenedesmus obliquus |
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Authors: | Tamiko Oh-hama Kiriakos Kotzabasis Horst Senger |
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Affiliation: | Institute of Applied Microbiology, The University of Tokyo, Japan;Fachbereich Biologie/Botanik, Philipps-Universität Marburg, Lahnberge, D-3550 Marburg, FRG. |
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Abstract: | Accumulation of chlorophyll and protochlorophyllide (PChlide) was followed during beterotrophic growth of the pigment mutant C-2A' of Scenedesmus obliquus L. in the darkness at 30 and 20°C. At 30°C the cells remained yellow with accumulation of protochlorophyllide, whereas they became green at 20°C with only traces of protochlorophyllide. The capacity of mutant cells to reduce PChlide to chlorophyllide (Chlide) in the dark with or without addition of 5-aminolevulinic acid as measured in isolated membranes, was high in cells grown at 20°C but negligible at 30°C. The high capacity to reduce PChlide created in cells growing at 20°C was only slightly diminished by exposure of cells to 38°C for 3 h. Mechanisms of temperature-sensitive chlorosis in algae and higher plants are discussed in relation to the results with pigment mutant C-2A' of Scenedesmus obliquus . It is assumed that either an activator of NADPH protochlorophyllide oxidoreductase (EC 1.6.99.1) or a different enzyme system can be activated by lower temperature as by light. |
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Keywords: | Dark protochlorophyllide reduction NADPH-protochlo-rophyllide oxidoreductase |
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