Premium
Temperature dependent reduction of protochlorophyllide in darkness followed by the assembly of active photosystems in pigment mutant C‐2A’ of Scenedesmus obliquus
Author(s) -
Kotzabasis Kiriakos,
Römer Susanne,
Senger Horst
Publication year - 1990
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1990.tb05253.x
Subject(s) - protochlorophyllide , darkness , chlorophyll , photosystem , pigment , photosystem ii , scenedesmus , biochemistry , biology , mutant , scenedesmus obliquus , photosystem i , oxidoreductase , photosynthesis , chemistry , botany , enzyme , algae , organic chemistry , gene
In the wild type of Scenedesmus obliquus strain D3 grown heterotrophically, the chlorophyll biosynthesis and thus the reduction of protochlorophyllide to chlorophyllide takes place in darkness. However, in pigment mutant C‐2A’ of Scenedesmus obliquus only traces of protochlorophyllide are reduced under optimal growth conditions in darkness. By lowering the growth temperature from 33° to 15–25°C, protochlorophyllide can be reduced in darkness. At 20°C this process is about 10 times more active than at 33°C, but reaches only about 13% of the light‐dependent chlorophyll biosynthesis. The chlorophylls synthesized at the lower temperatures are inserted into the pigment‐protein complexes and photosystem I as well as photosys‐tem II capacities are developed. The rate of light‐independent protochlorophyllide reduction at lower temperatures is not limited by the enzyme PChlide‐oxidoreductase itself, but rather by its substrate, being in turn limited by the amount of 5‐amino levulinic acid (ALA) available.