Abstract

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.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.