Abstract
The rate of photorespiration is only a half of wild type in both high CO2-grown and air-adapted cells of the Chlalmydomonas mutant with reduced rate of photorespiration (RPR1). The photosynthetic affinity for CO2 is apparently higher in high CO2 cells of RPR1 than that of wild type, but is not so clear in low-CO2-adapted cells. We expect that the reduced rate of photorespiration in RPR1 is a result of enhanced CCM function caused by lowered CO2 sensitivity. In this report, to help define the mutation in RPR1, we compared photosynthetic adaptation to different concentrations of CO2 and cDNA macro array analysis for 5% CO2 and air-adapting cells of wild type and RPR1-N21. We found a biphasic photosynthetic response to the adapted CO2 concentrations in both wild type and N21. The relationship to CCM, the mutant gene of N21, and the results of cDNA macro array analysis will be discussed.