Abstract
The mechanism of CO2-response in fresh water algae have been studied extensively, whereas little information is available in mechanistic bases of CO2-response in marine micro-algae. In order to understand CO2-response in marine diatoms, CO2 responsive genes were screened by cDNA-AFLP(cDNA- amplified fragment length polymorphism) comparing cDNA speacies from cells grown in 0.5% CO2 and air using the marine diatom Phaeodactylum tricornutum. CO2-responses of 20 cDNA fragments were so far confirmed. Of these 13 genes, including gene for triosephosphate isomerase, were found to repressed in air that is in agreement with the case of cyanobacterial CO2-response. On the other hand, the remaining 7 genes including genes for ferredoxin nitrite reductase were found to be induced in air that is opposite to the case of cyanobacterial CO2-response, indicating that CO2-response of nitrogen metabolism in marine diatoms is different from that in cyanobactera.
