Abstract: Photosynthesis contains a complex series of reactions, and carbon fixation is the core reaction of photosynthesis regulation. Fructose 1,6-bisphosphate aldolase (FBA) serves as the first enzyme to convert 3C into 6C compound after CO₂ been fixed. So FBA is a very important enzyme in photosynthetic process. Lately, at the use of antisense, the results of which also unveils that FBA has a strong potential in accelerate the rate of carbon fixation. In this article, we try to use gene overexpress technology to explore the function of FBA. The FBA gene from rice cytoplasm was transferred into filamentous, heterocystour cyanobacterium Anabaena sp. PCC 7120. Through antibiotic selection, we finally got the strain that could constantly express this meric gene. Cells were grown in BG-11 medium. The growth parameters, photosynthesis activity and enzyme activity of FBA were measured and compared between transgenic and wild type cells. The result showes that, compare to the wild strain, the transgenic strain showed a 31.2% higher in FBA activity, 24.4% higher in growth pace, 19.2% higher in net photosynthesis, and 20.6% much higher in ture photosynthesis. All the results prove that the increase of FBA level in Anabaena sp. PCC 7120 could help enhance the photosynthesis activity in transgenic strain and could help increase the cell grow rate. Our research could be an experiment support for the possible regulation role of FBA.

Key words: fructose 1, 6-bisphosphate aldolase(FBA), transgene, photosynthetic regulation