细胞内二氧化碳吸收与转换是水生生物光合碳同化的一个重要的生物学过程。在蓝藻中，主要有两个复合体参与这个过程，一个是包含CupA蛋白的NDH-1MS复合体，另一个是包含CupB蛋白的NDH-1MS复合体，前者属于低CO2诱导型，而后者属于组成型。目前，在这两个复合体的基因组成鉴定和功能研究方面已经取得了许多进展，然而，CO2的吸收与转换的活性调控机理尚有待于阐明。在前期工作中，我们在无机碳转运关键基因敲除的背景下、通过筛选集胞蓝藻6803的转座子突变体库，获得5个对低CO2敏感的突变体，并分离和鉴定到5个新功能基因。因此，我们拟以这些突变体为研究材料，通过生理生化、光合特性的研究，以期揭示这些新基因在CO2吸收与转化中的调控机理，为阐明蓝藻光合碳同化的运转机理提供理论依据。

Photosynthetic CO2 uptake and conversion within the cell is one of fundamental biological processes in aquatic photosynthetic organisms. High and low affinity CO2-uptake systems containing CupA (NDH-1MS) and CupB (NDH-1MS), respectively, have been identified in Synechocystis sp. PCC 6803. Although the constitution and the function of these complexes have been studied, the mechanism underlying the regulation in this process is still unclear. In the previous study, we cloned 5 genes involved in CCM from the selected mutants we have gotten by screening a transposon-tagged library of Synechocystis sp. PCC 6803. Therefore, in order to reveal the mechanisms underling the regulation in the CO2 uptake and conversion of these genes, we plan to investigate the physiological functions, the biochemical characters and the photosynthetic properties of these genes by using these mutants. This project will provide new bases for revealing the mechanism of photosynthetic carbon assimilation in aquatic photosynthetic organisms.