Comparative Analysis And Evolution Significance Of Metabolic Networks Between Chloroplast And Cyanobacteria

Chloroplast is an organelle specialized for carrying out photosynthesis in plants and descended from cyanobacteria according to endosymbiosis. During early evolution in earth history, the ancestral cyanobacteria were annexed by early primitive eukaryotes and gradually evolved into chloroplast through symbiosis. Although its genome is very different from cyanobacteria due to gene loss and transferring many genes to nuclear, chloroplast still retained many features of caynobacteria. Studies on the evolution of photosynthesis by molecular biology have provided some supports for endosymbiosis. However, most of the previous studies focused on the evolutionary process of individual proteins or enzymes, there have not been much study of chloroplast evolution by network comparison from system biology angle.During endosymbiosis, many genes of cyanobacteria were transferred to the nuclear genome of plants, translated in cytosol, and then imported into chloroplast. Such massive transportation of proteins requires a large amount of energy and sophisticated regulation from plant cells. Since the metabolic networks in chloroplasts are mostly constructed with proteins encoded in nuclear genome, do the networks exhibit some unique properties and...