Host: The Japanese Society of Plant Physiologists
Pages 0146
In cyanobacterium, peptidoglycan synthesis is essential for its cell division. It is widely agreed that plastid is originated from a single cyanobacterial ancestor, though no wall-like structure has been observed in plastids of green plants. We found all homologs to bacterial Mur genes for peptidoglycan synthesis from Physcomitrella patens. Pbps catalyze the final step of peptidoglycan synthesis. Disruption of PpPbp gene in P. patens causes appearance of macrochloroplasts. Main subfamily of Pbp possesses two functional domains, transglycosidase (TG) and transpeptidase (TP). To examine each function of putative domain in PpPbp, two mutations were introduced for each domain. When the plasmid containing PpPbp gene without mutations was transferred into the PpPbp KO line, the macrochloroplast phenotype was recovered. On the other hands, each PpPbp with two mutations for TG or TP domain could not recover the macrochloroplast phenotype. This result suggests that both activities are essential in P. patens chloroplast division.
