Exploring the molecular mechanism of cell cycle-mediated solid–liquid phase transition of chloroplast nucleoids
Chloroplasts maintain their own chromosomes, which is called chloroplast (cp) nucleoid — a complex of cpDNA and various proteins. The chloroplast nucleoids play an important role in cpDNA replication and repair, gene expression and genetics, flexibly changing its morphology in response to the cell cycle, light, nutrition and other environmental stimuli. During the cp division, cp nucleoids — normally form a “solid” spherical structure — become “liquid-like” prior to chloroplast division, drastically diffuse throughout the chloroplast. After the division is complete, cp nucleoids reform solid spherical structures. In this study, we aim to elucidate the regulatory mechanisms underling the solid–liquid phase transition of chloroplast nucleoids, mainly focusing on Holliday junction resolvase and DNA ligase in cp nucleoids.