Chloroplasts are essential organelles of plant cells for not only being the energy factory but also making plant cells adaptable to different environmental stimuli. The nuclear genome encodes most of the chloroplast proteins, among which a large percentage of membrane proteins have yet to be functionally characterized. | Arabidopsis Chloroplast protein for Growth and Fertility1 (CGF1) and CGF2 are essential for chloroplast development and female gametogenesis