Chloroplast division defects and mutation sites in plastid cpn60 mutants. (A-F) Chloroplasts in leaf mesophyll cells were observed by Nomarski optics. Since the background of ptcpn60β1-1 (br04) and ptcpn60β1–2 (SAIL_852_B03) is Col-0 and the background of ptcpn60α1-1 (arc2) is Ler, mutants were compared to their respective wild types. Scale bar = 10 μm. (G-H) Schematic diagram of ptCpn60β1 and ptCpn60α1. Mutation sites of ptcpn60β1-1 (br04) and ptcpn60α1-1 (arc2) are indicated by arrows and the positions of T-DNA insertions in ptcpn60β1–2 (SAIL_852_B03) and ptcpn60α1–2 (SALK_006606) are indicated by triangles. Exons are depicted as black boxes and UTRs are depicted as white boxes. bp, base pair. aa, amino acids.