Chloroplast FtsZ assembles a contractible ring via tubulin-like hetero-polymerization

Isolation of chloroplasts. Chloroplasts were isolated from first true leaf of Arabidopsis thaliana Col-0 or FtsZ knock-out mutants by the following method: the leaf sample was sliced into 2-4 pieces, then fixed with 1% glutaraldehyde at 4°C for 2 hours. Fixed samples were incubated with 100 mM EDTA at 45°C for 1 hour and gently pipetted several times to tear cell membranes. Intact non-dividing and dividing chloroplasts in lysate were imaged using a differential interference contrast microscope DMI 300B (Leica) and a digital camera system DFC320 (Leica).