Fig. 1

Fluorescence microscopy of FtsZ2 assemblies in situ. a, b Wide-field immunofluorescence micrograph of FtsZ2 in Z-rings (arrowheads) in wild-type leaf chloroplasts (a) and smaller-size Z-rings in cells of the apical meristem (b). Individual proplastids cannot be discerned in meristematic cells. c, d Confocal micrographs of filamentous and circular (arrows) FtsZ assemblies in leaf mesophyll chloroplasts in a plant expressing FtsZ2–mYFP at moderate (c) and high (d) levels. The arrowheads in c denote Z-rings at mid-chloroplast. Inserts in a, c, d depict immunoblots showing relative levels of the intrinsic, untagged FtsZ2 (marked by an asterisk) vs. FtsZ2-fusion protein. e, f Immunofluorescence localization of FtsZ2 in leaf mesophyll chloroplasts of mutants lacking MinE and ARC6 proteins, respectively. FtsZ mini-rings are indicated by arrows. The dashed lines in d–f denote chloroplast shapes. Scale bars correspond to 5 µm in a, c–f and 2 µm in b