Fig. 2.

Histological observation of oni2 shoots. (A–D) Longitudinal sections of shoots of the wild type (A), and mild oni2-1 (B) and severe oni2-1 mutants (C and D). Organ fusions between neighboring leaves were observed in oni2-1. Fused regions are labeled in magenta (D). (E and F) Transverse sections of wild-type (E) and oni2-1 (F) shoots. Organ fusions between neighboring leaves were observed. (G and H) Transverse sections of the third leaf of the wild type (G) and oni2-1 (H). The midrib was not well developed in oni2-1. (I and J) Enlargement of the midribs of the wild type (I) and oni2-1 (J). Lacunae were not observed in oni2-1. Bars = 200 µm in (A–D), 1 mm in (E–H) and 100 µm in (I) and (J).