Fig. 4. Sector phenotypes in Wab1 mutants. (A-E) Abaxial view of Wab1 leaves with auricle extension and/or ectopic auricle phenotypes with albino sectors exhibiting normal blade characteristics. (F) Scanning electron micrograph of adaxial surface of boxed region in C, illustrating unexpanded, dovetailed auricle-like cells in Wab1/wab1+ ectopic auricle tissue (right of arrowhead), and normal blade epidermal characteristics such as macrohairs in the wab1+/– sector (left of arrowhead). (G) Fluorescence micrograph of a transverse section through a sector adjacent to auricle extension, illustrating a sharp boundary between green, Wab1/wab1+ auricle-like tissue (which fluoresces red), and albino, wab1+/– tissue (which appears blue-green). (H) SEM of adaxial surface of sector boundary near that shown in G, with hairy, fully expanded auricle-like cells in the Wab1/wab1+ tissue (right of arrowhead) and normal blade cells including prickle hairs and macrohairs in the wab1+/– tissue (left of arrowhead). (I) Fluorescence micrograph of a transverse section through the sector shown in J. Green, Wab1/wab1+ tissue is very thin with widely spaced veins, a hairless adaxial surface and abaxial hairs characteristic of marginal sheath tissue. Albino wab1+/– tissue has the histological organization of normal blade tissue. (J) Abaxial view of sector adjacent to ectopic sheath tissue, arrowhead marks sector boundary. (K) Cartoon depicting an albino non-mutant (w3 wab1+/–) sector in a green Wab1/wab1+ leaf. Scale bar: 500 µm (F) and 100 µm (G-I).