Fig. 1.

Mutations in NEV prevent organ separation. (A) Scanning electron micrograph (SEM) of a wild-type Arabidopsis flower before organ separation (stage 13). The sepals, petals, stamens and gynoecium are colored purple, green, yellow and red, respectively. A few organs have been removed for clarity. (B) SEM of a wild-type flower after organ separation (stage 17). The remaining abscission zone (az) cells of each organ are colored as in A. (C) Floral organs remain attached in nev flowers (stage 17) compared with wild type (wt). (D,E) Cauline leaves in nev plants fail to detach after senescence (E), as compared with wild type (D). (F,G) Longitudinal sections of wild-type (F) and nev (G) flowers at the time of shedding (stage 16) stained with Toluidine Blue. Adjacent petal (p az) and sepal (s az) abscission zones at the base of each flower are indicated. In wild-type flowers, the remaining abscission zone cells have expanded, which does not occur in nev flowers in the absence of organ separation. Scale bars: 100 μm.