Figure 2.

Stomatal phenotype of wild-type and mutant plants in genes encoding for bHLH proteins. Wild-type plants develop stomata that are spaced by intervening cells. Cells do not enter into the stomatal pathway in spch mutants. The mute mutant does not develop stomata but forms meristemoids that abort after excessive asymmetric cell divisions. fama lacks mature stomata and, instead, develops clusters of guard mother cells or young guard cells. The scrm, scrm scrm2/+, and scrm scrm2 mutants phenocopy fama, mute, and spch, respectively. (Adapted from MacAlister et al. [2007] and Serna [2007].)