Figure 8.

Ectopic MYB16 expression in meristemoids leads to stomatal cluster formation by modulating polarity protein behavior during asymmetric cell division. In WT epidermis, SPCH represses MYB16 expression in meristemoids to ensure polarity establishment for proper stomatal patterning. However, in the MYB16 overexpression and ectopic expression lines, high MYB16 expression in meristemoids enhances the thickness in the cuticle. The change in the cuticle–cell wall continuum leads to the reduction and mis-polarization of polarity protein during asymmetric cell division, which further impairs the EPF-mediated inhibitory signaling and results in the formation of stomatal clusters. The dark gray shading represents the polarity complex.