Figure 3.

Cell surface receptors, but not ligands, involved in stomatal development can disrupt the coordination between epidermal and mesophyll cell densities. In panel (a), manipulation of various EPIDERMAL PATTERNING FACTORS (EPFs) in Arabidopsis thaliana mirrors the epidermal–mesophyll relationship shown in Fig. 2(o) (solid line, R ² = 0.54, P < 0.001, n = 35). The dashed lines in (a, b) refer to the regression model from Fig. 2(o); comparison of regression models was not significantly different in (a) (ANCOVA, P = 0.896). In (b), loss of cell surface receptors TOO MANY MOUTHS (TMM) and ERECTA altered the relationship between adaxial stomatal density and palisade mesophyll cell density in opposite ways. erecta plants increased adaxial stomata but decreased mesophyll cell density, while tmm decreased adaxial stomata and increased mesophyll cell density (see also Supporting Information Table S2). tmm was epistatic in all double mutant combinations tested (see also Table S3).