Misregulation of MYB16 expression causes stomatal cluster formation by disrupting polarity during asymmetric cell divisions (Plant Cell)

Water loss during photosynthesis is limited by specialized plant cells such as stomata, as well as cuticle formation on the epidermis. In Arabidopsis thaliana, stomata lineage is a good system in which to elucidate the interplay between biochemical signals and mechanical properties during leaf development. In this study, Yang et al. explored the connection between cuticle formation and stomata development. Using live-imaging, cell-type-specific perturbations, expression assays, and transmission electron microscopy (TEM), they investigated the function of MYB16, a regulator of cuticle formation, in the role of stomata patterning. MYB16 is localized to stomata lineage ground cells (SLGCs) and meristemoids, but its expression in meristemoids is switched off when SPEECHLESS (SPCH) is present. MYB16 overexpression and ectopic expression lines increase the number of stomata, stomata cluster formation, and enhance the thickness in the cuticle. Moreover, ectopic MYB16 expression alters the polarity setup during asymmetric cell divisions. This work shows how the timing of cuticle formation is crucial for the correct stomata patterning. (Summary by Andrea Gómez-Felipe @andreagomezfe) Plant Cell 10.1093/plcell/koab260