The contribution of mechanosensing to epidermal cell fate specification.

In land plants, the aerial epidermis is essential for growth control, protection and environmental interactions. Epidermal cell fate is specified early during embryogenesis and maintained throughout plant life. Molecular actors of epidermal specification have been characterized, but how epidermal fate is maintained during growth remains unclear. DEFECTIVE KERNEL 1 (DEK1) is required for epidermal cell fate maintenance during both embryonic and post-embryonic plant development. The activation of a mechanosensitive Ca channel was recently shown to depend on DEK1, suggesting that the interpretation of mechanical cues could be critical for maintaining epidermal cell fate. Here, we integrate these findings into the epidermal specification network and propose a model explaining why epidermal specification may depend upon the sensing of epidermal tension.