Brassinosteroid controls leaf air space patterning non-cell autonomously by promoting epidermal growth (opens in new tab)

ABSTRACTPlant leaves contain a complex network of intercellular air spaces, which allow efficient photosynthesis. However, how leaf air spaces are patterned is poorly understood. It has been proposed for almost a century that air spaces form by faster-growing epidermal tissue pulling slower growing mesophyll cells apart, but this has never been tested. Here, we characterise air space morphogenesis throughout in the first leaf of Arabidopsis thaliana and show that the plant hormone brassinoste...