Direct role of MUTE in cell state switch and symmetric cell division to create stomata

Precise cell division control is critical for developmental patterning. For the differentiation of a functional stoma, a cellular valve for efficient gas exchange, the single symmetric division of an immediate precursor is absolutely essential. Yet, the mechanism governing the single division event remains unclear. Here we report the complete inventories of gene expression by the Arabidopsis bHLH protein MUTE, a potent inducer of stomatal differentiation. We found that MUTE switches the gene expression program initiated by its sister bHLH, SPEECHLESS and directly induces a suite of cell-cycle genes and their transcriptional repressors. The architecture of the regulatory network initiated by MUTE represents an Incoherent Type 1 Feed-Forward Loop. Our study delineates the role for MUTE in orchestrating a transcriptional cascade leading to stomatal differentiation, and unravels a core regulatory circuit. RNA-seq profile of estradiol-inducible MUTE