Misexpression of stomatal fate reporters in bdyda1-1 mutants is consistent with the terminal fate specification defects. Confocal images of emerging second leaf of 6 dpg T1 plants. (A-H) BdSCRM2pro:YFP-BdSCRM2 reporter in WT (Bd21-3) (A-D) and bdyda1-1 mutant (E-H) during stomatal development. Early in WT development, BdSCRM2pro:YFP-BdSCRM2 appears only in the smaller daughter of an asymmetric division (A,B). However, at the same stage in the bdyda1-1 mutant, signal is also present in mis-specified larger daughter cells (E,F). Arrowheads in E indicate examples of improper re-enforcement of non-stomatal fate in larger daughter of asymmetric division. Arrows in F point to examples of improper inhibition of division potential. (I-N) BdMUTEpro:BdMUTE-YFP reporter in WT (I-K) and bdyda1-1 mutant (L-N) during SC recruitment and GMC and SC specification. Reporter expression in WT is present only in GMCs, subsidiary mother cells (SMCs), and SCs as stomata mature. In bdyda1-1, the same reporter also marks mis-specified and clustered GMCs, SMCs and SCs. Arrowheads in L and bracket in M indicate ectopic marker expression during the SC recruitment and GMC division, respectively. Scale bars: 10 μm. Cell outlines are visualized with PI. All images are oriented with the base of the leaf (younger cells) towards the bottom and the tip of the leaf (older cells) towards the top.