Fig. 4: The history-dependent recorder reveals two distinct stomatal populations.

a State 2 and State α stomata. A confocal image shows two stomata: one in State 2 (green triangle) and one in State α (white triangle). Below the image, the total proportion of stomata in each state is shown in a barplot, with each bar representing one of the three best-performing stomata recorder lines (labeled on the x-axis). n = 257, n = 172, and n = 174 stomata were characterized for T2P1, T2P4, and T2P7. b Alternate paths of stomatal development. The stereotypical understanding of stomatal development follows an anisocytic (A) scheme, with the meristemoid dividing asymmetrically three times before dividing into two guard cells. Non-anisocytic (NA) stomata divide asymmetrically zero, one, or two times before the terminal division. Recorder output is predicted to differ between stomata types due to varied timing of integrase onset. An A stomata is surrounded by exactly three cells of unequal size, while an NA stomata can have two, four, five, or three equally sized neighbor cells. c Characterization of recorder state in A vs. NA stomata. The boxes represent the proportion of each stoma type (anisocytic in light gray and non-anisocytic in dark gray) within each of the three stomata recorder lines (x-axis) that are in State 2 (left) and State α (right). Each box represents the middle quartiles of the respective dataset, and the whiskers represent the highest and lowest quartiles. The center of each box is the median. Each point represents the proportion of stomata in each state for one T2 seedling. 10 seedlings were counted per line. For each seedling, a minimum of 15 of each stomata type was counted (at least 30 total stomata per seedling). To evaluate the statistical significance between the result for A and NA stomata populations, a two-sided Student’s t test was performed (*p < 0.05, **p < 0.01, ***p < 0.001). From left to right in the plots, p-values are p = 0, p = 0.0001, p = 0, p = 0, p = 0.0001, p = 0.001. Source data are provided as a Source Data file.