Fig. 3

TCX2 controls stem cell division through cell-specific regulators and targets. a (Left) Medial longitudinal (left) and radial (right) sections of 5-day-old WT (top) and tcx2-mutant (bottom) plants. In medial longitudinal sections, asterisk labels QC cells and numbers denote columella cell files. In radial sections, white numbers denote xylem cells, yellow pericycle, and blue endodermis. Scale bar = 20 µm. (Middle) Length of 7-day-old WT (blue, n = 18) and tcx2 mutant (orange, n = 18) roots. Center line represents median; box bounds represent 25th and 75th percentiles; whiskers represent minimum and maximum values. Black X represents the mean. (Right) Quantification of stem cell phenotypes (top plot) and number of cell files (bottom plot) in 5-day old WT (n = 21) and tcx2 mutant (n = 17) roots. In top plot, green denotes the percent of roots that showed a phenotype, while gray denotes the percent of roots that did not show a phenotype. LRC, Col (Columella), QC refers to a cell disorganization phenotype in those cells. Asterisk denotes p < 0.1, Double asterisks denote p < 0.05, Wilcoxon test. b (Left) Medial longitudinal sections of 5-day-old WOX5:GFP (left), CYCD6:GFP (second from left), FEZ:FEZ-GFP (third from left), and TMO5:3xGFP (right) in WT (top) and tcx2-mutant (bottom) plants. For TMO5:3xGFP, a radial section (middle) was taken at the location of the white, dashed line. (Right) Quantification of GFP in WT (blue, n = 35, n = 8, n = 5 for CYCD6, FEZ, TMO5) and tcx2-mutant (orange, n = 25, n = 6, n = 10 for CYCD6, FEZ, TMO5) plants. Center line represents median; box bounds represent 25th and 75th percentiles; whiskers represent minimum and maximum excluding outliers. Black dots represent outliers. Colored dots represent individual data points. Asterisk denotes p < 0.1, double asterisks denote p < 0.05, Wilcoxon test. c (Left) Predicted direct targets of TCX2 and (right) predicted upstream regulators of TCX2 with stem cell (SC) phenotypes. Gene size represents the NMS score. Red borders represent the genes that have a known SC phenotype. Arrows represent predicted activation, bars repression, and circles no predicted sign. Thick edges were validated using qPCR/RNA-Seq. Black edges were predicted in the correct cell type but did not have a predicted sign. Blue edges have the correct cell type and correct sign, while orange edges have the correct cell type but the incorrect sign. Arrows with chevrons are DAPSeq validated. Source data are provided as a Source Data file.