Fig. 5: PpRopGAPs and PpREN inhibit branch initiation.

a Percentages of subapical cells that have developed side-branches in WT, mutant, and rescued mosses. Subapical cells are numbered according to their relative position to the tip cell. The number of cells used for quantification ranges between 12 and 80. Note that early formation of branches on the second subapical cells occurs in ropgap, ren mutants which could be rescued by PpREN. PpRopGAP1 overexpression not only inhibits premature branching but also strongly blocks branch formation in ropgap, ren mutants and WT cells. b Morphology of the bulges in WT and mutant subapical cells. N, nucleus. Scale bar: 10 µm. c Quantification of bulge width and height. d Mitotic division of WT and mutant subapical cells. Cells are visualized with Lifeact-mCherry. The phragmoplast leading edge is indicated (red arrow). Scale bar: 10 µm. e Quantification of phragmoplast expansion time. f Representative subapical cell divisions in the WT and PpRopGAP1 overexpression lines. Cells are labeled by Lifeact-mCherry and imaged with epifluorescence and bright light. Scale bars: 50 µm. Data are presented as mean values ± SD with individual points shown in (c, e). The number of cells used for quantification is shown at the bottom. Mutant or overexpression lines were statistically compared with WT using two-tailed student’s t-tests. ns, not significant. ****p < 0.0001. **p < 0.01. The exact p-values are available in Source Data. Similar results in (f) were obtained in three independent experiments. Source data are provided as a Source Data file.