Fig. 7: Emergence of the internode cellular organization in the inter-primordia region in wild-type and in plants with modified GA signaling activity.

a–l Time-lapse (0 h, 24 h, 34 h) visualization of the L1 of the SAM from confocal microscopy of Ler ((a–c) n = 4 independent plants), global della ((d–f) n = 5 independent plants), Col-0 ((g–i) n = 3 independent plants) and pCUC2::gai-1-VENUS transgenic ((j–l) n = 4 independent plants). The imaging time is indicated at the right-up corner of each panel. Cells outlined with yellow dotted lines are those incorporated into a primordium at 34 h, and cells in green are found in the IPR at 34 h. Those in magenta produce both primordium and IPR cells. White dotted lines mark the edge of the elder primordium (that have been removed at 34 h except in (c)). m–p Scanning electron microscopy images of the shoot apex of Ler (m), global della (n), Col-0 (o), and pCUC2::gai-1-VENUS (p) allowing to analyze the early establishment of internode just below the SAM. The different size of arrows indicates differences in early internode length in the different genetic backgrounds. The experiment was repeated twice with similar results. Scale bars = 20 μm (a–l), 50 μm (m–p).