Extended Data Fig. 5: An asymmetric auxin response output is specific for dorsiventral organs.
From: Specification of leaf dorsiventrality via a prepatterned binary readout of a uniform auxin input
a–f, The patterns of pDR5v2:GFP expression at the shoot apex during the transition to flowering (a, b) and at the reproductive phase (c–f) show dorsiventral organs (green) derive from meristem sites marked by a polarized transcriptional auxin response output. Early primordia of cauline leaves (b, p1, p2), bracts (d, p1, p2), and sepals (f). Subsequently, the auxin response output shifts to the middle domain and marks the primordium tip and underlying future midvein (b, p3, p4; d, p4, p5). In contrast, axillary (b) and floral (d) meristems (white), originate from sites marked by a uniform nuclear auxin response. (a, c, e) Meristem top views. (b, d, f) Optical longitudinal sections through primordia. Insets show the position of the optical section through the flower meristem (f). Green, dorsiventral leaf-like primordium; white, axillary or flower meristem; asterisks, shoot apical or flower meristem centre. Cell walls were stained by PI. Scale bars, 20 µm. Representative images from n = 5 (a) or n = 6 (c, e) meristems, and n = 5 (b) or n = 6 (d, f) primordia per developmental stage are shown.
