Fig. 1
From: A Rho-actin signaling pathway shapes cell wall boundaries in Arabidopsis xylem vessels
WAL is required for cell wall arches of pits. a Localization of GFP-WAL (pWAL:GFP-WAL) in metaxylem vessel cells in roots. Cell walls are labeled with propidium iodide (PI). Cortex (left) and mid-plane (right) from different cells are shown. The graph shows the intensity profile between the yellow arrowheads. GFP-WAL (green arrowheads) localized to the pit boundaries (red arrowheads). The boxed area is magnified in the right panel. Yellow and red broken lines indicate the edges of secondary cell walls (SW) and pit membranes (PiM), respectively. b Localization of GFP-WAL and active ROP11 domains (pMIDD1:MIDD1ΔN-tagRFP) in metaxylem vessel cells in roots. Cortex (left) and mid-plane (right) from different cells are shown. c WAL mRNA abundance in wal (SAIL_729_H08) plants. Values are mean ± s.d. (n = 3), ***p < 0.001 (Student’s t-test). d Differential interference contrast (DIC) of xylem vessels in roots of wild-type, wal, and wal pWAL:GFP-WAL plants. Arrowheads indicate enlarged secondary cell wall pits. e Surface area and aspect ratios of secondary cell wall pits. Values are mean ± s.d. (n > 300 pits), *p < 0.05; ***p < 0.001 (ANOVA with Scheffe test). f Electron micrographs of metaxylem vessel cells in roots. Yellow and blue brackets indicate pit aperture and pit membrane, respectively. Black arrowheads indicate the position of the primary cell wall layer. g Secondary cell walls of metaxylem vessels in roots of wild-type and wal plants. Secondary cell walls were stained with safranin. High-resolution confocal images were acquired with FV-OSR technology. Maximum intensity projection (left) and mid-plane (center) from different cells are shown. Right panels show magnification of the boxed regions. Yellow and blue brackets indicate pit aperture and pit membrane, respectively. White broken lines indicate the position of the primary cell wall layer. h Width of pit apertures and pit membranes. Values are mean ± s.d. (n > 240 pits), n.s., not significant; ***p < 0.001 (Student’s t-test). Bars = 5 μm (a, b, d, and g) and 2 μm (f). Source data are provided as a Source Data file
