Fig. 1. Phenotype of LONESOME HIGHWAY mutants. (A) Cross-section diagram of a mature Arabidopsis root; tissues are arranged radially from outside in: epidermis (white), cortex (purple), endodermis (dark blue) and stele [which consists of a ring of pericycle cells (light blue) that surrounds xylem (yellow) and phloem (red) arranged in bilateral symmetry]. (B,C) Confocal images of wild type (WT, B) and lhw-1 (C) expressing the xylem-associated pericycle marker J0121::GFP (green). Roots are counterstained with propidium iodide (PI, red) to visualize the outlines of cells. (D) Bright-field image of a lhw-1 root, which has all lateral roots (black arrowheads) emerging from a single side of the primary root. (E,F) Confocal image of basic fuchsin staining of xylem in wild type (E) and lhw-1 (F). (G,H) Confocal images of wild type (G) and lhw-1 (H) expressing the phloem marker APLpro::APL-GFP (green). (I,J) Whole-plant phenotypes of wild-type Col (I) and lhw SALK_079402 (J). (K) Root growth of wild type (left) and lhw-1 (right) on agar plates at 20 dpg. Notice the root-waving and short-root phenotypes in lhw-1. (L,M) Vascular pattern in mature (13 dpg) wild-type (L) and lhw-1 (M) cotyledons. (N,O) Higher-magnification images of xylem from images L and M, respectively. The black arrow points to the end of mature xylem elements; to the right, elongated cells typical of procambium are still seen. For each marker, the wild-type and lhw image pair are at the same magnification.