A Molecular Framework for Plant Regeneration

Plants and some animals have a profound capacity to regenerate organs from adult tissues. Molecular mechanisms for regeneration have, however, been largely unexplored. Here we investigate a local regeneration response in Arabidopsis roots. Laser-induced wounding disrupts the flow of auxin—a cell-fate–instructive plant hormone—in root tips, and we demonstrate that resulting cell-fate changes require the PLETHORA, SHORTROOT, and SCARECROW transcription factors. These transcription factors regulate the expression and polar position of PIN auxin efflux–facilitating membrane proteins to reconstitute auxin transport in renewed root tips. Thus, a regeneration mechanism using embryonic root stem-cell patterning factors first responds to and subsequently stabilizes a new hormone distribution.

[1]  P. Benfey,et al.  Intercellular movement of the putative transcription factor SHR in root patterning , 2001, Nature.

[2]  Tom Beeckman,et al.  Functional redundancy of PIN proteins is accompanied by auxin-dependent cross-regulation of PIN expression , 2005, Development.

[3]  Philip N Benfey,et al.  The SHORT-ROOT Gene Controls Radial Patterning of the Arabidopsis Root through Radial Signaling , 2000, Cell.

[4]  A. Nakano,et al.  The Arabidopsis GNOM ARF-GEF Mediates Endosomal Recycling, Auxin Transport, and Auxin-Dependent Plant Growth , 2003, Cell.

[5]  P. Benfey,et al.  The SCARECROW Gene Regulates an Asymmetric Cell Division That Is Essential for Generating the Radial Organization of the Arabidopsis Root , 1996, Cell.

[6]  E. Meyerowitz,et al.  Patterns of Auxin Transport and Gene Expression during Primordium Development Revealed by Live Imaging of the Arabidopsis Inflorescence Meristem , 2005, Current Biology.

[7]  R. Amasino,et al.  The PLETHORA Genes Mediate Patterning of the Arabidopsis Root Stem Cell Niche , 2004, Cell.

[8]  G. Mitchison,et al.  The polar transport of auxin and vein patterns in plants , 1981 .

[9]  Klaus Palme,et al.  AtPIN4 Mediates Sink-Driven Auxin Gradients and Root Patterning in Arabidopsis , 2002, Cell.

[10]  Gerald R. Fink,et al.  Post-transcriptional control of the Arabidopsis auxin efflux carrier EIR1 requires AXR1 , 2000, Current Biology.

[11]  Klaus Palme,et al.  The PIN auxin efflux facilitator network controls growth and patterning in Arabidopsis roots , 2005, Nature.

[12]  G. Jürgens,et al.  Coordinated polar localization of auxin efflux carrier PIN1 by GNOM ARF GEF. , 1999, Science.

[13]  M. Bennett,et al.  Regulation of phyllotaxis by polar auxin transport , 2003, Nature.

[14]  B. Scheres,et al.  Cell fate in the Arabidopsis root meristem determined by directional signalling , 1995, Nature.

[15]  Ottoline Leyser,et al.  An Auxin-Dependent Distal Organizer of Pattern and Polarity in the Arabidopsis Root , 1999, Cell.

[16]  S. Sabatini,et al.  SCARECROW is involved in positioning the stem cell niche in the Arabidopsis root meristem. , 2003, Genes & Development.

[17]  G. Jürgens,et al.  Local, Efflux-Dependent Auxin Gradients as a Common Module for Plant Organ Formation , 2003, Cell.

[18]  Michael Sauer,et al.  Efflux-dependent auxin gradients establish the apical–basal axis of Arabidopsis , 2003, Nature.

[19]  Klaus Palme,et al.  A PINOID-Dependent Binary Switch in Apical-Basal PIN Polar Targeting Directs Auxin Efflux , 2004, Science.

[20]  Claudia van den Berg,et al.  Short-range control of cell differentiation in the Arabidopsis root meristem , 1997, Nature.

[21]  B. Scheres,et al.  Dissection of Arabidopsis ADP-RIBOSYLATION FACTOR 1 Function in Epidermal Cell Polarityw⃞ , 2005, The Plant Cell Online.

[22]  B. Scheres,et al.  Mosaic analyses using marked activation and deletion clones dissect Arabidopsis SCARECROW action in asymmetric cell division. , 2004, Genes & development.

[23]  P. Benfey,et al.  Genetic evidence that the endodermis is essential for shoot gravitropism in Arabidopsis thaliana. , 1998, The Plant journal : for cell and molecular biology.