title: The proteome of Populus nigra woody root: response to bending.
abstract: OBJECTIVE
  Morphological and biomechanical alterations occurring in woody roots of many plant species in response to mechanical stresses are well documented; however, little is known about the molecular mechanisms regulating these important alterations. The first forest tree genome to be decoded is that of Populus, thereby providing a tool with which to investigate the mechanisms controlling adaptation of woody roots to changing environments. The aim of this study was to use a proteomic approach to investigate the response of Populus nigra woody taproot to mechanical stress.
  
  
  METHODS
  To simulate mechanical perturbations, the taproots of 30 one-year-old seedlings were bent to an angle of 90 ° using a steel net. A spatial and temporal two-dimensional proteome map of the taproot axis was obtained. We compared the events occurring in the above-bending, central bending and below-bending sectors of the taproot.
  
  
  RESULTS
  The first poplar woody taproot proteome map is reported here; a total of 207 proteins were identified. Spatial and temporal proteomic analysis revealed that factors involved in plant defence, metabolism, reaction wood formation and lateral root development were differentially expressed in the various sectors of bent vs. control roots, seemingly in relation to the distribution of mechanical forces along the stressed woody taproots. A complex interplay among different signal transduction pathways involving reactive oxygen species appears to modulate these responses.
  
  
  CONCLUSIONS
  Poplar woody root uses different temporal and spatial mechanisms to respond to mechanical stress. Long-term bending treatment seem to reinforce the defence machinery, thereby enabling the taproot to better overcome winter and to be ready to resume growth earlier than controls.
authors.affiliation: Dipartimento di Scienze e Tecnologie per l'Ambiente e il Territorio, University of Molise, 86090 Pesche, Italy.
authors.forename: Dalila
authors.initials: D
authors.lastname: Trupiano
authors.forename: Mariapina
authors.initials: M
authors.lastname: Rocco
authors.forename: Giovanni
authors.initials: G
authors.lastname: Renzone
authors.forename: Andrea
authors.initials: A
authors.lastname: Scaloni
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Viscosi
authors.forename: Donato
authors.initials: D
authors.lastname: Chiatante
authors.forename: Gabriella S
authors.initials: GS
authors.lastname: Scippa
mesh_terms: D000222:Adaptation, Physiological; D002874:Chromosome Mapping; D059647:Gene-Environment Interaction; D010940:Plant Proteins / Q000302:isolation & purification*; D018517:Plant Roots / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D032107:Populus / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D040901:Proteomics; D062211:Spatio-Temporal Analysis; D013314:Stress, Mechanical
chemical_list: D010940:Plant Proteins