title: The shoot apical meristem of oil palm (Elaeis guineensis; Arecaceae): developmental progression and dynamics.
abstract: OBJECTIVE
  Oil palm, an unbranched perennial monocotyledon, possesses a single shoot apical meristem (SAM), which is responsible for the initiation of the entire above-ground structure of the plant. To compare the palm SAM structure with those of other monocots and to study variations in its structure throughout the life of the plant, its organization was characterized from the embryonic stage to that of the reproductive plant.
  
  
  METHODS
  SAM structure was studied by a combination of stained histological sections, light and confocal microscopy, and serial section-based three-dimensional reconstructions.
  
  
  RESULTS
  The oil palm SAM is characterized by two developmental phases: a juvenile phase with a single tunica-corpus structure displaying a gradual increase in size; and a mature phase characterized by a stable size, a modified shape and an established histological zonation pattern. In mature plants, fluctuations in SAM shape and volume occur, mainly as a consequence of changes in the central zone, possibly in relation to leaf initiation.
  
  
  CONCLUSIONS
  Development of the oil palm SAM is characterized by a juvenile to mature phase transition accompanied by establishment of a zonal pattern and modified shape. SAM zonation is dynamic during the plastochron period and displays distinct features compared with other monocots.
authors.affiliation: IRD, UMR DIAPC, IRD/CIRAD Palm Development Group, 911 avenue Agropolis, BP 64501, 34394 Montpellier Cedex 5, France. stephane.jouannic@ird.fr
authors.forename: Stefan
authors.initials: S
authors.lastname: Jouannic
authors.forename: Marc
authors.initials: M
authors.lastname: Lartaud
authors.forename: Jonathan
authors.initials: J
authors.lastname: Hervé
authors.forename: Myriam
authors.initials: M
authors.lastname: Collin
authors.forename: Yves
authors.initials: Y
authors.lastname: Orieux
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Verdeil
authors.forename: James W
authors.initials: JW
authors.lastname: Tregear
mesh_terms: D028023:Arecaceae / Q000166:cytology* / Q000254:growth & development*; D018519:Meristem / Q000166:cytology* / Q000254:growth & development*; D018520:Plant Shoots / Q000166:cytology / Q000254:growth & development