Auxin: a major regulator of organogenesis.
Plant development is characterized by the continuous initiation of tissues and organs. The meristems, which are small stem cell populations, are involved in this process. The shoot apical meristem produces lateral organs at its flanks and generates the growing stem. These lateral organs are arranged in a stereotyped pattern called phyllotaxis. Organ initiation in the peripheral zone of the meristem involves accumulation of the plant hormone auxin. Auxin is transported in a polar way by influx and efflux carriers located at cell membranes. Polar localization of the PIN1 efflux carrier in meristematic cells generates auxin concentration gradients and PIN1 localization depends, in turn, on auxin gradients: this feedback loop generates a dynamic auxin distribution which controls phyllotaxis. Furthermore, PIN-dependent local auxin gradients represent a common module for organ initiation, in the shoot and in the root.
Bohn-Courseau
Isabelle
I
Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique, route de Saint-Cyr, Versailles cedex, France. isabelle.bohn@free.fr
D001693:Biological Transport, Active; D018548:Cotyledon / Q000502:physiology; D007210:Indoleacetic Acids / Q000378:metabolism*; D018519:Meristem / Q000502:physiology; D063245:Plant Development; D018521:Plant Physiological Phenomena; D018517:Plant Roots / Q000254:growth & development
D007210:Indoleacetic Acids