title: Modelling of auxin transport affected by gravity and differential radial growth.
abstract: When a tree stem deviates from verticality, as a result of different environmental factors, patterns of differential radial growth appear. Higher rates of wood production have been observed on the lower side of the tree and lower rates in the opposite side. Biological studies on plant hormones have shown that the concentration of auxin induces radial growth. They also have demonstrated the redistribution of auxin transport in response to gravity. Auxin is then designated as a mediator for differential growth. This paper presents a model for three-dimensional (3-D) auxin transport in conifer trees, which includes gravity dependence. We obtain realistic heterogeneous patterns of auxin distribution over the tree. Then, we propose a law of growth based on auxin concentration to simulate successive differential radial growths. The predicted growths are compared with experimental results of reconstruction of 3-D annual growth of Radiata pine.
authors.affiliation: Laboratoire Techniques de l'Imagerie, de la Modélisation et de la Cognition (TIMC UMR CNRS 5525), Institut d'Ingénierie de l'Information de Santé, Pavillon Taillefer, Faculté de Médecine, 38706 La Tronche cedex, France. loic.forest@imag.fr
authors.forename: Loïc
authors.initials: L
authors.lastname: Forest
authors.forename: Fernando
authors.initials: F
authors.lastname: Padilla
authors.forename: Salomé
authors.initials: S
authors.lastname: Martínez
authors.forename: Jacques
authors.initials: J
authors.lastname: Demongeot
authors.forename: Jaime
authors.initials: J
authors.lastname: San Martín
mesh_terms: D001692:Biological Transport / Q000502:physiology; D006112:Gravitation; D018522:Gravitropism / Q000502:physiology*; D007210:Indoleacetic Acids / Q000378:metabolism*; D008954:Models, Biological; D064028:Tracheophyta / Q000254:growth & development / Q000378:metabolism*
chemical_list: D007210:Indoleacetic Acids