title: Models for gibberellic acid transport and enzyme production and transport in the aleurone layer of barley.
abstract: Gibberellins are growth hormones produced in the embryo of grain released during germination. They promote growth through the production of enzymes in the aleurone layer surrounding the endosperm. These enzymes then diffuse into the endosperm and produce the sugars required by the growing acrospire. Here we model the transport of gibberellins into and along the aleurone layer, the consequent production of enzymes, and their transport into the endosperm. Simple approximate solutions of the governing equations are obtained which suggest that the enzymes are released immediately behind a gibberellin front which travels with almost constant speed along the aleurone layer. The model also suggests that this propagation speed is determined primarily by conditions near the scutellum-aleurone junction, which may enable the embryo to actively control the germination process.
authors.affiliation: Intelligent Energy Systems, Level 2, 10-12 Clarke St, Crows Nest, NSW 2065, Australia. rickob@internode.on.net
authors.forename: Ricky
authors.initials: R
authors.lastname: O'Brien
authors.forename: Nev
authors.initials: N
authors.lastname: Fowkes
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Bassom
mesh_terms: D001692:Biological Transport; D056625:Endosperm; D004798:Enzymes / Q000378:metabolism*; D018525:Germination; D005875:Gibberellins / Q000378:metabolism* / Q000502:physiology; D001467:Hordeum / Q000254:growth & development*; D007700:Kinetics; D008954:Models, Biological; D010937:Plant Growth Regulators
chemical_list: D004798:Enzymes; D005875:Gibberellins; D010937:Plant Growth Regulators; C007842:gibberellic acid