title: Systems analysis of shoot apical meristem growth and development: integrating hormonal and mechanical signaling.
abstract: The shoot apical meristem (SAM) is a small population of stem cells that continuously generates organs and tissues. This review covers our current understanding of organ initiation by the SAM in Arabidopsis thaliana. Meristem function and maintenance involves two major hormones, cytokinins and auxins. Cytokinins appear to play a major role in meristem maintenance and in controlling meristematic properties, such as cell proliferation. Self-organizing transport processes, which are still only partially understood, lead to the patterned accumulation of auxin at particular positions, where organs will grow out. A major downstream target of auxin-mediated growth regulation is the cell wall, which is a determinant for both growth rates and growth distribution, but feedbacks with metabolism and the synthetic capacity of the cytoplasm are crucial as well. Recent work has also pointed at a potential role of mechanical signals in growth coordination, but the precise mechanisms at work remain to be elucidated.
authors.affiliation: School of Biosciences, Cardiff University, Cardiff, Wales CF10 3AX, United Kingdom.
authors.forename: James A H
authors.initials: JA
authors.lastname: Murray
authors.forename: Angharad
authors.initials: A
authors.lastname: Jones
authors.forename: Christophe
authors.initials: C
authors.lastname: Godin
authors.forename: Jan
authors.initials: J
authors.lastname: Traas
mesh_terms: D001692:Biological Transport; D049109:Cell Proliferation; D003583:Cytokinins / Q000378:metabolism / Q000502:physiology; D007210:Indoleacetic Acids / Q000378:metabolism; D018519:Meristem / Q000254:growth & development* / Q000378:metabolism; D008954:Models, Biological; D010937:Plant Growth Regulators / Q000378:metabolism*; D018520:Plant Shoots / Q000166:cytology* / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D003583:Cytokinins; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators