title: Genetic control of root growth: from genes to networks.
abstract: BACKGROUND
  Roots are essential organs for higher plants. They provide the plant with nutrients and water, anchor the plant in the soil, and can serve as energy storage organs. One remarkable feature of roots is that they are able to adjust their growth to changing environments. This adjustment is possible through mechanisms that modulate a diverse set of root traits such as growth rate, diameter, growth direction and lateral root formation. The basis of these traits and their modulation are at the cellular level, where a multitude of genes and gene networks precisely regulate development in time and space and tune it to environmental conditions.
  
  
  METHODS
  This review first describes the root system and then presents fundamental work that has shed light on the basic regulatory principles of root growth and development. It then considers emerging complexities and how they have been addressed using systems-biology approaches, and then describes and argues for a systems-genetics approach. For reasons of simplicity and conciseness, this review is mostly limited to work from the model plant Arabidopsis thaliana, in which much of the research in root growth regulation at the molecular level has been conducted.
  
  
  CONCLUSIONS
  While forward genetic approaches have identified key regulators and genetic pathways, systems-biology approaches have been successful in shedding light on complex biological processes, for instance molecular mechanisms involving the quantitative interaction of several molecular components, or the interaction of large numbers of genes. However, there are significant limitations in many of these methods for capturing dynamic processes, as well as relating these processes to genotypic and phenotypic variation. The emerging field of systems genetics promises to overcome some of these limitations by linking genotypes to complex phenotypic and molecular data using approaches from different fields, such as genetics, genomics, systems biology and phenomics.
authors.affiliation: Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, 1030 Vienna, Austria.
authors.forename: Radka
authors.initials: R
authors.lastname: Slovak
authors.affiliation: Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, 1030 Vienna, Austria.
authors.forename: Takehiko
authors.initials: T
authors.lastname: Ogura
authors.affiliation: Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, 1030 Vienna, Austria.
authors.forename: Santosh B
authors.initials: SB
authors.lastname: Satbhai
authors.affiliation: Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, 1030 Vienna, Austria.
authors.forename: Daniela
authors.initials: D
authors.lastname: Ristova
authors.affiliation: Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Dr. Bohr-Gasse 3, 1030 Vienna, Austria wolfgang.busch@gmi.oeaw.ac.at.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Busch
mesh_terms: D053263:Gene Regulatory Networks; D017343:Genes, Plant; D008954:Models, Biological; D018517:Plant Roots / Q000235:genetics* / Q000254:growth & development*; D010944:Plants / Q000235:genetics*; D049490:Systems Biology
keywords: Arabidopsis thaliana; Root; genetics; modelling; networks; root development; root growth; root patterning; systems biology; systems genetics