title: Longitudinal zonation pattern in plant roots: conflicts and solutions.
abstract: Despite the relative simplicity of Arabidopsis root organization, there is no general agreement regarding the terminology used to describe the longitudinal zonation pattern (LZP) of this model system. In this opinion article, we examine inconsistencies in the terminology and provide a conceptual framework for the LZP that may be applied to all angiosperms. We propose that the root apical meristem (RAM) consists of the cell-proliferation domain where cells maintain a high probability to divide and the transition domain with a low probability of cell division; in both domains cells grow at the same, relatively low, rate. Owing to stochastic termination of cell proliferation in the RAM, the border between the domains is 'fuzzy'. Molecular markers analyzed together with quantitative growth and cell analyses could help to identify developmental zones along the root and lead to a better understanding of the LZP in angiosperms.
authors.affiliation: Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya ul. 35, Moscow, 127276 Russia. ivanov_vb@mail.ru
authors.forename: Victor B
authors.initials: VB
authors.lastname: Ivanov
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Dubrovsky
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D049109:Cell Proliferation; D018506:Gene Expression Regulation, Plant; D005819:Genetic Markers; D019684:Magnoliopsida / Q000235:genetics / Q000254:growth & development; D018519:Meristem / Q000235:genetics / Q000254:growth & development; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics* / Q000254:growth & development*; D013269:Stochastic Processes; D009626:Terminology as Topic
chemical_list: D029681:Arabidopsis Proteins; D005819:Genetic Markers; D010940:Plant Proteins