title: Phosphate starvation induces a determinate developmental program in the roots of Arabidopsis thaliana.
abstract: When growing under limiting phosphate (P) conditions, Arabidopsis thaliana plants show dramatic changes in root architecture, including a reduction in primary root length, increased formation of lateral roots and greater formation of root hairs. Here we report that primary root growth inhibition by low P is caused by a shift from an indeterminate to a determinate developmental program. In the primary root, the low P-induced determinate growth program initiates with a reduction of cell elongation followed by the progressive loss of meristematic cells. At later stages, cell proliferation ceases and cell differentiation takes place at the former cell elongation and meristematic regions of the primary root. In low P, not only the primary but also almost all mature lateral roots enter the determinate developmental program. Kinetic studies of expression of the cell cycle marker CycB1;1:uidA and the quiescent center (QC) identity marker QC46:GUS showed that in low P conditions, reduction in proliferation in the primary root was preceded by alterations in the QC. These results suggest that in Arabidopsis, P limitation can induce a determinate root developmental program that plays an important role in altering root system architecture and that the QC could act as a sensor of environmental signals.
authors.affiliation: Departamento de Ingeniería Genética, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional, Unidad Irapuato, Apartado Postal 629, 36500 Irapuato, Guanajuato, México.
authors.forename: Lenin
authors.initials: L
authors.lastname: Sánchez-Calderón
authors.forename: José
authors.initials: J
authors.lastname: López-Bucio
authors.forename: Alejandra
authors.initials: A
authors.lastname: Chacón-López
authors.forename: Alfredo
authors.initials: A
authors.lastname: Cruz-Ramírez
authors.forename: Fernanda
authors.initials: F
authors.lastname: Nieto-Jacobo
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Dubrovsky
authors.forename: Luis
authors.initials: L
authors.lastname: Herrera-Estrella
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D002453:Cell Cycle; D049109:Cell Proliferation; D015870:Gene Expression; D017343:Genes, Plant; D018519:Meristem / Q000166:cytology / Q000254:growth & development / Q000378:metabolism; D028061:Phosphate Transport Proteins / Q000235:genetics / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism*; D018517:Plant Roots / Q000166:cytology / Q000254:growth & development / Q000378:metabolism; D011401:Promoter Regions, Genetic
chemical_list: D029681:Arabidopsis Proteins; D015415:Biomarkers; D028061:Phosphate Transport Proteins; D010710:Phosphates