title: Grasses suppress shoot-borne roots to conserve water during drought.
abstract: Many important crops are members of the Poaceae family, which develop root systems characterized by a high degree of root initiation from the belowground basal nodes of the shoot, termed the crown. Although this postembryonic shoot-borne root system represents the major conduit for water uptake, little is known about the effect of water availability on its development. Here we demonstrate that in the model C4 grass Setaria viridis, the crown locally senses water availability and suppresses postemergence crown root growth under a water deficit. This response was observed in field and growth room environments and in all grass species tested. Luminescence-based imaging of root systems grown in soil-like media revealed a shift in root growth from crown-derived to primary root-derived branches, suggesting that primary root-dominated architecture can be induced in S. viridis under certain stress conditions. Crown roots of Zea mays and Setaria italica, domesticated relatives of teosinte and S. viridis, respectively, show reduced sensitivity to water deficit, suggesting that this response might have been influenced by human selection. Enhanced water status of maize mutants lacking crown roots suggests that under a water deficit, stronger suppression of crown roots actually may benefit crop productivity.
authors.affiliation: Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305;
authors.forename: Jose
authors.initials: J
authors.lastname: Sebastian
authors.affiliation: Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305;
authors.forename: Muh-Ching
authors.initials: MC
authors.lastname: Yee
authors.affiliation: Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305; Coordination for the Improvement of Higher Education Personnel (CAPES) Foundation, Ministry of Education of Brazil, Brasilia-DF 70.040-020, Brazil;
authors.forename: Willian
authors.initials: W
authors.lastname: Goudinho Viana
authors.affiliation: Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305; Unidad de Genómica Avanzada, Laboratorio Nacional de Genómica para la Biodiversidad, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, 36821 Irapuato, Mexico;
authors.forename: Rubén
authors.initials: R
authors.lastname: Rellán-Álvarez
authors.affiliation: Donald Danforth Plant Science Center, St. Louis, MO 63162;
authors.forename: Max
authors.initials: M
authors.lastname: Feldman
authors.affiliation: Donald Danforth Plant Science Center, St. Louis, MO 63162;
authors.forename: Henry D
authors.initials: HD
authors.lastname: Priest
authors.affiliation: Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305;
authors.forename: Charlotte
authors.initials: C
authors.lastname: Trontin
authors.affiliation: Department of Biotechnology, College of Life Sciences and Biotechnology, Yonsei University, Seoul 03722, Korea;
authors.forename: Tak
authors.initials: T
authors.lastname: Lee
authors.affiliation: Donald Danforth Plant Science Center, St. Louis, MO 63162;
authors.forename: Hui
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Donald Danforth Plant Science Center, St. Louis, MO 63162; Plant Physiology and Genetics Research, Agricultural Research Unit, US Department of Agriculture, St. Louis, MO 63132;
authors.forename: Ivan
authors.identifier: 0000-0001-6680-1722
authors.initials: I
authors.lastname: Baxter
authors.affiliation: Donald Danforth Plant Science Center, St. Louis, MO 63162;
authors.forename: Todd C
authors.initials: TC
authors.lastname: Mockler
authors.affiliation: Crop Functional Genomics, Institute of Crop Science and Resource Conservation, University of Bonn, D-53113 Bonn, Germany.
authors.forename: Frank
authors.identifier: 0000-0002-5155-0884
authors.initials: F
authors.lastname: Hochholdinger
authors.affiliation: Donald Danforth Plant Science Center, St. Louis, MO 63162;
authors.forename: Thomas P
authors.identifier: 0000-0002-3581-8211
authors.initials: TP
authors.lastname: Brutnell
authors.affiliation: Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305; jdinneny@carnegiescience.edu.
authors.forename: José R
authors.identifier: 0000-0002-3998-724X
authors.initials: JR
authors.lastname: Dinneny
mesh_terms: D055864:Droughts; D009154:Mutation; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D006109:Poaceae / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D032983:Setaria Plant / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D012987:Soil; D014867:Water / Q000378:metabolism*; D003313:Zea mays / Q000235:genetics / Q000254:growth & development / Q000378:metabolism
chemical_list: D012987:Soil; D014867:Water
keywords: Poaceae; Setaria; Zea mays; drought; root development