AtMYB93 is a novel negative regulator of lateral root development in Arabidopsis

Authors Organisations
  • Daniel J Gibbs(Author)
    University of Birmingham
  • Ute Voß(Author)
    University of Nottingham
  • Susan A Harding(Author)
    University of Birmingham
  • Jessica Fannon(Author)
    University of Birmingham
  • Laura A Moody(Author)
    University of Birmingham
  • Erika Yamada(Author)
    University of Birmingham
  • Kamal Swarup(Author)
    University of Nottingham
  • Candida Nobre Nibau(Author)
  • George W Bassel(Author)
    University of Birmingham
  • Anushree Choudhary(Author)
    University of Birmingham
  • Julien Lavenus(Author)
    University of Nottingham
  • Susan J Bradshaw(Author)
    University of Birmingham
  • Dov J Stekel(Author)
    University of Nottingham
  • Malcolm J Bennett(Author)
    University of Nottingham
  • Juliet C Coates(Author)
    University of Birmingham
Type Article
Original languageEnglish
Pages (from-to)1194-207
Number of pages14
JournalNew Phytologist
Volume203
Issue number4
Early online date06 Jun 2014
DOI
Publication statusPublished - Sep 2014
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Abstract

Plant root system plasticity is critical for survival in changing environmental conditions. One important aspect of root architecture is lateral root development, a complex process regulated by hormone, environmental and protein signalling pathways. Here we show, using molecular genetic approaches, that the MYB transcription factor AtMYB93 is a novel negative regulator of lateral root development in Arabidopsis. We identify AtMYB93 as an interaction partner of the lateral-root-promoting ARABIDILLO proteins. Atmyb93 mutants have faster lateral root developmental progression and enhanced lateral root densities, while AtMYB93-overexpressing lines display the opposite phenotype. AtMYB93 is expressed strongly, specifically and transiently in the endodermal cells overlying early lateral root primordia and is additionally induced by auxin in the basal meristem of the primary root. Furthermore, Atmyb93 mutant lateral root development is insensitive to auxin, indicating that AtMYB93 is required for normal auxin responses during lateral root development. We propose that AtMYB93 is part of a novel auxin-induced negative feedback loop stimulated in a select few endodermal cells early during lateral root development, ensuring that lateral roots only develop when absolutely required. Putative AtMYB93 homologues are detected throughout flowering plants and represent promising targets for manipulating root systems in diverse crop species.

Keywords

  • abscisic acid, ARABIDILLO, auxin, endodermis, lateral roots, MYB, negative regulation

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