Arabidopsis MYB28 and MYB29 transcription factors are involved in ammonium-mediated alterations of root-system architecture

Plant Signal Behav. 2021 Apr 3;16(4):1879532. doi: 10.1080/15592324.2021.1879532. Epub 2021 Feb 4.

Abstract

Ammonium (NH4+) is known to produce alterations in root-system architecture, notably, by inhibiting primary root elongation and stimulating lateral root branching. This stimulation is associated with higher auxin transport promoted by apoplast acidification. Recently, we showed that MYB28 and MYB29 transcription factors play a role in ammonium tolerance, since its double mutant (myb28myb29) is highly hypersensitive toward ammonium nutrition in relation to altered Fe homeostasis. In the present work, we observed that primary root elongation was lower in the mutant with respect to wild-type plants under ammonium nutrition. Moreover, ammonium-induced lateral root branching was impaired in myb28myb29 in a Fe-supply dependent manner. Further research is required to decipher the link between MYB28 and MYB29 functions and the signaling pathway leading to root-system architecture modification by NH4+ supply.

Keywords: Ammonium stress; Arabidopsis thaliana; glucosinolate; iron; lateral root; myb28myb29; primary root; signaling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ammonium Compounds / metabolism*
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / metabolism*
  • Histone Acetyltransferases / metabolism*
  • Iron / pharmacology
  • Plant Roots / anatomy & histology*
  • Plant Roots / drug effects
  • Plant Roots / metabolism*
  • Transcription Factors / metabolism*

Substances

  • Ammonium Compounds
  • Arabidopsis Proteins
  • Myb29 protein, Arabidopsis
  • Transcription Factors
  • Iron
  • GCN5 protein, Arabidopsis
  • Histone Acetyltransferases

Grants and funding

The research leading to these results has received funding from the Basque Government, IT-932-16 and the Spanish Government (BIO2014-56271-R and BIO2017-84035-R, co-funded by FEDER). IB holds a fellowship from the Basque Government.