ERF72 interacts with ARF6 and BZR1 to regulate hypocotyl elongation in Arabidopsis

J Exp Bot. 2018 Jul 18;69(16):3933-3947. doi: 10.1093/jxb/ery220.

Abstract

The phytohormones brassinosteroid (BR), auxin, and gibberellin (GA) regulate photomorphogenesis-related hypocotyl elongation in Arabidopsis via the co-operative interaction of BZR-ARF-PIF/DELLA (BAP/D) transcription factors/regulators. In addition, ethylene activates the PIF3 or ERF1 pathway through EIN3/EIL1 to balance hypocotyl elongation in Arabidopsis seedlings. However, the mechanism by which ethylene is co-ordinated with other phytohormones to produce light-regulated hypocotyl growth remains elusive. In this study, we found that hypocotyl cell elongation is regulated by a network involving ethylene, auxin, and BR signalling, which is mediated by interactions among ERF72, ARF6, and BZR1. ERF72 interacted directly with ARF6 and BZR1 in vitro and in vivo, and it antagonised regulation by ARF6 and BZR1 of the transcription of BEE3 and XTH7. In addition, light modulated the subcellular localisation of ERF72 and transcription of ERF72 through the EIN2-EIN3/EIL1 pathway, facilitating the function of ERF72 in photomorphogenesis. The expression of BEE3 and XTH7 was also regulated by the EIN2-EIN3/EIL1 pathway. Our findings indicate that a revised BZR-ARF-PIF/DELLA-ERF (BAP/DE) module integrates light and hormone signals to regulate hypocotyl elongation in Arabidopsis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / growth & development
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Darkness
  • Gene Expression Regulation, Plant / radiation effects
  • Hypocotyl / growth & development*
  • Light
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Plant Growth Regulators / metabolism
  • Plants, Genetically Modified
  • Protein Binding
  • RNA, Plant / genetics
  • Sequence Analysis, RNA
  • Signal Transduction
  • Subcellular Fractions / metabolism
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Transcription, Genetic / radiation effects

Substances

  • Arabidopsis Proteins
  • BZR1 protein, Arabidopsis
  • DNA-Binding Proteins
  • Nuclear Proteins
  • Plant Growth Regulators
  • RAP2.3 protein, Arabidopsis
  • RNA, Plant
  • Transcription Factors
  • auxin response factor 6, Arabidopsis