The bHLH Transcription Factor POPEYE Regulates Response to Iron Deficiency in Arabidopsis Roots

Terri A. Long, Hironaka Tsukagoshi, Wolfgang Busch, Brett Lahner, David E. Salt, Philip N. Benfey

Research output: Contribution to journalArticle

294 Citations (Scopus)

Abstract

Global population increases and climate change underscore the need for better comprehension of how plants acquire and process nutrients such as iron. Using cell type-specific transcriptional profiling, we identified a pericycle-specific iron deficiency response and a bHLH transcription factor, POPEYE (PYE), that may play an important role in this response. Functional analysis of PYE suggests that it positively regulates growth and development under iron-deficient conditions. Chromatin immunoprecipitation-on-chip analysis and transcriptional profiling reveal that PYE helps maintain iron homeostasis by regulating the expression of known iron homeostasis genes and other genes involved in transcription, development, and stress response. PYE interacts with PYE homologs, including IAA-Leu Resistant3 (ILR3), another bHLH transcription factor that is involved in metal ion homeostasis. Moreover, ILR3 interacts with a third protein, BRUTUS (BTS), a putative E3 ligase protein, with metal ion binding and DNA binding domains, which negatively regulates the response to iron deficiency. PYE and BTS expression is also tightly coregulated. We propose that interactions among PYE, PYE homologs, and BTS are important for maintaining iron homeostasis under low iron conditions.

Original languageEnglish
Pages (from-to)2219-2236
Number of pages18
JournalThe Plant Cell
Volume22
Issue number7
DOIs
Publication statusPublished - Jul 2010

Keywords

  • metal homeostasis
  • nicotianamine synthase
  • chelate reductase
  • gene-expression
  • ZN homeostasis
  • vacuolar iron
  • higher-plants
  • protein
  • transporter
  • mechanisms

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