Regulation of secondary wall synthesis and cell death by NAC transcription factors in the monocot Brachypodium distachyon

J Exp Bot. 2013 Mar;64(5):1333-43. doi: 10.1093/jxb/ers394. Epub 2013 Feb 5.

Abstract

In several dicotyledonous species, NAC transcription factors act as master switches capable of turning on programmes of secondary cell-wall synthesis and cell death. This work used an oestradiol-inducible system to overexpress the NAC transcription factor BdSWN5 in the monocot model Brachypodium distachyon. This resulted in ectopic secondary cell-wall formation in both roots and shoots. Some of the genes upregulated in the process were a secondary cell-wall cellulose synthase (BdCESA4), a xylem-specific protease (BdXCP1) and an orthologue of AtMYB46 (BdMYB1). While activation of BdMYB1 may not be direct, this study showed that BdSWN5 is capable of transactivating the BdXCP1 promoter through two conserved binding sites. In the course of Brachypodium development, the BdXCP1 promoter was observed to be active in all types of differentiating tracheary elements. Together, these results suggest that Brachypodium SWNs can act as switches that turn on secondary cell-wall synthesis and programmed cell death.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Binding Sites / genetics
  • Brachypodium / cytology*
  • Brachypodium / genetics
  • Brachypodium / metabolism*
  • Cell Death
  • Cell Wall / genetics
  • Cell Wall / metabolism*
  • Electrophoretic Mobility Shift Assay
  • Gene Expression Regulation, Plant
  • Genes, Plant / genetics
  • Molecular Sequence Data
  • Nicotiana / cytology
  • Nicotiana / genetics
  • Organ Specificity / genetics
  • Phylogeny
  • Plant Leaves / cytology
  • Plant Leaves / genetics
  • Plant Proteins / genetics
  • Plant Proteins / metabolism
  • Plants, Genetically Modified
  • Promoter Regions, Genetic / genetics
  • Protein Binding / genetics
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Transcriptional Activation
  • Xylem / genetics

Substances

  • Plant Proteins
  • Transcription Factors

Associated data

  • GENBANK/JQ693422
  • GENBANK/JQ693423
  • GENBANK/JQ693424
  • GENBANK/JQ693425
  • GENBANK/JQ693426
  • GENBANK/JQ693427
  • GENBANK/JQ693428
  • GENBANK/JQ693429