Characterisation of a pine MYB that regulates lignification

Plant J. 2003 Dec;36(6):743-54. doi: 10.1046/j.1365-313x.2003.01916.x.

Abstract

A member of the R2R3-MYB family of transcription factors was cloned from a cDNA library constructed from RNA isolated from differentiating pine xylem. This MYB, Pinus taeda MYB4 (PtMYB4), is expressed in cells undergoing lignification, as revealed by in situ RT-PCR. Electrophoretic mobility shift assays (EMSAs) showed that recombinant PtMYB4 protein is able to bind to DNA motifs known as AC elements. AC elements are ubiquitous in the promoters of genes encoding lignin biosynthetic enzymes. Transcriptional activation assays using yeast showed that PtMYB4 could activate transcription in an AC-element-dependent fashion. Overexpression of PtMYB4 in transgenic tobacco plants altered the accumulation of transcripts corresponding to genes encoding lignin biosynthetic enzymes. Lignin deposition increased in transgenic tobacco plants that overexpressed PtMYB4, and extended to cell types that do not normally lignify. Taken together, these findings are consistent with the hypothesis that PtMYB4 is sufficient to induce lignification, and that it may play this role during wood formation in pine.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis / genetics
  • Arabidopsis Proteins / chemistry
  • Arabidopsis Proteins / genetics
  • Base Sequence
  • DNA, Complementary / genetics
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / genetics*
  • Gene Expression Regulation, Plant / genetics*
  • Gene Library
  • Genes, myb / genetics*
  • Lignin / genetics
  • Molecular Sequence Data
  • Pinus / genetics*
  • Plant Proteins / chemistry
  • Plant Proteins / genetics
  • Plants, Genetically Modified / genetics
  • Plants, Genetically Modified / metabolism
  • RNA, Plant / genetics
  • RNA, Plant / isolation & purification
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Sequence Homology, Nucleic Acid
  • Tobacco / metabolism
  • Transcription Factors / chemistry
  • Transcription Factors / genetics*

Substances

  • Arabidopsis Proteins
  • DNA, Complementary
  • DNA-Binding Proteins
  • Plant Proteins
  • RNA, Plant
  • Transcription Factors
  • Lignin

Associated data

  • GENBANK/U62734
  • GENBANK/X62344
  • GENBANK/X74453
  • GENBANK/X78269