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Characterisation of a pine MYB that regulates lignification
Author(s) -
Patzlaff Astrid,
McInnis Stephanie,
Courtenay Adrian,
Surman Christine,
Newman Lisa J.,
Smith Caroline,
Bevan Michael W.,
Mansfield Shawn,
Whetten Ross W.,
Sederoff Ronald R.,
Campbell Malcolm M.
Publication year - 2003
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.2003.01916.x
Subject(s) - myb , promoter , gene , transcription factor , yeast , complementary dna , biology , xylem , transgene , transcription (linguistics) , enzyme , microbiology and biotechnology , recombinant dna , lignin , gene expression , biochemistry , botany , linguistics , philosophy
Summary 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 ( Pt MYB4), is expressed in cells undergoing lignification, as revealed by in situ RT‐PCR. Electrophoretic mobility shift assays (EMSAs) showed that recombinant Pt MYB4 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 Pt MYB4 could activate transcription in an AC‐element‐dependent fashion. Overexpression of Pt MYB4 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 Pt MYB4, and extended to cell types that do not normally lignify. Taken together, these findings are consistent with the hypothesis that Pt MYB4 is sufficient to induce lignification, and that it may play this role during wood formation in pine.