Current address: School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, UK.
Characterisation of a pine MYB that regulates lignification
Article first published online: 6 NOV 2003
The Plant Journal
Volume 36, Issue 6, pages 743–754, December 2003
How to Cite
Patzlaff, A., McInnis, S., Courtenay, A., Surman, C., Newman, L. J., Smith, C., Bevan, M. W., Mansfield, S., Whetten, R. W., Sederoff, R. R. and Campbell, M. M. (2003), Characterisation of a pine MYB that regulates lignification. The Plant Journal, 36: 743–754. doi: 10.1046/j.1365-313X.2003.01916.x
- Issue published online: 6 NOV 2003
- Article first published online: 6 NOV 2003
- Received 4 April 2003; revised 31 July 2003; accepted 2 September 2003.
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.