Secondary cell wall synthesis occurs in specialized cell types following completion of cell enlargement. By virtue of mechanical strength provided by a wall thickened with cellulose, hemicelluloses, and lignin, these cells can function as water-conducting vessels and provide structural support. Several transcription factor families regulate genes encoding wall synthesis enzymes. Certain NAC and MYB proteins directly bind to the SNBE and AC elements upstream of structural genes and other transcription factors. The most detailed model of this regulatory network is established predominantly for a eudicot, Arabidopsis thaliana. In grasses, both the patterning and the composition of secondary cell walls are distinct from that of eudicots. These differences suggest transcriptional regulation is similarly distinct. Putative rice and maize orthologs of several eudicot cell wall regulators genetically complement mutants of A. thaliana or result in wall defects when constitutively overexpressed; nevertheless, aside from a maize, ZmMYB31, and a switchgrass protein, PvMYB4, function has not been tested in a grass. Similar to the seminal work conducted in A. thaliana, gene expression profiling in maize, rice, and other grasses implicates additional genes as regulators. Characterization of these genes will continue to elucidate the relationship between the transcription regulatory networks of eudicots and grasses.
Keywords: transcription factors, secondary cell wall
Citation: Handakumbura PP and Hazen SP (2012) Transcriptional regulation of grass secondary cell wall biosynthesis: playing catch-up with Arabidopsis thaliana. Front. Plant Sci. 3:74. doi: 10.3389/fpls.2012.00074
Received: 05 March 2012; Accepted: 31 March 2012;
Published online: 23 April 2012.
Edited by:Jose Manuel Estevez, University of Buenos Aires and CONICET, Argentina
Reviewed by:Uener Kolukisaoglu, University of Tuebingen, Germany
Copyright: © 2012 Handakumbura and Hazen. This is an open-access article distributed under the terms of the Creative Commons Attribution Non Commercial License, which permits non-commercial use, distribution, and reproduction in other forums, provided the original authors and source are credited.
*Correspondence: Samuel P. Hazen, Biology Department, University of Massachusetts, 221 Morrill Science Center, Amherst, MA 01003, USA. e-mail: firstname.lastname@example.org