Skip to main content
padlock icon - secure page this page is secure

Free Content SECONDARY WALL ASSOCIATED MYB1 is a positive regulator of secondary cell wall thickening in Brachypodium distachyon and is not found in the Brassicaceae

Download Article:
 Download
(PDF)
 
Grass biomass is comprised chiefly of secondary walls that surround fiber and xylem cells. A regulatory network of interacting transcription factors in part regulates cell wall thickening. We identified Brachypodium distachyon SECONDARY WALL ASSOCIATED MYB1 (SWAM1) as a potential regulator of secondary cell wall biosynthesis based on gene expression, phylogeny, and transgenic plant phenotypes. SWAM1 interacts with cellulose and lignin gene promoters with preferential binding to AC‐rich sequence motifs commonly found in the promoters of cell wall‐related genes. SWAM1 overexpression (SWAM‐OE) lines had greater above‐ground biomass with only a slight change in flowering time while SWAM1 dominant repressor (SWAM1‐DR) plants were severely dwarfed with a striking reduction in lignin of sclerenchyma fibers and stem epidermal cell length. Cellulose, hemicellulose, and lignin genes were significantly down‐regulated in SWAM1‐DR plants and up‐regulated in SWAM1‐OE plants. There was no reduction in bioconversion yield in SWAM1‐OE lines; however, it was significantly increased for SWAM1‐DR samples. Phylogenetic and syntenic analyses strongly suggest that the SWAM1 clade was present in the last common ancestor between eudicots and grasses, but is not in the Brassicaceae. Collectively, these data suggest that SWAM1 is a transcriptional activator of secondary cell wall thickening and biomass accumulation in B. distachyon.
No References
No Citations
No Supplementary Data
No Article Media
No Metrics

Keywords: Brachypodium distachyon; MYB transcription factor; sclerenchyma cell; secondary cell wall

Document Type: Research Article

Publication date: November 1, 2018

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more