Analysis of the Arabidopsis IRX9/IRX9-L and IRX14/IRX14-L pairs of glycosyltransferase genes reveals critical contributions to biosynthesis of the hemicellulose glucuronoxylan
Wu, Ai-Min, Hornblad, Emma, Voxeur, Aline, Gerber, Lorenz, Rihouey, Christophe, Lerouge, Patrice and Marchant, Alan (2010) Analysis of the Arabidopsis IRX9/IRX9-L and IRX14/IRX14-L pairs of glycosyltransferase genes reveals critical contributions to biosynthesis of the hemicellulose glucuronoxylan. Plant Physiology, 153, (2), 542-554. (doi:10.1104/pp.110.154971).
The hemicellulose glucuronoxylan (GX) is a major component of plant secondary cell walls. However, our understanding of GX synthesis remains limited. Here, we identify and analyze two new genes from Arabidopsis (Arabidopsis thaliana), IRREGULAR XYLEM9-LIKE (IRX9-L) and IRX14-LIKE (IRX14-L) that encode glycosyltransferase family 43 members proposed to function during xylan backbone elongation. We place IRX9-L and IRX14-L in a genetic framework with six previously described glycosyltransferase genes (IRX9, IRX10, IRX10-L, IRX14, FRAGILE FIBER8 [FRA8], and FRA8 HOMOLOG [F8H]) and investigate their function in GX synthesis. Double-mutant analysis identifies IRX9-L and IRX14-L as functional homologs of IRX9 and IRX14, respectively. Characterization of irx9 irx10 irx14 fra8 and irx9-L irx10-L irx14-L f8h quadruple mutants allows definition of a set of genes comprising IRX9, IRX10, IRX14, and FRA8 that perform the main role in GX synthesis during vegetative development. The IRX9-L, IRX10-L, IRX14-L, and F8H genes are able to partially substitute for their respective homologs and normally perform a minor function. The irx14 irx14-L double mutant virtually lacks xylan, whereas irx9 irx9-L and fra8 f8h double mutants form lowered amounts of GX displaying a greatly reduced degree of backbone polymerization. Our findings reveal two distinct sets of four genes each differentially contributing to GX biosynthesis.
|Subjects:||Q Science > QH Natural history > QH301 Biology|
|Divisions:||University Structure - Pre August 2011 > School of Biological Sciences
|Date Deposited:||26 May 2010 13:14|
|Last Modified:||08 Jun 2012 12:50|
|Contributors:||Wu, Ai-Min (Author)
Hornblad, Emma (Author)
Voxeur, Aline (Author)
Gerber, Lorenz (Author)
Rihouey, Christophe (Author)
Lerouge, Patrice (Author)
Marchant, Alan (Author)
|RDF:||RDF+N-Triples, RDF+N3, RDF+XML, Browse.|
Actions (login required)