Two conifer GUX clades are responsible for distinct glucuronic acid patterns on xylan
Published version
Peer-reviewed
Repository URI
Repository DOI
Change log
Authors
Abstract
Wood of coniferous trees (softwood), is a globally significant carbon sink and an important source of biomass. Despite that, little is known about the genetic basis of softwood cell wall biosynthesis. Branching of xylan, one of the main hemicelluloses in softwood secondary cell walls, with glucuronic acid is critical for biomass recalcitrance. Here, we investigate the decoration patterns of xylan by conifer GlucUronic acid substitution of Xylan (GUX) enzymes.
· Through molecular phylogenetics we identify two distinct conifer GUX clades. Using transcriptional profiling we show that the genes are preferentially expressed in secondary cell wall forming tissues. With in vitro and in planta assays we demonstrate that conifer GUX enzymes from both clades are active glucuronyltransferases.
· Conifer GUX enzymes from each clade have different specific activities. While members of clade one add evenly spaced GlcA branches, the members of clade two are also capable of glucuronidating two consecutive xyloses Importantly, these types of xylan patterning are present in softwood.
· Since xylan patterning might modulate xylan-cellulose and xylan-lignin interactions, our results further the understanding of softwood cell wall biosynthesis and provide breeding or genetic engineering targets that can be used to modify softwood properties.
Description
Keywords
Journal Title
Conference Name
Journal ISSN
1469-8137
Volume Title
Publisher
Publisher DOI
Sponsorship
Biotechnology and Biological Sciences Research Council (BB/M015432/1)
Leverhulme Trust (RP2013-SL-008)
Biotechnology and Biological Sciences Research Council (1650974)
Biotechnology and Biological Sciences Research Council (BB/J014540/1)