title: The poplar glycosyltransferase GT47C is functionally conserved with Arabidopsis Fragile fiber8.
abstract: Xylan is the major hemicellulose in dicot wood. Unraveling genes involved in the biosynthesis of xylan will be of importance in understanding the process of wood formation. In this report, we investigated the possible role of poplar GT47C, a glycosyltransferase belonging to family GT47, in the biosynthesis of xylan. PoGT47C from the hybrid poplar Populus alba x tremula exhibits 84% sequence similarity to Fragile fiber8 (FRA8), which is involved in the biosynthesis of glucuronoxylan in Arabidopsis. Phylogenetic analysis of glycosyltransferase family GT47 in the Populus trichocarpa genome revealed that GT47C is the only close homolog of FRA8. In situ hybridization showed that the PoGT47C gene was expressed in developing primary xylem, secondary xylem and phloem fibers of stems, and in developing secondary xylem of roots. Sequence analysis suggests that PoGT47C is a type II membrane protein, and study of the subcellular localization demonstrated that fluorescent protein-tagged PoGT47C was located in the Golgi. Immunolocalization with a xylan monoclonal antibody LM10 revealed a nearly complete loss of xylan signals in the secondary walls of fibers and vessels in the Arabidopsis fra8 mutant. Expression of PoGT47C in the fra8 mutant restored the secondary wall thickness and xylan content to the wild-type level. Together, these results suggest that PoGT47C is functionally conserved with FRA8 and it is probably involved in xylan synthesis during wood formation.
authors.affiliation: Department of Plant Biology, University of Georgia, Athens, GA 30602, USA.
authors.forename: Gong-Ke
authors.initials: GK
authors.lastname: Zhou
authors.forename: Ruiqin
authors.initials: R
authors.lastname: Zhong
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Richardson
authors.forename: W Herbert
authors.initials: WH
authors.lastname: Morrison
authors.forename: C Joseph
authors.initials: CJ
authors.lastname: Nairn
authors.forename: Alicia
authors.initials: A
authors.lastname: Wood-Jones
authors.forename: Zheng-Hua
authors.initials: ZH
authors.lastname: Ye
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics*; D017124:Conserved Sequence; D014453:Glucuronosyltransferase / Q000737:chemistry / Q000235:genetics*; D016695:Glycosyltransferases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D032107:Populus / Q000145:classification / Q000201:enzymology*; D016415:Sequence Alignment; D014934:Wood / Q000378:metabolism; D014990:Xylans / Q000096:biosynthesis
chemical_list: D029681:Arabidopsis Proteins; D014990:Xylans; D016695:Glycosyltransferases; C515612:FRA8 protein, Arabidopsis; D014453:Glucuronosyltransferase