title: Two cotton fiber-associated glycosyltransferases, GhGT43A1 and GhGT43C1, function in hemicellulose glucuronoxylan biosynthesis during plant development.
abstract: Xylan is the major hemicellulosic constituent in dicot secondary cell walls. Cell wall composition of cotton fiber changes dynamically throughout development. Not only the amounts but also the molecular sizes of the hemicellulosic polysaccharides show substantial changes during cotton fiber development. However, none of the genes encoding glycosyltransferases (GTs) responsible for synthesizing xylan have been isolated and characterized in cotton fiber. In this study, we applied a bioinformatics approach and identified two putative GTs from cotton, designated GhGT43A1 and GhGT43C1, which belong to the CAZy GT43 family and are closely related to Arabidopsis IRX9 and IRX14, respectively. We show that GhGT43A1 is highly and preferentially expressed in 15 and 20 days post-anthesis (dpa) cotton fiber, whereas GhGT43C1 is ubiquitously expressed in most organs, with especially high expression in 15 dpa fiber and hypocotyl. Complementation analysis demonstrates that GhG43A1 and GhGT43C1 are orthologs of Arabidopsis IRX9 and IRX14, respectively. Furthermore, we show that overexpression of GhGT43A1 or GhGT43C1 in Arabidopsis results in increased xylan content. We also show that overexpression of GhGT43A1 or GhGT43C1 leads to more cellulose deposition. These findings suggest that GhGT43A1 and GhGT43C1 likely participate in xylan synthesis during fiber development.
authors.affiliation: Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan, 430079, China.
authors.forename: Long
authors.initials: L
authors.lastname: Li
authors.forename: Junfeng
authors.initials: J
authors.lastname: Huang
authors.forename: Lixia
authors.initials: L
authors.lastname: Qin
authors.forename: Yuying
authors.initials: Y
authors.lastname: Huang
authors.forename: Wei
authors.initials: W
authors.lastname: Zeng
authors.forename: Yue
authors.initials: Y
authors.lastname: Rao
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.forename: Xuebao
authors.initials: X
authors.lastname: Li
authors.forename: Wenliang
authors.initials: W
authors.lastname: Xu
mesh_terms: D017360:Arabidopsis / Q000201:enzymology; D002473:Cell Wall / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism; D032561:Cotton Fiber; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D016695:Glycosyltransferases / Q000302:isolation & purification / Q000378:metabolism*; D003368:Gossypium / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D009005:Monosaccharides / Q000032:analysis; D009154:Mutation / Q000235:genetics; D010368:Pectins / Q000378:metabolism; D010641:Phenotype; D010802:Phylogeny; D063245:Plant Development; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018547:Plant Stems / Q000033:anatomy & histology; D011134:Polysaccharides / Q000096:biosynthesis*; D014990:Xylans / Q000096:biosynthesis*
chemical_list: D009005:Monosaccharides; D010940:Plant Proteins; D011134:Polysaccharides; D014990:Xylans; C038910:glucuronoxylan; C007916:hemicellulose; D010368:Pectins; D002482:Cellulose; D016695:Glycosyltransferases