title: Arabidopsis galacturonosyltransferase (GAUT) 13 and GAUT14 have redundant functions in pollen tube growth.
abstract: Cell wall biosynthesis is indispensable for pollen tube growth. Despite its importance to sexual reproduction, the molecular mechanisms of pollen tube wall biosynthesis remain poorly understood. Here, we report functional characterization of two putative Arabidopsis galacturonosyltransferase genes, GAUT13 and GAUT14, which are essential for pollen tube growth. GAUT13 and GAUT14 encode the proteins that share a high amino acid sequence identity and are located in the Golgi apparatus. The T-DNA insertion mutants, gaut13 and gaut14, did not exhibit any observable defects, but the gaut13 gaut14 double mutants were defective in pollen tube growth; 35.2-37.3% pollen tubes in the heterozygous double mutants were swollen and defective in elongation. The outer layer of the cell wall did not appear distinctly fibrillar in the double mutant pollen tubes. Furthermore, distribution of homogalacturonan labeled with JIM5 and JIM7 in the double mutant pollen tube wall was significantly altered compared to wild-type. Our results suggest that GAUT13 and GAUT14 function redundantly in pollen tube growth, possibly through participation in pectin biosynthesis of the pollen tube wall.
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: You-Qun
authors.initials: YQ
authors.lastname: Wang
authors.forename: Yang-Yang
authors.initials: YY
authors.lastname: Liu
authors.forename: Jing-Xin
authors.initials: JX
authors.lastname: Wang
authors.forename: Xue-Qin
authors.initials: XQ
authors.lastname: Zhang
authors.forename: De
authors.initials: D
authors.lastname: Ye
authors.forename: Li-Qun
authors.initials: LQ
authors.lastname: Chen
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D014453:Glucuronosyltransferase / Q000235:genetics / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism; D009154:Mutation; D010368:Pectins / Q000096:biosynthesis; D010641:Phenotype; D053205:Pollen Tube / Q000254:growth & development*; D021381:Protein Transport
chemical_list: D029681:Arabidopsis Proteins; D010368:Pectins; D014453:Glucuronosyltransferase; C586031:galacturonosyltransferase 13, Arabidopsis thaliana; C586030:galacturonosyltransferase 14, Arabidopsis thaliana
keywords: Arabidopsis; GAUT13; GAUT14; cell wall; pectin; pollen tube.