title: The Role of LORELEI in Pollen Tube Reception at the Interface of the Synergid Cell and Pollen Tube Requires the Modified Eight-Cysteine Motif and the Receptor-Like Kinase FERONIA.
abstract: In angiosperms, pollen tube reception by the female gametophyte is required for sperm release and double fertilization. In Arabidopsis thaliana lorelei (lre) mutants, pollen tube reception fails in most female gametophytes, which thus remain unfertilized. LRE encodes a putative glycosylphosphatidylinositol (GPI)-anchored surface protein with a modified eight-cysteine motif (M8CM). LRE fused to citrine yellow fluorescent protein (LRE-cYFP) remains functional and localizes to the synergid plasma membrane-rich filiform apparatus, the first point of contact between the pollen tube and the female gametophyte. Structure-function analysis using LRE-cYFP showed that the role of LRE in pollen tube reception requires the M8CM, but not the domains required for GPI anchor addition. Consistently, LRE-cYFP-TM, where GPI anchor addition domains were replaced with a single-pass transmembrane domain, fully complemented the pollen tube reception defect in lre-7 female gametophytes. Ectopically expressed and delivered LRE-cYFP from pollen tubes could non-cell-autonomously complement the pollen tube reception defect in lre female gametophytes, only if they expressed FERONIA. Additionally, pollen tube-expressing LRE variants lacking domains critical for GPI anchor addition also rescued lre female gametophyte function. Therefore, LRE and FERONIA jointly function in pollen tube reception at the interface of the synergid cell and pollen tube.
authors.affiliation: School of Plant Sciences, University of Arizona, Tucson, Arizona 85721.
authors.forename: Xunliang
authors.identifier: 0000-0003-0445-0343
authors.initials: X
authors.lastname: Liu
authors.affiliation: School of Plant Sciences, University of Arizona, Tucson, Arizona 85721.
authors.forename: Claudia
authors.identifier: 0000-0002-5164-1356
authors.initials: C
authors.lastname: Castro
authors.affiliation: School of Plant Sciences, University of Arizona, Tucson, Arizona 85721.
authors.forename: Yanbing
authors.identifier: 0000-0002-9064-8104
authors.initials: Y
authors.lastname: Wang
authors.affiliation: School of Plant Sciences, University of Arizona, Tucson, Arizona 85721.
authors.forename: Jennifer
authors.identifier: 0000-0003-1019-2416
authors.initials: J
authors.lastname: Noble
authors.affiliation: School of Plant Sciences, University of Arizona, Tucson, Arizona 85721.
authors.forename: Nathaniel
authors.identifier: 0000-0003-3922-2228
authors.initials: N
authors.lastname: Ponvert
authors.affiliation: Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996.
authors.forename: Mark
authors.identifier: 0000-0002-4463-3382
authors.initials: M
authors.lastname: Bundy
authors.affiliation: School of Plant Sciences, University of Arizona, Tucson, Arizona 85721.
authors.forename: Chelsea
authors.initials: C
authors.lastname: Hoel
authors.affiliation: Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996.
authors.forename: Elena
authors.initials: E
authors.lastname: Shpak
authors.affiliation: School of Plant Sciences, University of Arizona, Tucson, Arizona 85721 rpalaniv@email.arizona.edu.
authors.forename: Ravishankar
authors.identifier: 0000-0003-0564-5564
authors.initials: R
authors.lastname: Palanivelu
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D056771:Ovule / Q000235:genetics / Q000378:metabolism*; D010770:Phosphotransferases / Q000235:genetics / Q000378:metabolism*; D053205:Pollen Tube / Q000378:metabolism* / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases
chemical_list: D029681:Arabidopsis Proteins; D008562:Membrane Glycoproteins; D010770:Phosphotransferases; C560561:LORELEI protein, Arabidopsis; C522131:At3g51550 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases