title: Species-specific interaction of EA1 with the maize pollen tube apex.
abstract: The egg apparatus-secreted polymorphic EA 1 peptide is required for micropylar pollen tube (PT) guidance in maize, the last step of the PT journey during the double fertilization process in flowering plants. In a recent study we have shown that maize PTs are attracted in vitro by EA 1 and that their growth is arrested at high peptide concentrations. Moreover, we have also shown that maize PTs are guided in vitro in a species-preferential manner to the micropylar opening of transgenic Arabidopsis ovules secreting the EA 1-GFP fusion protein. In support of these findings, we have improved the ligand-receptor labeling assay and report here that the EA 1 peptide interacts in vitro with the maize PT apex in a species-specific manner. Bound peptide gets internalized in large vesicles and is degraded. This finding indicates that the pollen tube remains sensitive to the attractant by its rapid internalization.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Uebler
authors.forename: Thomas
authors.initials: T
authors.lastname: Dresselhaus
authors.forename: Mihaela-Luiza
authors.initials: ML
authors.lastname: Márton
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D010455:Peptides / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D053205:Pollen Tube / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D013045:Species Specificity; D003313:Zea mays / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*
chemical_list: D010455:Peptides; D010940:Plant Proteins; D049452:Green Fluorescent Proteins