title: BURSTING POLLEN is required to organize the pollen germination plaque and pollen tube tip in Arabidopsis thaliana.
abstract: Pollen germination may occur via the so-called germination pores or directly through the pollen wall at the site of contact with the stigma. In this study, we addressed what processes take place during pollen hydration (i.e. before tube emergence), in a species with extra-poral pollen germination, Arabidopsis thaliana. A T-DNA mutant population was screened by segregation distortion analysis. Histological and electron microscopy techniques were applied to examine the wild-type and mutant phenotypes. Within 1 h of the start of pollen hydration, an intine-like structure consisting of cellulose, callose and at least partly de-esterified pectin was formed at the pollen wall. Subsequently, this 'germination plaque' gradually extended and opened up to provide passage for the cytoplasm into the emerging pollen tube. BURSTING POLLEN (BUP) was identified as a gene essential for the correct organization of this plaque and the tip of the pollen tube. BUP encodes a novel Golgi-located glycosyltransferase related to the glycosyltransferase 4 (GT4) subfamily which is conserved throughout the plant kingdom. Extra-poral pollen germination involves the development of a germination plaque and BUP defines the correct plastic-elastic properties of this plaque and the pollen tube tip by affecting pectin synthesis or delivery.
authors.affiliation: Department of Molecular Plant Physiology, Institute for Water and Wetland Research, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ, Nijmegen, the Netherlands.
authors.forename: Karin
authors.initials: K
authors.lastname: Hoedemaekers
authors.affiliation: Department of Molecular Plant Physiology, Institute for Water and Wetland Research, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ, Nijmegen, the Netherlands.
authors.forename: Jan
authors.initials: J
authors.lastname: Derksen
authors.affiliation: Department of Molecular Plant Physiology, Institute for Water and Wetland Research, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ, Nijmegen, the Netherlands.
authors.forename: Suzanne W
authors.initials: SW
authors.lastname: Hoogstrate
authors.affiliation: Department of Molecular Plant Physiology, Institute for Water and Wetland Research, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ, Nijmegen, the Netherlands.
authors.forename: Mieke
authors.initials: M
authors.lastname: Wolters-Arts
authors.affiliation: Department of Biology, University of Leicester, Leicester, LE1 7RH, UK.
authors.forename: Sung-Aeong
authors.initials: SA
authors.lastname: Oh
authors.affiliation: Department of Biology, University of Leicester, Leicester, LE1 7RH, UK.
authors.forename: David
authors.initials: D
authors.lastname: Twell
authors.affiliation: Department of Molecular Plant Physiology, Institute for Water and Wetland Research, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ, Nijmegen, the Netherlands.
authors.forename: Celestina
authors.initials: C
authors.lastname: Mariani
authors.affiliation: Department of Molecular Plant Physiology, Institute for Water and Wetland Research, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ, Nijmegen, the Netherlands.
authors.forename: Ivo
authors.initials: I
authors.lastname: Rieu
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D003593:Cytoplasm / Q000378:metabolism; D005936:Glucans / Q000378:metabolism; D016254:Mutagenesis, Insertional; D010368:Pectins / Q000378:metabolism*; D011058:Pollen / Q000235:genetics / Q000254:growth & development; D053205:Pollen Tube / Q000235:genetics / Q000254:growth & development; D054817:Pollination
chemical_list: D005936:Glucans; D010368:Pectins; C048306:callose
keywords: Arabidopsis thaliana; GT4-related glycosyltransferase; germination plaque; male fertility; pectin; pollen germination; pollen tube tip