title: Essential role of the V-ATPase in male gametophyte development.
abstract: Intracellular pH homeostasis is a prerequisite for biological processes and requires the action of proton pumps. The vacuolar H(+)-ATPase (V-ATPase) is involved in regulating pH in endomembrane compartments of all eukaryotic cells. In plants, there is an additional endomembrane proton pump, H(+)-pyrophosphatase (H(+)-PPase). However, the relative roles of the two types of pumps in endomembrane acidification and energization of secondary active transport are unclear. Here, we show that a strong T-DNA insertion allele of VHA-A, the single copy gene encoding the catalytic subunit of the Arabidopsis V-ATPase, causes complete male and partial female gametophytic lethality. Severe changes in the morphology of Golgi stacks and Golgi-derived vesicles in male gametophytes are the first visible symptoms of cell degeneration leading to a failure to develop mature pollen. Similar effects on Golgi morphology were observed in pollen tubes when growth was blocked by Concanamycin A, a specific V-ATPase inhibitor. Taken together, our results suggests that V-ATPase function is essential for Golgi organization and development of the male gametophyte.
authors.affiliation: ZMBP-Plant Physiology, Universität Tübingen, Auf der Morgenstelle 1, 72076 Tübingen, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Dettmer
authors.forename: Daniel
authors.initials: D
authors.lastname: Schubert
authors.forename: Olga
authors.initials: O
authors.lastname: Calvo-Weimar
authors.forename: York-Dieter
authors.initials: YD
authors.lastname: Stierhof
authors.forename: Renate
authors.initials: R
authors.lastname: Schmidt
authors.forename: Karin
authors.initials: K
authors.lastname: Schumacher
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics / Q000302:isolation & purification; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D035264:Flowers / Q000648:ultrastructure; D005718:Gametogenesis; D005816:Genetic Complementation Test; D006056:Golgi Apparatus / Q000201:enzymology; D006863:Hydrogen-Ion Concentration; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D025262:Vacuolar Proton-Translocating ATPases / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; C036483:T-DNA; D025262:Vacuolar Proton-Translocating ATPases