title: The endoplasmic reticulum is the main membrane source for biogenesis of the lytic vacuole in Arabidopsis.
abstract: Vacuoles are multifunctional organelles essential for the sessile lifestyle of plants. Despite their central functions in cell growth, storage, and detoxification, knowledge about mechanisms underlying their biogenesis and associated protein trafficking pathways remains limited. Here, we show that in meristematic cells of the Arabidopsis thaliana root, biogenesis of vacuoles as well as the trafficking of sterols and of two major tonoplast proteins, the vacuolar H(+)-pyrophosphatase and the vacuolar H(+)-adenosinetriphosphatase, occurs independently of endoplasmic reticulum (ER)-Golgi and post-Golgi trafficking. Instead, both pumps are found in provacuoles that structurally resemble autophagosomes but are not formed by the core autophagy machinery. Taken together, our results suggest that vacuole biogenesis and trafficking of tonoplast proteins and lipids can occur directly from the ER independent of Golgi function.
authors.affiliation: Centre for Organismal Studies, Plant Developmental Biology, University of Heidelberg, 69120 Heidelberg, Germany.
authors.forename: Corrado
authors.initials: C
authors.lastname: Viotti
authors.forename: Falco
authors.initials: F
authors.lastname: Krüger
authors.forename: Melanie
authors.initials: M
authors.lastname: Krebs
authors.forename: Christoph
authors.initials: C
authors.lastname: Neubert
authors.forename: Fabian
authors.initials: F
authors.lastname: Fink
authors.forename: Upendo
authors.initials: U
authors.lastname: Lupanga
authors.forename: David
authors.initials: D
authors.lastname: Scheuring
authors.forename: Yohann
authors.initials: Y
authors.lastname: Boutté
authors.forename: Márcia
authors.initials: M
authors.lastname: Frescatada-Rosa
authors.forename: Susanne
authors.initials: S
authors.lastname: Wolfenstetter
authors.forename: Norbert
authors.initials: N
authors.lastname: Sauer
authors.forename: Stefan
authors.initials: S
authors.lastname: Hillmer
authors.forename: Markus
authors.initials: M
authors.lastname: Grebe
authors.forename: Karin
authors.initials: K
authors.lastname: Schumacher
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D017930:Genes, Reporter; D006056:Golgi Apparatus / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D043564:Inorganic Pyrophosphatase / Q000235:genetics / Q000378:metabolism; D050356:Lipid Metabolism; D018519:Meristem / Q000201:enzymology / Q000235:genetics / Q000502:physiology / Q000648:ultrastructure; D018517:Plant Roots / Q000201:enzymology / Q000235:genetics / Q000502:physiology / Q000648:ultrastructure; D030821:Plants, Genetically Modified; D021381:Protein Transport; D011993:Recombinant Fusion Proteins; D013261:Sterols / Q000378:metabolism; D014617:Vacuoles / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D011993:Recombinant Fusion Proteins; D013261:Sterols; D000251:Adenosine Triphosphatases; D043564:Inorganic Pyrophosphatase