title: Seed germination is blocked in Arabidopsis putative vacuolar sorting receptor (atbp80) antisense transformants.
abstract: The membrane receptor protein from pea, peabp80, has been shown to function by in vitro binding studies, and in vivo in yeast mutant, as a vacuolar sorting receptor (VSR). Families of proteins with homology to peabp80 have been identified in many plants including Arabidopsis: The family of membrane receptors, atbp80a-f (Arabidopsis thaliana binding protein 80 kDa) is highly homologous to peabp80 and may also function as vacuolar sorting receptors. Interactions with vacuolar sorting determinants have been shown only in vitro for atbp80b. In this paper, atbp80b was over- and under-expressed in Arabidopsis. Transgenic plants that over-expressed atbp80b showed no visible phenotype. However, antisense transformants were defective in germination. In non-germinating antisense transformants the embryo appeared to be normal, but, using several methods, it was not possible to rescue the non-germinating seeds, indicating that the mechanisms were probably independent of a seed-coat-imposed inhibition. To make a correlation between the lack of germination and gene expression, transcription analysis of all atbp80 genes was performed in the non-germinating antisense seeds indicating that all the normally transcribed genes were not detected. Then, a gene expression study of atbp80s genes was carried-out following seed imbibition and in various organs during wild-type plant development showing that all the genes from the family were transcribed and differentially expressed.
authors.affiliation: UMR 5546 CNRS/Université Paul Sabatier, Pôle de Biotechnologies Végétales, 24 Chemin de Borde Rouge, BP 17 Auzeville, 31326 Castanet-Tolosan, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Laval
authors.forename: Frédéric
authors.initials: F
authors.lastname: Masclaux
authors.forename: Arnaud
authors.initials: A
authors.lastname: Serin
authors.forename: Marguerite
authors.initials: M
authors.lastname: Carrière
authors.forename: Caroline
authors.initials: C
authors.lastname: Roldan
authors.forename: Martine
authors.initials: M
authors.lastname: Devic
authors.forename: Rafael F
authors.initials: RF
authors.lastname: Pont-Lezica
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Galaud
mesh_terms: D016375:Antisense Elements (Genetics) / Q000235:genetics; D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D015870:Gene Expression; D018525:Germination / Q000235:genetics / Q000502:physiology*; D030821:Plants, Genetically Modified; D014170:Transformation, Genetic
chemical_list: D016375:Antisense Elements (Genetics); D029681:Arabidopsis Proteins; C106564:ELP protein, Arabidopsis