title: ABCB1 and ABCB19 auxin transporters have synergistic effects on early and late Arabidopsis anther development.
abstract: Arabidopsis abcb1 abcb19 double mutants defective in the auxin transporters ABCB1/PGP1 and ABCB19/PGP19 are altered in stamen elongation, anther dehiscence and pollen maturation. To assess the contribution of these transporters to stamen development we performed phenotypic, histological analyses, and in situ hybridizations on abcb1 and abcb19 single mutant flowers. We found that pollen maturation and anther dehiscence are precocious in the abcb1 but not in the abcb19 mutant. Accordingly, endothecium lignification is altered only in abcb1 anthers. Both abcb1 and abcb1 abcb19 stamens also show altered early development, with asynchronous anther locules and a multilayer tapetum. DAPI staining showed that the timing of meiosis is asynchronous in abcb1 abcb19 anther locules, while only a small percentage of pollen grains are non-viable according to Alexander's staining. In agreement, TAM (TARDY ASYNCHRONOUS MEIOSIS), as well as BAM2 (BARELY ANY MERISTEM)-involved in tapetal cell development-are overexpressed in abcb1 abcb19 young flower buds. Correspondingly, ABCB1 and ABCB19 mRNA localization supports the observed phenotypes of abcb1 and abcb1 abcb19 mutant anthers. In conclusion, we provide evidence that auxin transport plays a significant role both in early and late stamen development: ABCB1 plays a major role during anther development, while ABCB19 has a synergistic role.
authors.affiliation: IBPM-CNR Institute of Molecular Biology and Pathology, National Research Council, Sapienza University of Rome, Rome, 00185, Italy.|Department of Biology and Biotechnology, Sapienza University of Rome, Rome, 00185, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Cecchetti
authors.affiliation: IBPM-CNR Institute of Molecular Biology and Pathology, National Research Council, Sapienza University of Rome, Rome, 00185, Italy.|Department of Biology and Biotechnology, Sapienza University of Rome, Rome, 00185, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Brunetti
authors.affiliation: IBPM-CNR Institute of Molecular Biology and Pathology, National Research Council, Sapienza University of Rome, Rome, 00185, Italy.|Department of Biology and Biotechnology, Sapienza University of Rome, Rome, 00185, Italy.
authors.forename: Nadia
authors.initials: N
authors.lastname: Napoli
authors.affiliation: Department of Environmental Biology, Sapienza University of Rome, Rome, 00185, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Fattorini
authors.affiliation: Department of Environmental Biology, Sapienza University of Rome, Rome, 00185, Italy.
authors.forename: Maria Maddalena
authors.initials: MM
authors.lastname: Altamura
authors.affiliation: Department of Biology and Biotechnology, Sapienza University of Rome, Rome, 00185, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Costantino
authors.affiliation: IBPM-CNR Institute of Molecular Biology and Pathology, National Research Council, Sapienza University of Rome, Rome, 00185, Italy.
authors.forename: Maura
authors.initials: M
authors.lastname: Cardarelli
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D049109:Cell Proliferation; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D008031:Lignin / Q000378:metabolism; D008540:Meiosis; D009154:Mutation / Q000235:genetics; D011058:Pollen / Q000166:cytology / Q000235:genetics / Q000254:growth & development*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: C532604:ABCB19 protein, Arabidopsis; D018528:ATP-Binding Cassette Transporters; C114215:ATPGP1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D012333:RNA, Messenger; D008031:Lignin
keywords: Anther development; Arabidopsis; auxin transport; endothecium lignification; tapetum differentiation