title: Evaluation of the presence of arabinogalactan proteins and pectins during Quercus suber male gametogenesis.
abstract: OBJECTIVE
  Quercus suber (cork oak) is a dominant tree of the Fagaceae in forests of the south-west Iberian Peninsula. It is monoecious with a long progamic phase that provides a comprehensive system for comparative studies in development and sexual reproduction. In this study the distribution of arabinogalactan protein (AGPs) and pectin epitopes in anthers of Q. suber was assessed to map these hydroxyproline-rich glycoproteins and the galacturonate-rich acidic polysaccharides during pollen development. Methods Immunolocalization in male flowers was performed with a set of monoclonal antibodies directed against the carbohydrate moiety that recognizes AGPs and pectins. To identify AGP genes involved in cork oak male flower development, a search was conducted for annotated AGP genes in the available transcriptome data of the Cork Oak EST Consortium database (www.corkoakdb.org).
  
  
  RESULTS
  Ubiquitous labelling in all cell types was obtained with anti-homogalacturan antibodies for methyl-esterified pectins. In contrast, the antibody that labelled non-methyl-esterified homogalacturans had a preferential presence in microsporocyte cells walls at the beginning of pollen development. Intense labelling was obtained with anti-AGP antibodies both in the tapetum and in the intine wall near the pollen apertures and later in the generative cell wall and vegetative cell. Evaluation of the putative AGPs highly expressed in the male gametophyte was achieved by quantitative RT-PCR analysis in male and female cork oak flowers.
  
  
  CONCLUSIONS
  Four putative AGP genes were identified that are preferentially expressed in the male flower compared with the female flower. The putative Arabidopsis thaliana orthologues of these genes are associated with preferential expression in pollen, suggesting that the AGPs probably play a significant role in cork oak reproduction.
authors.affiliation: Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal, Center for Biodiversity, Functional & Integrative Genomics (BioFIG) and Plant Functional Biology Centre, Universidade do Minho, Campus de Gualtar, Braga 4710-057, Portugal Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal, Center for Biodiversity, Functional & Integrative Genomics (BioFIG) and Plant Functional Biology Centre, Universidade do Minho, Campus de Gualtar, Braga 4710-057, Portugal.
authors.forename: Mário Luís
authors.initials: ML
authors.lastname: Costa
authors.affiliation: Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal, Center for Biodiversity, Functional & Integrative Genomics (BioFIG) and Plant Functional Biology Centre, Universidade do Minho, Campus de Gualtar, Braga 4710-057, Portugal Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal, Center for Biodiversity, Functional & Integrative Genomics (BioFIG) and Plant Functional Biology Centre, Universidade do Minho, Campus de Gualtar, Braga 4710-057, Portugal.
authors.forename: Rómulo
authors.initials: R
authors.lastname: Sobral
authors.affiliation: Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal, Center for Biodiversity, Functional & Integrative Genomics (BioFIG) and Plant Functional Biology Centre, Universidade do Minho, Campus de Gualtar, Braga 4710-057, Portugal Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal, Center for Biodiversity, Functional & Integrative Genomics (BioFIG) and Plant Functional Biology Centre, Universidade do Minho, Campus de Gualtar, Braga 4710-057, Portugal.
authors.forename: Maria Manuela
authors.initials: MM
authors.lastname: Ribeiro Costa
authors.affiliation: Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal, Center for Biodiversity, Functional & Integrative Genomics (BioFIG) and Plant Functional Biology Centre, Universidade do Minho, Campus de Gualtar, Braga 4710-057, Portugal Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal, Center for Biodiversity, Functional & Integrative Genomics (BioFIG) and Plant Functional Biology Centre, Universidade do Minho, Campus de Gualtar, Braga 4710-057, Portugal.
authors.forename: Maria Isabel
authors.initials: MI
authors.lastname: Amorim
authors.affiliation: Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal, Center for Biodiversity, Functional & Integrative Genomics (BioFIG) and Plant Functional Biology Centre, Universidade do Minho, Campus de Gualtar, Braga 4710-057, Portugal Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal, Center for Biodiversity, Functional & Integrative Genomics (BioFIG) and Plant Functional Biology Centre, Universidade do Minho, Campus de Gualtar, Braga 4710-057, Portugal scoimbra@fc.up.pt.
authors.forename: Sílvia
authors.initials: S
authors.lastname: Coimbra
mesh_terms: D000595:Amino Acid Sequence; D000939:Epitopes / Q000235:genetics / Q000378:metabolism; D035264:Flowers / Q000254:growth & development / Q000378:metabolism; D008969:Molecular Sequence Data; D009088:Mucoproteins / Q000235:genetics* / Q000378:metabolism; D009928:Organ Specificity; D010368:Pectins / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011058:Pollen / Q000254:growth & development; D029963:Quercus / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D000939:Epitopes; D009088:Mucoproteins; D010940:Plant Proteins; C006619:arabinogalactan proteins; D010368:Pectins
keywords: AGP; Arabidopsis thaliana; Quercus suber; arabinogalactan proteins; cork oak; male gametophyte; microsporocyte cells walls; pectins; pollen development