title: Endomembrane proteomics reveals putative enzymes involved in cell wall metabolism in wheat grain outer layers.
abstract: Cereal grain outer layers fulfil essential functions for the developing seed such as supplying energy and providing protection. In the food industry, the grain outer layers called 'the bran' is valuable since it is rich in dietary fibre and other beneficial nutriments. The outer layers comprise several tissues with a high content in cell wall material. The cell wall composition of the grain peripheral tissues was investigated with specific probes at a stage of active cell wall synthesis. Considerable wall diversity between cell types was revealed. To identify the cellular machinery involved in cell wall synthesis, a subcellular proteomic approach was used targeting the Golgi apparatus where most cell wall polysaccharides are synthesized. The tissues were dissected into outer pericarp and intermediate layers where 822 and 1304 proteins were identified respectively. Many carbohydrate-active enzymes were revealed: some in the two peripheral grain fractions, others only in one tissue. Several protein families specific to one fraction and with characterized homologs in other species might be related to the specific detection of a polysaccharide in a particular cell layer. This report provides new information on grain cell walls and its biosynthesis in the valuable outer tissues, which are poorly studied so far. A better understanding of the mechanisms controlling cell wall composition could help to improve several quality traits of cereal products (e.g. dietary fibre content, biomass conversion to biofuel).
authors.affiliation: INRA, UR1268 Biopolymères, Interactions Assemblages, F-44316 Nantes, France.
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Chateigner-Boutin
authors.affiliation: INRA, UR1268 Biopolymères, Interactions Assemblages, F-44316 Nantes, France.
authors.forename: Muhtadi
authors.initials: M
authors.lastname: Suliman
authors.affiliation: INRA, UR1268 Biopolymères, Interactions Assemblages, F-44316 Nantes, France.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Bouchet
authors.affiliation: INRA, UR1268 Biopolymères, Interactions Assemblages, F-44316 Nantes, France.
authors.forename: Camille
authors.initials: C
authors.lastname: Alvarado
authors.affiliation: INRA, UR1268 Biopolymères, Interactions Assemblages, F-44316 Nantes, France.
authors.forename: Virginie
authors.initials: V
authors.lastname: Lollier
authors.affiliation: INRA, UR1268 Biopolymères, Interactions Assemblages, F-44316 Nantes, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Rogniaux
authors.affiliation: INRA, UR1268 Biopolymères, Interactions Assemblages, F-44316 Nantes, France.
authors.forename: Fabienne
authors.initials: F
authors.lastname: Guillon
authors.affiliation: INRA, UR1268 Biopolymères, Interactions Assemblages, F-44316 Nantes, France colette.larre@nantes.inra.fr.
authors.forename: Colette
authors.initials: C
authors.lastname: Larré
mesh_terms: D002473:Cell Wall / Q000201:enzymology / Q000378:metabolism*; D004043:Dietary Fiber / Q000378:metabolism*; D010940:Plant Proteins / Q000032:analysis / Q000378:metabolism; D040901:Proteomics; D014908:Triticum / Q000201:enzymology / Q000378:metabolism*
chemical_list: D004043:Dietary Fiber; D010940:Plant Proteins
keywords: Carbohydrate active enzymes; Golgi apparatus; cell wall; proteomics; subcellular fraction; wheat grain outer layers.