title: Ups and downs in alfalfa: Proteomic and metabolic changes occurring in the growing stem.
abstract: The expanding interest for using lignocellulosic biomass in industry spurred the study of the mechanisms underlying plant cell-wall synthesis. Efforts using genetic approaches allowed the disentanglement of major steps governing stem fibre synthesis. Nonetheless, little is known about the relations between the stem maturation and the evolution of its proteome. During Medicago sativa L. maturation, the different internodes grow asynchronously allowing the discrimination of various developmental stages on a same stem. In this study, the proteome of three selected regions of the stem of alfalfa (apical, intermediate and basal) was analyzed and combined with a compositional analysis of the different stem parts. Interestingly, the apical and the median regions share many similarities: high abundance of chloroplast- and mitochondrial-related proteins together with the accumulation of proteins acting in the early steps of fibre production. In the mature basal region, forisomes and stress-related proteins accumulate. The RT-qPCR assessment of the expression of genes coding for members of the cellulose synthase family likewise indicates that fibres and the machinery responsible for the deposition of secondary cell walls are predominantly formed in the apical section. Altogether, this study reflects the metabolic change from the fibre production in the upper stem regions to the acquisition of defence-related functions in the fibrous basal part.
authors.affiliation: Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), 5, Avenue des Hauts-Fourneaux, L-4362 Esch/Alzette, Luxembourg; Groupe de Recherche en Physiologie végétale (GRPV), Earth and Life Institute Agronomy (ELI-A), Université catholique de Louvain, 5 (bte 7.07.13) Place Croix du Sud, B-1348 Louvain-la-Neuve, Belgium.
authors.forename: Bruno
authors.initials: B
authors.lastname: Printz
authors.affiliation: Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), 5, Avenue des Hauts-Fourneaux, L-4362 Esch/Alzette, Luxembourg.
authors.forename: Gea
authors.initials: G
authors.lastname: Guerriero
authors.affiliation: Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), 5, Avenue des Hauts-Fourneaux, L-4362 Esch/Alzette, Luxembourg. Electronic address: kjell.sergeant@list.lu.
authors.forename: Kjell
authors.initials: K
authors.lastname: Sergeant
authors.affiliation: Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), 5, Avenue des Hauts-Fourneaux, L-4362 Esch/Alzette, Luxembourg.
authors.forename: Jenny
authors.initials: J
authors.lastname: Renaut
authors.affiliation: Groupe de Recherche en Physiologie végétale (GRPV), Earth and Life Institute Agronomy (ELI-A), Université catholique de Louvain, 5 (bte 7.07.13) Place Croix du Sud, B-1348 Louvain-la-Neuve, Belgium.
authors.forename: Stanley
authors.initials: S
authors.lastname: Lutts
authors.affiliation: Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), 5, Avenue des Hauts-Fourneaux, L-4362 Esch/Alzette, Luxembourg.
authors.forename: Jean-Francois
authors.initials: JF
authors.lastname: Hausman
mesh_terms: D005075:Biological Evolution; D002736:Chloroplasts / Q000235:genetics; D016000:Cluster Analysis; D015180:Electrophoresis, Gel, Two-Dimensional; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism; D000455:Medicago sativa / Q000166:cytology / Q000201:enzymology / Q000254:growth & development* / Q000378:metabolism*; D061848:Optical Imaging; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018547:Plant Stems / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*; D020543:Proteome / Q000378:metabolism*; D040901:Proteomics; D019265:Spectroscopy, Near-Infrared
chemical_list: D010940:Plant Proteins; D020543:Proteome; D005964:Glucosyltransferases; C478648:cellulose synthase
keywords: Cell wall; Cellulose synthase; DIGE; Fibres; Proteomics; Stem