title: Gene coexpression network analysis of oil biosynthesis in an interspecific backcross of oil palm.
abstract: Global demand for vegetable oils is increasing at a dramatic rate, while our understanding of the regulation of oil biosynthesis in plants remains limited. To gain insights into the mechanisms that govern oil synthesis and fatty acid (FA) composition in the oil palm fruit, we used a multilevel approach combining gene coexpression analysis, quantification of allele-specific expression and joint multivariate analysis of transcriptomic and lipid data, in an interspecific backcross population between the African oil palm, Elaeis guineensis, and the American oil palm, Elaeis oleifera, which display contrasting oil contents and FA compositions. The gene coexpression network produced revealed tight transcriptional coordination of fatty acid synthesis (FAS) in the plastid with sugar sensing, plastidial glycolysis, transient starch storage and carbon recapture pathways. It also revealed a concerted regulation, along with FAS, of both the transfer of nascent FA to the endoplasmic reticulum, where triacylglycerol assembly occurs, and of the production of glycerol-3-phosphate, which provides the backbone of triacylglycerols. Plastid biogenesis and auxin transport were the two other biological processes most tightly connected to FAS in the network. In addition to WRINKLED1, a transcription factor (TF) known to activate FAS genes, two novel TFs, termed NF-YB-1 and ZFP-1, were found at the core of the FAS module. The saturated FA content of palm oil appeared to vary above all in relation to the level of transcripts of the gene coding for β-ketoacyl-acyl carrier protein synthase II. Our findings should facilitate the development of breeding and engineering strategies in this and other oil crops.
authors.affiliation: PalmElit SAS, Montferrier-sur-Lez, F-34980, France.
authors.forename: Chloé
authors.initials: C
authors.lastname: Guerin
authors.affiliation: IRD, UMR DIADE, 911 Av. Agropolis, Montpellier, 34394, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Joët
authors.affiliation: IRD, UMR DIADE, 911 Av. Agropolis, Montpellier, 34394, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Serret
authors.affiliation: IRD, UMR DIADE, 911 Av. Agropolis, Montpellier, 34394, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Lashermes
authors.affiliation: IRD, UMR DIADE, 911 Av. Agropolis, Montpellier, 34394, France.
authors.forename: Virginie
authors.initials: V
authors.lastname: Vaissayre
authors.affiliation: CIRAD, UMR DIADE, Montpellier, 34398, France.
authors.forename: Mawussé D T
authors.initials: MD
authors.lastname: Agbessi
authors.affiliation: CIRAD, UMR DIADE, Montpellier, 34398, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Beulé
authors.affiliation: MGX-Montpellier GenomiX, c/o Institut de Génomique Fonctionnelle, 141 Rue de la Cardonille, Montpellier Cedex 5, 34094, France.
authors.forename: Dany
authors.initials: D
authors.lastname: Severac
authors.affiliation: PalmElit SAS, Montferrier-sur-Lez, F-34980, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Amblard
authors.affiliation: IRD, UMR DIADE, 911 Av. Agropolis, Montpellier, 34394, France.
authors.forename: James
authors.initials: J
authors.lastname: Tregear
authors.affiliation: PalmElit SAS, Montferrier-sur-Lez, F-34980, France.
authors.forename: Tristan
authors.initials: T
authors.lastname: Durand-Gasselin
authors.affiliation: CIRAD, UMR DIADE, Montpellier, 34398, France.
authors.forename: Fabienne
authors.initials: F
authors.lastname: Morcillo
authors.affiliation: IRD, UMR DIADE, 911 Av. Agropolis, Montpellier, 34394, France. stephane.dussert@ird.fr.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Dussert
mesh_terms: D028023:Arecaceae / Q000235:genetics / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism; D005638:Fruit / Q000378:metabolism; D053263:Gene Regulatory Networks; D006019:Glycolysis; D019308:Palmitic Acid / Q000378:metabolism; D010938:Plant Oils / Q000378:metabolism*; D018087:Plastids / Q000378:metabolism
chemical_list: D005227:Fatty Acids; D010938:Plant Oils; D019308:Palmitic Acid
keywords: Elaeis guineensis; coexpression network; fatty acid; fruit; glycolysis; metabolism; oil palm; palmitic acid; plastid; starch