title: The Glycerol-3-Phosphate Acyltransferase GPAT6 from Tomato Plays a Central Role in Fruit Cutin Biosynthesis.
abstract: The thick cuticle covering and embedding the epidermal cells of tomato (Solanum lycopersicum) fruit acts not only as a protective barrier against pathogens and water loss but also influences quality traits such as brightness and postharvest shelf-life. In a recent study, we screened a mutant collection of the miniature tomato cultivar Micro-Tom and isolated several glossy fruit mutants in which the abundance of cutin, the polyester component of the cuticle, was strongly reduced. We employed a newly developed mapping-by-sequencing strategy to identify the causal mutation underlying the cutin deficiency in a mutant thereafter named gpat6-a (for glycerol-3-phosphate acyltransferase6). To this end, a backcross population (BC1F2) segregating for the glossy trait was phenotyped. Individuals displaying either a wild-type or a glossy fruit trait were then pooled into bulked populations and submitted to whole-genome sequencing prior to mutation frequency analysis. This revealed that the causal point mutation in the gpat6-a mutant introduces a charged amino acid adjacent to the active site of a GPAT6 enzyme. We further showed that this mutation completely abolished the GPAT activity of the recombinant protein. The gpat6-a mutant showed perturbed pollen formation but, unlike a gpat6 mutant of Arabidopsis (Arabidopsis thaliana), was not male sterile. The most striking phenotype was observed in the mutant fruit, where cuticle thickness, composition, and properties were altered. RNA sequencing analysis highlighted the main processes and pathways that were affected by the mutation at the transcriptional level, which included those associated with lipid, secondary metabolite, and cell wall biosynthesis.
authors.affiliation: Unité Mixte de Recherche 1332 BFP, Institut National de la Recherche Agronomique, Université de Bordeaux, F-33140 Villenave d'Ornon, France (J.P., C.B., J.-P.M., F.W.J.T., C.R.);Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853 (L.B.B.M., E.A.F., J.K.C.R.);Laboratoire de Biogénèse Membranaire, Université de Bordeaux, Unité Mixte de Recherche 5200, F-33000 Bordeaux, France (J.J., F.D.); andLaboratoire de Biogénèse Membranaire, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5200, F-33000 Bordeaux, France (J.J., F.D.).
authors.forename: Johann
authors.initials: J
authors.lastname: Petit
authors.affiliation: Unité Mixte de Recherche 1332 BFP, Institut National de la Recherche Agronomique, Université de Bordeaux, F-33140 Villenave d'Ornon, France (J.P., C.B., J.-P.M., F.W.J.T., C.R.);Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853 (L.B.B.M., E.A.F., J.K.C.R.);Laboratoire de Biogénèse Membranaire, Université de Bordeaux, Unité Mixte de Recherche 5200, F-33000 Bordeaux, France (J.J., F.D.); andLaboratoire de Biogénèse Membranaire, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5200, F-33000 Bordeaux, France (J.J., F.D.).
authors.forename: Cécile
authors.identifier: 0000-0001-6460-4637
authors.initials: C
authors.lastname: Bres
authors.affiliation: Unité Mixte de Recherche 1332 BFP, Institut National de la Recherche Agronomique, Université de Bordeaux, F-33140 Villenave d'Ornon, France (J.P., C.B., J.-P.M., F.W.J.T., C.R.);Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853 (L.B.B.M., E.A.F., J.K.C.R.);Laboratoire de Biogénèse Membranaire, Université de Bordeaux, Unité Mixte de Recherche 5200, F-33000 Bordeaux, France (J.J., F.D.); andLaboratoire de Biogénèse Membranaire, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5200, F-33000 Bordeaux, France (J.J., F.D.).
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Mauxion
authors.affiliation: Unité Mixte de Recherche 1332 BFP, Institut National de la Recherche Agronomique, Université de Bordeaux, F-33140 Villenave d'Ornon, France (J.P., C.B., J.-P.M., F.W.J.T., C.R.);Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853 (L.B.B.M., E.A.F., J.K.C.R.);Laboratoire de Biogénèse Membranaire, Université de Bordeaux, Unité Mixte de Recherche 5200, F-33000 Bordeaux, France (J.J., F.D.); andLaboratoire de Biogénèse Membranaire, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5200, F-33000 Bordeaux, France (J.J., F.D.).
authors.forename: Fabienne Wong Jun
authors.initials: FW
authors.lastname: Tai
authors.affiliation: Unité Mixte de Recherche 1332 BFP, Institut National de la Recherche Agronomique, Université de Bordeaux, F-33140 Villenave d'Ornon, France (J.P., C.B., J.-P.M., F.W.J.T., C.R.);Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853 (L.B.B.M., E.A.F., J.K.C.R.);Laboratoire de Biogénèse Membranaire, Université de Bordeaux, Unité Mixte de Recherche 5200, F-33000 Bordeaux, France (J.J., F.D.); andLaboratoire de Biogénèse Membranaire, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5200, F-33000 Bordeaux, France (J.J., F.D.).
authors.forename: Laetitia B B
authors.identifier: 0000-0002-6921-7246
authors.initials: LB
authors.lastname: Martin
authors.affiliation: Unité Mixte de Recherche 1332 BFP, Institut National de la Recherche Agronomique, Université de Bordeaux, F-33140 Villenave d'Ornon, France (J.P., C.B., J.-P.M., F.W.J.T., C.R.);Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853 (L.B.B.M., E.A.F., J.K.C.R.);Laboratoire de Biogénèse Membranaire, Université de Bordeaux, Unité Mixte de Recherche 5200, F-33000 Bordeaux, France (J.J., F.D.); andLaboratoire de Biogénèse Membranaire, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5200, F-33000 Bordeaux, France (J.J., F.D.).
authors.forename: Eric A
authors.initials: EA
authors.lastname: Fich
authors.affiliation: Unité Mixte de Recherche 1332 BFP, Institut National de la Recherche Agronomique, Université de Bordeaux, F-33140 Villenave d'Ornon, France (J.P., C.B., J.-P.M., F.W.J.T., C.R.);Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853 (L.B.B.M., E.A.F., J.K.C.R.);Laboratoire de Biogénèse Membranaire, Université de Bordeaux, Unité Mixte de Recherche 5200, F-33000 Bordeaux, France (J.J., F.D.); andLaboratoire de Biogénèse Membranaire, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5200, F-33000 Bordeaux, France (J.J., F.D.).
authors.forename: Jérôme
authors.initials: J
authors.lastname: Joubès
authors.affiliation: Unité Mixte de Recherche 1332 BFP, Institut National de la Recherche Agronomique, Université de Bordeaux, F-33140 Villenave d'Ornon, France (J.P., C.B., J.-P.M., F.W.J.T., C.R.);Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853 (L.B.B.M., E.A.F., J.K.C.R.);Laboratoire de Biogénèse Membranaire, Université de Bordeaux, Unité Mixte de Recherche 5200, F-33000 Bordeaux, France (J.J., F.D.); andLaboratoire de Biogénèse Membranaire, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5200, F-33000 Bordeaux, France (J.J., F.D.).
authors.forename: Jocelyn K C
authors.identifier: 0000-0003-1881-9631
authors.initials: JK
authors.lastname: Rose
authors.affiliation: Unité Mixte de Recherche 1332 BFP, Institut National de la Recherche Agronomique, Université de Bordeaux, F-33140 Villenave d'Ornon, France (J.P., C.B., J.-P.M., F.W.J.T., C.R.);Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853 (L.B.B.M., E.A.F., J.K.C.R.);Laboratoire de Biogénèse Membranaire, Université de Bordeaux, Unité Mixte de Recherche 5200, F-33000 Bordeaux, France (J.J., F.D.); andLaboratoire de Biogénèse Membranaire, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5200, F-33000 Bordeaux, France (J.J., F.D.).
authors.forename: Frédéric
authors.identifier: 0000-0002-0183-7000
authors.initials: F
authors.lastname: Domergue
authors.affiliation: Unité Mixte de Recherche 1332 BFP, Institut National de la Recherche Agronomique, Université de Bordeaux, F-33140 Villenave d'Ornon, France (J.P., C.B., J.-P.M., F.W.J.T., C.R.);Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853 (L.B.B.M., E.A.F., J.K.C.R.);Laboratoire de Biogénèse Membranaire, Université de Bordeaux, Unité Mixte de Recherche 5200, F-33000 Bordeaux, France (J.J., F.D.); andLaboratoire de Biogénèse Membranaire, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5200, F-33000 Bordeaux, France (J.J., F.D.) christophe.rothan@bordeaux.inra.fr.
authors.forename: Christophe
authors.initials: C
authors.lastname: Rothan
mesh_terms: D000595:Amino Acid Sequence; D002874:Chromosome Mapping; D005638:Fruit / Q000033:anatomy & histology / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D005992:Glycerol-3-Phosphate O-Acyltransferase / Q000235:genetics / Q000378:metabolism*; D018551:Solanum lycopersicum / Q000033:anatomy & histology / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D008563:Membrane Lipids / Q000378:metabolism*; D008958:Models, Molecular; D009154:Mutation; D010641:Phenotype; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011058:Pollen / Q000033:anatomy & histology / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D011994:Recombinant Proteins; D016415:Sequence Alignment; D017423:Sequence Analysis, RNA
chemical_list: D008563:Membrane Lipids; D010940:Plant Proteins; D011994:Recombinant Proteins; C000521:cutin; D005992:Glycerol-3-Phosphate O-Acyltransferase