title: Induced mutations in tomato SlExp1 alter cell wall metabolism and delay fruit softening.
abstract: Fruit ripening and softening are key traits for many fleshy fruit. Since cell walls play a key role in the softening process, expansins have been investigated to control fruit over ripening and deterioration. In tomato, expression of Expansin 1 gene, SlExp1, during fruit ripening was associated with fruit softening. To engineer tomato plants with long shelf life, we screened for mutant plants impaired in SlExp1 function. Characterization of two induced mutations, Slexp1-6_W211S, and Slexp1-7_Q213Stop, showed that SlExp1 loss of function leads to enhanced fruit firmness and delayed fruit ripening. Analysis of cell wall polysaccharide composition of Slexp1-7_Q213Stop mutant pointed out significant differences for uronic acid, neutral sugar and total sugar contents. Hemicelluloses chemistry analysis by endo-β-1,4-d-glucanase hydrolysis and MALDI-TOF spectrometry revealed that xyloglucan structures were affected in the fruit pericarp of Slexp1-7_Q213Stop mutant. Altogether, these results demonstrated that SlExp1 loss of function mutants yield firmer and late ripening fruits through modification of hemicellulose structure. These SlExp1 mutants represent good tools for breeding long shelf life tomato lines with contrasted fruit texture as well as for the understanding of the cell wall polysaccharide assembly dynamics in fleshy fruits.
authors.affiliation: INRA, UMR1403, IPS2, CNRS-UMR 9213, Université Paris-Sud, Université d'Evry, Université Paris-Diderot, Sorbonne Paris-Cité, 2 rue Gaston Crémieux, 91057 Evry, France; ALSIA, Centro Ricerche Metapontum Agrobios, SS Jonica 106 Km 448.2, 75012 Metaponto (MT), Italy. Electronic address: sminoia@hotmail.com.
authors.forename: Silvia
authors.initials: S
authors.lastname: Minoia
authors.affiliation: INRA, UMR1403, IPS2, CNRS-UMR 9213, Université Paris-Sud, Université d'Evry, Université Paris-Diderot, Sorbonne Paris-Cité, 2 rue Gaston Crémieux, 91057 Evry, France. Electronic address: boualem@evry.inra.fr.
authors.forename: Adnane
authors.initials: A
authors.lastname: Boualem
authors.affiliation: INRA, UMR1403, IPS2, CNRS-UMR 9213, Université Paris-Sud, Université d'Evry, Université Paris-Diderot, Sorbonne Paris-Cité, 2 rue Gaston Crémieux, 91057 Evry, France. Electronic address: marcel@evry.inra.fr.
authors.forename: Fabien
authors.initials: F
authors.lastname: Marcel
authors.affiliation: INRA, UMR1403, IPS2, CNRS-UMR 9213, Université Paris-Sud, Université d'Evry, Université Paris-Diderot, Sorbonne Paris-Cité, 2 rue Gaston Crémieux, 91057 Evry, France. Electronic address: troadec@evry.inra.fr.
authors.forename: Christelle
authors.initials: C
authors.lastname: Troadec
authors.affiliation: INRA, UR1268 Biopolymers, Interactions and Assemblies, rue de la Géraudière, F-44316 Nantes, France. Electronic address: Bernard.Quemener@nantes.inra.fr.
authors.forename: Bernard
authors.initials: B
authors.lastname: Quemener
authors.affiliation: ALSIA, Centro Ricerche Metapontum Agrobios, SS Jonica 106 Km 448.2, 75012 Metaponto (MT), Italy. Electronic address: francesco.cellini@alsia.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Cellini
authors.affiliation: ALSIA, Centro Ricerche Metapontum Agrobios, SS Jonica 106 Km 448.2, 75012 Metaponto (MT), Italy. Electronic address: angelo.petrozza@alsia.it.
authors.forename: Angelo
authors.initials: A
authors.lastname: Petrozza
authors.affiliation: INRA, UR1268 Biopolymers, Interactions and Assemblies, rue de la Géraudière, F-44316 Nantes, France. Electronic address: Jacqueline.Vigouroux@nantes.inra.fr.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Vigouroux
authors.affiliation: INRA, UR1268 Biopolymers, Interactions and Assemblies, rue de la Géraudière, F-44316 Nantes, France. Electronic address: marc.lahaye@nantes.inra.fr.
authors.forename: Marc
authors.initials: M
authors.lastname: Lahaye
authors.affiliation: ALSIA, Centro Ricerche Metapontum Agrobios, SS Jonica 106 Km 448.2, 75012 Metaponto (MT), Italy. Electronic address: filomena.carriero@alsia.it.
authors.forename: Filomena
authors.initials: F
authors.lastname: Carriero
authors.affiliation: INRA, UMR1403, IPS2, CNRS-UMR 9213, Université Paris-Sud, Université d'Evry, Université Paris-Diderot, Sorbonne Paris-Cité, 2 rue Gaston Crémieux, 91057 Evry, France. Electronic address: bendahm@evry.inra.fr.
authors.forename: Abdelhafid
authors.initials: A
authors.lastname: Bendahmane
mesh_terms: D002473:Cell Wall / Q000235:genetics* / Q000378:metabolism; D018360:Crystallography, X-Ray; D005638:Fruit / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D044643:Glucan 1,4-beta-Glucosidase / Q000378:metabolism; D005936:Glucans / Q000378:metabolism; D018551:Solanum lycopersicum / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D008958:Models, Molecular; D016296:Mutagenesis; D009154:Mutation; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism; D017434:Protein Structure, Tertiary; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013997:Time Factors; D014574:Uronic Acids / Q000378:metabolism; D014990:Xylans / Q000378:metabolism
chemical_list: D005936:Glucans; D010940:Plant Proteins; D011134:Polysaccharides; D014574:Uronic Acids; D014990:Xylans; C029353:xyloglucan; C007916:hemicellulose; D044643:Glucan 1,4-beta-Glucosidase
keywords: Cell wall structure; Expansin gene; Fruit firmness; Fruit ripening; Long shelf life; Tilling; Tomato