title: Biomechanical properties of the tomato (Solanum lycopersicum) fruit cuticle during development are modulated by changes in the relative amounts of its components.
abstract: In this study, growth-dependent changes in the mechanical properties of the tomato (Solanum lycopersicum) cuticle during fruit development were investigated in two cultivars with different patterns of cuticle growth and accumulation. The mechanical properties were determined in uniaxial tensile tests using strips of isolated cuticles. Changes in the functional groups of the cuticle chemical components were analysed by attenuated total reflectance-Fourier transform infrared (ATR-FTIR). The early stages of fruit growth are characterized by an elastic cuticle, and viscoelastic behaviour only appeared at the beginning of cell enlargement. Changes in the cutin:polysaccharide ratio during development affected the strength required to achieve viscoelastic deformation. The increase in stiffness and decrease in extensibility during ripening, related to flavonoid accumulation, were accompanied by an increase in cutin depolymerization as a result of a reduction in the overall number of ester bonds. Quantitative changes in cuticle components influence the elastic/viscoelastic behaviour of the cuticle. The cutin:polysaccharide ratio modulates the stress required to permanently deform the cuticle and allow cell enlargement. Flavonoids stiffen the elastic phase and reduce permanent viscoelastic deformation. Ripening is accompanied by a chemical cleavage of cutin ester bonds. An infrared (IR) band related to phenolic accumulation can be used to monitor changes in the cutin esterification index.
authors.affiliation: Departamento de Biología Molecular y Bioquímica, IHSM La Mayora UMA-CSIC, Universidad de Málaga, E-29071, Málaga, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: España
authors.affiliation: Instituto de Ciencias de Materiales de Sevilla, Universidad de Sevilla-CSIC, Isla de la Cartuja, 41092, Sevilla, Spain.
authors.forename: José A
authors.initials: JA
authors.lastname: Heredia-Guerrero
authors.affiliation: Departamento de Biología Molecular y Bioquímica, IHSM La Mayora UMA-CSIC, Universidad de Málaga, E-29071, Málaga, Spain.
authors.forename: Patricia
authors.initials: P
authors.lastname: Segado
authors.affiliation: Instituto de Ciencias de Materiales de Sevilla, Universidad de Sevilla-CSIC, Isla de la Cartuja, 41092, Sevilla, Spain.
authors.forename: José J
authors.initials: JJ
authors.lastname: Benítez
authors.affiliation: Departamento de Biología Molecular y Bioquímica, IHSM La Mayora UMA-CSIC, Universidad de Málaga, E-29071, Málaga, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Heredia
authors.affiliation: Instituto de Hortofruticultura Subtropical y Mediterránea (IHSM) La Mayora UMA-CSIC, Algarrobo-Costa, E-29750, Málaga, Spain.
authors.forename: Eva
authors.initials: E
authors.lastname: Domínguez
mesh_terms: D001696:Biomechanical Phenomena; D004548:Elasticity; D004951:Esterification; D005638:Fruit / Q000254:growth & development* / Q000502:physiology*; D005838:Genotype; D018551:Solanum lycopersicum / Q000235:genetics / Q000502:physiology*; D008563:Membrane Lipids / Q000378:metabolism; D010636:Phenols / Q000378:metabolism; D019441:Plant Epidermis / Q000254:growth & development* / Q000502:physiology*; D017550:Spectroscopy, Fourier Transform Infrared; D014783:Viscosity
chemical_list: D008563:Membrane Lipids; D010636:Phenols; C000521:cutin
keywords: attenuated total reflectance-Fourier transform infrared (ATR-FTIR); biomechanics; cuticle; cutin; flavonoids; tomato (Solanum lycopersicum) fruit