title: A reevaluation of the key factors that influence tomato fruit softening and integrity.
abstract: The softening of fleshy fruits, such as tomato (Solanum lycopersicum), during ripening is generally reported to result principally from disassembly of the primary cell wall and middle lamella. However, unsuccessful attempts to prolong fruit firmness by suppressing the expression of a range of wall-modifying proteins in transgenic tomato fruits do not support such a simple model. 'Delayed Fruit Deterioration' (DFD) is a previously unreported tomato cultivar that provides a unique opportunity to assess the contribution of wall metabolism to fruit firmness, since DFD fruits exhibit minimal softening but undergo otherwise normal ripening, unlike all known nonsoftening tomato mutants reported to date. Wall disassembly, reduced intercellular adhesion, and the expression of genes associated with wall degradation were similar in DFD fruit and those of the normally softening 'Ailsa Craig'. However, ripening DFD fruit showed minimal transpirational water loss and substantially elevated cellular turgor. This allowed an evaluation of the relative contribution and timing of wall disassembly and water loss to fruit softening, which suggested that both processes have a critical influence. Biochemical and biomechanical analyses identified several unusual features of DFD cuticles and the data indicate that, as with wall metabolism, changes in cuticle composition and architecture are an integral and regulated part of the ripening program. A model is proposed in which the cuticle affects the softening of intact tomato fruit both directly, by providing a physical support, and indirectly, by regulating water status.
authors: Department of Plant Biology , Cornell University, Ithaca, New York 14853, USA.
authors: Montserrat
authors: M
authors: Saladié
authors: Antonio J
authors: AJ
authors: Matas
authors: Tal
authors: T
authors: Isaacson
authors: Matthew A
authors: MA
authors: Jenks
authors: S Mark
authors: SM
authors: Goodwin
authors: Karl J
authors: KJ
authors: Niklas
authors: Ren
authors: R
authors: Xiaolin
authors: John M
authors: JM
authors: Labavitch
authors: Kenneth A
authors: KA
authors: Shackel
authors: Alisdair R
authors: AR
authors: Fernie
authors: Anna
authors: A
authors: Lytovchenko
authors: Malcolm A
authors: MA
authors: O'Neill
authors: Chris B
authors: CB
authors: Watkins
authors: Jocelyn K C
authors: JK
authors: Rose
mesh_terms: D001696:Biomechanical Phenomena; D020171:Botrytis / Q000502:physiology; D002473:Cell Wall / Q000378:metabolism*; D005638:Fruit / Q000254:growth & development / Q000378:metabolism* / Q000382:microbiology / Q000648:ultrastructure; D018551:Solanum lycopersicum / Q000254:growth & development / Q000378:metabolism* / Q000382:microbiology / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D019441:Plant Epidermis / Q000378:metabolism* / Q000648:ultrastructure; D011134:Polysaccharides / Q000378:metabolism*; D014867:Water / Q000378:metabolism; D014885:Waxes / Q000737:chemistry
chemical_list: D011134:Polysaccharides; D014885:Waxes; D014867:Water