title: Cell wall metabolism of peaches and nectarines treated with UV-B radiation: a biochemical and molecular approach.
abstract: BACKGROUND
  Ultra-violet B (UV-B) radiation has been shown to improve, at least in selected genotypes, both the health-promoting potential and the aesthetic properties of tomato and peach fruits during their post-harvest period. The effects of post-harvest UV-B treatment on the cell-wall metabolism of peaches and nectarines (Prunus persica L. Batsch) were assessed in this study. Three cultivars, Suncrest (melting flesh, MF) and Babygold 7 (non-melting flesh, NMF) peaches and Big Top (slow melting, SM) nectarine, differing in the characteristics of textural changes and softening during ripening, were analysed.
  
  
  RESULTS
  The effects of UV-B differ in relation to the cultivar considered. In MF 'Suncrest' fruit, UV-B treatment significantly reduced the loss of flesh firmness despite the slight increase in the presence and activity of endo-polygalacturonase. The activity of exo-polygalacturonase increased as well, while endo-1,4-β-D-glucanase/β-D-glucosidase, β-galactosidase and pectin methylesterase were substantially unaffected by the treatment. The UV-B-induced reduction of flesh softening was paralleled by the inhibition of PpExp gene transcription and expansin protein accumulation. The UV-B treatment did not induce differences in flesh firmness between control and UV-B-treated NMF 'Babygold 7' and SM 'Big Top' fruit.
  
  
  CONCLUSIONS
  Based on these results, post-harvest UV-B treatment may be considered a promising tool to improve shelf-life and quality of peach fruit.
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, via del Borghetto 80, 56124 Pisa, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Scattino
authors.affiliation: Department of Agricultural and Environmental Sciences - Production, Landscape, Agroenergy, University of Milan, Via Celoria 2, Milan, Italy.
authors.forename: Noemi
authors.initials: N
authors.lastname: Negrini
authors.affiliation: Department of Agricultural and Environmental Sciences - Production, Landscape, Agroenergy, University of Milan, Via Celoria 2, Milan, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Morgutti
authors.affiliation: Department of Agricultural and Environmental Sciences - Production, Landscape, Agroenergy, University of Milan, Via Celoria 2, Milan, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Cocucci
authors.affiliation: Department of Plant Sciences, University of California at Davis, One Shields Avenue, Davis, CA 95616, USA.
authors.forename: Carlos H
authors.initials: CH
authors.lastname: Crisosto
authors.affiliation: Institute of Life Sciences, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà 33, 56127 Pisa, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Tonutti
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, via del Borghetto 80, 56124 Pisa, Italy.
authors.forename: Antonella
authors.identifier: http://orcid.org/0000-0001-6481-4570
authors.initials: A
authors.lastname: Castagna
authors.affiliation: Department of Agriculture, Food and Environment, University of Pisa, via del Borghetto 80, 56124 Pisa, Italy.
authors.forename: Annamaria
authors.initials: A
authors.lastname: Ranieri
mesh_terms: D002473:Cell Wall / Q000528:radiation effects; D063427:Food Quality; D005638:Fruit / Q000528:radiation effects*; D006801:Humans; D000068239:Prunus persica / Q000528:radiation effects; D014466:Ultraviolet Rays
keywords: Endo-PG; UV-B treatment; expansins; flesh softening; peach; post-harvest