title: Short-term UV-B exposure induces metabolic and anatomical changes in peel of harvested lemons contributing in fruit protection against green mold.
abstract: UV-B radiation (UVBR) is a small fraction of the solar spectrum from 280 to 315nm. UVBR produces photomorphogenic acclimation responses in plants, modulating their cellular structure and physiology. Here, changes in the peel of harvested lemons after short time exposure to UVBR were analyzed and its potential effects against fungal infection were studied. In the flavedo, UVBR treatment induced variations in the respiratory profiles and increased the phenolic compound contents. Final products of the flavonoid pathway (flavones, flavonols and anthocyanins) increased more markedly than their precursors (flavanones and dihydroflavonols). The increased accumulation of soluble phenolics in the flavedo of treated lemons is associated with the high antioxidant activity found in the flavedo of these samples. Supporting the biochemical determinations, anatomical observations showed abundant intravacuolar deposits of phenolic compounds and an increase in the cell wall thickness in UVBR-treated samples. Metabolic and anatomical modifications associated to UVBR improved natural defenses against Penicillium digitatum, the causal agent of green mold disease. Our results suggest that mature postharvest lemons exposed to the artificial radiation showed phenotypic plasticity, allowing an acclimation response to UVBR which confers fruit resistance to pathogens. Thus, combination of UVBR with other treatments could represent an important improvement to control postharvest diseases on citrus.
authors.affiliation: Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, UNT, Chacabuco 461, T4000ILI, San Miguel de Tucumán, Tucumán, Argentina.
authors.forename: V E
authors.initials: VE
authors.lastname: Ruiz
authors.affiliation: Cátedra de Fisiología Vegetal-Facultad de Agronomía y Zootecnia, UNT, Florentino Ameghino s/n, T4105, El Manantial, Lules, Tucumán, Argentina.
authors.forename: R
authors.initials: R
authors.lastname: Interdonato
authors.affiliation: Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, UNT, Chacabuco 461, T4000ILI, San Miguel de Tucumán, Tucumán, Argentina.
authors.forename: L
authors.initials: L
authors.lastname: Cerioni
authors.affiliation: Cátedra de Anatomía Vegetal-Facultad de Ciencias Naturales e IML, UNT and Instituto de Morfología Vegetal, Fundación Miguel Lillo, Miguel Lillo 205, T4000ILI San Miguel de Tucumán, Tucumán, Argentina.
authors.forename: P
authors.initials: P
authors.lastname: Albornoz
authors.affiliation: Laboratorio de Desarrollo e Investigación, SA San Miguel, Lavalle 4001, T4000BAB San Miguel de Tucumán, Argentina.
authors.forename: J
authors.initials: J
authors.lastname: Ramallo
authors.affiliation: Cátedra de Fisiología Vegetal-Facultad de Ciencias Naturales e IML, UNT, Miguel Lillo 205, T4000ILI San Miguel de Tucumán, Tucumán, Argentina.
authors.forename: F E
authors.initials: FE
authors.lastname: Prado
authors.affiliation: Cátedra de Fisiología Vegetal-Facultad de Ciencias Naturales e IML, UNT, Miguel Lillo 205, T4000ILI San Miguel de Tucumán, Tucumán, Argentina.
authors.forename: M
authors.initials: M
authors.lastname: Hilal
authors.affiliation: Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, UNT, Chacabuco 461, T4000ILI, San Miguel de Tucumán, Tucumán, Argentina. Electronic address: vrapisarda@fbqf.unt.edu.ar.
authors.forename: V A
authors.initials: VA
authors.lastname: Rapisarda
mesh_terms: D002957:Citrus / Q000382:microbiology / Q000528:radiation effects*; D010407:Penicillium / Q000528:radiation effects*; D010636:Phenols / Q000032:analysis; D010935:Plant Diseases; D014466:Ultraviolet Rays
chemical_list: D010636:Phenols
keywords: Citrus; Penicillium digitatum; Phenolic compounds; Postharvest; UV-B radiation