Short-term UV-B exposure inducesmetabolic and anatomical changes in peel of harvested lemons contributing in fruit protection against green mold

INTERDONATO, ROQUE; RAMALLO, JACQUELINE; RAPISARDA, VIVIANA; CERIONI, LUCIANA; PRADO, FERNANDO; RUÍZ, VERÓNICA; ALBORNOZ, PATRICIA; HILAL, MIRNA; INTERDONATO, ROQUE; RAMALLO, JACQUELINE; RAPISARDA, VIVIANA; CERIONI, LUCIANA; PRADO, FERNANDO; RUÍZ, VERÓNICA; ALBORNOZ, PATRICIA; HILAL, MIRNA

JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2016 vol. 159 p. 59 - 65

1011-1344

UV-B radiation (UVBR) is a small fraction of the solar spectrum from 280 to 315 nm. UVBR produces photomorphogenicacclimation responses in plants, modulating their cellular structure and physiology. Here, changes inthe peel of harvested lemons after short time exposure to UVBR were analyzed and its potential effects againstfungal infection were studied. In the flavedo, UVBR treatment induced variations in the respiratory profiles andincreased the phenolic compound contents. Final products of the flavonoid pathway (flavones, flavonols and anthocyanins)increasedmoremarkedly than their precursors (flavanones and dihydroflavonols). The increased accumulationof soluble phenolics in the flavedo of treated lemons is associated with the high antioxidant activityfound in the flavedo of these samples. Supporting the biochemical determinations, anatomical observationsshowed abundant intravacuolar deposits of phenolic compounds and an increase in the cell wall thickness inUVBR-treated samples. Metabolic and anatomical modifications associated to UVBR improved natural defensesagainst Penicilliumdigitatum, the causal agent of green mold disease. Our results suggest thatmature postharvestlemons exposed to the artificial radiation showed phenotypic plasticity, allowing an acclimation response toUVBR which confers fruit resistance to pathogens. Thus, combination of UVBR with other treatments could representan important improvement to control postharvest diseases on citrus.