Unravelling the biochemical basis of fruit chilling injury: proteomic and metabolomic differences between mealy and non-mealy peach fruit

MONTI, LAURA; GABILONDO, JULIETA; BUSTAMANTE, CLAUDIA; LARA, MARÍA VALERIA; BUDDE, CLAUDIO OLAF; DRINCOVICH, MARÍA FABIANA

Buenos Aires

Congreso; Reunión Conjunta de Biociencias; 2017

Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB)

Peaches are highly perishable and deteriorate quickly at ambienttemperature. Cold storage is commonly used to prevent fruit decay;however, it affects fruit quality causing physiological disorders collectivelytermed ?chilling injury? (CI). One of the principal phenotypicexpressions of CI in peach is flesh mealiness or lack of juiciness.In the present work, the differences between mealy and non-mealyfruits of Springlady cultivar, were assessed using proteomic and metabolomicanalysis. Harvested fruits were stored at 0 ºC and 90%relative humidity for 21 days followed by 4 days (time required forripeness) at 20 ºC. The apparent juice content was evaluated usinga visual scale of 0 to 5 (0 = Healthy and 5 Maximum mealiness).Individual fruits with contrasting flesh mealiness were selected forproteomic and metabolomic studies. Quantitative proteomic profiling,performed using the Orbitrap technology, revealed drastic differencesin the amount of 213 proteins between mealy and non-mealyfruits. The differentially expressed proteins were identified andclassified considering their biological role. Significant differenceswere found in proteins involved in lipid, cell wall and protein metabolism;as well as in enzymes involved in secondary metabolism,such as chalcone-flavone isomerase and carotene desaturase. Amarked decrease in the levels of enzymes involved in the controlof the redox state, such as superoxide dismutase and a glutathioneperoxidase, was detected in mealy with respect to non-mealy fruits.Metabolomic analyzes, performed by GC-MS, showed a decreasein the level of sugars, such as sucrose, galactose and raffinose, inmealy with respect with non-mealy fruits, as well as in most of theamino acids detected, with no significant changes in organic acidscontent. Overall, the present work identifies the biochemical basisof mealiness in peach fruits, and reveals that an altered redox statemay be key in mediating many of such biochemical alterations.