INVESTIGADORES
IGLESIAS Alberto Alvaro
congresos y reuniones científicas
Título:
Oxidative Stress and Mitochondrial Dysfunction in Frost-Exposed Valencia Orange Fruit
Autor/es:
M.L. FALCONE FERREYRA; V. PEROTTI; S. GARRÁN; P.C. ANDERSON; D. VÁZQUEZ; A.A. IGLESIAS; F.E. PODESTÁ
Lugar:
Iguazú, Misiones, Argentina
Reunión:
Congreso; XL Reunión de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2004
Institución organizadora:
SAIB
Resumen:
BIOCELL 28 (Suppl.), 2004 108PL-P8.OXIDATIVE STRESS AND MITOCHONDRIAL DYSFUNCTION IN FROST-EXPOSED VALENCIA ORANGE FRUITFalcone Ferreyra ML1, Perotti V1, Garrán S2, Anderson PC2, Vázquez D2, Iglesias AA3, Podestá FE1.1CEFOBI (CONICET-UNR); 2Est. Exp. Agríc. Concordia INTA; and 3Fac. de Bioq. y Cs. Biológicas, UNL. Suipacha 531. 2000. Rosario. Argentina. E-mail: mfalcone@fbioyf.unr.edu.arLow temperatures cause severe damage in Valencia orange fruit (Citrus sinensis L. Osbeck). We have reported before an increased fermentative metabolism in the endocarp of frost-damaged fruits. In this work, levels of antioxidant enzymes and mitochondrial functionality were analyzed in affected tissue. Total protein content on a fresh weight basis showed a sharp decrease (37%) in frozen fruits (both in soluble and mitochondrial fractions). Induction of APX, CAT and POD was observed in native gels by activity staining, while a Mn-SOD slightly decreased. MDH activity in, and reduction of exogenous cytocrome c by, isolated mitochondriaindicated a lower organelle integrity. Respiration rate of whole fruit was significatively reduced by 30%, whereas the flavedo showed a more pronounced descent (53%). Biochemical andinternal quality parameters were also affected: volatile compounds, L-malate and titratable acidity increased, while juice content and maturity index showed a marked decrease in frozen fruits compared to a control. In conclusion, results suggest that cold imposes oxidative stress in oranges, associated to less active and functional mitochondria. Oxidative stress could be used as a marker to detect frost-induced damage in citrus fruit