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23 Congress of the International Union for Biochemistry and Molecular Biology
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44 Annual Meeting of the Brazilian Society for Biochemistry and Molecular Biology
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Foz do Iguaçu, PR, Brazil, August 24 to 28 , 2015
GUAVA ‘PALUMA’ RIPENING AND ITS RELATION WITH MITOCHONDRIAL
RESPIRATION AND ASCORBIC ACID CONTENT
Mar, C.C1; Santana, D.B1; Silva, G.M.C1; Oliveira, A.V1; Dias, F.M1; Vieira, E.L1;
Mazorra, L.M1; Oliveira, J.G1.
1
Departamento de bioquímica e fisiologia da pós-colheita de frutos e hortaliças,
laboratório de melhoramento genético vegetal, Universidade Estadual do Norte
Fluminense Darcy Ribeiro, Campos dos Goytacazes - RJ, Brasil.
During fruit ripening, respiration is coupled to the oxidation of a diversity of organic
compounds such as carbohydrates derived from cell wall degradation. In particular, the
synthesis of ascorbic acid (AA, vitamin C) is linked with the mitochondrial oxygen
uptake and utilizes L-galactono-1,4-lactone (L-GalL) as substrate; however, the
relationship between the respiratory changes and AA accumulation during ripening of
guava fruit is unclear. To understand this, we evaluated the AA content in guava fruit on
different ripening degree and its correlations with mitochondrial respiration. It was
confirmed that guava mitochondria synthesized AA from L-GalL being observed a
correlation with of the fruit softening degree. Furthermore, the respiratory rate of
mitochondria was increased, ranging from 73.7 nmolO2min-1mg-1 in green-mature fruit to
147.6 nmolO2min-1mg-1 in full ripe fruit. The AA content also increased during the guava
ripening. These results suggest that AA content of guava fruit could be linked with a
higher L-GalL oxidation in mitochondria during the fruit ripening.
Key words: L-galactono-1,4-lactone, mitochondria, respiratory rate
Brazilian Society for Biochemistry and
Molecular Biology (SBBq)