Respiratory metabolism during cold storage of apple fruit. II. Alternative oxidase is induced at the climacteric

Abstract

Changes in mitochondrial respiration were investigated during cold storage of apple fruit (Malus domestica Borkh. cv. Reinette du Canada). Postharvest calcium treatment of the apples had no effect on the aspects of mitochondrial metabolism studied, suggesting that the role of calcium in fruit ripening is not related to respiration. A transient increase in mitochondrial oxidative capacity occurred during storage around day 80 after harvest. This climacteric burst was associated with an enhanced capacity of the alternative pathway, but not of the cytochrome pathway. The major factor determining this rise in alternative pathway capacity at the climacteric was the transient increase in the amount of alternative oxidase (AOX) protein. Antibodies raised against the Sauromatum guttatum enzyme recognized a reduced form product of ampproximately 37 kDa and a 67‐kDa band corresponding to the oxidized form of the protein. During cold storage of the apple fruit, alternative pathway capacity correlated with the levels of the AOX and was ampparently not dependent on major changes in the oxidation state of the enzyme. This is the first work to report that the respiratory climacteric and the induction of AOX are tightly and temporally linked.

Induction of alternative oxidase chain under salt stress conditions

“…Consistently, the stress induced AOX-protein has a molecular mass of about 35 kDa, as in Nicotiana tabacum (Vanlerberghe and McIntosh 1992a,b), Glycine max (Kearns et al 1992), Solanum tuberosum (Hiser and McIntosh 1990), Phaseolus vulgaris (Lennon et al 1997), Acer pseudoplatanus (Aubert et al 1997) and Malus domestica (Duque and Arrabaça 1999).…”

Atividade Respiratória Em Mitocôndrias Isoladas Da Polpa Do Mamão Uenf/Caliman 01 E Tainung 01 Na Conservação Do Fruto Em Pós-Colheita

“…À atividade AOX, atribui-se principalmente a participação no controle do balanço entre a oxidação do substrato respiratório e o transporte de elétrons na ctem, e no controle da geração de espécies reativas de oxigênio, além de sua participação na termogênese em algumas plantas, na resistência a estresses e certas patogenicidades e participação na reprogramação celular (aRnhoLdt-Schmitt et al, 2006;MCDONALD, 2008;LI-JUN et al, 2010;XU et al, 2012;VANLERBERGHE, 2013). No amadurecimento de frutos, a AOX está associada ao aumento na respiração dos frutos climatéricos, juntamente com a proteína desacopladora (DUQUE; ARRABAÇA, 1999;VERCESI et al, 2006). Dessa forma, a possibilidade de minimizar a atividade da AOX pode ser uma maneira de influenciar no controle das transformações bioquímicas relacionadas ao amadurecimento, possivelmente prolongando a vida útil do fruto de mamão.…”

“…Há dois sistemas dissipadores de energia conhecidos em mitocôndrias vegetais, a via operada pela oxidase alternativa e a proteína desacopladora (UcP) (BORECKY;VERCESI, 2005). Já foram verificadas rotas mitocondriais alternativas, operadas por estes dois sistemas dissipadores de energia, durante o desenvolvimento de frutos de manga (CONSIDINE et al, 2001), maçã (DUQUE;aRRaBaça, 1999), tomate (aLmeida et al, 2002) e tubérculos de batata (PinheiRo et al, 2004). a operação de sistemas dissipadores de energia tem a função de equilibrar a capacidade de geração de compostos necessários às diversas rotas de biossíntese na fosforilação oxidativa mitocôndrial.…”

Dinitro-o-cresol induces apoptosis-like cell death but not alternative oxidase expression in soybean cells

“…Some evidence indicates that AOX may act as a safety valve for the control of ROS generation from mitochondria and are consistent with its activation in many PCD systems (Simons et al, 1999). Also, AOX induction was reported at the onset of the climacteric during ripening in fruits (Duque and Arrabac -a, 1999), to which senescence rapidly follows.…”