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Furlanetto 2014 Thesis University of Parana

From Bioblast
Publications in the MiPMap
Furlanetto ALD de Matos (2014) Estresse oxidativo e transição de permeabilidade mitocondrial em células embriogênicas somáticas de Auraucária angustifolia estressadas pelo frio. Thesis University of Parana 53pp.

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Furlanetto ALD de Matos (2014) Thesis University of Parana

Abstract: Araucaria angustifolia is listed as critically endangered by International Union for Conservation of Nature (IUCN) red list of threatened species. The development and propagation of this species is strongly affected by abiotic stress, such as the temperature variation. We previously shown the activation of plant uncoupling mitochondrial protein (PUMP) in embryogenic A. angustifolia cells submitted to cold stress, an effect associated to oxidative stress. In this work, we advanced in these studies by submitting these cells to cold stress (4 ± 1°C for 24h or 48h) and evaluating the cellular and mitochondrial response associated to oxidative stress, namely: the H2O2 levels, the activity of antioxidant enzymes and lipid peroxidation. In mitochondria from these cells were evaluated the activity of NAD(P)H alternative dehydrogenases and mitochondrial permeability transition (MPT). The cold stress did not affect the morphology and viability of embryogenic A. angustifolia cells; however, increased the H2O2 levels by ~35% (at 24h and 48h) and lipid peroxidation by ~15% and 30% after 24h and 48h of stress, respectively. The activity of catalase was decreased by ~20% after 48h of cold stress while ascorbate peroxidase (APx) and dehydroascorbate redutase (DHAR) activities were increased by ~100% and ~64%, respectively. For the cells exposition to cold stress by 24h only dehydroascorbate redutase (MDHAR) had the activity increased by ~172%. Glutathione reductase (GR) and superoxide dismutase activities remained unchanged under both stress conditions. In mitochondria, the cold stress promoted a significant inhibition of external alternative NAD(P)H dehydrogenases (~40% at 24h of stress and ~65% at 48h of stress) while the mitochondrial permeability transition (MPT) was slightly inhibited in both, 24h and 48h of stress. The cold stress induces the oxidative stress in embryogenic A. angustifolia cells, which result in up-regulation of the enzymatic defense mainly the activation of gluthatione-ascorbate cycle in a compensatory way to the inhibition of catalase and external NAD(P)H dehydrogenases. These results contribute to understanding the pathway to overcoming the cold in this gymnosperm and are important for the development of conservation methods of this species such as in vitro micropropagation. Keywords: Araucaria angustifolia, Embryogenic cells, Plant mitochondria, Cold stress, Antioxidant enzymes


Labels: MiParea: Respiration, Comparative MiP;environmental MiP 

Stress:Oxidative stress;RONS, Temperature  Organism: Plants 

Preparation: Isolated mitochondria 


Coupling state: LEAK, OXPHOS  Pathway:HRR: Oxygraph-2k