Resumo

MARIANO, André Bellin et al. Improved method for isolation of coupled mitochondria of Araucaria angustifolia (Bert.) O. Kuntze. Braz. arch. biol. technol. [online]. 2004, vol.47, n.6, pp. 873-879. ISSN 1516-8913.  http://dx.doi.org/10.1590/S1516-89132004000600006.

A method for the isolation of coupled mitochondria from the callus of Araucaria angustifolia is described for the first time. Mitochondria were isolated from embryogenic callus of A. angustifolia. They were metabolically active, able to sustain oxidative phosphorylation as shown by respiratory control ratio values, which were about 2.4 when respiring on succinate as substrate. Oxygen uptake experiments, using freeze-thawed disrupted mitochondria, showed the presence of alternative rotenone-insensitive NAD(P)H dehydrogenases, which were stimulated by Ca²⁺. The procedure now described for the isolation of A. angustifolia mitochondria is an important new tool, allowing the investigation of mitochondrial bioenergetics and metabolism and physiology of plants.

Palavras-chave : Araucaria angustifolia; callus; plant mitochondria; respiratory chain.