Figure 4.

The effect of pyruvate on AOX activity. Leaf mitochondria were isolated from transgenic tobacco (B9) with 5 mm pyruvate present in all of the isolation media. These mitochondria were subsequently washed in media either also containing 5 mm pyruvate (traces A and B) or lacking pyruvate (traces C and D) prior to the O₂ electrode analysis shown above. Note that in traces B and D, 2 mm pyruvate was added to the assay medium containing mitochondria 1 min prior to the addition of NADH. Additions were made at the following final concentrations: 2 mm NADH, 1 mm ADP, 16 μm myxothiazol (myxo), 2 mm pyruvate (pyr), 10 mm DTT, and 100 μm n-propyl gallate (nPG). Numbers on traces refer to rates of O₂ uptake (nmol O₂ mg⁻¹ protein min⁻¹). Representative results are shown.