Preparation of leaf mitochondria from Arabidopsis thaliana

Arabidopsis thaliana is, perhaps, the most important model species in modern plant biology. However, the isolation of organelles from leaves of this plant has been difficult. Here, we present two different protocols for the isolation of mitochondria, yielding either highly functional crude mitochondria or highly purified mitochondria. The crude mitochondria were well coupled with the substrates tested (malate + glutamate, glycine and NADH), exhibiting respiratory control ratios of 2.1-3.9. Purified mitochondria with very low levels of chlorophyll contamination were obtained by Percoll gradient centrifugation, yielding 1.2 mg of mitochondrial protein from 50 g of leaves.