Combining proteomics of root and shoot mitochondria and transcript analysis to define constitutive and variable components in plant mitochondria

► The root mitochondrial proteome in Arabidopsis was compared to leaf mitochondria. ► Differences in TCA cycle, photorespiration and cysteine and formate metabolism. ► Microarrays showed correlation to mRNA but also post-transcriptional processes. ► Broader comparisons provided evidence for specialization of plant mitochondria. ► Clustering showed constitutive vs variably expressed components of mitochondria.