Mitochondria of plant leaves contain two thioredoxins. Completion of the thioredoxin profile of higher plants

The distribution of mitochondrial (mt) thioredoxins in plants has been analyzed. Mitochondria from spinach, soybean, and potato leaves contain two different mt-thioredoxins in about equal amount whereas potato tuber mitochondria possess only one such protein. This pattern suggests that a specific process, as yet unknown, of photoautotrophic metabolism is linked to a thioredoxin system in green plant mitochondria, and another thioredoxin function (e.g., in regulating alpha-ketoacid dehydrogenase complexes) may be common in all mitochondria. The mt-thioredoxins described here can be differentiated from other leaf thioredoxins. They are neither identical with chloroplast thioredoxins nor with thioredoxin h preparations previously described.