Malate Dehydrogenases in the Rusted Bean Leaf.

Rust growth in the bean leaf was accompanied by the appearance of one new malate dehydrogenase isozyme and continuation of one otherwise lost during the development of the healthy leaf. The new isozyme was contributed by the fungus, the other by the leaf. Both enzymes were cytoplasmic proteins. Rusting caused the loss of a mitochondrial isozyme.