Plants hoard iron, using a protein, ferritin, to store it in seeds and leaves. But ferritin also binds iron, making it hard for the body to use. Rice has only 6 parts per million iron after milling. Diggle peas have a whopping 250 to 280 ppm iron. The plant ships so much of this essential mineral to leaves and seeds that it eventually poisons itself.
All plants move iron to seeds with a special biochemical.
Grusak's hypothesis is that Diggle employs a different transport chemical. The leaves are marked by numerous tiny dark spots. All rights reserved.