Chemical identification of iron reductants exuded by plant roots

Abstract

Different varieties of plants exhibit varying abilities to mobilize iron from the soil and to some extent this is dependent upon the reduction of the iron from the ferric form to the ferrous form. Tomato, barley, soybean, and sunflower were studied to identify the iron reductants exuded by roots during periods of iron stress. The tomato reductants were fractionated into one major and at least three minor components. The major component has been identified as chlorogenic acid and considerable data has been collected on the other components. The reductant extract from sunflower has chlorogenic acid as a primary component. The reductant fractions from soybean and barley are similar but different from those of tomato and sunflower. The barley reductants contain glucose and the soybean reductants contain glucose and galactose as well as a ultraviolet light absorbing aglycone.

Key words:

• Iron absorption
• iron reduction
• chlorogenic acid