Abstract: Fe accumulation and mobilization in root apoplast of soybean ( Clycine max (L.) Merr. ) seedlings grown under Fe supplement of 10-6 mol/L FeEDTA, or Fe-deficient condition were studied. Under Fe sufficient condition, the content of the root apoplastic Fe pools of soybean seedlings changed in a rhythmic fashion of alternative accumulation and mobilization in every three-day cycling, together with orchestrated rhythmic changes of root Fe ( Ⅲ )-reduction capacity and peroxidase activity. In Fe deficient condition, Fe content in the root apoplastic pools deceased steadily almost to nil, and the root Ye( Ⅲ )-reduction capacity and peroxidase activity, ahhrough under went rhythmic changes but only in 2-day cycling. The results showed an important relation among root apoplastic Ye pools, Fe( Ⅲ )-reduction capacity and peroxidase activity.

Key words: Soybean, Root apoplastie Fe pools, Root Fe( Ⅲ)-reduction capacity, Peroxidase, Iron nutrition