Biochemistry of Metal Micronutrients in the Rhizosphere: An Introduction (J.A. Manthey, D.G. Luster, and D.E. Crowley). Iron in Biology (J.B. Neilands). Iron Acquisition and Virulence of the Bacterial Genus Aeromonas (B.R. Byers and J.E.L. Arceneaux). Iron Uptake and Siderophore Formation in the Actinorhizal Symbiont Frankia (G.L. Boyer and D.B. Aronson). The Role of Siderophores in Symbiotic Nitrogen Fixation by Legume Root Nodule Bacteria (L.L. Barton, C.R. Vester, P.R. Gill, Jr., and J.B. Neilands). Microbial Siderophores and Rhizosphere Ecology (J.S. Buyer, M.G. Kratzke, and L.J. Sikora). Role of Siderophores in Plant Growth Promotion and Plant Protection by Fluorescent Pseudomonads (M. H fte, M.V. Woestyne, and W. Verstraete). Contribution of Mycorrhizal Fungi to Micronutrient Uptake by Plants (E. George, V. R mheld, and H. Marschner). Contributions of VA-Mycorrhiza to Zinc Uptake in Plants (A.K. Sharma, P.C. Srivastava, and B.N. Johri). Control of Mn Status in Pla nts and Rhizosphere: Genetic Aspects of Host and Pathogen Effects in the Wheat Take-All Interaction (Z. Rengel, J.F. Pedler, and R.D. Graham). The Interactions of Manganese and Iron (H.M. Reisenauer). The Chemistry and Role of Metal Ion Chelation in Plant Uptake Processes (S.H. Laurie and J.A. Manthey). Recent Aspects of Mn and Zn Absorption and Translocation in Cereals (M.J. Webb). Modeling of Iron Availability in the Plant Rhizosphere (D.E. Crowley and D. Gries). Mechanisms of Iron Acquisition by Graminaceous (Strategy II) Plants (S. Mori). Genetically Controlled Uptake and Use of Iron by Plants (V.D. Jolley and J.C. Brown). Mechanisms of Iron Uptake from Rhodotorulate-Iron by Tomato (G.W. Miller, S. Hasegawa, A. Shigematsu, and G.W. Welkie). Enzymatic Iron Reduction at the Root Plasma Membrane: Partial Purification of the NADH-Fe Chelate Reductase (M.J. Holden, D.G. Luster, and R.L. Chaney). Iron Uptake in Arabidopsis thaliana (Y. Yi, J.A. Saleeba, and M.L. Guerinot) . The Role of Root Apoplast Acidification by the H+ Pump in Mineral Nutrition of Terrestrial Plants (J.-B. Thibaud, H. Sentenec, and C. Grignon). Salinity Alters Root Cell Wall Properties and Trace Metal Uptake in Barley (C.G. Suhayda, R.E. Redmann, and X. Wang). Soil Factors Influencing the Mobilization of Iron in Calcareous Soils (R.H. Loeppert, L.-C. Wei, and W.R. Ocumpaugh).