Hydroxamate siderophores in the iron nutrition of plants

Effect of hydroxamate siderophores on Fe release and Pb(II) adsorption by goethite

“…1) contribute to hexadentate ligation of Fe 3ϩ in 5 membered rings with an exceptional combination of high specificity and stability (1:1 complex formation constant of 10 31 (Telford and Raymond, 1996), as compared to 10 25 for Fe-EDTA). These siderophores are common in soil environments (Powell et al, 1982;Crowley and Gries, 1994). Their soil solution concentrations increase significantly with organic matter content and with proximity to living plant roots (Powell et al, 1982;Crowley et al, 1987).…”

“…These siderophores are common in soil environments (Powell et al, 1982;Crowley and Gries, 1994). Their soil solution concentrations increase significantly with organic matter content and with proximity to living plant roots (Powell et al, 1982;Crowley et al, 1987). Watteau and Berthelin (1994) demonstrated the efficacy of trihydroxamate siderophores as promoters of Fe(III)-mineral dissolution by incubating samples of synthetic goethite (␣-FeOOH) over a month long period at 24°C with Suillus granulatus, an ectomychorrhizal fungus, and with an abiotic 126 ( M solution of desferrioxamine B.…”

“…Fungi produce mainly trihydroxamate siderophores, a typical example being desferrioxamine B (Powell et al, 1982;Crumbliss, 1991;Albrecht-Gary and Crumbliss, 1998), in which three hydroxamate groups ( Fig. 1) contribute to hexadentate ligation of Fe 3ϩ in 5 membered rings with an exceptional combination of high specificity and stability (1:1 complex formation constant of 10 31 (Telford and Raymond, 1996), as compared to 10 25 for Fe-EDTA).…”

“…Siderophores are Fe(III)-specific ligands of low relative molecular mass that are synthesized by fungi and bacteria as a response to iron stress (Powell et al, 1982;Telford and Raymond, 1996). Fungi produce mainly trihydroxamate siderophores, a typical example being desferrioxamine B (Powell et al, 1982;Crumbliss, 1991;Albrecht-Gary and Crumbliss, 1998), in which three hydroxamate groups ( Fig.…”

The Role of Ligand Exchange in the Uptake of Iron from Microbial Siderophores by Gramineous Plants

“…A variety of plant species have the ability to acquire Fe from MS, such as PSB, coprogen, ferrichrome A, and FeFOB (Jurkevitch et al, 1986(Jurkevitch et al, , 1988Crowley et al, 1991). Among plant species reported were peanut and cotton (Bar-Ness et al, 1991), oat (Powell et al, 1982;Reid et al, 1984;Crowley et al, 1988), sorghum and sunflower (Cline et al, 1984), and cucumber (Wang et al, 1993). However, the concentrations of siderophores required for a complete remedy of chlorotic plants were higher than those of the synthetic chelators.…”