1.14.11.60 malfunction mutants defective in the expression of S8H show increased sensitivity to growth on pH 7.0 media supplemented with an immobile source of Fe and reduced secretion of fraxetin. Transgenic lines overexpressing S8H exhibit an opposite phenotype. Supplementing the media containing immobile Fe with fraxetin partially rescues the s8h mutants 1.14.11.60 metabolism the enzyme is involved in biosynthesis of iron(III)-chelating coumarins in higher plants. Under iron-deficiency conditions, a branch of the phenylpropanoid pathway consisting of feruloyl-CoA 6'-hydroxylase 1, scopoletin 8-hydroxylase, and CYP82C4 is strongly induced, thus leading to the synthesis of scopoletin and its conversion into redox-active fraxetin and sideretin. In the rhizosphere, the redox-active coumarins act in concert with other components of the strategy I iron acquisition machinery by solubilizing and reducing iron from sparingly available sources 1.14.11.60 metabolism the enzyme is involved in coumarin biosynthesis and is part of mechanisms used by plants to assimilate iron 1.14.11.60 metabolism the enzyme participates in Fe acquisition by mediating the biosynthesis of fraxetin (7,8-dihydroxy-6-methoxycoumarin), a coumarin derived from the scopoletin pathway. Fraxetin secretion is a decisive factor for calcicole-calcifuge behavior (i.e. the ability/inability to thrive on alkaline soils) of plants 1.14.11.60 physiological function the enzyme participates in Fe acquisition by mediating the biosynthesis of fraxetin (7,8-dihydroxy-6-methoxycoumarin), a coumarin derived from the scopoletin pathway. Fraxetin secretion is a decisive factor for calcicole-calcifuge behavior (i.e. the ability/inability to thrive on alkaline soils) of plants