9 - Functions of Mineral Nutrients: Micronutrients

Abstract

Publisher Summary The chapter summarizes the role of micronutrients followed by their deficiencies and toxicities. The section on iron covers chloroplast development and photosynthesis, localization and binding state of iron, and root responses to iron deficiency and iron toxicity. The section on manganese covers manganese-containing enzymes, manganese-dependent or activated enzymes, photosynthesis and oxygen (O2) evolution, proteins, carbohydrates, lipids, and cell division. Copper covers copper proteins, carbohydrates, lipid and nitrogen metabolism, lignification, pollen formation, and fertilization. The section on zinc covers zinc-containing enzymes, zinc-activated enzymes, protein synthesis, carbohydrate metabolism, tryptophan and indoleacetic acid synthesis, membrane integrity, zinc-binding forms, and bioavailability. Nickel covers nickel-containing enzymes, role of nickel in nitrogen metabolism, and nickel content in plants. The enzymes covered under molybdenum are nitrate reductase, nitrogenase, xanthine oxidase/dehydrogenase, and sulfite reductase. The section also documents gross metabolic changes of molybdenum. Boron covers boron complexes with organic structures, root elongation and nucleic acid metabolism, cell wall synthesis, phenol metabolism, auxin (IAA) and tissue differentiation, membrane function, pollen germination and pollen tube growth, carbohydrate, and protein metabolism. The section on chlorine discusses photosynthetic O2 evolution, tonoplast proton-pumping ATPase, stomatal regulation, chlorine supply and plant growth, and chlorine supply and osmoregulation. The chapter also includes a summary on the mechanism of (heavy) metal tolerance in higher plants and the various mechanisms into which they can be grouped.