title: Fixating on metals: new insights into the role of metals in nodulation and symbiotic nitrogen fixation.
abstract: Symbiotic nitrogen fixation is one of the most promising and immediate alternatives to the overuse of polluting nitrogen fertilizers for improving plant nutrition. At the core of this process are a number of metalloproteins that catalyze and provide energy for the conversion of atmospheric nitrogen to ammonia, eliminate free radicals produced by this process, and create the microaerobic conditions required by these reactions. In legumes, metal cofactors are provided to endosymbiotic rhizobia within root nodule cortical cells. However, low metal bioavailability is prevalent in most soils types, resulting in widespread plant metal deficiency and decreased nitrogen fixation capabilities. As a result, renewed efforts have been undertaken to identify the mechanisms governing metal delivery from soil to the rhizobia, and to determine how metals are used in the nodule and how they are recycled once the nodule is no longer functional. This effort is being aided by improved legume molecular biology tools (genome projects, mutant collections, and transformation methods), in addition to state-of-the-art metal visualization systems.
authors.affiliation: Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid Madrid, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: González-Guerrero
authors.affiliation: Department of Plant and Microbial Biology, North Carolina State University Raleigh, NC, USA.
authors.forename: Anna
authors.initials: A
authors.lastname: Matthiadis
authors.affiliation: Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid Madrid, Spain.
authors.forename: Ángela
authors.initials: Á
authors.lastname: Sáez
authors.affiliation: Department of Plant and Microbial Biology, North Carolina State University Raleigh, NC, USA.
authors.forename: Terri A
authors.initials: TA
authors.lastname: Long
keywords: copper; iron; legume; metals; nodule; rhizobia; symbiotic nitrogen fixation (SNF); zinc