title: Identification  and expression analysis of multiple FRO gene copies in Medicago  truncatula.
abstract: Iron  (Fe) is an essential element for plant growth. Commonly, this element is found  in an oxidized form in soil, which is poorly available for plants. Therefore,  plants have evolved ferric-chelate reductase enzymes (FRO) to reduce iron into  a more soluble ferrous form. Fe scarcity in plants induce the FRO enzyme  activity. Although the legume Medicago truncatula has been employed as a  model for FRO activity studies, only one copy of the M. truncatula MtFRO1 gene  has been characterized so far. In this study, we identified multiple gene  copies of the MtFRO gene in the genome of M. truncatula by an in  silico search, using BLAST analysis in the database of the M. truncatula Genome Sequencing Project and the National Center for Biotechnology  Information, and also determined whether they are functional. We identified  five genes apart from MtFRO1, which had been already characterized. All  of the MtFRO genes exhibited high identity with homologous FRO genes  from Lycopersicon esculentum, Citrus junos and Arabidopsis  thaliana. The gene copies also presented characteristic conserved FAD and  NADPH motifs, transmembrane regions and oxidoreductase signature motifs. We  also detected expression in five of the putative MtFRO sequences by  semiquantitative RT-PCR analysis, performed with mRNA from root and shoot  tissues. Iron scarcity might be a condition for an elevated expression of the MtFRO genes observed in different M. truncatula tissues.
authors.affiliation: Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, México.
authors.forename: Ma
authors.initials: M
authors.lastname: Del C Orozco-Mosqueda
authors.forename: G
authors.initials: G
authors.lastname: Santoyo
authors.forename: R
authors.initials: R
authors.lastname: Farías-Rodríguez
authors.forename: L
authors.initials: L
authors.lastname: Macías-Rodríguez
authors.forename: E
authors.initials: E
authors.lastname: Valencia-Cantero
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004790:Enzyme Induction; D038181:FMN Reductase / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D007501:Iron / Q000378:metabolism; D046913:Medicago truncatula / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000201:enzymology / Q000235:genetics; D018520:Plant Shoots / Q000201:enzymology / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
chemical_list: D010940:Plant Proteins; D012333:RNA, Messenger; D007501:Iron; D038181:FMN Reductase; C023903:ferric citrate iron reductase