title: Peroxiredoxins and NADPH-dependent thioredoxin systems in the model legume Lotus japonicus.
abstract: Peroxiredoxins (Prxs), thioredoxins (Trxs), and NADPH-thioredoxin reductases (NTRs) constitute central elements of the thiol-disulfide redox regulatory network of plant cells. This study provides a comprehensive survey of this network in the model legume Lotus japonicus. The aims were to identify and characterize these gene families and to assess whether the NTR-Trx systems are operative in nodules. Quantitative reverse transcription-polymerase chain reaction and immunological and proteomic approaches were used for expression profiling. We identified seven Prx, 14 Trx, and three NTR functional genes. The PrxQ1 gene was found to be transcribed in two alternative spliced variants and to be expressed at high levels in leaves, stems, petals, pods, and seeds and at low levels in roots and nodules. The 1CPrx gene showed very high expression in the seed embryos and low expression in vegetative tissues and was induced by nitric oxide and cytokinins. In sharp contrast, cytokinins down-regulated all other Prx genes, except PrxQ1, in roots and nodules, but only 2CPrxA and PrxQ1 in leaves. Gene-specific changes in Prx expression were also observed in response to ethylene, abscisic acid, and auxins. Nodules contain significant mRNA and protein amounts of cytosolic PrxIIB, Trxh1, and NTRA and of plastidic NTRC. Likewise, they express cytosolic Trxh3, Trxh4, Trxh8, and Trxh9, mitochondrial PrxIIF and Trxo, and plastidic Trxm2, Trxm4, and ferredoxin-Trx reductase. These findings reveal a complex regulation of Prxs that is dependent on the isoform, tissue, and signaling molecule and support that redox NTR-Trx systems are functional in the cytosol, mitochondria, and plastids of nodules.
authors.affiliation: Departamento de Nutrición Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas, 50080 Zaragoza, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Tovar-Méndez
authors.forename: Manuel A
authors.initials: MA
authors.lastname: Matamoros
authors.forename: Pilar
authors.initials: P
authors.lastname: Bustos-Sanmamed
authors.forename: Karl-Josef
authors.initials: KJ
authors.lastname: Dietz
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Cejudo
authors.forename: Nicolas
authors.initials: N
authors.lastname: Rouhier
authors.forename: Shusei
authors.initials: S
authors.lastname: Sato
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tabata
authors.forename: Manuel
authors.initials: M
authors.lastname: Becana
mesh_terms: D005091:Exons / Q000235:genetics; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics; D018525:Germination / Q000187:drug effects; D015151:Immunoblotting; D007438:Introns / Q000235:genetics; D000070116:Lotus / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D009249:NADP / Q000378:metabolism*; D009569:Nitric Oxide / Q000494:pharmacology; D009928:Organ Specificity / Q000187:drug effects / Q000235:genetics; D054464:Peroxiredoxins / Q000235:genetics / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000494:pharmacology; D018515:Plant Leaves / Q000187:drug effects / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D053204:Root Nodules, Plant / Q000187:drug effects / Q000235:genetics; D012639:Seeds / Q000187:drug effects / Q000254:growth & development; D013879:Thioredoxins / Q000378:metabolism*
chemical_list: D010937:Plant Growth Regulators; D010940:Plant Proteins; D012333:RNA, Messenger; D009569:Nitric Oxide; D013879:Thioredoxins; D009249:NADP; D054464:Peroxiredoxins