title: Metabolic changes of iron uptake in N(2)-fixing common bean nodules during iron deficiency.
abstract: Iron is an important nutrient in N(2)-fixing legume nodules. The demand for this micronutrient increases during the symbiosis establishment, where the metal is utilized for the synthesis of various iron-containing proteins in both the plant and the bacteroid. Unfortunately, in spite of its importance, iron is poorly available to plant uptake since its solubility is very low when in its oxidized form Fe(III). In the present study, the effect of iron deficiency on the activity of some proteins involved in Strategy I response, such as Fe-chelate reductase (FC-R), H(+)-ATPase, and phosphoenolpyruvate carboxylase (PEPC) and the protein level of iron regulated transporter (IRT1) and H(+)-ATPase proteins has been investigated in both roots and nodules of a tolerant (Flamingo) and a susceptible (Coco blanc) cultivar of common bean plants. The main results of this study show that the symbiotic tolerance of Flamingo can be ascribed to a greater increase in the FC-R and H(+)-ATPase activities in both roots and nodules, leading to a more efficient Fe supply to nodulating tissues. The strong increase in PEPC activity and organic acid content, in the Flamingo root nodules, suggests that under iron deficiency nodules can modify their metabolism in order to sustain those activities necessary to acquire Fe directly from the soil solution.
authors.affiliation: Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie, Technopark de Borj Cedria, BP 901, Hammam Lif 2050, Tunisia. slatni tarek@yahoo.fr
authors.forename: Tarek
authors.initials: T
authors.lastname: Slatni
authors.forename: Gianpiero
authors.initials: G
authors.lastname: Vigani
authors.forename: Imen Ben
authors.initials: IB
authors.lastname: Salah
authors.forename: Saber
authors.initials: S
authors.lastname: Kouas
authors.forename: Marta
authors.initials: M
authors.lastname: Dell'Orto
authors.forename: Houda
authors.initials: H
authors.lastname: Gouia
authors.forename: Graziano
authors.initials: G
authors.lastname: Zocchi
authors.forename: Chedly
authors.initials: C
authors.lastname: Abdelly
mesh_terms: D001692:Biological Transport; D002264:Carboxylic Acids / Q000032:analysis; D038181:FMN Reductase / Q000378:metabolism*; D005290:Ferric Compounds / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D005838:Genotype; D007501:Iron / Q000032:analysis / Q000378:metabolism; D000090463:Iron Deficiencies; D035925:Iron-Regulatory Proteins / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D009586:Nitrogen Fixation; D027805:Phaseolus / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D010730:Phosphoenolpyruvate Carboxylase / Q000235:genetics / Q000378:metabolism*; D010935:Plant Diseases; D010940:Plant Proteins / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000378:metabolism; D053204:Root Nodules, Plant / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D013559:Symbiosis
chemical_list: D002264:Carboxylic Acids; D005290:Ferric Compounds; D035925:Iron-Regulatory Proteins; D010940:Plant Proteins; D007501:Iron; D038181:FMN Reductase; C023903:ferric citrate iron reductase; D006180:Proton-Translocating ATPases; D010730:Phosphoenolpyruvate Carboxylase; D009584:Nitrogen