title: Silencing of the FRO1 gene and its effects on iron partition in Nicotiana benthamiana.
abstract: To evaluate the dynamic role of the ferric-chelate reductase enzyme (FCR) and to identify possible pathways of regulation of its activity in different plant organs an investigation was conducted by virus-induced gene silencing (VIGS) using tobacco rattle virus (TRV) to silence the ferric reductase oxidase gene (FRO1) that encodes the FCR enzyme. Half of Nicotiana benthamiana plants received the VIGS vector and the rest remained as control. Four treatments were imposed: two levels of Fe in the nutrient solution (0 or 2.5 μM of Fe), each one with silenced or non-silenced (VIGS-0; VIGS-2.5) plants. Plants grown without iron (0; VIGS-0) developed typical symptoms of iron deficiency in the youngest leaves. To prove that FRO1 silencing had occurred, resupply of Fe (R) was done by adding 2.5 μM of Fe to the nutrient solution in a subset of chlorotic plants (0-R; VIGS-R). Twelve days after resupply, 0-R plants had recovered from Fe deficiency while plants containing the VIGS vector (VIGS-R) remained chlorotic and both FRO1 gene expression and FCR activity were considerably reduced, consequently preventing Fe uptake. With the VIGS technique we were able to silence the FRO1 gene in N. benthamiana and point out its importance in chlorophyll synthesis and Fe partition.
authors.affiliation: MeditBio - Center for Mediterranean Bioresources and Food, University of Algarve, FCT, Ed8, Campus of Gambelas, 8005-139 Faro, Portugal. Electronic address: fmgama@ualg.pt.
authors.forename: Florinda
authors.initials: F
authors.lastname: Gama
authors.affiliation: MeditBio - Center for Mediterranean Bioresources and Food, University of Algarve, FCT, Ed8, Campus of Gambelas, 8005-139 Faro, Portugal.
authors.forename: Teresa
authors.initials: T
authors.lastname: Saavedra
authors.affiliation: MeditBio - Center for Mediterranean Bioresources and Food, University of Algarve, FCT, Ed8, Campus of Gambelas, 8005-139 Faro, Portugal.
authors.forename: Susana
authors.initials: S
authors.lastname: Dandlen
authors.affiliation: LEAF - Linking Landscape, Environment, Agriculture and Food, Instituto Superior de Agronomia, University of Lisbon, Tapada da Ajuda, 1349-017 Lisbon, Portugal.
authors.forename: Amarilis
authors.initials: A
authors.lastname: de Varennes
authors.affiliation: MeditBio - Center for Mediterranean Bioresources and Food, University of Algarve, FCT, Ed8, Campus of Gambelas, 8005-139 Faro, Portugal.
authors.forename: Pedro J
authors.initials: PJ
authors.lastname: Correia
authors.affiliation: MeditBio - Center for Mediterranean Bioresources and Food, University of Algarve, FCT, Ed8, Campus of Gambelas, 8005-139 Faro, Portugal.
authors.forename: Maribela
authors.initials: M
authors.lastname: Pestana
authors.affiliation: MeditBio - Center for Mediterranean Bioresources and Food, University of Algarve, FCT, Ed8, Campus of Gambelas, 8005-139 Faro, Portugal.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Nolasco
mesh_terms: D002734:Chlorophyll / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D017343:Genes, Plant; D018527:Hydroponics; D007501:Iron / Q000378:metabolism*; D018515:Plant Leaves / Q000502:physiology; D010942:Plant Viruses / Q000235:genetics; D014026:Nicotiana / Q000235:genetics* / Q000378:metabolism*
chemical_list: D002734:Chlorophyll; D007501:Iron
keywords: Ferric reductase oxidase gene; Ferric-chelate reductase; Iron deficiency; Tobacco rattle virus; Virus-induced gene silencing