Observatorio de I+D+i UPM

Memorias de investigación
Communications at congresses:
MtZIP6 is a novel metal transporter required for symbiotic nitrogen fixation in nodules of Medicago truncatula plants.
Year:2015
Research Areas
  • Natural sciences and health sciences
Information
Abstract
Symbiotic nitrogen fixation (SNF) carried out by the interaction rhizobia-legumes takes place in legume root nodules. Many of the enzymes involved in SNF are metalloproteins that obtain their metal cofactor from the host plant. Metals reach the nodule through the vasculature, where they are released in the apoplast on the infection/differentiation zone (zone II) of the nodule (Rodriguez-Haas et al., 2013). From there, these oligonutrients have to cross a number of membranes to be used for metalloprotein synthesis (plasma membrane, endoplasmic reticulum, symbiosomes,..). Although several proteins have been suggested to mediate metal transport to the endosymbiotic nitrogen-fixing rhizobia (bacteroids), very little is known about transporters that mediate metal uptake from the apoplast. Recently, we have identified MtNramp1, the first iron transporter to mediate this uptake (Tejada-Jiménez et al., 2015). However, other transporters must mediate zinc, manganese or copper uptake from the nodule apoplast. Transcriptomic studies in Medicago truncatula revealed that MtZIP6, a ZIP family member, had a maximum of expression in the nodule. ZIP6 promoter::GUS fusions showed that MtZIP6 expression was confined to the nodule zone II, the region where metals have to be incorporated from the apoplast. These results were also validated by immunohistochemistry in nodule sections expressing MtZIP6 bound to 3xHA epitopes under the MtZIP6 promoter. This experiment showed that MtZIP6 is very likely localized in the plasma membrane and confirmed its expression in zone II of the nodule. Expression of MtZIP6 in Saccharomyces cerevisiae metal transport mutants showed MtZIP6 as a divalent metal importer, capable of transporting zinc, manganese, or iron. Loss of MtZIP6 function in M. truncatula knocked-down plants revealed a reduced plant and nodule size, and a reduced nitrogenase activity in comparison to control plants. Altogether these results suggest that MtZIP6 is an important element in the process of symbiotic nitrogen fixation by its ability to transport metals through the plasma membrane of the nodule cells
International
Si
Congress
XIV Congreso Hispano-Luso de Fisiología Vegetal. XXI Reunión de la Sociedad Española de Fisiología Vegetal
970
Place
Toledo
Reviewers
Si
ISBN/ISSN
0000000000
Start Date
14/06/2015
End Date
17/06/2015
From page
95
To page
95
XIV Congreso Hispano-Luso de Fisiología Vegetal. XXI Reunión de la Sociedad Española de Fisiología Vegetal
Participants
  • Autor: Angela Enriqueta Saez Somolinos (UPM)
  • Autor: Juan Imperial Ródenas (UPM)
  • Autor: Manuel Gonzalez Guerrero (UPM)
Research Group, Departaments and Institutes related
  • Creador: Grupo de Investigación: BIOLOGÍA MOLECULAR Y COMPUTACIONAL
  • Centro o Instituto I+D+i: Centro de Biotecnología y Genómica de Plantas, CBGP
  • Departamento: Biotecnología - Biología Vegetal
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