Séminaire IBIP
Les séminaires ont lieu sur le Campus Montpellier SupAgro/INRA de La Gaillarde (2, place P. Viala Montpellier)

Jeudi 6 novembre 2014
Amphi 2 (Bâtiment 2 bis) à 14h

Regulation of Mn uptake and interplay with Fe transport in Arabidopsis

Loren Castaings
BPMP, Equipe Transport et Signalisation du Fer

Manganese (Mn) is a trace element important for oxidative stress responses and essential as a cofactor of the photosynthetic machinery. Mn deficiency is a serious and widespread plant nutritional disorder while Mn toxicity can become a problem in poorly drained acidic soils. In Arabidopsis, the natural resistance-associated macrophage protein 1 (NRAMP1), has been shown to mediate Mn uptake in roots (Cailliatte et al. (2010) Plant Cell 22: 904). As for all potentially toxic compounds, Mn entry within root cells must be tightly controlled. How this occurs in Arabidopsis is still unknown but might involve post-translational regulation of NRAMP1. Moreover it is still not clear, whether NRAMP1 provides the only route of entry of Mn across the plasma membrane. Several lines of evidence suggest that Mn can be transported along with iron (Fe) by the Fe high affinity transporter IRT1. To address the questions of NRAMP1 and IRT1 functional redundancy and the regulations of Mn uptake by NRAMP1, an in-depth study of the double mutant nramp1 irt1 supported by a promoter swap strategy, and the study of Mn-controlled NRAMP1 stability and localisation in planta and in yeast have been undertaken respectively. First results obtained with these approaches will be presented.

Contact : Loren Castaings

Contacts IBIP :
Sabine Zimmermann
Alexandre Martiniere
Christine Granier
Chantal Baracco