Les séminaires ont lieu sur le Campus Montpellier SupAgro/INRA de La Gaillarde (2, place P. Viala Montpellier)
Jeudi 3 février 2011
Amphi 208 (Cœur d’Ecole) à 14h
Arabidopsis PIP aquaporins – whole plant physiological studies and plant-environment interactions
Dr. Tony Schäffner
Institute of Biochemical Plant Pathology / Helmholtz Center München, Germany
PIP (plasma membrane intrinsic proteins, aquaporins) are abundant proteins and facilitate membrane water permeation. They are thought to impact on whole-plant and cell water relations. However, a direct effect in planta has been only demonstrated for a few PIP isoforms using e.g. root and cell pressure probes. We established a new tool to analyze water relocation from root to shoot in intact plants using 2H-tracing. After raising the 2H content of the medium of hydroponically grown Arabidopsis plants the 2H increase in the aerial parts was recorded until a new equilibrium of 2H content was reached. The fitting parameters of an equation modeling the kinetics allowed to estimate the relative water flux qleaf from roots into rosettes. pip2;1 and pip2;2 aquaporin knockout plants showed a significantly reduced qleaf. Expression patterns of both genes imply that changes in root hydraulics and in leaf water uptake/ distribution were contributing in an integrated fashion. To assess genome-environment relations we grow plants in environmental simulation chambers allowing to control irradiance (spectrum and intensity), temperature, humidity and chamber atmosphere. pip mutants will be analyzed under conditions of reduced water availability and enhanced temperature assessing physiological and molecular parameters. If time allows the talk will also inlcude a few aspects from a different project on a plant glycosyltransferase which affects plant defense responses.
Contact : Christophe Maurel