Les séminaires ont lieu sur le Campus Montpellier SupAgro/INRA de La Gaillarde (2, place P. Viala Montpellier)
Jeudi 21 novembre 2013
Salle 104 (Château) à 14h
Phosphate sensing in root development – The yin and yang of P and iron
Leibniz-Institute of Plant Biochemistry, Halle -Saale, Germany
Inorganic phosphate (Pi) constitutes a major node in metabolism and its bioavailability directly impacts plant performance. To cope with Pi shortage, a common constraint in many ecosystems as a result of complex soil chemistries involving Fe and other metals, plants activate a set of adaptive responses to enhance Pi recycling and acquisition by reprogramming metabolism and restructuring of root system architecture. As the physiology of responses to Pi limitation has become increasingly understood, current research focuses on the sensory mechanisms that monitor, transmit, and integrate information about external and internal Pi status. We have taken genetic approaches in Arabidopsis thaliana to dissect Pi sensing in root development and identified several phosphate deficiency response (pdr) mutations that alter the sensitivity of primary root growth in response to both Pi and Fe bioavailability in the rhizosphere. PDR genes code for proteins with roles in the secretory pathway or cell nucleus and are required for maintaining the root stem cell niche in conditions of Pi deprivation. Our data highlight complex antagonistic interactions between external Piii and Fe bioavailability and suggest that dynamic Fe homeostasis in root meristems mediates local Piii sensing.
Contact : Hatem Rouached