Regulation of ammonium transport in Arabidopsis and Medicago

• Applicant: Professor Dr. Uwe Ludewig
• Subject Area: Plant Physiology
• Term: from 2008 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 72497070

Transporters of the AMT/Rh family are responsible for the high affinity ammonium transport across microbial, animal and higher plant membranes. We will investigate the regulatory network that integrates environmental factors, stress conditions and other cellular functions with AMT-ammonium transport in Arabidopsis. Furthermore, the structure of a plant AMT will be resolved by crystallization. Molecular determinants of how AMTs select their substrate will also be identified.We will also functionally characterize and compare the function of AMTs from Medicago truncatula, a legume that is able to form symbiotic relationships with soil bacteria and fungi. The analysis will involve heterologous AMT expression, identification of the in planta localization and establishment of mutants with genetically impaired ammonium transport. The temporal and spatial changes of the key metabolite glutamine during symbiosis will be analyzed with recently developed novel fluorescent glutamine sensors.

• DFG Programme: Research Grants