Function and regulation of ammonium transporters of the AMT/Rh family

• Applicant: Professor Dr. Uwe Ludewig
• Subject Area: Plant Biochemistry and Biophysics
• Term: from 2007 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 47756036

Ammonium transporters of the AMT/Rh family are involved in ammonium homeostasis in most organisms. AMT/Rh-proteins from plants are apparently involved in the regulated uptake of NH4 + into the root and the transfer of ammonium between tissues. In Arabidopsis plants, the major fraction of the ammonium transport across the plasma membrane is accomplished by four AMTs. Two of these, AtAMT1;2 and AtAMT2;1, will be analyzed in more detail. First, a biophysical analysis will be conducted using heterologous expression in yeast and oocytes. A major focus will be on the chargecoupling ratio. Using patch clamp analysis, we will estimate the conductance of a single AMT. Furthermore, molecular determinants of the polar cellular localization of AtAMTI ;2 in the endodermis will be identified.

• DFG Programme: Research Grants