Genetic analysis of nicotianamine synthase functions in Arabidopsis thaliana and their role in iron and metal uptake regulation

• Applicant: Professorin Dr. Petra Bauer
• Subject Area: Plant Cell and Developmental Biology
• Term: from 2002 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5388231

The accurate transport of iron is the basis for iron homeostasis. The metal chelator nicotianamine represents one transport mechanism for iron and can itself presumably be relocated via membrane-bound YELLOWSTRIPE-LIKE (YSL) proteins. The lack of nicotianamine or its transporter causes leaf chlorosis in tomato and maize, respectively. The precise role of nicotianamine for transport and sequestering of iron and as signal for the regulation of iron uptake is not understood. Our long-term goal is to unravel the function of nicotianamine within the network of iron uptake components. Although there is a nicotianamine-free tomato mutant we believe that Arabidopsis has multiple advantages which will make it an optimal experimental system which we propose to establish with this AFGN application. We aim at determining the role of the different members of the gene families for metabolism and transport of nicotianamine at a molecular, biochemical and genetic level with special emphasis on regulatory aspects (4 nicotianamine synthase nas genes, 2 nicotianamine aminotransferase naat-like genes, 8 ysl genes, in collaboration with Prof. E. Walker, Amherst, USA). One of the most important tools to be identified from this project is a nicotianamine-free Arabidopsis mutant that will be analysed in a combinatorial approach with ysl and further iron uptake mutants in the future.

• DFG Programme: Research Grants