Integration of trehalose-6-phosphate signaling by FAF proteins in Arabidopsis thaliana

• Applicant: Professor Dr. Markus Schmid
• Subject Area: Plant Cell and Developmental Biology
• Term: from 2007 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 49804230

Plants produce new organs throughout their lives from groups of pluripotent stem cells called meristems, located at the tips of the shoot and the root. The size of the shoot meristem is tightly controlled by a feedback loop, which involves the homeodomain transcription factor WUSCHEL (WUS) and the CLAVATA (CLV) genes. This regulatory circuit is further fine-tuned by the sugars sucrose and trehalose. We have identified a family of four related plant-specific proteins, encoded by the FANTASTIC FOUR (FAF) genes, that can modulate shoot meristem size in Arabidopsis. Interestingly, the FAF proteins interact with TPS1, an enzyme that synthesizes trehalose-6- phosophate, a precursor of the disaccharide trehalose. Here we propose a series of experiments to investigate the molecular function of the FAF proteins in meristem and growth control. We also seek to follow up on our data indicating the regulation of the FAF proteins by BPM proteins. Finally, we will analyze how the FAF proteins modulate TPS1 function to affect trehalose homeostasis and the effect of these trehalose metabolizing proteins on development. In addition to offering a comprehensive analysis of an interesting and novel protein family, the proposed work will enhance our knowledge of how metabolites, in this case trehalose and its precursor trehalose-6-phosphate, contribute to development and growth.

• DFG Programme: Research Grants