Characterization of the gibberelic acid (GA) signaling proteins and identification of novel GA signaling components from Arabidopsis

• Applicant: Professor Dr. Claus Schwechheimer
• Subject Area: Plant Cell and Developmental Biology
• Term: from 2007 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 49803746

In the present proposal, we want to use a combination of biochemistry, cell biology, genetics and functional genomics to improve our understanding of the gibberellic acid (GA) signaling network. GA controls important plant growth processes such as germination, elongation growth and flowering time. GA responses require the proteolysis of the DELLA repressors, which interact with the GID1 GA receptors in a GA-dependent manner. We have recently finished the genetic and molecular characterization of the three Arabidopsis GID1 GA receptor genes and shown that the gid1 triple mutant is GA insensitive with respect to GA-controlled DELLA protein degradation and gene expression. We now want to investigate the protein interactions between the DELLA proteins, GID1 and the E3 ligase subunit SLY1, their post-translational modifications, as well as the role of previously uncharacterized GA-regulated transcription factors and signaling proteins in GA signaling. The project ultimately will broaden our understanding of GA signaling and its cross-talk with other pathways.

• DFG Programme: Research Grants
• International Connection: USA
• Participating Persons: Professorin Dr. Christiane Gatz; Dr. Tai-ping Sun