Scanning the Arabidopsis proteome for targets of small signaling molecules. Yeast threehybrid approach towards the identification of jasmonate receptors

• Applicant: Dr. Erich Kombrink
• Subject Area: Plant Cell and Developmental Biology
• Term: from 2007 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 50008380

Multicellular organisms, whether plant or animal, coordinate their growth and development and many responses to the environment by using small signaling molecules for communication between cells or organs. The established plant hormones include auxin, cytokinin, gibberellin, brassinosteroids, abscisic acid (ABA), and jasmonic acid (JA), which mediate numerous physiological and biochemical responses. However, in comparison to animal systems, our knowledge about the molecular mechanisms of hormone perception and signaling in plants is still fragmentary, despite the recent success of identifying receptors for several of these highly active compounds, e.g. auxin, cytokinin, gibberellin, and brassinosteroids. Other receptors remained elusive or in question, namely those for JA and ABA. We want to search for the primary targets of JA and ABA by using a new experimental approach, the yeast three-hybrid technology, which allows direct functional cloning of proteins that interact with synthetic hybrid ligands in vivo. Using several cDNA libraries synthesized from several organs, tissues, and plants that have received different kinds of stress, the whole expressed genome (proteome) of Arabidopsis thaliana will be scanned for JA and ABA targets, thereby providing a system-wide overview of JA- and ABA-binding proteins. Significantly, the development of the yeast three-hybrid technology for application to plant systems will allow the systematic search for targets of other organic small molecules and hence will be beneficial for the whole plant science community.

• DFG Programme: Research Grants