The role of the plasma membrane-associated E3 ubiquitin ligase SAUL1 in suppression of premature senescence and reduced growth in plants

• Applicant: Professor Dr. Stefan Hoth
• Subject Area: Plant Physiology
• Term: from 2008 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 67172109

Like in many organisms, plant senescence commences age-dependently and leads to cell death. This process becomes visible by chlorophyll degradation resulting in yellowing of leaves. Leaf senescence is genetically associated with aging and developmentally welldefined to guarantee recycling of resources from senescing leaves into young leaves or seeds to optimize growth and reproduction. We will use saul1 mutant plants, which we have established as low light-inducible, age-independent and highly reproducible model system for senescence and cell death, to decipher the underlying regulatory signaling network. Association of the E3 ubiquitin ligase SAUL1 and its closest homologue to the plasma membrane renders them extremely interesting regulators of key signaling components at the plasma membrane. We are aiming to find out the mechansim for SAUL1 plasma membrane association and to identify all interacting proteins as well as putative targets for ubiquitination through SAUL1. We will also use the saul1 model system to define similarities and differences between low light and salt or osmotic stress responses, respectively. Our research project will help to understand the molecular regulation of senescence and cell death that attribute for limited yield in agriculture.

• DFG Programme: Research Grants