Cytochrome P450 CYP89A9 Is Involved in the Formation of Major Chlorophyll Catabolites during Leaf Senescence in Arabidopsis

Author profile

Bastien Christ & Iris Süssenbacher

Bastien Christ

Current Position: Post-doc in the group of Prof. Stefan Hörtensteiner at the Institute of Plant Biology at Zürich University (Switzerland).

Education: PhD (2013) in the group of Prof. Stefan Hörtensteiner at the Institute of Plant Biology at Zürich University (Switzerland). M.S. (2009) in Plant Ecology and Physiology and B.S. (2007) in Biology at Neuchâtel University (Switzerland).

Non-scientific Interests: Running, paragliding and ski-touring.

After completing my Master's thesis on protein import into chloroplasts in Prof. Felix Kessler's lab (Neuchâtel University, Switzerland), I started my PhD in the group of Prof. Stefan Hörtensteiner at Zürich University working on chlorophyll breakdown. At that time, the degradation of phototoxic chlorophyll catabolites occurring within the chloroplast was already well described, but the enzymes responsible for the modifications of colorless catabolites in the cytosol were still unknown. Using molecular and biochemical approaches, we could identify and characterize two enzymes that modify colorless chlorophyll catabolites in Arabidopsis (Christ, et al. (2012), Plant Physiology; Christ, Süssenbacher, et al. (2013), Plant Cell). These two enzymes, MES16 and CYP89A9, are thought to facilitate reallocation of chlorophyll catabolites from the chloroplast to the vacuole by increasing their polarity, but their exact physiological roles remain to be elucidated. My current Post-doc position in Stefan Hörtensteiner's lab gives me the opportunity to further investigate unsolved questions on chlorophyll catabolite modifications. I am now also working on other aspects of chloroplast biology such as the proteome of senescent chloroplasts in Arabidopsis and the interaction between ER and chloroplast envelope in senescent cells.

Iris Süssenbacher

Current Position: Graduate student at the research group of Prof. Kräutler, Institute of Organic Chemistry and Center of Molecular Biosciences (CMBI), University of Innsbruck, Austria.

Education: Mag. rer. nat. in Chemistry (2011) at University of Innsbruck, Austria.

Non-scientific Interests: Watching movies, playing PS3 and cooking.

I attended a school with a focus on natural science where I discovered my interest and talent in this field. After graduation, I decided to study chemistry at the University of Innsbruck. I finished my diploma degree in 2011 with my thesis on the discovery of 'New chlorophyll catabolites in leaves of Arabidopsis thaliana'. During this time, it was very interesting for me as a chemist to get some insight into biological science. This was one reason to continue my work on this topic as PhD student at the research group of Prof. Kräutler. The main focus of my research is the structural elucidation of these new types of chlorophyll breakdown products and the discovery of further compounds of interest in wild type as well as some mutants of Arabidopsis thaliana. For these analyses I use modern spectroscopic and spectrometric as well as analytical methods. These findings will, I hope, lead to a better understanding of how plants break down chlorophyll. I'm really thankful for the opportunity to work in this interesting field of research together with people in our lab and my collaborators. I'm looking forward to continue working with them as we discover new interesting compounds.