A Role for TIC55 as a Hydroxylase of Phyllobilins, the Products of Chlorophyll Breakdown during Plant Senescence

Author Profile

Mareike Hauenstein

Highlighted Paper: Hauenstein et al et al. (2016). A role for TIC55 as a hydroxylase of phyllobilins, the products of chlorophyll breakdown during plant senescence. Plant Cell. Advance Publication September 21, 2015; doi:10.1105/tpc.16.00630.

Current Position: PhD student in the group of Prof. Dr. Stefan Hörtensteiner at the Department of Plant and Microbial Biology at the University of Zurich..

Education: Bachelor in Biology at the University of Zurich (2013), Master in Plant Biology at the Department of Plant and Microbial Biology at the University of Zurich (2015).

Non-scientific Interests: Climbing, motorbiking, cooking.

During my Bachelor's studies I got the opportunity to participate in a practical course in Prof. Dr. Stefan Hörtensteiner's group. The comprehensive topic of his group is the pathway of chlorophyll breakdown. An ubiquitous process that all of us can observe by eye in our everyday life, chlorophyll breakdown causes the change of leaf color in fall and the color change of ripening fruits. I learned that this was a crucial step for the plant in order to protect itself from oxidative damage during nutrient recycling and that it requires an array of consecutively acting enzymes. I found it fascinating to ask how we can use compound analysis, biochemical and genetic tools to understand these processes at the molecular level. Each member of the group was focusing on a distinct part of the pathway, on the pathway in different species, or on its regulation. When I decided to join this group for my Master's thesis project, I started working on the identification of the enzyme responsible for the common side-chain modification, the hydroxylation of the C3² of chlorophyll catabolites. During my Master's and the beginning of my PhD we were finally able to assign this function to TIC55. It was fun adding another piece to the puzzle of chlorophyll catabolism. Since little is known about the physiological function of the side chain modifications, I hope that I can further contribute to solving this fascinating puzzle.