Prof. Dr. Hans-Henning Kunz

Exploring the relevance of plastid ion transport for organellar function and photosynthesis

Plants and all other life forms rely on a sufficient supply of nutrient metals. Mobilized and taken up through the root, these ions need to be distributed in the right amounts to all different cell types. In every cell an additional fine-tuned shuffling takes place which is critical to set up the organellar ion homeostasis.

Research in the Kunz lab focusses on the leaf plastid, also known as the chloroplast. Chloroplasts possess three protein containing membranes: an outer and an inner envelope membrane and the thylakoid membrane which harbors the photosynthetic machinery. Charged molecules such as metal ions can pass these membranes only assisted by specific transport proteins. We work towards identifying the genes encoding for these plastid ion transport proteins. Besides biochemical assays to characterize the carriers and channels in vivo and in vitro, we study gain and loss-of-function mutants to understand the role of specific metal ions for chloroplast function and photosynthesis. Additionally, we assess the importance of plastid ion homeostasis for plant performance with focus on abiotic stress conditions. To accelerate research in our field, we have constructed organelle-specific artificial micro RNA libraries that enable plastid-specific forward genetic screens.

Students who join our diverse group receive training in protein biochemistry, molecular biology, genetics, elemental analysis using Total Reflection X-Ray Fluorescence, live-imaging, and chlorophyll fluorescence based phenotyping.