Plant Molecular Biology

Our focus has been the role of small GTPases in intracellular transport, signaling, plant defense and actin modulation. We have been studying the localization and dynamic properties of individual subunits of the COPII-coat complex in order to determine their function in anterograde transport between the ER and the Golgi apparatus.

By co-expressing fluorescent protein fusions of these subunits with different types of fluorescent markers we have been able to investigate the interaction between the COPII-machinery and the different types of cytoskeletal filaments. By combining co-localization data with results from inhibitor experiments, we have been able to ascertain the role of microfilaments and microtubules in intracellular transport and organelle dynamics.

We are also studying a signaling cascade leading from Rac-like GTPases to the ARP 2/3 complex and the role of this cascade in plant cell morphogenesis. The use of cytoskeletal markers has enabled us to visualize changes in organization and dynamics in different mutants.