Start of funding 01.01.2019

High resolution imaging of microtubule dynamics and computational modelling

Prof. Dr. Farhah Assaad
Technische Universität München
School of Life Sciences Weihenstephan WZW

Prof. Dr. David Erhardt
Carnegie Institution for Science
Plant Biology



Understanding dynamic changes in microtubule arrays and in protein-protein interactions in response to developmental or environmental cues is crucial to understanding plant adaptive responses. Several features of plant microtubule dynamics are unique. First, plant MTOCs are pleiotropic rather than central. Second, whereas in animal cells the minus end is stable and the plus end dynamic, in plants both the plus and minus ends are dynamic. Because plant microtubule minus ends can be nucleated at different places at different times, and because they are not stable, plus end capture mechanisms and membrane anchors may play a particularly important role in the stability of higher order microtubule arrays in plants. To explore the role of membranes in organizing microtubules in plants, our group has carried out immunoprecipitation experiments with mass spectrometry readout (IP-MS). This approach has identified interesting interactions between a membrane associated tethering complex (TRAPPII) and microtubule associated +TIP protein (MAP65). One of our major scientific objectives is to understand the regulation, dynamics and implications of TRAPPII-MAP65 interactions in plant cells, throughout cell division or after exposure to blue light. We are generating transgenics with a combination of mutations or markers for FRET-FLIM experiments, including targeted phosphovariants, at the TRAPPII or MAP65 loci. These will be imaged at the Carnegie at different cell cycle stages or with blue light stimulus, and analysed with image analysis and computational modelling algorithms developed by the group of Prof. Ehrhardt at the Carnegie Institute on Stanford Campus. Dave Ehrhardt’s laboratory has lead the field of plant cell biology over the last decade. He has extensive expertise with microtubule dynamics, including quantitative microscopy of microtubule nucleation, treadmilling, catastrophe and severing.