- This event has passed.
PhD Transfer Exam – Michael Bunsick (Lumba lab)
October 21, 2020 @ 1:30 pm - 2:30 pm
“An Investigation into the Mechanisms and Identities of Rhizospheric Small Molecule Signals”
Wednesday, October 21, 2020 at 1:30pm
Join Zoom Meeting:
https://utoronto.zoom.us/j/85872677796
Meeting ID: 858 7267 7796
Passcode: 590612
Abstract
Plants shape their ecological interactions by exuding small molecules through their roots. Nearby symbiotic fungi and root parasites use these molecular cues to coordinate their growth and development with the plant. One of these small molecules is the plant hormone strigolactone. Plants emit strigolactone into the soil to attract symbiotic arbuscular mycorrhizal (AM) fungi. However, the parasitic plant Striga hermonthica also recognizes this signal and uses it as a cue to germinate. Unfortunately, both Striga and AM fungi are recalcitrant to genetic analysis, so we cannot directly ask fundamental questions about their biology. To get around this problem I propose to use evolutionarily related model organisms as proxy systems. With these systems I will ask two questions about these rhizospheric interactions. First, I will determine whether other plant-derived small molecules mediate fungal-plant interactions. To this end, I will use Saccharomyces cerevisiae as a model system, since prior work has found it can respond to strigolactone. With this yeast, I propose to build a collection of transcriptional reporters and determine whether other plant-derived small molecules alter their expression. Second, I will determine the mechanism strigolactone uses to initiate Striga germination. My previous work with the model plant Arabidopsis thaliana suggests that strigolactone activates a collection of α/β-hydrolase receptors which inhibit the activity of SUPPRESSOR OF MAX2 1 (SMAX1).