I am interested in the mechanisms that enable plants to grow and develop, and to optimize their responses to environmental conditions. The research projects in my laboratory generate an understanding of how plant cells proliferate, expand and differentiate. We focus on the dynamics and organization of microtubules, amazing filamentous polymers made up of globular protein subunits called tubulins. Tubulins are signalling switches that exploit the conformational changes that occur when their bound GTP molecules undergo hydrolysis to coordinate the rapid growth and disassembly of microtubules. This is important because microtubules are the components of cellular nano-machines that carry out work that is essential for cellular development, and these machines are continually undergoing rearrangements as cells switch from one activity to another.

 

I grew up in Ottawa, in close proximity to nature, an amazing natural history and science and technology museum. I was the sort of kid who couldn’t be pulled away from the frog pond each spring, and kept a menagerie of fish, amphibians, reptiles, rodents and even had a pet leech called Maurice.  I had the good fortune of being born into a family of keen gardeners, outdoor recreation and nature enthusiasts. We had a cottage on an amazing island in the Rideau Lakes north of Kingston, where I spent many summers. The high school I went to in Ottawa, Hillcrest, had an enriched program in science, with a very dedicated group of teachers. It was hard to avoid becoming a biologist, though I did tinker with the idea of being a competitive cross-country skier. 

 

As an undergraduate student at Carleton University, while not training and competing in ski races, I found time to get interested in plant biology from courses taught by Professor Margaret McCully. I also had the good fortune to work for three consecutive summers in the laboratory of cell biologist George Setterfield. Although I completed an honours project on somatic hybridization as a means of transferring disease resistance between plant species, it was a directed study I did in 1983 on the role of microtubules and cell shape determination that captured my greatest interest. I am still working on that project.

 

In 1985, after a year or so working as a research associate in Dave Brown’s lab at the University of Ottawa studying the effects of methyl mercury on microtubule-dependent nerve development, Professor Brian Gunning recruited me to his lab in the Department of Developmental Biology at the Australian National University in Canberra, and I moved about as far away from home as possible to start a PhD.  My PhD supervisor, Richard Williamson, introduced me to the giant internodal cells of characean algae, and I utilized my newly developed skills in immunofluorescence microscopy to develop methods to explore the relationship between mechanical strain, microtubule orientation, and cell shape. While following the recovery of microtubules after drug-induced disassembly, I noticed a tendency for microtubules to nucleate off pre-existing microtubules, which led to my idea that in the absence of centrosomes, branch-form assembly through the association of initiating factors along the length of microtubules, leads to  dispersed microtubule arrays in plant cells are formed by factors associating with the lattice. About ten years later, gamma tubulin complexes were identified. 

 

After completing my PhD at the end of 1988, I completed a 3-year National Research Fellowship in the Williamson lab where, with the help of visiting Professor Peter Hepler, who was on sabbatical from the University of Massachusetts, developed a method for visualizing - for the first time - microtubules in living algal and plant cells by microinjecting fluorescently labelled tubulin that I had purified from sheep brains. This was no trivial exercise, involving early morning trips to the abattoir to collect fresh sheep brains. The work coincided with the introduction of confocal laser scanning microscopy. By today’s standards, the dynamics I could document now seems primitive. Nevertheless, the ability to confirm that microtubule assembly can occur at the cell cortex and the branch-form assembly I had proposed from fixed material, were important advances. 

 

In 1992, I was awarded an Alexander Von Humboldt Fellowship and moved to Germany to join the labs of Dr Diedrik Menzel at the Max-Planck Institute for Cell Biology and Professor Eberhard Schnepf at the University of Heidelberg. There I developed a method called freeze-shattering that made it possible to permeabilize cells for immunofluorescence, such as those with waxy cuticles that resisted wall digesting enzymes. Trying this technique out on various algal and plant species, I came across the model system Arabidopsis thaliana.

 

Late in 1993, when I moved back to Canberra to continue my Queen Elizabeth II Fellowship that I had been awarded in 1991, I decided to switch focus on algal internodal cells to carry out an immunofluorescence-based screen for temperature-sensitive microtubule organization-defective mutants, using the powerful model system Arabidopsis thaliana. This labour-intensive screen took over a year but resulted in the discovery of the MOR1 and CLASP microtubule-associated proteins, which have dominated my research program for over 25 years.

 

In 1996, I applied for and was successful in getting a faculty position at the ANU, which I held until 2004, when I moved to the University of British Columbia to join the Botany Department as a Professor and Canada Research Chair (CRC) in Plant Cell Biology. I am currently in my third CRC term. Between 2006 and 2018, I was Academic Director of the UBC Bioimaging Facility.