Platform for Plant Stress Signaling Analysis earns crucial NSERC-RTI grant
The Platform for Plant Stress Signaling Analysis at CSB examines the ways plants respond to drought, salt, infection and other stresses. We have been using this platform for 17 years, but many of the instruments are showing signs of wear. To update our facility, a group led by Professor Keiko Yoshioka has won a highly competitive NSERC Research Tools and Instruments Grant.
This important infrastructure revitalization allows existing work to continue on crop damage that is exacerbated by climate change, while allowing new studies to flourish. The newly funded instruments are ideal items for a shared platform and will ensure usage at full capacity.
Professor Yoshioka will uncover mechanisms of plant stress signal transduction and crosstalk. The Yoshioka lab focuses on signal transduction of plant stress responses; environmental effects on plant immunity; and abiotic and biotic stress response networks. These studies will feed into the production of stress-resistant plants.
Professor Heather McFarlane was recently appointed to pursue studies on finding a pathway to improve bio-products. Her lab will use the NSERC-RTI facility to uncover the molecular mechanisms of cell wall signaling, to improve cell wall engineering and plant biomass production.
Professor Darrell Desveaux will be tracking plant disease progression via systems-level analyses. The Desveaux lab is dedicated to the development of high-throughput assays for “Systems-Level” probes of plant-pathogen interactions.
Professor and Chair Nicholas Provart will leverage large datasets to understand plant resilience under drought stress. His lab has developed the INTACT (Isolation of Nuclei Tagged in Specific Cell Types) system for studying cell-type-specific drought responses in guard cells. The NSERC-RTI grant will assist them to pursue molecule-level work on understanding the role of hundreds of promising candidate genes in guard cell-specific drought response.
Learning to isolate and analyze DNA, RNA, proteins, and metabolites using the updated equipment is an essential component of any training program in cell and molecular biology. The skills of dozens of BSc, MSc and PhD students will grow from learning to use this platform, and Canadian crops will benefit. Congratulations!
Congratulations to F Michael Barrett Award 2022 winners from CSB!
Students taking our CSB497/CSB498/CSB499 courses earned valuable experience in CSB research labs, gaining skills and knowledge in specific fields including developmental biology, plant biology, and stem cell biology. Our professors welcome the curiosity and questioning that these undergraduates bring to their lab.
Six of these fourth year scientists gave exceptional presentations on the research they performed, and were presented with the F Michael Barrett Award for 2022. Congratulations!
The students, their research supervisor and their topic of research are as follows:
Sarah Robinson (Tepass lab)
Pebble RhoGEF: A characterization of knockdown phenotype with p35 and a genetic screen with Cyst RhoGEF in Drosophila imaginal wing discs
Vamanadev Hiralall (Tropepe lab)
CRISPR/Cas9‐mediated Mutagenesis to Investigate the Role of Musashi1 and ATF3 in Zebrafish Müller Glial Dedifferentiation
Wen Lei (Gilbert lab)
Investigating the Effect of Substrate Stiffness and ECM Tethering Synergy on Myoblast Cell Fate
Miya Tseng-West (Yoshioka lab)
Effects of Beneficial Canadian Soilborne Bacteria on Plant Immunity: Exploring Root Colonization
Enoch McAtee (Mitchell lab)
Identifying cis‐regulatory elements using CRISPR/Cas‐9
Kris Choi (Calarco lab)
Creation and Evaluation of FUS and TDP‐43 Transgenic Caenorhabditis elegans as Amyotrophic Lateral Sclerosis Disease Models
David G Butler (1936-2022), Professor of Endocrinology
We are sad to share the news that our emeritus Professor David G Butler passed away in February 2022.
Born in Vancouver, BC, David Butler obtained his PhD with Professor Ian Chester-Jones at the University of Sheffield in 1964 and was recruited to the Department of Zoology that same year. He began his tenure as a Professor in Endocrinology at the newly constructed Ramsay Wright Zoological Laboratory building, complete with Space Age animal facilities, cold rooms and dedicated biochemical preparation rooms. The Department of Zoology has evolved into the current Department of Cell & Systems Biology.
Professor Butler had a passion for speaking with the public about science, sparked by presentations he viewed as a school child in BC. He was a regular presenter at UofT Day outreach events (pictured here in 1991). He was also dedicated to students in Zoology; Dr Alia Cadinouche states that he “introduced me to scientific research and provided me with much encouragement throughout”. Dr Gavin Oudit fondly recalls that Prof Butler would share the ”key aspects of his research training, occasionally sprinkled with Canadian history and his love for the BC coast.”
Visitors at UofT Day events in the 90s clamoured to see his Alligatoridae caiman (which Prof Butler used for his studies of the pressor effects of angiotensin peptide), along with his other species of interest; eels, bowfins and ducks. Butler’s expertise allowed him to fulfill his natural calling of comparative endocrinology. Dr Oudit lauds Prof Butler’s great skill in surgical techniques. “His elegant self-crafted surgical expertise was exemplified by his ability to cannulate independently the lateral and medial nasal glands in ducks thereby allowing the elucidation of the neural versus the humoral control of these remarkable exocrine glands.”
Part of Prof Butler’s legacy is that Dr Oudit continues to pursue a passion for angiotensin through clinical studies of the role of angiotensin peptides in the cardiovascular system and in SARS-CoV-2 infection.
Professor Butler’s diverse interests and impressive accomplishments are detailed in his obituary at this link.
Cell wall success with two awards for the McFarlane lab at CSPB 2021!
Our colleagues Natalie Hoffmann and Eduardo Ramirez-Rodriquez won awards for their research on cell wall biosynthesis at the annual Canadian Society of Plant Biologists (CSPB) meeting, held virtually on Nov 27, 2021. Congratulations!
For plants, we often consider nutrients inside plant cells to be most important, but many fundamental materials come from the exterior wall of plant cells; products like wood, cotton, and biofuels. Graduate students Hoffmann and Ramirez-Rodriguez use two different approaches in the laboratory of Professor Heather McFarlane to understand how cell walls are made.
Hoffmann genetically disrupted manufacture of xyloglucan molecules important for cell wall formation during cell expansion. Components like xyloglucan are made inside the cell and transported to the exterior wall by a process called cell wall secretion. The cell wall secretion delivery system passes lipid-coated packages through endomembranes inside the cell, including a large sorting centre, the Golgi organelle. By integrating microscopic analysis with her genetic disruptions, Hoffmann's award winning talk showed defects in many endomembrane components (including the Golgi), as if a mislabelled package had snarled the entire delivery system. Hoffmann used her "very visual" sensibilities to evocatively explain the fluorescent and electron microscope images in her talk titled "Alteration of xyloglucan biosynthesis disrupts endomembrane structure and function".
Under salty or dry conditions, plants can grow to be twisted and stunted due to changes in the cell wall. Ramirez Rodriguez studies the protein changes that occur in plant cells under cell wall stress, including stress caused by herbicides. Cells under stress will change protein activity by adding phosphate molecules; these phosphorylation signals can result in the deformed plants seen in a dry, salty field. Ramirez-Rodriquez has isolated proteins that show phosphorylation changes under stress. By testing plants with genetically-encoded defects in his target proteins, he identified altered plants that show compromised cell wall integrity. He even describes one deformed seedling that looked like a pine cone! Knowing how his target proteins interact to cause phosphorylation has led to a deeper understanding of cell wall stress signalling in plants. His award winning poster was titled "Leveraging phosphoproteomics to uncover mechanisms of cell wall integrity signaling".
The CSPB Eastern Regional Meeting brought together plant biology researchers from academic, government, and industry labs in Eastern Canada for a day of talks, posters, and networking. Hoffmann was eager to present, as it had been along time since her last talk. Sitting at home, Ramirez-Rodriquez was anxious that no visitors would appear at his virtual poster, but his chat and headphones reflected a steady stream of interest. Both Hoffmann and Ramirez-Rodriquez are grateful to CSPB and enjoyed the opportunity to virtually meet other plant scientists and learn about their struggles and accomplishments.
Congratulations to CSB's Graduate Student Award Recipients!
Congratulations to our Graduate Students who earned recognition for their accomplishments at our Graduate Student Awards on December 10th, 2021!
Valerie Anderson Graduate Fellowship
- Awarded for academic merit to an outstanding student in any subdiscipline of plant biology.
Recipient: Matthew Bergman (Phillips Lab)
Kenneth C. Fisher Fellowship
- Awarded in recognition of a student who maintains a high standard of academic and research achievement, balanced with outstanding extra-curricular contributions to their department.
Recipient: Kathryn McTavish (Guttman Lab)
Sheila Freeman Graduate Award in Zoology
- Awarded to an incoming or in-progress graduate student focusing their studies in animal biology.
Recipient: Jeffrey Stulberg (Tropepe Lab)
Dr. Clara Winifred Fritz Memorial Fellowship in Plant Pathology
- Awarded to a student studying in the area of plant pathology demonstrating academic excellence.
Recipient: Zachary Kileeg (Mott Lab)
Duncan L. Gellatly Memorial Fellowship
- Awarded each year to one or two graduate students demonstrating excellence in Virology and/or Molecular Biology research
Recipient: Charlotte Martin (Calarco Lab)
Duncan L. Gellatly Memorial Fellowship
Recipient: Louis Dacquay (McMillen Lab)
Yoshio Masui Prize in Developmental, Molecular or Cellular Biology
- Awarded to a master’s or doctoral student in the Department on the basis of academic merit.
Recipient: Ernest Iu (Plotnikov Lab)
David F. Mettrick Fellowship
- Awarded to a graduate student in CSB engaged in any aspect of zoological research.
Recipient: Steven Chen (Chang Lab)
Dr. Klaus Rothfels Memorial Scholarship
- Scholarship awarded on the basis of academic standing.
Recipient: Arely Cruz-Sanchez (Arruda-Carvalho Lab)
Senior Alumni Association Prize in Cell & Systems Biology
- Awarded to a student in the department based on academic merit.
Recipient: Tammy Lee (Saltzman Lab)
Hilbert and Reta Straus Award
- Awarded to a full-time graduate student who has demonstrated high research achievement in the fields of plant molecular or cellular biology.
Recipient: Tamar Av-Shalom (Guttman Lab and Desveaux Lab)
Vietnamese-Canadian Community Graduate Award in Zoology
- Awarded to a master’s or doctoral student studying animal biology based on academic merit and who exhibits research potential, excellent communication skills and leadership.
Recipient: Shanelle Mullany (Mitchell Lab)
Elizabeth Ann Wintercorbyn Award
- This first award is made to a student engaged in research work which is likely to prove beneficial to medicine.
Recipient: Jonathan Burnie (Guzzo Lab)
Elizabeth Ann Wintercorbyn Award
- The second half of the award goes to a student engaged in research work which is likely to prove beneficial to agriculture.
Recipient: Avesh Chadee (Vanlerberghe Lab)
Ramsay Wright Scholarship in Cell and Systems Biology
- Awarded to a CSB student engaged in research in zoology.
Recipient: Areej Al-Dailami (Lange Lab)
Zoology International Scholarship
- This is the first of two awards for international students demonstrating high academic performance.
Recipient: Tara McDonnell (Tropepe Lab)
Zoology International Scholarship
- This is the second award, again, going to international students demonstrating high academic performance.
Recipient: Sonia Evans (Phillips Lab)
Zoology Sesquicentennial Graduate Award
- Awarded to a graduate student enrolled in full-time studies in CSB, on the basis of academic merit.
Recipient: Mouly Rahman (McGowan Lab)
Alfred and Florence Aiken and Dorothy Woods Memorial Graduate Scholarship in Cell and Systems Biology
- Awarded based on academic merit.
Recipient: Anita Taksokhan (Peever Lab)
Rustom H. Dastur Graduate Scholarship in Cell and Systems Biology
- Awarded to a graduate student studying plant sciences, on the basis of academic merit.
Recipient: Arnaud N’Guessan (Nguyen Ba Lab)
Awards from earlier this year:
Dr. Christine Hone-Buske Scholarship for Outstanding Publication by a PhD Student
(Awarded in March)
Recipient: Dr Julia Gauberg (Senatore Lab)
Joan M. Coleman Ontario Graduate Scholarship in Science and Technology
(Awarded in June as part of the OGS competition)
Recipient: Avesh Chadee (Vanlerberghe Lab)
Sherwin S. Desser Ontario Graduate Scholarship in Science and Technology
(Awarded in June 2021 as part of the OGS competition)
Recipient: Chengyin Li (Saltzman Lab)
Plotnikov lab finds key to reducing (cellular) stress is spikes of mDia1
When you’re dancing, running or even walking, fibroblast cells stretch and adapt to all your vigorous movements. What allows these dynamic cells in our bodies to keep their shape and position without being torn apart? Fernando Valencia in Sergey Plotnikov’s lab at Cell & Systems Biology has determined that cells respond to internal forces by activating Dia1 proteins at force-bearing focal adhesions, which dampens tension on the actin cytoskeleton and helps the cell control its shape and maintain its integrity.
Cells under external tension experience internal forces through attachment points on their surface called focal adhesions. Actin and myosin proteins are components of the cytoskeleton that form dynamic stress fibers at the focal adhesions. Plotnikov wondered if there was a protein that would regulate recruitment of cytoskeletal components to lengthen or shorten these fibers.
Valencia was fascinated to work in Plotnikov’s lab since physical forces are such a fundamental property in science. As a new student, he and Plotnikov decided to focus on formin proteins, which were known to be found in proximity to actin. Through chemical and genetic tests, they found that disrupting expression of the mouse formin protein mDia1 greatly reduced the rate of actin incorporation into stress fibers.
In cells depleted of mDia1, Valencia observed that the stress fibers suffer mechanical damage. Under normal conditions, stress fiber repair would be mediated by the zyxin protein, but under reduced mDia1 levels, the effectiveness of this repair system is also degraded. Thus mDia1 has a pivotal role in safeguarding stress fibers against mechanical damage.
By combining live-cell imaging with mathematical modelling, Valencia showed that actin polymerization at focal adhesions exhibits pulsatile dynamics. They conclude that activity of mDia1 dampens the mechanical tension on the stress fibers through spikes of mDia1 activity triggered by contractile forces.
This work is published in the journal Developmental Cell as “Force-dependent activation of actin elongation factor mDia1 protects the cytoskeleton from mechanical damage and promotes stress fiber repair”
What Sits at the Centre of Wound Healing?
The science of rapid wound healing has new insights due to discoveries in fruit flies from the Fernandez-Gonzalez lab at University of Toronto. The results of their collaboration, community and perseverance were published in the journal Cell Reports as “p38-mediated cell growth and survival drive rapid embryonic wound repair”. Congratulations to Gordana Scepanovic who earned the 2022 Christina Hone-Buske Scholarship for this ground-breaking work!
The Fernandez-Gonzalez lab in Biomedical Engineering use lasers to cut cell membranes in the fruit fly embryo. They have developed image analysis techniques to examine the dynamics of wound repair as the lesion expands, then contracts to seal the damage. Their techniques show that the actin and myosin II cytoskeletal proteins polarize to form cables around the wound which draw the wound shut to limit the risk of infection and tissue loss.
As a result of a chat with Ran Kafri, a cell signaling specialist at SickKids Hospital, Fernandez-Gonzalez considered targeting p38 in embryos, since in adult flies the p38 signaling protein is involved in responses to tissue damage. His student Miranda Hunter used a chemical inhibitor of p38 in embryos and was excited to find that inhibiting p38 resulted in a delay in wound closure.
Hunter has since graduated with a PhD from Cell & Systems Biology (CSB), and passed this result to new CSB PhD student Gordana Scepanovic to take on a deeper study of this observation. Scepanovic altered p38 chemically and genetically and used all the tools in the lab to look at the contractile cytoskeletal apparatus around the wound. She went through months of frustration as the properties of the cytoskeleton didn’t change no matter how she disrupted p38.
After long hours of perseverance at the microscope, Scepanovic had the amazing insight that although the cytoskeletal ring wasn’t altered by p38 disruption, the size of the cells around the wound looked different. In addition, disruption of p38 reduced survival in cells adjacent to the wound.
Scepanovic decided to measure cell size and survival in her fly embryos, confident from her previous “negative” results that the contractile ring was unaltered. This meant she was breaking new ground for her lab and needed new means to measure these metrics.
As they attended a scientific conference, Scepanovic and Fernandez-Gonzalez reviewed the talks and posters they had seen and determined that the most appropriate tool in the community was the membrane bound Resille protein that could outline the periphery of the cell to allow measurement of cell height.
Scepanovic’s insight was shown to be correct: cell height was unchanged, while cell surface area expanded after wounding, confirming that the volume of the cells around the lesion increased during wound repair. In fact, the actomyosin cytoskeleton was not sufficient to close the wound if cellular swelling was blocked. She identified the NKCC ion transporter as an important p38-regulated component of cellular swelling.
Scepanovic also found that wounds were excessively large when she inhibited p38. Hunter had previously studied the role of Reactive Oxygen Species (ROS) in promoting formation of the contractile ring, so Scepanovic looked at ROS in cells with altered p38. She found that p38 plays a key role in the regulation of ROS during wound repair, allowing sufficient ROS production for cytoskeletal polarity, but not enough to damage cells.
These fundamental insights put p38 at the centre of a complex web of wound repair mechanisms and may lead to new pharmacological interventions to promote rapid tissue repair by targeting p38 and associated regulators.