Bryden O'Gallagher MSc Candidate, Plaxton Lab, Queen's University Exploring the role of the dual-targeted 'mammalian type' purple acid phosphatase AtPAP17 in Arabidopsis thaliana phosphate and ROS metabolism
Orthophosphate (H2PO4-, Pi) is an essential, but environmentally limiting macronutrient required for many fundamental metabolic processes. Pi starved (–Pi) plants undergo a complex array of morphological and biochemical/molecular adaptations, collectively known as the ‘Pi starvation response’. Purple acid phosphatases (PAPs) play an indispensable role in the PSR by scavenging and recycling Pi from intra- and extracellular Pi-monoesters. The aim of this thesis has been to integrate biochemical and genetic approaches to help assess the role of AtPAP17 (one of 29 predicted Arabidopsis PAPs) in Pi and ROS metabolism. AtPAP17 is unique to previously characterized PAPs as it: i) is transcriptionally induced in response to Pi-starvation, leaf senescence, salinity, drought, as well as immune-related biotic stress, and ii) exists as a low molecular weight (35 kDa) ‘mammalian like’ PAP that exhibits both acid phosphatase and peroxidase activity. I determined the H2O2 peroxidase kinetics of purified AtPAP17, while demonstrating that this PAP is de novo synthesized and dual-targeted to the secretome and intracellular fraction of –Pi, senescing, or salt stressed Arabidopsis, but rapidly turned over following Pi resupply to –Pi plants. Nevertheless, loss of AtPAP17 expression in an atpap17 mutant did not influence the ability of Arabidopsis to acclimate to Pi deprivation, salinity or oxidative stress, or to recycle Pi during leaf senescence. This research field is enabling the development of innovative strategies for engineering Pi-efficient and stress-tolerant crops, urgently needed to reduce inputs of unsustainable Pi fertilizers for maximum agronomic benefit and long-term global food security and ecosystem preservation.
Howard Teresinki PhD Candidate, Snedden Lab, Queen's University Identification and characterization of novel targets for a subfamily of Arabidopsis calmodulin-like (CML) proteins
Calcium is a ubiquitous second messenger in signal transduction pathways of all eukaryotic cells. In plants, calcium signalling plays critical roles in a variety of developmental processes as well as during cellular responses to abiotic and biotic stress. The evolutionarily-conserved calcium sensor, Calmodulin (CaM), responds to calcium signals and, through protein-protein interactions in cells, facilitates downstream responses. Plants possess an additional and unique family of “calmodulin-like” (CML) calcium sensors which, in Arabidopsis thaliana, contains 50 members. Despite this expanded complexity, few of the binding partners and/or in vivo functions of CMLs are known. Here I present data from my PhD thesis demonstrating that CaM and a subfamily of biochemically unusual CMLs are capable of interacting with specialized structural domains from among three distinct and unrelated protein families in Arabidopsis. I utilised a combination of genetic, biochemical, and biophysical approaches to explore the physical properties and physiological roles of CML interactions with these putative targets. Collectively, my data suggests novel functions for plant CMLs in gene regulation and cytoskeletal activity.
Dr. Arinjay Banerjee Laboratory for Zoonotic Viruses and Comparative Immunology, University of Saskatchewan Past, present and future of SARS-CoV-2
Dr. Arinjay Banerjee is a postdoctoral researcher in Dr. Karen Mossman’s laboratory at McMaster University. Over the last 6 years, he has studied emerging zoonotic viruses, such as coronaviruses that spill over from wildlife species (eg. bats) to infect humans and cause severe disease. More recently, Dr. Banerjee has been investigating SARS-CoV-2 and its interaction with the human immune system. In this talk, he will discuss his current research on SARS-CoV-2 and work that his team shall undertake at the Vaccine and Infectious Disease Organization to investigate emerging zoonotic viruses and develop countermeasures.
Dr. David Ng AMBL, Michael Smith Laboratories, University of British Columbia The Phylo Trading Card Game: A crowdsourced game-based learning approach to biodiversity education
The Phylo Trading Card game is an exercise in crowdsourced game design with the explicit intent of introducing biodiversity and other STEM concepts to its players. The Phylo game is a competitive and interactive way for participants to engage with species and ecosystems. This seminar will talk about the origins and progression of the project as a tool for STEM related game-based learning. The talk will also briefly mention a pilot study that revolved around human perceptions of wildlife and identifying whether such perceptions may be altered by using the game as a potential tool. Utilizing an in-lab study design, this research identified the impact of this novel educational approach and compared it to more traditional teaching methods across criteria including ecological perceptions, knowledge, positive and negative affect, and species recall.