Millie Smith, MSc Candidate, Plaxton Lab Phosphorylation of the cytosolic glucose-6-phosphate dehydrogenase isozyme AtG6PD6 in response to phosphate nutrition of the model plant Arabidopsis thaliana Glucose-6-phosphate dehydrogenase (G6PD) is a tightly regulated enzyme that catalyzes the first committed step of the oxidative pentose phosphate pathway (OPPP). The OPPP plays a pivotal role in generating reducing power in the form of NADPH, and carbon skeletons (e.g., ribose-5-P) needed for anabolism and cell growth. Our recent phosphoproteomics study discovered that the cytosolic G6PD isozyme, AtG6PD6, became hyperphosphorylated at multiple N-terminal residues 48 h following resupply of 2 mM phosphate (Pi) to Pi-starved (–Pi) Arabidopsis thaliana cell cultures. Although other phosphoproteomic studies have documented in vivo N-terminal phosphorylation of AtG6PD6 and its orthologs from other plant species, the functions and mechanisms of this phosphorylation event remain unknown. My research seeks to test the hypothesis that phosphorylation activates AtG6PD6 to enhance OPPP flux during the rapid resumption of cell growth that follows Pi resupply to –Pi Arabidopsis. Immunoblotting with a phosphosite-specific antibody confirmed that AtG6PD6 from Pi-resupplied, but not –Pi, Arabidopsis suspension cells and roots was phosphorylated at Ser18. This correlated with an increase in extractable G6PD activity following Pi-resupply to –Pi Arabidopsis seedlings (i.e., root extracts). Although the native enzyme is highly unstable in vitro, a partial purification of phosphorylated AtG6PD6 was achieved from Pi-replete suspension cells. The purified preparation was rapidly dephosphorylated by incubating with exogenous λ-phosphatase, and the kinetic properties were investigated. Assessing the interplay between Pi nutrition and cytosolic G6PD phosphorylation may contribute to our understanding of post-translational OPPP control in plants, while identifying targets for developing Pi-efficient crop varieties. Such cultivars are urgently needed to alleviate agriculture’s over-reliance on massive applications of non-renewable and polluting Pi fertilizers.
Dr. Marc Laflamme, Professor, University of Toronto Mississauga Complexity in the oldest animal communities My research focuses on the Ediacaran Period (635-538 Ma), which represents a pivotal time in Earth history, marked by the transition from single-celled organisms into complex multicellular animals. My interests lie in the natural history and functional morphology of the Ediacara biota, a group of soft-bodied organisms whose affinities are fiercely debated, and whose disappearance from the fossil record prior to the Cambrian explosion of animals is equally perplexing. The geobiological context in which the first animals evolved (and in which the Ediacara biota disappeared) thus represents one of the most crucial transitions in the history of life, incorporating Earth’s first major biotic crisis, as well as its most dramatic evolutionary radiation. I hope to showcase how innovative computational approaches to investigating fossil morphology has led to the discovery of some of the earliest evidence for facilitation and Ediacaran nurseries, while dedicated studies into the decay of soft-tissues has led to novel conclusions surrounding biases in the fossil record of early life.
Dr. Laurence Yang, Assistant Professor, Queen's University Toward precision whole-cell simulators Manufacturing industries find computer simulations to be indispensable: they speed up design, increase product quality, and reduce R&D costs while helping to find alternatives to traditional design methods. Likewise, the bio-manufacturing industry has relied on simulators to model reactors and processes. Increasingly, companies are finding value in simulating the living cell factories themselves (microbes, mammalian cell lines, etc.). We will demonstrate cell modeling with examples from multiple organisms (Pseudomonas, Escherichia coli, algae), and for varying applications (drug discovery, bioproducts, discovery). We discuss modeling of microbial stress responses in the context of antimicrobial resistance. With recent advances in integrated genome-scale models of metabolism and protein expression, we developed a framework to predict microbial response to thermal, oxidative, and acid stresses. The models accurately compute how E. coli changes gene expression and metabolic states in response to these stresses, together with variations in nutrient availability. Furthermore, these models explain the molecular mechanisms underlying improved fitness observed for several microbes that were adaptively evolved under oxidative stress. We then show how the modeling method extends to eukaryotes, using algae as an example.
Kate Mitchell, MSc Candidate, Martin Lab The impact of wind turbines on the distribution of wintering and migrating raptors Renewable energy sources, such as wind power, are rapidly expanding as governments aim to fight climate change. However, wind turbines may negatively impact surrounding wildlife. Raptors are birds of prey, essential in maintaining their ecosystems. Raptor collisions with wind turbines are heavily studied, but the spatial displacement of these birds due to wind turbines has received less attention. Understanding collisions and displacement are both necessary to comprehend the overall effects of wind turbines on raptors. In this study, we used standardized surveys to record the presence, number, and location of wintering and migrating raptors on Amherst Island for three years before and after the wind turbines were built to assess whether the wind turbines have affected raptor distributions.
Dr. Saeid Mobini, Phytotron Facility Manager, Queen's University Revolutionizing Soybean Breeding: Incorporating Speed Breeding Techniques Speed breeding is an innovative agricultural methodology that revolutionizes the traditional plant breeding process by leveraging controlled environments and specialized lighting to accelerate crop growth cycles, significantly shortening the time required to produce successive generations of plants. This cutting-edge technique empowers plant breeders to expedite genetic selection, enhance diversity exploration, and swiftly develop improved crop varieties to address critical global challenges, including food security, climate change, and disease resistance. Speed breeding's adaptability to various crop species has positioned it as a transformative tool in modern agriculture, driving crop improvement and sustainability advancements.
Tazi Rodrigues, MSc Candidate, Blanchfield Lab Patterns, consequences, and processes of mutualism evolution in the legume-rhizobium system Cooperation between species is widespread in nature yet the circumstances under which
mutualism evolves remain mysterious. My research uses the legume-rhizobium interaction to better understand patterns in mutualism evolution across geographic space, the ecological consequences of engaging in mutualism, and how mutualism evolves at a molecular level. Currently, our understanding of the legume-rhizobium interaction comes from a few well-studied temperate species. My research advances the field of legume-rhizobium research by sampling, sequencing, and analyzing non-model species from other parts of the globe, including the tropics. Legume-rhizobium interactions are greatly influenced by nutrient and partner availability in their habitat. I investigated changes in microbial community assembly on legumes across a large latitudinal gradient to understand how this interaction changes in temperate and tropical habitats. Although legumes hosted similar numbers of rhizobia partners across the range, tropical legumes associated with more non-rhizobia strains suggesting that tropical plants are less choosy of their symbiotic partners. There are many predicted benefits of being a less choosy host or generalist host to many symbiotic microbes. Using meta-analysis methods, I demonstrated that legume hosts that associate with many different rhizobial partners are more likely to find a compatible partner when introduced to a novel habitat. Generalist legumes establish in many new ranges and therefore experience greater ecological success compared to legume species that specialized on only a few rhizobia partners. It is unclear whether or how mutualism effects rates of molecular evolution. Most of the literature is focused on understanding how parasitic interactions are predicted to increase evolutionary rates in interacting species. I generated new sequence data from several non-model mutualistic species and found that mutualistic lineages in plants and rhizobia show elevated rates of molecular evolution. Therefore, mutualists may experience greater genetic change because they adapt to both a changing environment and symbiotic partners. Dr. Tia Harrison, Postdoctoral Fellow, Queen's University Patterns, consequences, and processes of mutualism evolution in the legume-rhizobium system Cooperation between species is widespread in nature yet the circumstances under which
mutualism evolves remain mysterious. My research uses the legume-rhizobium interaction to better understand patterns in mutualism evolution across geographic space, the ecological consequences of engaging in mutualism, and how mutualism evolves at a molecular level. Currently, our understanding of the legume-rhizobium interaction comes from a few well-studied temperate species. My research advances the field of legume-rhizobium research by sampling, sequencing, and analyzing non-model species from other parts of the globe, including the tropics. Legume-rhizobium interactions are greatly influenced by nutrient and partner availability in their habitat. I investigated changes in microbial community assembly on legumes across a large latitudinal gradient to understand how this interaction changes in temperate and tropical habitats. Although legumes hosted similar numbers of rhizobia partners across the range, tropical legumes associated with more non-rhizobia strains suggesting that tropical plants are less choosy of their symbiotic partners. There are many predicted benefits of being a less choosy host or generalist host to many symbiotic microbes. Using meta-analysis methods, I demonstrated that legume hosts that associate with many different rhizobial partners are more likely to find a compatible partner when introduced to a novel habitat. Generalist legumes establish in many new ranges and therefore experience greater ecological success compared to legume species that specialized on only a few rhizobia partners. It is unclear whether or how mutualism effects rates of molecular evolution. Most of the literature is focused on understanding how parasitic interactions are predicted to increase evolutionary rates in interacting species. I generated new sequence data from several non-model mutualistic species and found that mutualistic lineages in plants and rhizobia show elevated rates of molecular evolution. Therefore, mutualists may experience greater genetic change because they adapt to both a changing environment and symbiotic partners. |
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