Using Antarctic green algae to study photosynthesis in extreme environments

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More than 70% of the Earth's biosphere is permanently below 5C, including most of the oceans, polar and alpine regions. Photosynthetic microorganisms, including eukaryotic algae, are the dominant primary producers in cold habitats, but we know very little of how photosynthesis operates in the extreme cold. The overarching goal of my research program is to understand how photosynthetic organisms thrive under extreme conditions. I use the extremophilic green alga Chlamydomonas sp. UWO241 (hereafter UWO241) to address questions on acclimation and evolutionary adaptation to extreme environments. Working with a well-characterized non-model system such as UWO241 provides an unprecedented opportunity for novel discoveries.******The study of Antarctic organisms is a new field that has garnered significant attention due to recent climate change trends that threaten polar environments. Cold extremophiles (psychrophiles) are also recognized as a source of novel metabolites and cold-adapted enzymes for biotechnological applications and are excellent candidates for outdoor bioreactors and bioremediation in cold countries, such as Canada. I use bioinformatics together with molecular and cell biology to elucidate how extremophilic algae overcome the constraints imposed by low temperatures and unfavorable light.******Over the next five years, I will focus on three short-term objectives designed to build on my knowledge: 1) Investigating how extreme conditions shaped the UWO241 genome, with emphasis on duplicated genes and their protein products. I will focus on CPN60, a chloroplast chaperone complex essential for ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) folding and encoded by an expanded gene family in the UWO241 genome; 2) Examining the functional and structural properties of psychrophilic RubisCO activase (Rca), a regulatory enzyme necessary for proper RubisCO activity. I hypothesize that Rca has inherently high structural flexibility and high activity at low temperatures making it an important factor for photosynthesis in the cold; 3) Elucidating the molecular and physiological strategies of polar algae for growth and survival under extreme photoperiods (extended annual light/dark cycles), including the chlorophyll synthesis pathway in Antarctic algae. In the long-term, I am interested in identifying evolutionary adaptations common to cold-adapted organisms. To address this, I will include algae from the Arctic in my research and focus on photosynthesis, respiration and chloroplast-mitochondria interactions. Ultimately, I will apply the insights obtained from extremophiles to mesophilic algae and crop plants and improve growth at low temperatures.******My research program will provide opportunities for young HQP in a new and emerging area of biology. The projects described here will provide HQP with technical and soft skills that are valued in any scientific workplace, and will prepare them for future careers in academia, industry or government. **