Using Antarctic green algae to study photosynthesis in extreme environments

利用南极绿藻研究极端环境下的光合作用

• 批准号: RGPIN-2019-05763
• 负责人: Cvetkovska, Marina
• 金额: $ 2.04万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=715788
• 关键词: Using; Antarctic; green; algae; study

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.

超过70%的地球生物圈永久低于5摄氏度，包括大部分海洋，极地和高山地区。光合微生物，包括真核藻类，是寒冷栖息地的主要初级生产者，但我们对光合作用在极端寒冷中的运作知之甚少。我的研究计划的首要目标是了解光合生物如何在极端条件下茁壮成长。我使用极端的绿色衣原体属UWO 241（以下简称UWO 241）来解决驯化和进化适应极端环境的问题。与UWO 241等特征良好的非模型系统合作，为新发现提供了前所未有的机会。 南极生物的研究是一个新的领域，由于最近的气候变化趋势威胁到极地环境，因此受到了极大的关注。冷极端微生物（嗜冷菌）也被认为是生物技术应用中新型代谢物和冷适应酶的来源，是加拿大等寒冷国家户外生物反应器和生物修复的绝佳候选者。我使用生物信息学与分子和细胞生物学来阐明极端藻类如何克服低温和不利光线的限制。 在接下来的五年里，我将专注于三个短期目标，旨在建立我的知识：1）调查极端条件如何塑造UWO 241基因组，重点是重复的基因及其蛋白质产物。我将集中在CPN 60，一个叶绿体伴侣复合物所必需的核酮糖-1，5-二磷酸羧化酶/加氧酶（RubisCO）折叠和UWO 241基因组中的一个扩展的基因家族编码; 2）检查嗜冷RubisCO活化酶（Rca），适当的RubisCO活性所必需的调节酶的功能和结构特性。我推测，Rca具有固有的高结构灵活性和高活性，在低温下，使其在寒冷的光合作用的一个重要因素; 3）阐明极地藻类的生长和生存在极端光周期（延长的年度光/暗周期）的分子和生理策略，包括叶绿素合成途径在南极藻类。从长远来看，我感兴趣的是识别适应寒冷的生物体所共有的进化适应。为了解决这个问题，我将在我的研究中包括来自北极的藻类，并专注于光合作用，呼吸作用和叶绿体-线粒体相互作用。最终，我将把从极端微生物中获得的见解应用于嗜温藻类和作物植物，并改善低温下的生长。 我的研究计划将为年轻的HQP提供生物学新兴领域的机会。这里描述的项目将为HQP提供在任何科学工作场所都有价值的技术和软技能，并为他们未来在学术界，工业界或政府的职业生涯做好准备。