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.

地球生物圈中有70％以上的生物圈永久低于5C，包括大多数海洋，极地和高山区。光合微生物（包括真核藻类）是冷栖息地中的主要生产者，但我们对光合作用在极度寒冷中的运作方式几乎不知道。我的研究计划的总体目标是了解光合生物如何在极端条件下蓬勃发展。我使用极端的绿色藻类衣原体sp。 UWO241（以下简称UWO241）解决有关适应和进化对极端环境的问题。使用诸如UWO241之类的特征良好的非模型系统，为新发现提供了前所未有的机会。 对南极生物的研究是一个新领域，由于最近威胁着极地环境的气候变化趋势，它引起了极大的关注。冷极端粒子（精神噬菌体）也被认为是用于生物技术应用的新型代谢产物和冷适应的酶的来源，并且是加拿大等寒冷国家的室外生物反应器和生物修复的绝佳候选者。我将生物信息学与分子和细胞生物学一起使用，以阐明极端藻类如何克服低温和不利光施加的约束。 在接下来的五年中，我将重点关注三个旨在基于我的知识的短期目标：1）研究极端条件如何影响UWO241基因组，重点是重复的基因及其蛋白质产品。我将重点介绍CPN60，这是一种对核糖1,5-双磷酸羧化酶/氧酶（Rubisco）折叠所必需的叶绿体伴侣伴侣，并由UWO241基因组中扩张的基因家族编码； 2）检查精神鲁比斯科活化酶（RCA）的功能和结构特性，这是一种适用于适当的Rubisco活性所必需的调节酶。我假设RCA在低温下具有固有的高结构灵活性和高活性，这使其成为寒冷中光合作用的重要因素。 3）阐明极性光周期（扩展的年度光/暗循环），包括在南极藻类中的叶绿素合成途径，阐明极性藻类的分子和生理策略。从长远来看，我有兴趣确定冷适应生物体常见的进化适应。为了解决这个问题，我将在我的研究中包括北极的藻类，并关注光合作用，呼吸和叶绿体线粒体相互作用。最终，我将应用从极端粒子获得的见解到中藻和作物植物，并在低温下改善生长。 我的研究计划将为年轻的HQP提供新的生物学领域的机会。此处描述的项目将为HQP提供任何科学工作场所中有价值的技术和软技能，并将为学术界，工业或政府的未来职业做好准备。