Temperature, photosynthesis, and rubisco: biochemistry and physiology of land plant productivity in response to global change

温度、光合作用和 rubisco：陆地植物生产力响应全球变化的生物化学和生理学

• 批准号: 327103-2013
• 负责人: Kubien, David
• 金额: $ 1.82万
• 依托单位: University of New Brunswick
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=571924
• 关键词: Temperature; photosynthesis; rubisco; biochemistry; physiology

Photosynthesis is the process by which plants, algae, and some bacteria use solar energy to convert CO2 into biomass. Photosynthesis is the energetic basis of essentially all terrestrial and aquatic food webs, and produces food, fuel, shelter, and other materials that sustain human civilization. The basic metabolism is well known, but crucial aspects of how photosynthesis responds to the abiotic environment are unclear. For example, there are multiple hypotheses about why photosynthetic rates decline above a certain optimum temperature. Further, Rubisco, the enzyme that actually catalyses CO2 uptake, is a poor catalyst compared to most other enzymes, but our understanding of of the subtle relationships between its function and structure is in its infancy. Moreover, Rubisco has been characterized from very few species, and presently we model future crop and forest yields using constants that may be ill-suited to the purpose. My research asks questions about the temperature responses of photosynthesis, and the characteristics of Rubisco. My students and I will conduct detailed mechanistic analyses of photosynthesis at high temperatures, on plants with altered photosynthetic capacity. We use an array of physiological and biochemical techniques to comprehensively test hypotheses, within the context of established theoretical models. In the short-term, Rubisco studies will focus on how the expression of Rubisco-encoding genes changes with environment, or between closely related species with biochemically distinct Rubiscos. These studies will evaluate the possibility that plants optimise the enzyme for specific growth conditions. Toward the end of the grant cycle, we will determine the characteristics, particularly the temperature sensitivities, of key crop and boreal forest Rubiscos. The CO2 released by fossil fuel use is causing temperatures to rise and precipitation patterns to change. Photosynthesis links the atmosphere and biosphere, and my research expands our understanding of photosynthetic responses to global change, including the specific role of Rubisco.

光合作用是植物、藻类和一些细菌利用太阳能将二氧化碳转化为生物质的过程。光合作用是基本上所有陆地和水生食物网的能量基础，并产生食物，燃料，住所和维持人类文明的其他材料。基本的新陈代谢是众所周知的，但光合作用如何响应非生物环境的关键方面还不清楚。例如，关于为什么光合速率在某一最佳温度以上下降有多种假设。此外，Rubisco，实际上催化CO2吸收的酶，与大多数其他酶相比是一种较差的催化剂，但我们对其功能和结构之间微妙关系的理解仍处于起步阶段。此外，Rubisco的特点是从很少的物种，目前我们模拟未来的作物和森林产量使用常数，可能不适合的目的。 我的研究提出了有关光合作用的温度响应和Rubisco特性的问题。我和我的学生将在高温下对光合作用能力改变的植物进行详细的光合作用机理分析。我们使用一系列的生理和生化技术来全面测试假设，在既定的理论模型的背景下。在短期内，Rubisco的研究将集中在Rubisco编码基因的表达如何随环境变化，或在具有生物化学上不同的Rubisco的密切相关的物种之间变化。这些研究将评估植物在特定生长条件下优化酶的可能性。在赠款周期结束时，我们将确定关键作物和北方森林Rubiscos的特性，特别是温度敏感性。 化石燃料使用释放的二氧化碳导致气温上升和降水模式改变。光合作用联系大气和生物圈，我的研究扩展了我们对光合作用对全球变化的反应的理解，包括Rubisco的具体作用。