Interactive Effects of Temperature and CO2 Levels on C3 and C4 Plants

温度和二氧化碳水平对 C3 和 C4 植物的交互影响

• 批准号: 154273-2012
• 负责人: Sage, Rowan
• 金额: $ 2.91万
• 依托单位: University of Toronto
• 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=569403
• 关键词: Interactive; Effects; Temperature; CO2; Levels

The proposed research will improve our understanding of photosynthesis in plants affected by high rates of photorespiration occurring in warm environments. Through this work, we intend to identify new ways to improve crop performance by reducing photorespiratory limitations and thus enhancing the photosynthetic capacity of C3 plants. We will evaluate how C3 plants compensate for high rates of photorespiration by (i) studying mechanisms enhancing intracellular refixation of photorespired CO2, and (ii) the early evolution of the C4 photosynthetic pathway. In the refixation project, we will evaluate whether the formation of chloroplast sheaths around the leaf cell periphery enhances the reassimilation of photorespired CO2. We will examine if chloroplast sheath formation is inducible under low CO2 and warm temperatures promoting photorespiration, and whether species from warm environments have a better ability to recapture photorespired CO2 than those from cool climates. We will also evaluate whether plants producing chloroplast sheaths have a similar potential for photorespiratory CO2 refixation as plants engineered to release photorespired CO2 within the chloroplast. The work on the early evolution of C4 photosynthesis will evaluate the functional significance of a suite of traits termed "proto-Kranz" anatomy that appear in C3 species that are closely related to C4 plants within an evolutionary lineage. Proto-Kranz anatomy may be the first definitive stage of C4 evolution and could explain how the C4 evolutionary process is initiated. We also will generate hybrids between C3 and C4 Atriplex species in order to examine the genetic controls over the expression of C4 traits. This will be accomplished by comparing transcriptomes of hybrids with differing degrees of C4 trait expression. In addition to the discovery potential of this research, funds provided will support the training of a new generation of expertise that will help the world meet the increasing demands for food, fiber and renewable energy that photosynthesis provides.

拟议的研究将提高我们对受温暖环境中发生的高光呼吸率影响的植物光合作用的理解。通过这项工作，我们打算通过减少光呼吸限制来找到提高作物性能的新方法，从而增强 C3 植物的光合作用能力。 我们将评估 C3 植物如何通过 (i) 研究增强光呼吸 CO2 细胞内再固定的机制，以及 (ii) C4 光合作用途径的早期进化来补偿高光呼吸速率。 在再固定项目中，我们将评估叶细胞外围叶绿体鞘的形成是否增强光呼吸二氧化碳的再同化。我们将研究叶绿体鞘的形成是否可以在低二氧化碳和促进光呼吸的温暖温度下诱导，以及来自温暖环境的物种是否比来自凉爽气候的物种具有更好的重新捕获光呼吸二氧化碳的能力。我们还将评估产生叶绿体鞘的植物是否具有与经过改造以在叶绿体内释放光呼吸二氧化碳的植物相似的光呼吸二氧化碳再固定潜力。关于 C4 光合作用早期进化的工作将评估一系列称为“原克兰兹”解剖学特征的功能意义，这些特征出现在与进化谱系中与 C4 植物密切相关的 C3 物种中。 Proto-Kranz 解剖学可能是 C4 进化的第一个决定性阶段，并且可以解释 C4 进化过程是如何启动的。我们还将在 C3 和 C4 滨藜物种之间产生杂交种，以检查对 C4 性状表达的遗传控制。这将通过比较具有不同 C4 性状表达程度的杂种的转录组来实现。除了这项研究的发现潜力之外，所提供的资金还将支持新一代专业知识的培训，这将帮助世界满足对光合作用提供的食品、纤维和可再生能源日益增长的需求。