Dissecting C4 leaf biogenesis and C3 and C4 pollen development during exposure to high temperature to enable global food security

剖析高温下 C4 叶片的生物发生以及 C3 和 C4 花粉的发育，以确保全球粮食安全

• 批准号: RGPIN-2015-04874
• 负责人: Sage, Tammy
• 金额: $ 2.04万
• 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: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=664069
• 关键词: Dissecting; C4; leaf; biogenesis; C3

Global agriculture is facing a time of crisis. Increasing population growth, persistent loss of arable land, increasing meat consumption and global climate change collectively threaten global food production. To maintain global food security, cereal production will have to increase 70% by 2050. Yields of major food crops - rice, wheat and corn - decline with increasing temperatures; for example, rice and wheat yields decline 10% and 3 to 4%, respectively, for every 1 °C increase in temperature above the optimal growth temperature. Efforts to maintain food security have led to major international initiatives to enhance the photosynthetic efficiency and improve crop stress tolerance. My research contributes to these efforts by developing a basic understanding of the functional development of C4 photosynthesis, the most efficient form of primary production in the biosphere, and heat stress tolerance of plant reproduction. To sustain my contribution, this proposal request funds for two projects. First, to support ongoing efforts to engineer the C4 photosynthetic pathway into our major crops such as wheat and rice, we will examine the evolutionary development of the C4 leaf structure, with the aim of identifying the genes central to the origin of organelle enrichment in cells where the carbon concentrating mechanisms resides in a C4 photosynthetic leaf. Our research should help overcome one of the main bottlenecks currently hindering C4 engineering, This effort will emphasize molecular and cellular assessment of leaf development in C3 and C4 species Atriplex pair and their hybrids and the grass subtribe Neurachninae. The Neurachninae is the only grass lineage known to contain C3, C2, and C4 species, and as such has been suggested as a model system for studies of photosynthetic pathway evolution in the grasses. Second, we will exploit recent advances in our lab in understanding the mechanisms controlling heat sterility in crops. Exposure to 32°-36 °C severely reduces pollen viability and thus seed set, particularly in canola, maize, wheat and rice. With continued climate warming, Canada's major crops such as wheat and canola may also encounter increased incidences of pollen sterility. We have found that heat reduces pollen survival via production of reactive oxygen species and have identified a gene that confers heat tolerance by detoxifying oxidative compounds. In the proposed research, we intend to examine the role of high temperature induced protein oxidation during reproduction in major crop species in order to provide researchers with information needed to enhance heat tolerance during this critical stage of the plant life cycle. *****

全球农业正面临危机。人口增长、耕地持续减少、肉类消费增加和全球气候变化共同威胁着全球粮食生产，到 2050 年，谷物产量必须增加 70%。主要粮食作物——水稻、小麦和玉米——的产量随温度升高而下降；例如，温度每升高1°C，水稻和小麦的产量分别下降10%和3%至4%。维护粮食安全的努力导致了旨在提高光合作用效率和提高作物耐受胁迫能力的重大国际举措，我的研究通过对 C4 光合作用（初级生产中最有效的形式）的功能发展有了基本了解，为这些努力做出了贡献。为了维持我的贡献，该提案资助了两个项目的请求，首先，为了支持对小麦和水稻等主要作物进行 C4 光合作用途径的持续努力，我们将研究进化。发展C4 叶结构，旨在识别细胞中细胞器富集起源的核心基因，其中碳浓缩机制位于 C4 光合叶中，我们的研究应有助于克服目前阻碍 C4 工程的主要瓶颈之一。将强调对 C3 和 C4 物种 Atriplex 对及其杂交种以及草亚族 Neurachininae 的叶子发育进行分子和细胞评估 Neurachininae 是已知含有 C3 的唯一草谱系。 C2 和 C4 物种，因此被建议作为研究草类光合作用途径进化的模型系统。 其次，我们将利用我们实验室的最新进展来了解控制作物热不育的机制。 -36°C 严重降低花粉活力，从而降低结籽率，尤其是油菜、玉米、小麦和水稻。随着气候持续变暖，加拿大的主要作物，如小麦和油菜，花粉不育的发生率也可能增加。我们发现，通过产生活性氧来降低热花粉的存活率，并鉴定出一种通过解毒氧化化合物来赋予耐热性的基因。在拟议的研究中，我们打算研究高温诱导的蛋白质氧化在主要作物繁殖过程中的作用。物种，以便为研究人员提供在植物生命周期的这一关键阶段增强耐热性所需的信息。