Joint NSF/ERA-CAPS: Phytochrome Control of Resource Allocation and Growth in Arabidopsis and in Brassicaceae Crops

PI: Jennifer Nemhauser（华盛顿大学-西雅图）ERA-CAPS合作者：Karen Halliday（英国苏格兰爱丁堡大学）和Mark Stitt（德国Golm马克斯普朗克分子植物生理学研究所）对于植物来说，光是一种携带环境信息的信号，也是光合作用的能量来源。光敏色素是一种蛋白质，当暴露在光线下时，它们的活性会发生变化，而光敏色素反过来又会指导植物细胞中的许多变化，包括哪些基因被打开，哪些基因被关闭的大规模重新编程。例如，光敏色素使植物能够通过照射到植物细胞的光线质量的细微变化来探测附近的植被。这种光激活的监视机制引发了植物结构、生物量形成和繁殖时间的变化，所有这些性状都与作物产量密切相关。这些增长战略的变化要求对资源配置进行相应的调整，但如何实现这一目标却鲜为人知。该项目将开始填补这一关键的知识空白，这将导致提高作物性能的新思路。在外联和培训方面，该项目将为不同群体的本科生和研究生提供国际研究培训机会。此外，该项目将扩大现有的推广工作，包括每年为一名视觉艺术家提供为期12周的驻留，以开发新的可视化工具，用于分子遗传学概念，特别是与农业和生物燃料有关的概念。该项目建立在合作实验室的新研究基础上，该研究表明光敏色素和碳信号之间的串导对碳资源利用效率和资源保护至关重要。主要目的是确定光敏色素在C资源管理中的作用。该项目还将描述遮荫诱导的冠层氮素再分配的遗传基础和影响。这一性状强烈影响氮素利用效率和林分光合作用，在许多作物中与产量密切相关。该项目将进行跨尺度的系统研究，提供有关信号整合的机制信息，时间分辨转录组和代谢物谱，以及有关生物量积累的定量信息，定义为碳到蛋白质和细胞壁成分的通量，以及生长动态。实验结果将被整合到模型中，以测试假设，并在系统层面上获得理解。目的是建立模型，预测光敏色素和光合作用对资源管理和生物量生产的双重作用。该项目将在参考物种拟南芥（Arabidopsis thaliana）和密切相关的作物芸苔（Brassica rapa）上开展平行工作。参考物种的快速生命周期和更大的资源库将加速知识的获取。B. rapa带来了更大尺寸的优势，并允许新的见解直接应用于粮食作物。研究结果将通过国内和国际会议以及主要国际期刊的出版物广泛提供。所有数据集均可通过该联盟网站以及包括但不限于生物数据存储库（BioDare; https://www.biodare.ed.ac.uk/）和植物系统生物学建模（PlaSMo;http://www.plasmo.ed.ac.uk/）数据库在内的长期存储库访问。该联盟的网站还将宣传这个项目的总体目标和进展，并提供更广泛的信息传播链接，包括针对非科学家的外展。

PI: Jennifer Nemhauser (University of Washington-Seattle)ERA-CAPS Collaborators: Karen Halliday (University of Edinburgh, Scotland, UK) and Mark Stitt (Max Planck Institute of Molecular Plant Physiology, Golm, Germany)For plants, light is a signal that carries information about the environment, and a source of energy for photosynthesis. Phytochromes are proteins that change activity when exposed to light, and, in turn, light-activated phytochromes direct many changes in plant cells, including massive re-programming of which genes are being turned on and which are being kept off. For example, phytochromes enable plants to detect nearby vegetation through subtle shifts in the quality of light hitting the plant cell. This light-activated surveillance mechanism initiates changes in plant architecture, biomass formation and the timing of reproduction, all traits that are strongly linked to crop yield. These changes in growth strategy require corresponding adjustments in resource deployment and yet little is known about how this is accomplished. This project will start to fill in this critical knowledge gap that will lead to new ideas for improving crop performance. With regard to outreach and training, this project will provide international research training opportunities for a diverse group of undergraduate and graduate students. In addition, the project will extend existing outreach efforts to include a yearly 12-week residency for a visual artist to develop new visualization tools for molecular genetic concepts, particularly those relating to agriculture and biofuels. This project builds on new research from the partner labs showing that cross talk between phytochrome and carbon signaling is central to C resource use efficiency and resource conservation. A principal aim will be to determine the role of phytochrome in C resource management. The project will also delineate the genetic basis and impact of shading-induced N re-allocation in canopies. This trait strongly impacts on N use efficiency and stand photosynthesis, and in many crops is closely linked to yield. The project will conduct a systematic study across scales, delivering mechanistic information about signal integration, time-resolved transcriptome and metabolite profiles, and quantitative information about biomass accumulation, defined as the flux of carbon to protein and cell wall components, and growth dynamics. The experimental findings will be integrated into models to test hypotheses and to gain understanding at a system level. An aim will be to build models that predict the dual action of phytochrome and photosynthesis on resource management and biomass production. The project will run parallel work programs in the reference species, Arabidopsis thaliana, and the closely related crop Brassica rapa. The rapid life cycle and larger resource pool of the reference species will accelerate knowledge acquisition. B. rapa brings the advantage of larger size, and allows new insights to be directly applied to a food crop. Results will be made broadly accessible through national and international meetings and through publications in leading international journals. All datasets will be accessible through the consortium website, as well as through long-term repositories that include but are not limited to the Biological Data Repository (BioDare; https://www.biodare.ed.ac.uk/) and the Plant Systems Biology Modelling (PlaSMo;http://www.plasmo.ed.ac.uk/) database. The consortium website will also serve to advertise the general aims and advances of this project with links to more general dissemination of information, including outreach targeted to non-scientists.