PlantSynBio: Optimized CAM Engineering for Improving Water-use Efficiency in Plants

景天酸代谢和组织肉质化是提高植物水分利用效率和耐旱性(和盐分)的代谢和解剖适应。这些特性是植物王国中最广泛和最成功的缓解干旱胁迫的适应方式之一，因此，对于设计适应气候变化的作物来说，这些特性非常有用。该项目的目标是单独测试景天酸代谢的优化合成版本，并与工程组织肉质结合测试。本项目开发的合成基因电路可广泛应用于其他食品、饲料、纤维和生物燃料作物，以提高它们的生产力，提高水分利用效率，并在未来更炎热和更干燥的环境中耐受干旱/盐分胁迫。该项目还将通过招生努力，针对科学、技术、工程和数学领域历史上代表性不足的群体的学生，为日益多样化的科学劳动力提供培训。此外，该项目将通过为本科生和研究生以及博士后学者提供独特的培训机会，为未来的科学家提供以证据为基础、以视觉为重点的科学交流方面的培训和准备，将植物生物化学、合成生物学和生物技术与信息图表、互动可视化和可视化社交媒体相结合。调查人员将通过制作两个高质量的视频来描述该项目的成果，以展示这些生物技术创新的社会效益，从而提高公众对更具气候适应性的作物的认识。最后，将通过强有力的评估活动对培训和推广活动进行评估，以评估其对公共科学活动的影响。未来干旱严重程度和持续时间的增加将显著减缓满足未来预计作物需求所需的作物生产力增长速度，并威胁全球粮食安全。因此，通过在C3光合作用作物中引入合成景天酸代谢来抑制光呼吸和提高水分利用效率的创新合成生物学方法是必不可少的。这项拟议的研究将产生优化的合成羧化、脱羧化、淀粉降解和完整的景天酸代谢基因电路。由此产生的植物将被评估以改善生长、生产力、水分利用效率以及耐缺水和耐盐性。此外，在拟南芥和大豆中，表达优化的景天酸代谢基因电路的植物将在有和没有工程组织肉质的情况下进行评估，大豆是美国至关重要的C3光合作用作物。经验测试将伴随着详细的基因组规模转录和代谢组谱分析和Diel通量平衡分析建模，以证实合成景天酸代谢基因循环的每一次迭代的能量效率预测。该项目的更广泛影响包括通过在不断变化的环境中提高作物生产力、水利用效率和耐旱性/盐碱度来改善国家粮食、饲料、纤维和生物燃料的安全。外展和培训目标包括通过招收代表不足的学生来确保培训日益多样化的科学劳动力，为未来的科学家提供科学交流方面的培训和准备，通过描述合成CAM和工程组织肉质的概念的视频提高公众对提高作物气候适应性的必要性的认识，以及评估培训、外展和参与活动，以产生教学和社会影响。该奖项由植物基因组研究计划和综合组织系统分部的生理机制和生物力学计划共同资助。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Crassulacean acid metabolism and tissue succulence are metabolic and anatomical adaptations that improve water-use efficiency and drought (and salinity) stress tolerance in plants. These traits are among the most widespread and successful adaptations in the plant kingdom for mitigating drought stress, and thus, represent highly useful traits for the design of climate-resilient crops. The goal of this project is to test optimized synthetic versions of crassulacean acid metabolism alone and in combination with engineered tissue succulence. The proposed synthetic gene circuits developed by this project can be applied widely to other food, feed, fiber, and biofuel crops to improve their productivity, improve water-use efficiency, and drought/salinity stress tolerance under the hotter and drier environments of the future. The project will also provide training of an increasingly diverse scientific workforce through student recruitment efforts that target students from historically underrepresented groups in science, technology, engineering, and mathematics. In addition, the project will provide training and preparedness of future scientists in evidence-based, visually focused, scientific communication through unique training opportunities for undergraduate and graduate students, and postdoctoral scholars in plant biochemistry, synthetic biology, and biotechnology blended with infographics, interactive visualizations, and visual social media. The investigators will increase public awareness of the need for more climate-resilient crops through the production of two high-quality videos describing the project deliverables to showcase the societal benefit of these biotechnological innovations. Lastly, the training and outreach activities will be evaluated through robust assessment activities to appraise their impact on public science outreach.Future increases in drought severity and duration will significantly slow the rate of crop productivity increases needed to satisfy future projected crop demands and threaten global food security. Therefore, innovative synthetic biology approaches for curtailing photorespiration and improving water-use efficiency via the introduction of synthetic crassulacean acid metabolism into C3 photosynthesis crops are essential. The proposed research will generate optimized synthetic carboxylation, decarboxylation, starch degradation, and complete crassulacean acid metabolism gene circuits. The resulting plants will be evaluated for improved growth, productivity, water-use efficiency, and water-deficit and salinity tolerance. In addition, plants expressing optimized crassulacean acid metabolism gene circuits will be evaluated with and without engineered tissue succulence in Arabidopsis and soybean, a critically important C3 photosynthesis crop for the U.S.. Empirical testing will be accompanied by detailed, genome-scale transcriptomic and metabolome profiling and diel flux balance analysis modeling to corroborate energetic efficiency predictions for each iteration of the synthetic crassulacean acid metabolism gene circuits. The broader impacts of the project include improving national food, feed, fiber, and biofuel security by enhancing crop productivity, water-use efficiency, and drought/salinity tolerance in a changing environment. Outreach and training goals include ensuring the training of an increasingly diverse scientific workforce through recruitment of underrepresented students, providing training and preparedness of future scientists in scientific communication, increasing public awareness of the need to improve the climate-resiliency of crops using videos describing the concepts of synthetic CAM and engineered tissue succulence, and assessing training, outreach and engagement activities for didactic and societal impacts.This award was co-funded by the Plant Genome Research Program and the Physiological Mechanisms and Biomechanics Program in the Division of Integrative Organismal Systems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.