Engineering an inorganic carbon highway to improve C3 photosynthesis

光合作用仍然是基因工程的目标，除了在减少大气二氧化碳方面的重要作用外，它在提高作物产量方面具有巨大潜力。光合作用通过碳固定提供了世界上大部分的生物量。 通过学习如何在模型植物中为碳固定酶Rubisco提供更多的碳酸氢盐，正在开发可应用于作物的技术。该项目使用合成生物学方法来增加Rubisco的碳酸氢盐供应，从而增强光合作用，在模型植物中。受训人员从事涉及遗传学、生物化学和分子生物学的多学科项目。来自不同群体的本科生在学年和夏季获得研究经验。一项新的教育公众的努力正在通过一个网站和Youtube频道上的教育视频进行。计划与公共广播服务站合作制作一部专业视频，解释利用合成生物学来增强光合作用以及植物在从大气中清除二氧化碳方面的作用。该视频将通过PBS Learning Media提供，用于K-12教育。C3作物植物占植物的大约85%，包括大豆和小麦等粮食作物，缺乏在Rubisco附近聚集二氧化碳的能力。基于存在于蓝藻和藻类中的碳浓缩机制，在作物中合成碳浓缩机制（CCM）具有大幅提高产量的潜力。安装基于微区室的CCM不仅需要在叶绿体内实际构建微区室，还需要提供可转化为二氧化碳的额外碳酸氢盐。 为了评估来自微生物的碳酸氢盐转运蛋白是否可以在叶绿体中起作用，将其编码基因转化到其中叶绿体碳酸酐酶已被去除的突变体背景中。突变体中碳酸酐酶的缺失导致受损的、碳酸氢盐缺乏的表型，其被预测为被功能性碳酸氢盐转运蛋白拯救。正在分析的转化植物不仅拯救的碳酸氢盐需要的表型，而且对光合作用，生长，活性氧，基质pH值和脂肪酸合成的影响。除了在具有碳浓缩机制的C3植物的改造工程中提供必要的一步之外，建模预测，仅仅通过将无机碳泵并入叶绿体就可以提高产量，甚至在一个完整的微区室之前-该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响进行评估，被认为值得支持审查标准。

Photosynthesis remains a target for genetic engineering that exhibits great potential for enhancing crop yield, in addition to its important role in reducing atmospheric carbon dioxide. Photosynthesis provides most of the world’s biomass through carbon fixation. By learning how to provide increased bicarbonate to the carbon-fixing enzyme Rubisco in a model plant, technology is being developed that can be applied to crop plants. This project uses synthetic biology approaches to increase bicarbonate supply to Rubisco, and consequently enhance photosynthesis, in a model plant. Trainees are engaged in multidisciplinary projects involving genetics, biochemistry, and molecular biology. Undergraduates from diverse groups are gaining research experience during the academic year and summer months. A new effort to educate the public is occurring through instructive videos on a website and Youtube channel. Collaboration with a Public Broadcasting Service station is planned to create a professional video explaining the use of synthetic biology to enhance photosynthesis and the role of plants in removing carbon dioxide from the atmosphere. The video is to be made available through PBS Learning Media for K-12 education.C3 crop plants, which constitute approximately 85 percent of plants, including food crops like soybean and wheat, lack the ability to concentrate carbon dioxide near Rubisco. Synthesis of a carbon-concentrating mechanism (CCM) in crop plants, based on ones that exist in cyanobacteria and algae, has the potential to substantially increase yields. Installation of a microcompartment-based CCM requires not only the actual construction of the microcompartment within the chloroplast, but also the provision of additional bicarbonate that can be converted into carbon dioxide. In order to assess whether bicarbonate transporters from microorganisms can function in the chloroplast, their encoding genes are being transformed into a mutant background in which chloroplast carbonic anhydrase has been removed. The absence of carbonic anhydrase in the mutant causes an impaired, bicarbonate-deficient, phenotype that is predicted to be rescued by a functional bicarbonate transporter. The transformed plants are being analyzed not only for the rescue of the bicarbonate-requiring phenotype, but also for effects on photosynthesis, growth, reactive oxygen species, stromal pH, and fatty acid synthesis. In addition to providing an essential step in the transformative engineering of C3 plants with carbon-concentrating mechanisms, modeling predicts that yield can be enhanced by the mere incorporation of inorganic carbon pumps into chloroplasts, even before a full microcompartment-based CCM is installed.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.