Identification and characterization of chloroplast C3 and C4 monocarboxylate and dicarboxylate transporters, and their use in engineering single cell

C4光合作用是一种高效的光合作用形式，依靠循环代谢物运输来提高光合活性叶绿体内的二氧化碳浓度。我们对最重要的C4作物玉米中促进这种代谢物循环的分子机制的理解仍然不完整。具体来说，编码促进苹果酸盐和丙酮酸盐分别从束鞘细胞叶绿体输入和输出的蛋白质的基因，以及编码将丙酮酸盐输入叶肉细胞叶绿体的蛋白质的基因，尚未被鉴定或表征。我的博士项目的第一阶段将致力于识别这些玉米转运蛋白，使用生物信息学筛选，然后使用一种新的植物转运蛋白功能实验细菌筛选，以加速发现过程。我的博士项目的第二阶段将利用这些新发现的转运蛋白之一，以及以前在玉米或细菌中发现的转运蛋白，试图将单细胞C4碳浓缩机制设计到模型C3植物拟南芥中。这将是目前将C4光合作用效率提高的工程技术应用于C3作物（如水稻和小麦）的重要一步。BBSRC优先领域：数据驱动生物学。食品、营养和健康。持续提高农业生产水平。生物科学的系统方法。

C4 photosynthesis is a highly efficient form of photosynthesis that depends on cyclical metabolite transport to enhance CO2 concentration inside photosynthetically active chloroplasts. Our understanding of the molecular machinery that facilitate this metabolite cycle in maize, the most important C4 crop, is still incomplete. Specifically, the genes encoding the proteins that facilitate import and export of malate and pyruvate respectively from bundle sheath cell chloroplasts, and the gene encoding the protein that imports pyruvate into the mesophyll cell chloroplast, have yet to be identified or characterised. The first phase of my DPhil project will aim to identify these maize transporters, using a bioinformatic screen, followed by a novel experimental bacterial screen for plant transporter function, to accelerate the discovery process. The second phase of my DPhil project will utilize one of these newly discovered transporters, as well as previously characterized transporters in maize or bacteria, to attempt to engineer a single-cell C4 carbon-concentrating mechanism into the model C3 plant Arabidopsis thaliana. This would represent a significant step forward in the current effort to engineer the enhanced efficiency of C4 photosynthesis into C3 crop plants such as rice and wheat.BBSRC priority areas:Data driven biology. Food, nutrition and health. Sustainably enhancing agricultural production. Systems approaches to the biosciences.