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，它依赖于循环代谢产物的运输来提高光合作用活跃的叶绿体内的二氧化碳浓度。我们对促进玉米代谢产物循环的分子机制的了解仍然不完整。玉米是最重要的C4作物。具体地说，编码促进苹果酸和丙酮酸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DPhil项目的第一阶段将致力于使用生物信息筛选来识别这些玉米转运蛋白，然后是一种新的植物转运蛋白功能的实验性细菌筛选，以加快发现过程。我的DPhil项目的第二阶段将利用这些新发现的转运蛋白之一，以及之前在玉米或细菌中表征的转运蛋白，试图在模式C3植物拟南芥中设计一种单细胞C4碳浓缩机制。这将代表着当前在水稻和小麦等C3作物中提高C4光合作用效率的努力向前迈出了重要的一步。BBSRC的优先领域：数据驱动生物学。食物、营养和健康。可持续地提高农业生产。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.