The Chloroplast Copper Delivery System

智力优势营养素的有效性会限制植物的生长和生产力。植物需要微量营养素铜来进行光合作用，在光合作用中，阳光被用来固定大气中的二氧化碳，这是地球上所有生物质形成的原因。然而，除了光合作用之外，其他过程也需要铜。因此，当这种元素在土壤中的含量有限时，植物必须选择如何最好地利用这种宝贵的资源。研究发现，控制植物叶片细胞内铜如何使用的运输系统受到可用铜量的调节。调节机制涉及铜控制的选择性降解的光合亚细胞区室内的铜转运蛋白。 这一发现意味着植物可以选择性地感知叶片内各种细胞隔室中可用的铜的量，并且该信息反过来用于控制特定蛋白质的稳定性。这种机制在自然界中以前没有观察到，这项研究的目的是确定可以感知铜和控制转运蛋白周转的细胞机制。光合生产力的这一调节过程的影响将进行测试。微量营养素的可用性如何影响光合机制的组装是细胞生物学中必须解决的一个基本问题。更广泛的影响光合作用是驱动地球上所有生命的过程。更好地了解光合机制是如何组装的，将使人们能够在使用肥料和铜基杀菌剂方面做出更好的决定，从而有利于环境，并可能提高农业生产力，特别是在边际土壤上。 该研究还对需要最佳光合活性的生物燃料生产产生潜在影响。该项目将培训一批年轻科学家，包括科罗拉多州立大学的本科生，并包括以植物生物学和光合作用模块的形式为当地小学开展外联活动。

INTELLECTUAL MERITNutrient availability can limit plant growth and productivity. Plants need the micronutrient copper to perform photosynthesis, the process in which sunlight is used in order to fix carbon dioxide from the atmosphere and which is responsible for all biomass formation on the planet. However, copper is also required for other processes, next to photosynthesis. Therefore, when this element is available in limiting amounts in the soil, choices must be made by the plant about how to best use this precious resource. It was found that the transport systems that control how copper is used within the cells of a plant leaf are regulated by the amount of copper that is available. The mechanism of regulation involves a copper-controlled selective degradation of a copper transporter within the photosynthetic sub-cellular compartment. This finding implies that plants can selectively sense the amount of copper that is available in various cellular compartments within a leaf and that this information in turn is used to control specific protein stability. Such a mechanism had not been observed before in nature and this research is aimed at identifying the cellular machineries that can sense copper and that control transporter turnover. Implications of this regulatory process for photosynthetic productivity will be tested. How micronutrient availability affects the assembly of the photosynthetic machinery is a fundamental question in cell biology that has to be addressed. BROADER IMPACTSPhotosynthesis is the process which drives all of life on earth. A better understanding of how the photosynthetic machinery is assembled will allow people to make better decisions regarding the use of fertilizers and copper-based fungicides, thus benefitting the environment and potentially improving agricultural productivity, especially on soils that are marginal. The research also has potential impact for biofuel production in which optimal photosynthetic activity is required. The project will train a group of young scientists including undergraduate students at Colorado State University and includes an outreach component for local elementary schools in the form of modules about plant biology and photosynthesis.