Copper Delivery In Plant Plastids

植物质体中的铜传递

• 批准号: 0418993
• 负责人: Marinus Pilon
• 金额: --
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0418993&HistoricalAwards=false
• 关键词: Copper; Delivery; Plant; Plastids

SummaryCopper Delivery in Plant plastidsPI: Marinus PilonBiology department, Colorado State UniversityLife as we know it is made possible by the process of photosynthesis, which is responsible for carbon fixation and thus biomass production. Photosynthesis in the green parts of plants takes place in specialized sub-cellular structures called chloroplasts. Chloroplasts contain the molecular machinery to use the energy of sunlight to drive a series of chemical reactions that include the production of carbohydrates (sugars) from water taken up by the plant roots and carbon dioxide from the air. To carry out its tasks the chloroplast needs specific redox active metal ions, particularly copper, iron and manganese. These ions are taken up from the soil and must be delivered to the chloroplasts. Copper delivery is the topic of this proposal. Although present in only very small amounts, copper is a very important metal ion for photosynthesis, and when its delivery to plastids is disturbed the plants can no longer grow. Copper ions are needed in two processes in photosynthesis: electron transport and photoprotection. When paired with the protein plastocyanin, copper is used in the conversion of light energy into chemical energy by means of electron transport. The enzyme superoxide dismutase is involved in photo-protection: it uses copper as a cofactor to protect the chloroplast from dangerous reactive oxygen species, which are formed as a by-product of photosynthetic electron transport, and thus indirectly the result of the action of plastocyanin. Thus, for optimal photosynthesis both plastocyanin and superoxide dismutase must obtain copper, yet both proteins compete for copper when the supply is limited, creating an interesting dilemma for how copper should be utilized. A set of proteins, including two chloroplast localized membrane transporters called PAA1 and PAA2, orchestrate the delivery of copper to chloroplasts. Exactly how this delivery machinery works and how it is regulated to allow the delivery of copper under varying conditions of copper supply is the topic of this project. The biochemical properties of copper delivery proteins will be analyzed, the effects of mutations in the genes encoding these proteins on growth and photosynthesis will be studied and their expression analyzed as a function of varying copper supply and demand. Models for the regulation of copper delivery will be tested by generating double mutations. Copper is a necessary component of the photosynthetic machinery and correct delivery is a prerequisite for enhanced crop yield and quality. Metal ions are also important for human health and nutrition. A better understanding of plant mechanisms involved in metal uptake, transport and homeostasis may lead to the development of crops with enhanced nutritional value. Apart from the significance to our understanding of biological processes this project will provide training and intellectual development opportunities for students both in the research lab and in the classroom. A postdoctoral researcher, two graduate students and several undergraduate students will take part in the proposed research project. The project involves collaboration with labs in the US and abroad, including personnel exchange and training opportunities.

植物质体中的铜传递PI：Marinus Pilon科罗拉多州立大学生物系我们所知道的生命是通过光合作用过程实现的，光合作用负责碳固定，从而产生生物量。 植物绿色部分的光合作用发生在称为叶绿体的特殊亚细胞结构中。 叶绿体包含分子机制，利用阳光的能量来驱动一系列化学反应，包括从植物根部吸收的水和空气中的二氧化碳中产生碳水化合物（糖）。 为了完成其任务，叶绿体需要特定的氧化还原活性金属离子，特别是铜，铁和锰。 这些离子从土壤中被吸收，必须被输送到叶绿体。 铜的交割是本提案的主题。 虽然铜的含量非常少，但它是光合作用中非常重要的金属离子，当它向质体的输送受到干扰时，植物就不能生长。 铜离子参与光合作用的两个过程：电子传递和光保护。 当与蛋白质质体蓝素配对时，铜用于通过电子传递将光能转化为化学能。 超氧化物歧化酶参与光保护：它使用铜作为辅助因子来保护叶绿体免受危险的活性氧物种的伤害，活性氧物种是光合电子传递的副产物，因此间接地是质体蓝素作用的结果。 因此，最佳光合作用的质体蓝素和超氧化物歧化酶必须获得铜，但这两种蛋白质竞争铜时，供应是有限的，创造了一个有趣的困境，应该如何利用铜。 一组蛋白质，包括两个叶绿体定位的膜转运蛋白PAA1和PAA2，协调铜到叶绿体的传递。 该项目的主题是，这种交付机制究竟如何工作，以及如何监管，以允许在不同的铜供应条件下交付铜。 铜传递蛋白的生化特性将进行分析，这些蛋白质的编码基因的突变对生长和光合作用的影响将进行研究，并分析其表达作为不同的铜供应和需求的函数。 将通过产生双突变来测试铜输送调节模型。铜是光合机制的必要组成部分，正确输送是提高作物产量和质量的先决条件。 金属离子对人体健康和营养也很重要。 更好地了解植物对金属的吸收、运输和体内平衡的机制，可能会导致开发出营养价值更高的作物。 除了对我们理解生物过程的重要性外，该项目还将在研究实验室和课堂上为学生提供培训和智力发展的机会。 一名博士后研究员，两名研究生和几名本科生将参加拟议的研究项目。 该项目涉及与美国和国外实验室的合作，包括人员交流和培训机会。