Mechanisms of Transport Through Plasmodesmata

所有生物体都是由细胞组成的，细胞是生命的基本单位。 虽然一些微生物，如细菌，是单细胞的，但大多数植物和动物是多细胞的，由数十亿个细胞和数十或数百种不同的细胞类型组成。 每种细胞类型都有一个专门的功能，例如植物中不同的细胞类型可以从土壤中吸收营养，进行光合作用或促进生长。 不同细胞类型之间的交流对于植物的正常生长和生存能力至关重要。 这个项目将研究一个细胞与细胞之间的通讯系统，包括通过称为胞间连丝的特殊通道运输信号分子。 控制运输过程的基因已经确定，它们在发育和生理学中的作用将得到研究。 例如，一个这样的基因编码一种伴侣蛋白，一种可以解开其他分子的蛋白质，使它们能够通过胞间连丝。 这些研究将为植物生物学提供新的见解，从而为提高作物生产力提供策略。 外联活动将针对当地社区的高中生以及代表性不足的群体，为他们提供科学方面的培训和指导。 这种培训对于美国劳动力保持强大的科学和技术基础非常重要。植物细胞与细胞之间的一种重要而独特的通讯形式是通过胞间连丝（plasmodesmata）（嵌入细胞壁的专门通道）传递基于蛋白质和RNA的信号。尽管它们对植物发育、生理和防御具有重要意义，但通过胞间连丝运输的一般机制和调控知之甚少。该项目将使用遗传学，细胞生物学和生物物理学方法来了解对植物生长至关重要的调节转录因子如何能够在细胞之间运输，传递重要的发育信号。已经开发了一种新的遗传筛选来发现参与这些蛋白质的细胞间运输的基因。杰克逊实验室已经用这种方法鉴定了两种基因，一种是伴侣蛋白，另一种是GT3。这些发现表明了蛋白质运输的机制，例如通过蛋白质的部分解折叠，或通过GTdR的信号传导，以允许它们通过胞间连丝通道运输。这项提案将进一步研究这些基因促进运输的机制，并发现控制这一过程的新因素。对贩运机制的研究有可能通过提供工具来选择性地调节发育调节剂的贩运，限制病原体的传播，或了解代谢物向对植物生长至关重要的汇组织的运输，从而大大提高植物生产力。因此，该提案将推进植物生物学基础领域的知识，并将为美国农业带来潜在的改善。该项目还将在各个层次培训一些年轻科学家，并开发资源，让高中生参与现代生物学研究。首席研究员指导冷泉港实验室的“未来伙伴”计划，该计划允许当地高中生在研究实验室体验生活。 他还将与纽约皇后区的一所主要为少数族裔学生服务的高中开展教育交流。这项活动使学生接触到科学研究的兴奋和应用，否则他们很少有机会接触科学研究。

All organisms are made up of cells, a basic unit of life. While some microorganisms, such as bacteria, are single celled, most plants and animals are multicellular, composed of many billions of cells, and tens or hundreds of different cell types. Each cell type has a specialized function, for example different cell types in plants function to take up nutrients from the soil, to photosynthesize, or to promote growth. Communication between different cell types is critical for the proper growth and viability of plants. This project will study a system for cell-to-cell communication, involving the transport of signaling molecules through special channels called plasmodesmata. Genes that control the transport process have been identified, and their role in development and physiology will be studied. For example, one such gene encodes a chaperone, a protein that can unwind other molecules, to allow them to pass through plasmodesmata. These studies will provide new insights into plant biology, that could provide strategies to improve crop plant productivity. Outreach activities will target high school students from the local community, as well as underrepresented groups, to provide them training and mentorship in science. Such training is important to maintain a strong science and technology base for the U.S. workforce.An important and unique form of cell-to-cell communication in plants occurs by the trafficking of protein and RNA based signals through plasmodesmata, specialized channels that are embedded in the cell wall. Despite their central importance to plant development, physiology and defense, the general mechanism and regulation of trafficking through plasmodesmata is poorly understood. This project will use genetic, cell biological and biophysical approaches to understand how regulatory transcription factors important for plant growth are able to traffic between cells, to transmit important developmental signals. A novel genetic screen has been developed to discover genes that are involved in cell-to-cell trafficking of these proteins. The Jackson lab has already identified two genes, a chaperonin, and a GTPase, using this approach. These discoveries suggest mechanisms by which the proteins traffic, for example by partial unfolding of the protein, or by signaling by the GTPase, to allow their transport through the plasmodesmal channel. This proposal will further investigate the mechanism by which these genes facilitate transport, and will discover new factors that control the process. Studies of the trafficking mechanisms have the potential to make significant improvements to plant productivity, by providing tools to selectively regulate trafficking of developmental regulators, to limit the spread of pathogens, or to understanding the transport of metabolites into sink tissues, which is critical for plant growth. Hence, this proposal will advance knowledge in a fundamental area of plant biology, and will bring potential improvements to US agriculture. The project will also train a number of young scientists at various levels, as well as develop resources to involve high school students in modern biology research. The Principal Investigator directs the "Partners For the Future" Program at Cold Spring Harbor Laboratory, which allows local high school students to experience life in a research lab. He will also develop an educational exchange with a high school in Queens, New York, which predominantly serves minority students. This activity brings exposure to the excitement and applications of scientific research to students who otherwise have little opportunity for contact with scientific research.