Subcellular Localization of Signal Molecules and Their Effect on Plants (Biological Sciences)

该项目将采取双管齐下的方法，更深入地了解植物细胞如何感知信号并将其转导成反应。(1)根瘤菌诱导植物固氮根瘤的形成，它们共同提供农业生物固定氮的主要输入。细胞和分子生物学方法将被用于分析根瘤菌-苜蓿体系中根毛结瘤的早期事件（结瘤基因机制）。一种新开发的方法将允许将细菌细胞和纯化的“nod因子”应用于或注射到单个根毛细胞中。视频增强（包括共聚焦激光扫描）光学显微镜图像将允许在体内观察根毛细胞的诱导反应，这些图像将与体外电子显微镜图像相关联。将检查内部钙离子水平、细胞骨架元素、钙调蛋白和内质网的瞬态和长期响应变化。应该对结瘤的细胞、遗传和分子方面有一个更清晰的认识。(2)光感受器光敏色素介导了植物一系列光激活的发育过程。针对光敏色素的单克隆和多克隆抗体将用于检测和定位（视频显微镜下）豌豆茎囊泡中光敏色素膜相关部分的分布，如果成功，则用于细胞中（与Winslow Briggs一起）。互动活动将包括一门名为“性别与科学”的课程，教授给来自不同科学和人文学科的本科生和研究生；在“生物学家显微术”课程中讲授视频增强、基于计算机的显微方法；几个研讨会;组织非正式小组讨论，讨论与科学领域的女性（和男性）相关的几个主题。该项目进一步推进了VPW计划的目标，即(1)为女性提供在工程和NSF支持的科学学科中发展职业的机会；(2)通过为在工业、政府和学术机构工作的女性科学家和工程师提供更大的知名度，鼓励女性在科学和工程领域追求职业。通过鼓励妇女参与科学，这是对国家未来科学活力的宝贵投资。

This project will take a two-pronged approach to give greater insight into how signals are perceived and transduced into responses in plant cells. (1) Rhizobium bacteria induce the formation of nitrogen fixing nodules in plants and together they provide the major input of biologically fixed nitrogen in agriculture. Cellular and molecular biological methods will be brought to bear on the analysis of early events of nodulation (nod gene mechanisms) of root hairs in the Rhizobium meliloti-alfalfa system (with Sharon Long). A newly developed method will allow bacterial cells and purified "nod factors" to be applied to or injected into single root hair cells. Video- enhanced (including confocal laser scanning) light microscopic images will permit the in vivo observations of induced responses in nodulating root hair cells, and these images will be correlated with in vitro electron microscopic images. Transient and longer response changes in internal calcium ion levels, cytoskeletal elements, calmodulin and the endoplasmic reticulum will be examined. A clearer understanding of the cellular, genetic and molecular aspects of nodulation should result. (2) The photoreceptor phytochrome mediates a host of light-activated developmental processes in plants. Monoclonal and polyclonal antibodies against phytochrome will be used to detect and localize (video microscopically) the distribution of the membrane-associated fractions of phytochrome in pea stem vesicles, and if that is successful, in cells (with Winslow Briggs). Interactive activities will consist of a course entitled Gender and Science, taught to undergraduate and graduate students from different disciplines in the sciences and humanities; lectures in a "Microscopy for Biologists" course on video-enhanced, computer-based microscopic methods; several seminars; and organization of informal panel discussions on several topics pertinent to women (and men) in science. This project furthers VPW program objectives which are (1) to provide opportunities for women to advance their careers in engineering and in the disciplines of science supported by NSF and (2) to encourage women to pursue careers in science and engineering by providing greater visibility for women scientists and engineers employed in industry, government, and academic institutions. By encouraging the participation of women in science, it is a valuable investment in the Nation's future scientific vitality.