The Contribution of Calcium to Plant Cell Development

在本提案中，PI将解决生理和 关于钙（Ca）贡献的结构问题 3种植物特异系统：1）细胞分裂素诱导芽 2）光敏色素刺激孢子萌发 3）在小孢子蕨属中萌发和花粉管生长 紫露草和烟草。在生理学研究中，他将 确定细胞内游离Ca是否响应于 刺激。钙变化的动力学将在显微镜下检查。 在已被感染的Funaria的靶细胞中， 用吸收剂Ca-指示剂染料偶氮胂-III显微注射。 还将特别注意 磷脂酰肌醇（PI）循环介导的发展。 增强或抑制部分PI的药理学试剂 将测试其对发展的影响。结构 研究将集中于细胞骨架和膜成分。的 Ca中的助熔剂改变这些组分的能力将是 在光学显微镜水平上使用荧光染色进行分析， 和抗体，并在电子显微镜水平上使用 通过快速冷冻固定方法制备的材料， 其中细胞质结构被保留， 忠诚 钙离子作为细胞内的信使在许多 有机体它们被认为是将刺激与反应结合起来的 从而介导或触发许多重要的发展 事件钙离子作为细胞内信使的作用 在植物中没有得到很好的研究。这些研究将有助于 理解钙在刺激/反应中的作用 植物中的耦合

In this proposal the PI will address physiolgical and structural questions concerning the contribution of calcium (Ca) to three specific plant systems: 1) cytokinin-induced bud formation in Funaria, 2) phytochrome-stimulated spore germination in Onoclea, and 3) germination and pollen tube growth in Tradescantia and Nicotiana. In the physiolgical studies he will determine if the intracellular free Ca changes in response to a stimulus. The kinetics of Ca changes will be examined micro- spectrophotometrically in target cells of Funaria that have been microinjected with the absorbant Ca-indicator dye arsenazo-III. Particular attention will also be given to the role of the phosphatidyl inositol (PI) cycle in mediating development. Pharmacological agents that enhance or inhibit portions of the PI cycle will be tested for their effect on development. Structural studies will focus on cytoskeletal and membrane components. The ability of fluxes in Ca to modify these components will be analyzed at the light microscope level using fluorescent stains and antibodies, and at the electron microscope level using material that has been prepared by a rapid freeze fixation method, in which cytoplasmic structure is preserved with exceptional fidelity. Calcium ions act as intracellular messengers in many organisms. They are thought to couple the stimulus to the response and thus to mediate or trigger many important developmental events. The role of calcium ions as intracellular messengers has not been as well studied in plants. These studies will contribute to an understanding of the role of Ca in stimulus/response coupling in plants.