CONFOCAL IMAGING OF CHANGES IN CYTOPLASMIC CA2+ IN GUARD CELLS OF ARABIDOPSIS

胞浆Ca ~（2+）的升高是一个普遍存在的信号传导过程 在真核细胞中。 生理反应的特异性 由Ca 2+信号启动的信号部分由细胞的性质编码。 胞浆Ca ~（2+）增加。 在植物细胞中， 叶片中的气体交换，对各种刺激的特异性（光， 温度，脱落酸，二氧化碳）被认为是由空间编码， 时间和幅度（STA）的变化在Ca 2+信号。 我们计划 利用单个保卫细胞成像技术来分析这些复杂的Ca 2+信号 利用NCMIR提供的技术。 以前的研究 J.I.博士的实验室Schroeder的研究表明，保卫细胞可以 用钙离子敏感染料钙绿色和Fura 2通过一个 非侵入性酯负载技术。 这一重大进展可以 现在可以用来研究这些细胞中的Ca 2+信号。 等问题 作为Ca 2+的来源（细胞外或细胞内），STA性质 信号和信号的可能振荡将是 处理。 从NCMIR获得的图像中获得的信息 将与在 施罗德实验室，利用电生理技术， 如膜片钳和单电极电压钳。 相结合 这些技术将产生重要的信息的性质和 运输过程的调节， 保卫细胞中的Ca 2+信号。 这项工作将使用拟南芥 守卫细胞 A.保卫细胞功能缺陷的拟南芥突变体 在施罗德实验室被隔离了 这些变种人将会 测试其CA 2+信号表型的变化，因此特异性 突变可以与保卫细胞信号传导中的限定作用相关联。 的 突变体的工作将特别集中在激素脱落酸（阿坝）。 阿坝调节保卫细胞膨压，因此，气孔开度， Ca 2+介导的离子通道调节。 许多变种人现在 施罗德实验室提供的异常阿坝 应答 使用这些阿坝突变体和整合的 在国家气象研究中心和施罗德实验室可用的技术， 产生关于这种作用机制的重要信息， 重要植物激素。 该项目的工作正在进行中。

The elevation of cytosolic Ca2+ is a ubiquitous signaling process in eukaryotic cells. Specificity of the physiological response initiated by the Ca2+ signal is in part encoded by the nature of the cytosolic Ca2+ increase. In plant cells, the cell pairs that regulate gaseous exchange in the leaf, specificity to various stimuli (light, temperature, abscisic acid, CO2) is thought to be encoded by spatial, temporal and amplitude (STA) variations in the Ca2+ signal. We plan to dissect these comples Ca2+ signals using single guard cell imaging utilizing the techniques available at NCMIR. Previous studies in the laboratory of Dr. J.I. Schroeder have shown that guard cells can be loaded with the Ca2+ -sensitive dyes Calcium green and Fura 2 by a non-invasive ester loading technique. This significant advance can now be utilized to study Ca2+ signals in these cells. Questions such as the source of Ca2+ (extracellular or intracellular), the STA nature of the signal and the possible oscillation of the signal will be addressed. The information obtained from the images obtained at NCMIR will be combined with concurrent experiments performed in the Schroeder laboratory that utilize electrophysiological techniques such as patch clamping and single electrode voltage clamp. The combination of these techniques will yield important information on the nature and regulation of the transport processes that underlie the generation of Ca2+ signals in guard cells. The work will use Arabidopsis thaliana guard cells. A. thaliana mutants defective in guard cell function have been isolated in the Schroeder laboratory. These mutants will be tested for variations in their CA2+ signaling phenotype, so specific mutations can be linked to defined roles in guard cell signaling. The mutant work will focus particularly on the hormone Absisic acid (ABA). ABA regulates guard cell turgor, and therefore, stomatal aperture by Ca2+-mediated regulation of ion channels. Many mutants are now available in the Schroeder laboratory which show aberrant ABA responses. Using these ABA mutants and an integration of the techniques available at NCMIR and in the Schroeder laboratory could yield important information on the mechanism of action of this important plant hormone. Work on this project is underway.