RUI: Characterization of Cultured Guard Cell Protoplasts

气孔是植物气生器官中的生物阀门， 同时调节光合作用和蒸腾作用。 的 气孔的开闭受收缩或 形成其边缘的“保卫细胞”肿胀。 的 气孔周围保卫细胞的叶绿体 不与叶肉中的那些同时衰老（变黄） 同一片叶子的组织。 该项目的长期目标是 培养气孔保卫细胞， 独特的生理特性，包括 它们的叶绿体 这种培养物可以用来研究 叶绿体衰老诱导和调控。 这 实验室建立了气孔保卫细胞的原生质体， 栽培中的烟草。 然而，最佳条件 细胞存活率尚未确定。 多种培养 将对条件进行评估，以确定最佳条件 for cell细胞survival生存. 以确定是否有任何独特的 保卫细胞的特性在培养中得以维持，一些 新鲜分离菌株的生理生化特性 保卫细胞原生质体将与原生质体进行比较 培养的细胞。 将进行相同的实验， 保卫细胞原生质体从衰老（褪绿）叶：1）到 评估其相对于 保卫细胞的非衰老叶，和2）以确定是否 在这些细胞的保卫细胞的性质上存在任何差异， 这两种叶子可以解释为什么 衰老的叶子不能对光线作出反应而张开。 这项研究的目的是开发培养 气孔保卫细胞从叶片的条件下，不仅 使其得以生存，同时也维持其分化 特性. 这种培养细胞的可用性将 极大地促进了对生理功能的进一步研究， 这些细胞控制着水和气体的流通 在树叶的表面。 由于含有叶绿素的 保卫细胞的细胞器，叶绿体， 在某些生理条件下， 这些细胞将提供一个极好的模型系统， 在其中研究调节的功能状态， 叶绿体 由于这项研究将在一个 本科院校，它也将提供一个优秀的 本科生有机会获得第一手资料 有植物细胞生物学研究经验。

Stomata are biological valves in the aerial organs of plants that regulate simultaneously photosynthesis and transpiration. The opening and closing of stomata are affected by the shrinking or swelling of "guard cells" which form their edges. The chloroplasts of the guard cells that surround the stomatal pore do not senesce (yellow) at the same time as those in mesophyll tissue of the same leaf. The long range goal of the project is to culture stomatal guard cells in ways that preserve their unique physiological properties, including the functionality of their chloroplasts. Such cultures could be used to study the induction and regulation of chloroplast senescence. This laboratory has established protoplasts of stomatal guard cells of Nicotiana glauca in culture. However, optimal conditions for cell survival have not yet been identified. A variety of culture conditions will be evaluated to identify those that are optimal for cell survival. To determine whether any of the unique properties of guard cells are maintained in culture, some of the physiological and biochemical properties of freshly isolated guard cell protoplasts will be compared to those of protoplasts of cultured cells. The same experiments will be performed with guard cell protoplasts from senescing (chlorotic) leaves: 1) to evaluate their viability relative to those of guard cells of non-senescing leaves, and 2) to determine whether there are any differences in the properties of guard cells of the two types of leaves that might explain why the stomata of senescing leaves fail to open in response to light. This research is directed at developing techniques for culturing stomatal guard cells from leaves under conditions that not only permit their survival but also maintain their differentiated properties. The availability of such cultured cells would greatly facilitate further research on the physiological function of these cells which regulate the passage of water and gases across the surfaces of leaves. Since the chlorophyll-containing organelles, chloroplasts, of guard cells behave differently from the chloroplasts of other cells under some physiological conditions, these cells would provide an excellent model system in which to study the regulation of the functional state of chloroplasts. Since this research will be conducted at an undergraduate institution it will also provide an excellent opportunity for undergraduate students to gain first hand experience in research in plant cell biology.