Programmed cell death in plant development

程序性细胞死亡（PCD）是一种遗传激活的过程，其中选择的细胞组织自己的破坏。PCD在所有真核生物界中普遍存在，并且被单细胞和多细胞生物体用作正常发育的一部分或响应于外部刺激。在植物中，PCD是生长和存活所必需的，可以是发育调节的或环境诱导的。发育PCD的一个独特的例子是花边植物叶片中的穿孔（孔）形成。这些孔位于纵脉和横脉之间等距离，使叶子呈格子状。在穿孔形成期间，离散的细胞亚群经历PCD，而相邻细胞保持完整。花边植物原产于马达加斯加，在水族箱条件下很难生长。本人已成功地建立了一个无菌培养系统，用于花边植物PCD的研究。我们仍然不知道是什么线索触发PCD在叶发育的特定阶段，到目前为止的信号通路和分子机制的关注。本研究对花边植物穿孔形成过程中的细胞死亡过程进行了表征，表明花边植物是研究体内发育PCD的理想模式系统。因此，我的研究的长期目标是实现一个基本的理解，在发育PCD使用花边植物叶片形态建成作为模型系统的机制。这将通过以下目标实现：1.花边植物PCD关键调控因子和信号通路的鉴定。2.确定自噬在花边植物PCD过程中的作用。3.通过遗传转化表征PCD期间的细胞器动态。4.花色苷等酚类化合物参与花边植物PCD的研究。5. PCD细胞与NPCD细胞差异表达基因的鉴定。这些结果将帮助我们确定动物和植物PCD之间是否存在共同机制，或者它们是否独立进化。 在过去的20年里，植物PCD的研究引起了人们极大的兴趣;然而，参与发育调控PCD的信号通路、分子机制和基因在很大程度上仍然未知。拟议的研究将使我的实验室小组以一种新颖的方式推进对植物PCD所涉及的各种机制的理解，这种方式不仅在加拿大而且在国际上都是独一无二的。

Programmed cell death (PCD) is a genetically-enabled process in which select cells organize their own destruction. PCD is ubiquitous in all eukaryotic kingdoms and is employed by both unicellular and multicellular organisms as part of normal development or in response to external stimuli. In plants, PCD is necessary for growth and survival and can either be developmentally regulated or environmentally induced. A unique example of developmental PCD is perforation (hole) formation in lace plant leaves. These holes are situated equidistantly between longitudinal and transverse veins, giving leaves a lattice-like pattern. During perforation formation, discrete subpopulations of cells undergo PCD while adjacent cells remain intact. Lace plant is native to Madagascar and difficult to grow in aquarium conditions. I have successfully developed a sterile culture system to work on developmental PCD in lace plant. We still do not know what cues trigger PCD at a specific stage of leaf development, so far as the signaling pathways and the molecular mechanisms are concerned. I have characterized the cell death process during perforation formation in lace plant and showed that this aquatic plant is an ideal model system to study developmental PCD in vivo. Therefore, the long term objective of my research is to achieve a fundamental understanding of the mechanisms involved in developmental PCD using lace plant leaf morphogenesis as a model system. This will be achieved through the following objectives: 1. Identification of key regulators and signaling pathways in lace plant PCD. 2. Determination of the role of autophagy during lace plant PCD. 3. Characterization of organelle dynamics during PCD via genetic transformation. 4. Investigation of anthocyanin and other phenolic compounds involved in lace plant PCD. 5. Identification of differentially expressed genes between PCD cells and NPCD cells. These results will help us to determine whether there are common mechanisms between animal and plant PCD or whether they evolved independently. Research in plant PCD has garnered remarkable interest in the past 20 years; however, the signaling pathways, molecular mechanisms, and genes involved in developmentally regulated PCD are still largely unknown. The proposed research will permit my lab group to advance the understanding of various mechanisms involved in plant PCD in a novel way that is unique not only in Canada, but internationally.