A Global View of Regenerating Plant Cells

描述（由申请人提供）：多细胞生命的所有主要分支都具有修复受损组织的能力，使用来自成人身体的细胞产生用于组织补充和器官修复的替代细胞。最近在哺乳动物中的研究表明，来自一种组织的成体干细胞可能具有产生另一种组织的特化细胞的灵活性，从而提高了成体干细胞可能提供再生受损组织的治疗的可能性。植物和动物共享许多基本的细胞过程，包括RNA干扰，这是一种原始的防御系统，也控制着两个王国的发育。植物是再生的典型模型，因为几乎所有的植物物种都很容易使用为一个目的保留的细胞来替换另一个目的的受损细胞，类似于哺乳动物中的成体干细胞灵活性（“发育可塑性”）。我们在植物中使用体内再生系统，该系统提供了强大的分析工具，以帮助理解模式植物拟南芥中细胞命运可塑性的过程。我们解决的假设，部分分化的细胞首先必须恢复到更基本的干细胞的命运，也许类似于胚胎干细胞，为了在再生过程中产生新的细胞类型。此外，我们使用基因组学来发现可能在细胞水平上引发再生的候选物。在实验方面，我们使用根尖，它具有简单和高度组织化的结构，以及大量的荧光标记物来分析再生组织细胞中发生的分子事件。在目标1中，我们使用高分辨率显微镜来观察单个细胞，监测它们的身份及其向干细胞的潜在逆转，以确定细胞如何改变它们的身份。在目标2中，我们测量各种不同干细胞中的基因活性，以获得干细胞身份的全面目录。这是使用我们开发的新技术来捕获特定的细胞类型，并使用微阵列监测它们的综合基因活性。在目标3中，我们使用相同的方法来获得经历再生的细胞的全面读数。然后，我们使用Aim 2中确定的干细胞身份基因目录来询问再生细胞是否具有与基底干细胞相同的因子。在目标4中，我们研究了基因中的突变体，这些突变体的表达与早期再生有关。这项工作旨在了解在细胞水平上触发组织再生的基本机制。这些结果的目的是提供洞察的基本机制，再生植物中，可以涉及到潜在的相似的机制，在植物中的共同基因或不同的基因，控制类似的过程。

DESCRIPTION (provided by applicant): All major branches of multi-cellular life have the ability to repair damaged tissue, using cells from the adult body to generate replacement cells for tissue replenishment and organ repair. Recent work in mammals has suggested that adult stem cells arising from one tissue may have the flexibility to give rise to specialized cells of another tissue, raising the possibility that adult stem cells may provide a therapy to regenerate damaged tissue. Plants and animals share many basic cellular processes, including RNA interference, a primitive defense system that has also controls development in both kingdoms. Plants are a quintessential model for regeneration, as almost all plant species readily use cells set aside for one purpose to replace damaged cells of another purpose, analogously to adult stem cell flexibility in mammals ("developmental plasticity"). We use an in vivo regeneration system in plants that affords powerful analytical tools to help understand the process of cell fate plasticity in the model plant Arabidopsis thaliana. We address the hypothesis that partially differentiated cells first must revert to more basic stem cell fates perhaps similar to embryonic stem cells, in order to give rise to new cell types during regeneration. In addition, we use genomics to discover the candidate that may trigger regeneration at the cellular level. On the experimental side, we use the root tip, which has a simple and highly organized structure, and a large selection of fluorescent markers to analyze the molecular events that occur in cells in regenerating tissue. In Aim 1, we use high-resolution microscopy to visualize individual cells, monitor their identities and their potential reversion to stem cells in order to determine how cells can transform their identity. In Aim 2, we measure gene activity in a variety of different stem cells to obtain a comprehensive catalog of stem cell identity. This is done using new techniques we have developed to capture specific cell types and monitor their comprehensive gene activity using microarrays. In Aim 3, we use the same methods to obtain comprehensive readouts of the cells that undergo regeneration. We then use the catalog of stem cell identity genes identified in Aim 2 to ask whether regenerating cells possess any common factors with basal stem cells. In Aim 4, we look at mutants in genes whose expression implicates them in early regeneration. This work is aimed at understanding the fundamental mechanisms that trigger tissue regeneration at the level of the cell. These results are aimed at providing insights into the fundamental mechanisms of regeneration in plants that can be related to potentially similar mechanisms in plants either at the level of common genes or different genes that control analogous processes.