Plant Biology Postdoctoral Fellowship Starter Grant Study: To Investigate the Genes and Processes Involved in Meristem Development

顶端分生组织和根分生组织是植物胚胎中最重要的结构，负责进一步的发育。这些分生组织形成成熟植株的地上部分和地下部分。顶端分生组织发育的两个方面是其功能的中心。首先，顶端分生组织必须保持一个增殖的、未分化的细胞池。这个池不断地为器官生成提供新的细胞。同样重要的是保持分生组织细胞的增殖和随后的分化之间的平衡。由于细胞分裂，分生组织细胞位于顶端分生组织尖端的远端，这些远端细胞必须被允许进入特定的发育途径，最终导致分化。因此，顶端分生组织可以被认为有两个区域，一个中心区域包含处于未分化状态(或未被诱导到分化状态)的分生组织细胞，以及周围的区域，细胞在那里进入特定的发育途径，走向分化状态。作为确定控制分生组织发育的基因的第一步，必须识别在这两个过程中存在缺陷的突变。CLV1突变体形成过多的未分化分生组织细胞，可能需要维持分生组织中细胞增殖和细胞分化之间的平衡。另外两个基因座，CLV2和CLV3，基于它们相似的表型，似乎也参与了相同的过程。这位研究者建议通过解决以下几个问题来研究分生组织的发育：(1)CLV1基因座编码的基因产物是什么；这是否为其功能提供了任何线索？(2)CLV1的mRNA表达模式是什么？(3)CLV2是否与CLV1和CLV3具有相同的途径，这些基因之间是否有直接相互作用的证据？(4)是否有其他基因与CLV1和CLV3相互作用？这些研究应该为分生组织发育过程中涉及的一些基因和过程提供令人兴奋的新信息。

The apical and root meristem are the most important structures of the plant embryo responsible for further development. These meristems give rise to the aerial and underground portions of the mature plant. Two aspects of apical meristem development are central to its function. First, the apical meristem must maintain a pool of proliferating, undifferentiated cells. This pool continually provides new cells for organ generation. Equally important is maintaining the balance between the proliferation of the meristem cells and their subsequent differentiation. As meristem cells become distal to the apical meristem tip as a result of cell division, these distal cells must be allowed to enter a specific developmental pathway leading to eventual differentiation. Thus the apical meristem can be thought of as having two zones, a central zone containing meristem cells in an undifferentiated state (or uninduced towards a differentiated state), and a surrounding peripheral zone where cells are entering a specific developmental pathway toward a differentiated state. As a first step toward determining the genes controlling meristem development, mutations with defects in these two processes must be identified. CLV1 mutants develop excess undifferentiated meristem cells and may be required to maintain the balance between cell proliferation and cell differentiation in the meristem. Two other loci, CLV2 and CLV3, also appear to be involved in the same process based on their similar phenotype. This investigator proposed to investigate meristem development by addressing several questions: (1) What is the gene product encoded by the CLV1 locus; and does this give any clues to its function?; (2) What is the mRNA expression pattern for CLV1?; (3) Does CLV2 function in the same pathway as CLV1 and CLV3, and is there any evidence for direct interactions between these loci?; and (4) Are there other genes that interact with CLV1 and CLV3? These studies should provide exciting n ew information about some of the genes and processes involved in meristem development.