Mechanisms Underlying Plant Cell Development

9723895 Verbeke细胞分化的过程对我们理解植物的生长发育具有重要意义，但这方面的实验研究还很少。在发育过程中，每个细胞必须以某种方式确定其相对于其他细胞的位置，并必须相应地分化。然而，对于细胞建立其位置并随后产生合适的细胞类型的机制几乎一无所知。尽管细胞和组织的分化肯定是基因组选择性表达的结果，但一个关键的问题是我们无法在表型和基因之间建立联系。在基因结构甚至功能的知识似乎呈指数级增长的时候，关于这些基因实际上是如何导致细胞分化和形成组织、器官和生物体的，人们仍然知之甚少。决定是个体细胞分化状态的反映。因此，研究表现出高度决心的细胞可能是非常有用的，如抵抗重新分化所表明的那样。植物的表皮细胞就是这样的实体。在没有伤害的情况下(通常是尽管有伤害)，植物表皮细胞在发育过程中不能重新分化或改变它们的命运。然而，花器官融合是这一规则的自然例外。这里描述的工作的总体目标是了解更多关于植物细胞分化的控制。这些实验代表了传递位置信息的细胞间通信事件和信号的持续特征。要解决的具体问题将集中在重新分化因子的化学特性的表征上。这里描述的长春花系统是少数几个以扩散因子的形式记录细胞-细胞相互作用的直接实验证据的植物系统之一。这也是植物系统中第一个明确的文献，表明同一花中的两个表面上相同的器官可能本质上和关键的彼此不同。

9723895 Verbeke The process of cellular differentiation is of fundamental significance to our understanding of plant growth and development, yet experimental studies in this area have been rare. During development, each cell must somehow determine its position relative to others, and must differentiate accordingly. However, almost nothing is known about the mechanisms by which cells establish their positions and subsequently give rise to appropriate cell types. Although cell and tissue differentiation must certainly be the result of selective expression of the genome, a critical problem has been our inability to make the connection between phenotype and genotype. At a time when knowledge of gene structure and even function seems to be increasing exponentially, there is still little known about how these genes actually cause cells to differentiate and form tissues, organs, and organisms. Determination is a reflection of the state of differentiation of individual cells. For this reason, it may be quite useful to study cells which display a high degree of determination, as indicated by a resistance to redifferentiate. Plant epidermal cells are such entities. In the absence of wounding (and usually in spite of wounding), plant epidermal cells are developmentally incompetent to redifferentiate or change their fate. However, fusing floral organs are naturally occurring exceptions to this rule. The overall goal of the work described here is to learn more about the controls of plant cell differentiation. These experiments represent an ongoing characterization of the cell-to-cell communication events and signals which convey positional information. The specific question to be addressed will focus on characterization of the chemical identity of the redifferentiation factors. The periwinkle system described here is one of only a few plant systems in which dire ct experimental evidence documenting cell-cell interaction in the form of diffusible factors has been shown. This is also the first clear documentation in a plant system that two apparently identical organs in the same flower may be inherently and critically different from one another.