The Role of Cauliflower in Specifying Floral Meristem Identity in Arabidopsis

诱导成花后，花发育的第一步是分生组织的产生。在拟南芥中，至少有三个基因（CAULIFLOWER、APETALA1和LEAFY）是确定花分生组织特性所必需的。这位研究者最近分离出了CAULIFLOWER和APETALA1基因。这一建议描述了一种结合遗传和分子的方法来确定花椰菜如何与其他基因相互作用以促进开花。研究者建议分离和表征一个等位基因突变系列，并通过扫描电子显微镜分析产生的表型。CAULIFLOWER的转录调控将通过确定各种突变背景下的空间和时间表达模式来研究。进一步的研究将确定CAULIFLOWER蛋白是否直接与APETALA1相互作用，并将确定CAULIFLOWER特异性结合的DNA序列。进一步的研究将探讨促进CAL在花分生组织特异性表达所需的顺式和反式因子，并确定CAL和AP1功能冗余的分子基础。这些研究将有助于进一步了解APETALA1的作用，并对了解花分生组织的遗传和分子调控有重要贡献。拟南芥的花椰菜表型与餐桌花椰菜Brassica oleracea产生的异常花序结构惊人地相似。由于拟南芥和芸苔属亲缘关系较近的植物物种，且这些突变体的表型相似，因此研究者将利用克隆的CAL和AP1基因来研究花椰菜表型的分子基础。最后，由于菜花表型已经在与拟南芥有远亲关系的植物中被描述过，而且菜花基因还没有从任何其他植物物种中分离出来，因此对该基因的表征应该对其在不同植物系统中的作用有重要的了解。

After floral induction, the first step in the development of flowers is the generation of floral meristems. At least three genes, CAULIFLOWER, APETALA1, and LEAFY, are necessary for the specification of floral meristem identity in Arabidopsis. This investigator has recently isolated the CAULIFLOWER and APETALA1 genes. This proposal describes a combined genetic and molecular approach for determining how CAULIFLOWER interacts with other genes to promote flowering. The investigator proposes to isolate and characterize an allelic series of cal mutants and analyze the resulting phenotypes by scanning electron microscopy. The transcriptional regulation of CAULIFLOWER will be investigated by determining the spatial and temporal pattern of expression in a variety of mutant backgrounds. Additional studies will determine if the CAULIFLOWER protein interacts directly with APETALA1, and will identify the DNA sequences to which CAULIFLOWER specifically binds. Further studies will investigate the cis- and trans-acting factors needed to promote floral meristem-specific expression of CAL, and will determine the molecular basis for the functional redundancy of CAL and AP1. These studies will be integrated into efforts to understand the role of APETALA1 and should lead to significant contributions towards understanding the genetic and molecular control of floral meristem specification. The cauliflower phenotype in Arabidopsis is strikingly similar to the anomalous inflorescence structures produced in the dinner table cauliflower, Brassica oleracea. Since Arabidopsis and Brassica are closely related plant species, and since the phenotypes of these mutants is similar, the investigator will use the cloned CAL and AP1 genes to investigate the molecular basis of the cauliflower phenotype. Finally, since the cauliflower phenotype has been described in plants that are distantly related to Arabidopsis, and since the CAULIFLOWER gene has not been isolated from any other plant s pecies, the characterization of this gene should yield significant insights into its role in diverse plant systems.