The Role of Cauliflower in Specifying Floral Meristem Identity in Arabidopsis

花诱导后，花发育的第一步是花分生组织的产生。至少有三个基因，即花椰菜、APETALA1和LEAFY，是拟南芥花分生组织特征确定所必需的。这位研究人员最近分离了花椰菜和APETALA1基因。这项建议描述了一种遗传和分子相结合的方法来确定花椰菜如何与其他基因相互作用来促进开花。这位研究人员建议分离和表征一系列等位基因突变，并用扫描电子显微镜分析由此产生的表型。花椰菜的转录调控将通过确定在不同突变背景下表达的空间和时间模式来研究。进一步的研究将确定花椰菜蛋白是否直接与APETALA1相互作用，并将确定花椰菜特定结合的DNA序列。进一步的研究将探讨促进CAL的花分生组织特异性表达所需的顺式和反式作用因子，并将确定CAL和AP1功能冗余的分子基础。这些研究将被整合到了解APETALA1的作用的努力中，并将对理解花分生组织规格的遗传和分子控制做出重大贡献。拟南芥的花椰菜表型与餐桌花椰菜中产生的异常花序结构惊人地相似。由于拟南芥和油菜是亲缘关系密切的植物物种，而且这些突变体的表型很相似，所以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，由于花椰菜的表型已经在与拟南芥有较远亲缘关系的植物中被描述，而且花椰菜基因还没有从任何其他植物S种中分离出来，因此该基因的特征应该对其在不同植物系统中的作用产生重要的见解。

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.