Dept. of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA.
Semin Cell Dev Biol. 2010 Feb;21(1):80-6. doi: 10.1016/j.semcdb.2009.11.012. Epub 2009 Nov 13.
Proper regulation of floral homeotic gene (or ABCE gene) expression ensures the development of floral organs in the correct number, type, and precise spatial arrangement. This review summarizes recent advances on the regulation of floral homeotic genes, highlighting the variety and the complexity of the regulatory mechanisms involved. As flower development is one of the most well characterized developmental processes in higher plants, it facilitates the discovery of novel regulatory mechanisms. To date, mechanisms for the regulation of floral homeotic genes range from transcription to post-transcription, from activators to repressors, and from microRNA- to ubiquitin-mediated post-transcriptional regulation. Region-specific activation of floral homeotic genes is dependent on the integration of a flower-specific activity provided by LEAFY (LFY) and a region- and stage-specific activating function provided by one of the LFY cofactors. Two types of regulatory loops, the feed-forward and the feedback loop, provide properly timed gene activation and subsequent maintenance and refinement in proper spatial and temporal domains of ABCE genes. Two different microRNA/target modules may have been independently recruited in different plant species to regulate C gene expression. Additionally, competition among different MADS box proteins for common interacting partners may represent a mechanism in whorl boundary demarcation. Future work using systems approaches and the development of non-model plants will provide integrated views on floral homeotic gene regulation and insights into the evolution of morphological diversity in flowering plants.
花器官同源异型基因（或 ABCE 基因）表达的适当调控确保了花器官在正确的数量、类型和精确的空间排列中发育。本综述总结了花器官同源异型基因调控的最新进展，强调了所涉及的调控机制的多样性和复杂性。由于花的发育是高等植物中最具特征的发育过程之一，因此它有助于发现新的调控机制。迄今为止，花器官同源异型基因的调控机制从转录到转录后，从激活子到抑制剂，从 microRNA 到泛素介导的转录后调控都有涉及。花器官同源异型基因的区域特异性激活依赖于由 LEAFY（LFY）提供的花特异性活性和由 LFY 共因子之一提供的区域和阶段特异性激活功能的整合。两种类型的调控环，前馈环和反馈环，提供了 ABCE 基因在适当的时空域中适时的基因激活以及随后的维持和细化。两种不同的 microRNA/靶标模块可能已经在不同的植物物种中被独立招募来调节 C 基因的表达。此外，不同 MADS 框蛋白之间对共同相互作用伙伴的竞争可能代表了轮辋边界划分的一种机制。使用系统方法和非模式植物的发展的未来工作将提供对花器官同源异型基因调控的综合观点，并深入了解开花植物形态多样性的进化。
