Soltis Douglas E, Ma Hong, Frohlich Michael W, Soltis Pamela S, Albert Victor A, Oppenheimer David G, Altman Naomi S, dePamphilis Claude, Leebens-Mack Jim
Department of Botany and the Genetics Institute, University of Florida, Gainesville, FL 32611, USA.
Trends Plant Sci. 2007 Aug;12(8):358-67. doi: 10.1016/j.tplants.2007.06.012. Epub 2007 Jul 19.
Through multifaceted genome-scale research involving phylogenomics, targeted gene surveys, and gene expression analyses in diverse basal lineages of angiosperms, our studies provide insights into the most recent common ancestor of all extant flowering plants. MADS-box gene duplications have played an important role in the origin and diversification of angiosperms. Furthermore, early angiosperms possessed a diverse tool kit of floral genes and exhibited developmental 'flexibility', with broader patterns of expression of key floral organ identity genes than are found in eudicots. In particular, homologs of B-function MADS-box genes are more broadly expressed across the floral meristem in basal lineages. These results prompted formulation of the 'fading borders' model, which states that the gradual transitions in floral organ morphology observed in some basal angiosperms (e.g. Amborella) result from a gradient in the level of expression of floral organ identity genes across the developing floral meristem.
通过多方面的基因组规模研究，包括系统发育基因组学、靶向基因调查以及在被子植物不同基部谱系中的基因表达分析，我们的研究为所有现存开花植物的最近共同祖先提供了见解。MADS盒基因复制在被子植物的起源和多样化过程中发挥了重要作用。此外，早期被子植物拥有多样化的花基因工具包，并表现出发育“灵活性”，与真双子叶植物相比，关键花器官身份基因的表达模式更为广泛。特别是，B功能MADS盒基因的同源物在基部谱系的花分生组织中表达更为广泛。这些结果促使形成了“边界渐消”模型，该模型指出，在一些基部被子植物（如无油樟）中观察到的花器官形态的逐渐转变是由于花器官身份基因在发育中的花分生组织中的表达水平梯度所致。
