重要性：Therefore, understanding the genetic and developmental mechanisms involved in the origin of these key innovations has long been of interest to evolutionary biologists.

研究背景：In flowering plants, floral nectar spurs are a prime example of a key innovation, with the independent evolution of spurs associated with increased diversification rates in multiple angiosperm lineages due to their ability to promote reproductive isolation via pollinator specialization.

提出问题：As none of the traditional plant model taxa have nectar spurs, little is known about the genetic and developmental basis of this trait.

研究结果：Nectar spurs are a defining feature of the columbine genus Aquilegia (Ranunculaceae), a lineage that has experienced a relatively recent and rapid radiation. We use a combination of genetic mapping, gene expression analyses, and functional assays to identify a gene crucial for nectar spur development, POPOVICH (POP), which encodes a C2H2 zinc-finger transcription factor. POP plays a central role in regulating cell proliferation in the Aquilegia petal during the early phase (phase I) of spur development and also appears to be necessary for the subsequent development of nectaries. 

结论：The identification of POP opens up numerous avenues for continued scientific exploration, including further elucidating of the genetic pathway of which it is a part, determining its role in the initial evolution of the Aquilegia nectar spur, and examining its potential role in the subsequent evolution of diverse spur morphologies across the genus.

p.s. 该基因名“POPOVICH”取自圣安东尼奥马刺篮球队主教练Gregg Popovich。Ballerini认为该基因就像篮球队的教练一样，教练通过调节球员的活动来控制圣安东尼奥马刺队的发展，而该基因通过调节其它基因的活性来控制花蜜马刺的发育。