Evolution of spur-length diversity in Aquilegia petals is achieved solely through cell-shape anisotropy
Evolution of spur-length diversity in Aquilegia petals is achieved solely through cell-shape anisotropy
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DOI：
10.1098/rspb.2011.1873
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发表时间：
2012-04-22
影响因子：
4.7
通讯作者：
Mahadevan, L.
中科院分区：
文献类型：
--
作者：
Puzey, Joshua R.;Gerbode, Sharon J.;Mahadevan, L.
自达尔文以来，人们一直在研究花瓣刺和专门传粉者相互作用的作用。Aquilegia花瓣刺表现出惊人的大小和形状多样性，与专门的授粉者，从蜜蜂到天蛾在适应性辐射的教科书的例子。尽管距长度的进化意义，显着知之甚少Aquilegia距形态发生和它的进化。使用实验测量，无论是在组织和细胞水平，结合数值模拟，我们已经调查了细胞分裂和细胞形状的相对作用，在确定形态的Aquilegia花瓣刺。相反，几十年来的假设牵连一个离散的分生区作为驱动程序的马刺的增长，我们发现，Aquilegia花瓣马刺通过各向异性细胞扩张发展。此外，细胞各向异性的变化占该属中99%的刺长变化，这表明Aquilegia快速辐射的真正进化创新是调整细胞形状的机制。
The role of petal spurs and specialized pollinator interactions has been studied since Darwin. Aquilegia petal spurs exhibit striking size and shape diversity, correlated with specialized pollinators ranging from bees to hawkmoths in a textbook example of adaptive radiation. Despite the evolutionary significance of spur length, remarkably little is known about Aquilegia spur morphogenesis and its evolution. Using experimental measurements, both at tissue and cellular levels, combined with numerical modelling, we have investigated the relative roles of cell divisions and cell shape in determining the morphology of the Aquilegia petal spur. Contrary to decades-old hypotheses implicating a discrete meristematic zone as the driver of spur growth, we find that Aquilegia petal spurs develop via anisotropic cell expansion. Furthermore, changes in cell anisotropy account for 99 per cent of the spur-length variation in the genus, suggesting that the true evolutionary innovation underlying the rapid radiation of Aquilegia was the mechanism of tuning cell shape.