School of Plant Science, University of Tasmania, Hobart, 7001 Tas., Australia.
Ecol Lett. 2010 Feb;13(2):175-83. doi: 10.1111/j.1461-0248.2009.01410.x. Epub 2009 Nov 30.
Angiosperm evolution transformed global ecology, and much of this impact derives from the unrivalled vegetative productivity of dominant angiosperm clades. However, the origins of high photosynthetic capacity in angiosperms remain unknown. In this study, we describe the steep trajectory of leaf vein density (D(v)) evolution in angiosperms, and predict that this leaf plumbing innovation enabled a major shift in the capacity of leaves to assimilate CO(2). Reconstructing leaf vein evolution from an examination of 504 angiosperm species we found a rapid three- to fourfold increase in D(v) occurred during the early evolution of angiosperms. We demonstrate how this major shift in leaf vein architecture potentially allowed the maximum photosynthetic capacity in angiosperms to rise above competing groups 140-100 Ma. Our data suggest that early terrestrial angiosperms produced leaves with low photosynthetic rates, but that subsequent angiosperm success is linked to a surge in photosynthetic capacity during their early diversification.
被子植物的进化改变了全球生态系统，而这种影响的很大一部分源于优势被子植物类群无与伦比的营养生长生产力。然而，被子植物高光合能力的起源仍然未知。在这项研究中，我们描述了被子植物叶片叶脉密度（D(v)）进化的陡峭轨迹，并预测这种叶片结构的创新使叶片同化 CO(2)的能力发生了重大转变。通过对 504 种被子植物的研究，我们发现 D(v)在被子植物早期进化过程中迅速增加了 3 到 4 倍。我们展示了这种叶片脉管结构的重大转变如何使被子植物的最大光合能力超过了 140-100 Ma 时的竞争群体。我们的数据表明，早期的陆地被子植物产生的叶片光合作用速率较低，但随后被子植物的成功与它们早期多样化过程中光合能力的突增有关。
