C4 photosynthesis boosts growth by altering physiology, allocation and size
C4 photosynthesis boosts growth by altering physiology, allocation and size
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DOI：
10.1038/nplants.2016.38
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发表时间：
2016-05-01
期刊：
影响因子：
18
通讯作者：
Osborne, Colin P.
中科院分区：
文献类型：
--
作者：
Atkinson, Rebecca R. L.;Mockford, Emily J.;Osborne, Colin P.
C-4光合作用是一组复杂的叶片解剖学和生物化学适应，与祖先的C-3光合作用类型相比，已经进化了60多次以促进碳吸收（1-3）。虽然C-4光合作用有可能推动更快的生长速度（4，5），直接比较C-3和C-4植物的实验没有显示出一致的效果（1，6，7）。这是有问题的，因为差异生长是生态理论的一个关键要素（8，9）解释C-4萨凡纳对全球变化的反应（10，11），并研究通过引入C-4光合作用来提高C-3作物生产力（12）。在这里，我们通过比较382种草的生长情况，考虑到生态多样性和进化历史，解决了这个长期存在的问题。C-4光合作用导致19-88%的每日生长增强。出乎意料的是，在关键的幼苗建立阶段，这种增强在很大程度上是由叶面积与质量的高比率驱动的，而不是每单位叶面积的快速生长。C-4叶子的组织密度较低，因此可以以相同的碳成本生产更多的叶子。因此，C-4植物比C-3植物对根的投资更多。我们的数据表明，C-3和C-4物种之间的功能性状差异，同时驱动更快的增长和更大的投资，在水和养分的收购，具有重要的生态和农艺意义。
C-4 photosynthesis is a complex set of leaf anatomical and biochemical adaptations that have evolved more than 60 times to boost carbon uptake compared with the ancestral C-3 photosynthetic type(1-3). Although C-4 photosynthesis has the potential to drive faster growth rates(4,5), experiments directly comparing C-3 and C-4 plants have not shown consistent effects(1,6,7). This is problematic because differential growth is a crucial element of ecological theory(8,9) explaining C-4 savannah responses to global change(10,11), and research to increase C-3 crop productivity by introducing C-4 photosynthesis(12). Here, we resolve this long-standing issue by comparing growth across 382 grass species, accounting for ecological diversity and evolutionary history. C-4 photosynthesis causes a 19-88% daily growth enhancement. Unexpectedly, during the critical seedling establishment stage, this enhancement is driven largely by a high ratio of leaf area to mass, rather than fast growth per unit leaf area. C-4 leaves have less dense tissues, allowing more leaves to be produced for the same carbon cost. Consequently, C-4 plants invest more in roots than C-3 species. Our data demonstrate a general suite of functional trait divergences between C-3 and C-4 species, which simultaneously drive faster growth and greater investment in water and nutrient acquisition, with important ecological and agronomic implications.