C 4 photosynthesis and the economic spectra of leaf and root traits independently influence growth rates in grasses
C 4 photosynthesis and the economic spectra of leaf and root traits independently influence growth rates in grasses
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C 4 光合作用以及叶和根性状的经济谱独立影响草的生长速率
DOI：
10.1111/1365-2745.13412
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发表时间：
2020
影响因子：
5.5
通讯作者：
Simpson K
中科院分区：
文献类型：
--
作者：
Simpson K
光合作用途径是物种间生长速率差异的重要原因，C4物种的碳吸收增强导致其比C3物种生长更快。促进快速资源获取的叶片性状可能会进一步增强C4物种的生长能力。然而，根系经济性状与叶片性状之间的相互作用以及C3和C4光合途径植物采取的不同生长策略尚不清楚。植物经济性状可以与光合途径相互作用或独立作用，影响生长速率，或C3和C4物种可以分离出沿着共同的生长速率-性状关系。光合作用途径独立于叶和根的功能性状而起作用，引起快速生长。利用C4光合作用，植物可以实现比C3对应物更快的生长（平均0.04 g g− 1天−1），对于给定的一套功能性状值，叶和根氮的投资较少。叶和根性状对RGR具有加性效应，植物通过具有资源获取叶性状（高比叶面积和低叶干物质含量）或根性状（高比根长度和面积，低根直径）实现快速生长，但两者都导致更快的生长速率（高达0.06 g g-1day-1）。C4光合作用可以提供一个更大的相对增加RGR的植物与一个“慢”的生态策略比那些快速增长。然而，地上和地下的策略并不协调，因此物种可以具有“慢”或“快”的叶和根性状的任何组合。C4光合作用提高了给定经济性状组合的生长速率，并显著改变了植物叶片和根系的氮经济。然而，叶和根经济性状独立地起作用，以进一步促进生长。C4牧草的快速生长促进了在炎热、阳光充足的条件下的竞争优势。
Photosynthetic pathway is an important cause of growth rate variation between species such that the enhanced carbon uptake of C4species leads to faster growth than their C3counterparts. Leaf traits that promote rapid resource acquisition may further enhance the growth capacity of C4species. However, how root economic traits interact with leaf traits, and the different growth strategies adopted by plants with C3and C4photosynthetic pathways is unclear. Plant economic traits could interact with, or act independently of, photosynthetic pathway in influencing growth rate, or C3and C4species could segregate out along a common growth rate–trait relationship.We measured leaf and root traits on 100+ grass species grown from seeds in a controlled, common environment to compare with relative growth rates (RGR) during the initial phase of rapid growth, controlling for phylogeny and allometric effects.Photosynthetic pathway acts independently to leaf and root functional traits in causing fast growth. Using C4photosynthesis, plants can achieve faster growth than their C3counterparts (by an average 0.04 g g−1day−1) for a given suite of functional trait values, with lower investments of leaf and root nitrogen. Leaf and root traits had an additive effect on RGR, with plants achieving fast growth by possessing resource‐acquisitive leaf traits (high specific leaf area and low leaf dry matter content) or root traits (high specific root length and area, and low root diameter), but having both leads to an even faster growth rate (by up to 0.06 g g−1day−1). C4photosynthesis can provide a greater relative increase in RGR for plants with a ‘slow’ ecological strategy than in those with fast growth. However, above‐ground and below‐ground strategies are not coordinated so that species can have any combination of ‘slow’ or ‘fast’ leaf and root traits.Synthesis. C4photosynthesis increases growth rate for a given combination of economic traits, and significantly alters plant nitrogen economy in the leaves and roots. However, leaf and root economic traits act independently to further enhance growth. The fast growth of C4grasses promotes a competitive advantage under hot, sunny conditions.