Leaf carbon and water status control stomatal and non-stomatal limitations of photosynthesis in trees.
Leaf carbon and water status control stomatal and non-stomatal limitations of photosynthesis in trees.
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DOI：
10.1111/nph.16436
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发表时间：
2020-01
期刊：
影响因子：
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通讯作者：
Yann Salmon;A. Lintunen;Alexia Dayet;Tommy Chan;R. Dewar;T. Vesala;T. Hölttä
中科院分区：
文献类型：
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作者：
Yann Salmon;A. Lintunen;Alexia Dayet;Tommy Chan;R. Dewar;T. Vesala;T. Hölttä
光合速率同时受到气孔限制和非气孔限制。然而，控制非气孔限制光合作用（NSL）和它们的协调与气孔控制在不同的时间尺度上仍然知之甚少。根据最近的优化假说，NSL取决于叶片渗透或水分状况，并与气孔控制协调，以最大限度地提高叶片光合作用。在温室条件下，以欧洲赤松（Pinus sylvestris）、欧洲云杉（Picea abies）、垂枝桦（Betula Pendula）和欧洲山杨（Populus tremula）幼苗为材料，通过干旱和刻槽试验，研究了叶片渗透和水分状况对NSL的依赖性及其与气孔控制的协调性，以检验最优化假设的假设和预测。NSL和气孔导度均服从叶片渗透浓度和叶水势的幂律函数。此外，气孔导度与土壤-叶片导度的平方根成正比，正如最优化假设所预测的那样。虽然NSL对叶片渗透或水分状况的依赖的详细机制不在本研究的范围内，我们的研究结果支持的假设，NSL和气孔控制协调，以最大限度地提高叶片光合作用，并允许NSL的影响被包括在树木气体交换模型。
Photosynthetic rate is concurrently limited by stomatal and non-stomatal limitations. However, the controls on non-stomatal limitations to photosynthesis (NSL) and their coordination with stomatal control on different timescales remain poorly understood. According to a recent optimization hypothesis, NSL depends on leaf osmotic or water status, and is coordinated with stomatal control so as to maximize leaf photosynthesis. Drought and notching experiments were conducted on Pinus sylvestris, Picea abies, Betula Pendula, and Populus tremula seedlings in greenhouse conditions to study the dependence of NSL on leaf osmotic and water status, and its coordination with stomatal control, on timescales of minutes and weeks, to test the assumptions and predictions of the optimization hypothesis. Both NSL and stomatal conductance followed power-law functions of leaf osmotic concentration and leaf water potential. Moreover, stomatal conductance was proportional to the square root of soil-to-leaf hydraulic conductance, as predicted by the optimization hypothesis. While the detailed mechanisms underlying the dependence of NSL on leaf osmotic or water status lie outside the scope of this study, our results support the hypothesis that NSL and stomatal control are coordinated to maximize leaf photosynthesis, and allow the effect of NSL to be included in models of tree gas-exchange.