Stomatal and mesophyll conductances to CO2 in different plant groups: Underrated factors for predicting leaf photosynthesis responses to climate change?
Stomatal and mesophyll conductances to CO2 in different plant groups: Underrated factors for predicting leaf photosynthesis responses to climate change?
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DOI：
10.1016/j.plantsci.2014.06.011
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发表时间：
2014-09-01
期刊：
影响因子：
5.2
通讯作者：
Diaz-Espejo, Antonio
中科院分区：
文献类型：
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作者：
Flexas, Jaume;Carriqui, Marc;Diaz-Espejo, Antonio
预计本世纪末的气候变化条件将对植物在自然条件下的性能产生影响。预计影响较大的变量是CO2浓度和温度的增加。虽然人们普遍认为CO2同化率可以随着CO2浓度的增加而增加，但已有研究表明，高CO2浓度的驯化会导致光合作用相关生理参数的降低，如最大羧化速率（V-c，V-max）、气孔导度（g（s））和叶肉对CO2的导度（g（m））。一方面，大多数以前的模拟工作都忽略了潜在的作用，由驯化的g（m），高CO2和温度。另一方面，气候变化对被子植物以外的植物分支的影响，如蕨类植物，很少受到关注，也没有研究评估的潜在影响，增加CO2和温度对这些物种在这项研究中，我们预测了几个代表性的物种被子植物，裸子植物和蕨类植物增加CO2和温度的反应。我们的研究结果表明，在这些可预见的环境条件下，具有较低光合能力的物种-如一些蕨类植物和裸子植物-将按比例更受青睐。这种差异的主要原因是在被子植物中具有高光合作用能力的植物中，gs和g施加的较低的扩散限制，这降低了增加CO2的积极影响。然而，如果两个电导率- g（s）和g（m）-适应并下调到高CO2，则低扩散物种的这种明显优势将被取消，这基本上是未知的，特别是对于裸子植物和蕨类植物。因此，为了更好地了解不同的植物对未来气候的反应，研究敦促在实际的光合作用响应/适应增加CO2和温度的蕨类植物，裸子植物和其他低估的植物群体进行评估。(C)2014爱思唯尔爱尔兰有限公司版权所有。
The climate change conditions predicted for the end of the current century are expected to have an impact on the performance of plants under natural conditions. The variables which are foreseen to have a larger effect are increased CO2 concentration and temperature. Although it is generally considered CO2 assimilation rate could be increased by the increasing levels of CO2, it has been reported in previous studies that acclimation to high CO2 results in reductions of physiological parameters involved in photosynthesis, like the maximum carboxylation rate (V-c,V-max), stomatal conductance (g(s)) and mesophyll conductance to CO2 (g(m)). On the one hand, most of the previous modeling efforts have neglected the potential role played by the acclimation of g(m), to high CO2 and temperature. On the other hand, the effect of climate change on plant clades other than angiosperms, like ferns, has received little attention, and there are no studies evaluating the potential impact of increasing CO2 and temperature on these species.In this study we predicted responses of several representative species among angiosperms, gymnosperms and ferns to increasing CO2 and temperature. Our results show that species with lower photosynthetic capacity - such as some ferns and gymnosperms - would be proportionally more favored under these foreseen environmental conditions. The main reason for this difference is the lower diffusion limitation imposed by gs and g in plants having high capacity for photosynthesis among the angiosperms, which reduces the positive effect of increasing CO2. However, this apparent advantage of low-diffusion species would be canceled if the two conductances - g(s) and g(m) - acclimate and are down regulated to high CO2, which is basically unknown, especially for gymnosperms and ferns. Hence, for a better understanding of different plant responses to future climate, studies are urged in which the actual photosynthetic response/acclimation to increased CO2 and temperature of ferns, gymnosperms and other under-evaluated plant groups is assessed. (C) 2014 Elsevier Ireland Ltd. All rights reserved.