Differential leaf expansion can enable hydraulic acclimation to sun and shade
Differential leaf expansion can enable hydraulic acclimation to sun and shade
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DOI：
10.1111/j.1365-3040.2012.02498.x
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发表时间：
2012-08-01
影响因子：
7.3
通讯作者：
Brodribb, Timothy J.
中科院分区：
文献类型：
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作者：
Carins Murphy, Madeline R.;Jordan, Gregory J.;Brodribb, Timothy J.
虽然叶片大小是对环境变化最敏感的植物性状之一，但大叶片与小叶片的功能优势仍不清楚。我们假设，由于辐照度的差异而引起的物种内叶片大小的改变可以使叶片适应不同的光合或蒸发条件，同时保持水力供应（静脉密度）和蒸发需求之间的有效平衡。为了验证这一点，我们比较了木本被子植物红椿（Toona ciliata M。Roem.）在受控条件下在高和低辐照度下生长。我们的研究结果证实，在这个物种中，差异叶片扩张调节静脉和气孔的密度，使叶片水力传导度和气孔导度保持比例。更广泛的野外生长树种样本表明，在所有情况下，阳光和阴影引起的叶片脉序和气孔特征的差异并不受叶片大小的调节。然而，我们的研究结果表明，叶片大小的可塑性可以提供一种有效的方式，植物驯化的水力和气孔导度的对比蒸发条件的阳光和阴影。
Although leaf size is one of the most responsive plant traits to environmental change, the functional benefits of large versus small leaves remain unclear. We hypothesized that modification of leaf size within species resulting from differences in irradiance can allow leaves to acclimate to different photosynthetic or evaporative conditions while maintaining an efficient balance between hydraulic supply (vein density) and evaporative demand. To test this, we compared the function and anatomy of leaf hydraulic systems in the leaves of a woody angiosperm (Toona ciliata M. Roem.) grown under high and low irradiance in controlled conditions. Our results confirm that in this species, differential leaf expansion regulates the density of veins and stomata such that leaf hydraulic conductance and stomatal conductance remain proportional. A broader sample of field-grown tree species suggested that differences in leaf venation and stomatal traits induced by sun and shade were not regulated by leaf size in all cases. Our results, however, suggest that leaf size plasticity can provide an efficient way for plants to acclimate hydraulic and stomatal conductances to the contrasting evaporative conditions of sun and shade.