Stomatal protection against hydraulic failure: a comparison of coexisting ferns and angiosperms
Stomatal protection against hydraulic failure: a comparison of coexisting ferns and angiosperms
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DOI：
10.1111/j.1469-8137.2004.01060.x
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发表时间：
2004-06-01
期刊：
影响因子：
9.4
通讯作者：
Holbrook, NM
中科院分区：
文献类型：
--
作者：
Brodribb, TJ;Holbrook, NM
•研究了蕨类植物（蕨类植物和卷柏）叶子的水力特性，以确定这些早期维管植物的水分传导和水分流失过程是否与被子植物相似。•在季节性干燥的热带森林中，从阳光和阴凉处检查了八种蕨类植物和相关的木本被子植物。•四种植物中的最大叶片水力传导率（Kleaf） 蕨类植物在采样的阴生被子植物范围内，但远低于喜光被子植物。被子植物和蕨类植物叶子的水力传导率对干燥表现出相似的反应，一旦叶子水势降至阈值以下，叶子就会迅速下降。被子植物中的气孔关闭与导致Kleaf损失50%的水势密切相关，而蕨类植物被发现在Kleaf凹陷之前关闭气孔。•该蕨类植物样本中气孔的对比行为表明这可能是蕨类植物和被子植物之间的内在差异，被子植物中较低的安全裕度可能增强了气体交换和木质部的优化 投资。
•Hydraulic characteristics of pteridophyte (fern andSelaginella) foliage were investigated to determine whether the processes of water conduction and water loss are coordinated in these early vascular plants similarly to angiosperms.•Eight species of pteridophytes and associated woody angiosperms were examined from the sun and shade in a seasonally dry tropical forest.•Maximum leaf hydraulic conductivity (Kleaf) in the four pteridophytes was within the range of the sampled shade angiosperms but much lower than that of the sun‐dwelling angiosperms. Hydraulic conductivity of both angiosperm and pteridophyte leaves showed a similar response to desiccation, withKleafbecoming rapidly depressed once leaf water potential fell below a threshold. Stomatal closure in angiosperms corresponded closely with the water potential responsible for 50% loss ofKleafwhile pteridophytes were found to close stomata beforeKleafdepression.•The contrasting behaviour of stomata in this sample of pteridophytes suggest that this may be an intrinsic difference between pteridophytes and angiosperms, with lower safety margins in angiosperms possibly enhancing both optimization of gas exchange and xylem investment.