Leaf gas films of Spartina anglica enhance rhizome and root oxygen during tidal submergence.
Leaf gas films of Spartina anglica enhance rhizome and root oxygen during tidal submergence.
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DOI：
10.1111/j.1365-3040.2011.02405.x
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发表时间：
2011-12
期刊：
影响因子：
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通讯作者：
A. Winkel;T. Colmer;O. Pedersen
中科院分区：
文献类型：
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作者：
A. Winkel;T. Colmer;O. Pedersen
一些湿地植物叶片疏水性表面的气膜在洪水期间完全淹没时可以促进O(2)和CO(2)的交换。本文研究了大米草(Spartina Anglica)在自然潮汐淹没过程中根茎的原位曝气，重点研究了叶片气膜在水下气体交换中的作用。对水下净光合作用也进行了室内对照实验研究。在现场实验中，将O(2)微电极插入根茎中，并在两个潮汐淹没事件中测量到Po(2)；一个在白天，一个在夜间。植物的叶片气态膜完好或被移除。根茎Po(2)在完全淹水过程中显著下降，夜间下降最严重。叶片气膜：(1)水下光合作用增强，在光照下，根茎中的Po(2)保持在10kpa以上；(2)促进O(2)从水中进入叶片，使根茎Po(2)在黑暗中保持在5kpa左右。这项研究首次现场演示了叶气膜对沉水湿地植物内部曝气的有益影响。叶片气膜可能有助于提高英美沙棘的耐淹性，这一特征也有望在淹没时惠及其他湿地植物物种。
Gas films on hydrophobic surfaces of leaves of some wetland plants can improve O(2) and CO(2) exchange when completely submerged during floods. Here we investigated the in situ aeration of rhizomes of cordgrass (Spartina anglica) during natural tidal submergence, with focus on the role of leaf gas films on underwater gas exchange. Underwater net photosynthesis was also studied in controlled laboratory experiments. In field experiments, O(2) microelectrodes were inserted into rhizomes and pO(2) measured throughout two tidal submergence events; one during daylight and one during night-time. Plants had leaf gas films intact or removed. Rhizome pO(2) dropped significantly during complete submergence and most severely during night. Leaf gas films: (1) enhanced underwater photosynthesis and pO(2) in rhizomes remained above 10 kPa during submergence in light; and (2) facilitated O(2) entry from the water into leaves so that rhizome pO(2) was about 5 kPa during darkness. This study is the first in situ demonstration of the beneficial effects of leaf gas films on internal aeration in a submerged wetland plant. Leaf gas films likely contribute to submergence tolerance of S. anglica and this feature is expected to also benefit other wetland plant species when submerged.