Some observations on oxygen transport in conifer seedlings
Some observations on oxygen transport in conifer seedlings
复制标题
针叶树幼苗氧运输的一些观察
DOI：
10.1111/j.1469-8137.1972.tb04810.x
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发表时间：
1972
期刊：
影响因子：
9.4
通讯作者：
D. Read
中科院分区：
文献类型：
--
作者：
W. Armstrong;D. Read
总结
用极谱法测定了针叶树幼苗根系的氧扩散通量。通过将根部保持在23° C的厌氧溶液浸泡，并将其地上部分置于空气中，测试的25棵幼苗中有8棵的通量率相当可观。当地上部分被放置在氧气中，有一个很大的增加流量从每个松树幼苗。虽然它们的一般反应几乎无法测量，但从8棵云杉开始，它们的反应显著增加，但增幅要小得多。通过植物的氧运输似乎是通过扩散，主要是在气相中和显着的流量率从根与地上部分在空气中可能表明一些能力的湿土耐性有关的幼苗。
当外部氧浓度增加五倍时，松根的氧通量不成比例地增加，表明植物中的呼吸作用可能会影响通量率。通过将浸浴介质冷却至30 ℃，获得了呼吸作用的进一步证明-通量速率的大幅增加。随着呼吸减少冷却，从松树幼苗的通量率增加了约五倍的外部氧浓度增加了五倍。冷却并没有引起任何明显的反应，从云杉幼苗。
内部扩散阻力和氧气泄漏从根的次顶端部分可能占高顶端流量率的情况下，在松树和极低的读数记录的云杉幼苗。
Summary
The diffusive flux of oxygen from the roots of intact conifer seedlings was measured by a polarographic technique. With an anaerobic solution bathing the roots maintained at 23° C and with their aerial parts in air, flux rates were appreciable from eight of the twenty-five seedlings tested. When the aerial parts were placed in oxygen, there was a large increase in flux from each pine seedling. While their general response was barely measurable, a significant but much smaller increase occurred from eight of the spruce. Oxygen transport through the plants appeared to be by diffusion chiefly in the gas phase and significant flux rates from the roots with aerial parts in air might indicate some capacity for wet soil tolerance in the seedlings concerned.
When the external concentration of oxygen was increased five-fold there was a disproportionate increase in oxygen flux from pine roots indicating that respiration in the plants might be affecting the flux rates. By cooling the bathing medium to 30 C a further demonstration of the respiratory effect-a large increase in flux rate-was obtained. With respiration reduced by cooling, the flux rates from the pine seedlings increased approximately five-fold for a five-fold increase in the external oxygen concentration. Cooling did not induce any pronounced response from the spruce seedlings.
Internal diffusional resistance and oxygen leakage from the sub-apical parts of the roots may account for the absence of high apical flux rates in the pines and the extremely low readings recorded for the spruce seedlings.