Mustroph Angelika, Albrecht Gerd
Department of Plant Physiology, Institute for Biology, Humboldt-University Berlin, Philippstrasse 13/Haus 12, D-10115 Berlin, Germany.
J Plant Physiol. 2007 Apr;164(4):394-407. doi: 10.1016/j.jplph.2006.02.007. Epub 2006 Apr 17.
A hypoxic pre-treatment (HPT) can improve the anoxic survival of flooding sensitive plants. Here, we tested whether a 4-d HPT of wheat plants (Triticum aestivum L.) would improve their anoxic resistance, and if so, why. We found that the metabolic adjustment during prolonged HPT involved an increased lactate excretion rate, the up-regulation of glycolytic and fermentative enzymes as well as the accumulation of various sugars. Therefore, HPT wheat roots could sustain a 3 times higher ethanolic fermentation rate during an anoxic period compared to non-pre-treated (NHPT) roots. Nevertheless, the enhanced fermentation rate provided temporary relief to the energy crisis only, and both NHPT and HPT plants died after 5d of anoxia in illumination. Comparison of different low oxygen incubation systems using excised roots or roots of intact plants revealed striking differences. The benefits of intact shoots, oxygen transport as well as additional sugar supply enabled a more stable energy supply of anoxia-treated NHPT and HPT roots. However, the height of the fermentation rate was correlated with a high ATP content during dark anoxic incubation, but not in illumination.
缺氧预处理（HPT）可以提高对水淹敏感植物的缺氧存活率。在此，我们测试了对小麦植株（普通小麦）进行4天的HPT是否会提高其抗缺氧能力，如果是，原因是什么。我们发现，长时间HPT期间的代谢调整涉及乳酸排泄率增加、糖酵解和发酵酶上调以及各种糖类积累。因此，与未预处理（NHPT）的根相比，HPT小麦根在缺氧期间的乙醇发酵率可维持高3倍。然而，提高的发酵率仅为能量危机提供了暂时缓解，在光照条件下缺氧5天后，NHPT和HPT植株均死亡。使用离体根或完整植株的根对不同低氧培养系统进行比较，结果显示出显著差异。完整地上部分、氧气运输以及额外的糖分供应的益处，使得缺氧处理的NHPT和HPT根的能量供应更加稳定。然而，黑暗缺氧培养期间发酵率的高低与高ATP含量相关，而在光照条件下则不然。
