Institute of Biology I, Aachen Biology and Biotechnology, RWTH Aachen University, 52074 Aachen, Germany; email:
Annu Rev Plant Biol. 2015;66:345-67. doi: 10.1146/annurev-arplant-043014-114813. Epub 2015 Jan 12.
Oxygen is an indispensable substrate for many biochemical reactions in plants, including energy metabolism (respiration). Despite its importance, plants lack an active transport mechanism to distribute oxygen to all cells. Therefore, steep oxygen gradients occur within most plant tissues, which can be exacerbated by environmental perturbations that further reduce oxygen availability. Plants possess various responses to cope with spatial and temporal variations in oxygen availability, many of which involve metabolic adaptations to deal with energy crises induced by low oxygen. Responses are induced gradually when oxygen concentrations decrease and are rapidly reversed upon reoxygenation. A direct effect of the oxygen level can be observed in the stability, and thus activity, of various transcription factors that control the expression of hypoxia-induced genes. Additional signaling pathways are activated by the impact of oxygen deficiency on mitochondrial and chloroplast functioning. Here, we describe the molecular components of the oxygen-sensing pathway.
氧气是植物中许多生化反应的必需底物，包括能量代谢（呼吸作用）。尽管氧气非常重要，但植物缺乏将氧气分配到所有细胞的主动运输机制。因此，大多数植物组织内会出现陡峭的氧气梯度，环境干扰会进一步降低氧气的可用性，从而使这种情况恶化。植物具有多种应对策略来适应氧气可用性的时空变化，其中许多策略涉及代谢适应，以应对低氧引起的能量危机。当氧气浓度降低时，应对策略会逐渐被诱导，而在重新供氧时又会迅速逆转。氧气水平的直接影响可以观察到各种转录因子的稳定性，从而影响控制低氧诱导基因表达的转录因子的活性。氧气缺乏对线粒体和叶绿体功能的影响会激活其他信号通路。在这里，我们描述了氧气感应途径的分子组成部分。
