Energy Metabolism Research Group, Max Planck Institute of Molecular Plant Physiology, D-14476 Potsdam-Golm, Germany.
Plant Cell Physiol. 2011 Nov;52(11):1957-72. doi: 10.1093/pcp/pcr128. Epub 2011 Sep 27.
The occurrence of hypoxic conditions in plants not only represents a stress condition but is also associated with the normal development and growth of many organs, leading to adaptive changes in metabolism and growth to prevent internal anoxia. Internal oxygen concentrations decrease inside growing potato tubers, due to their active metabolism and increased resistance to gas diffusion as tubers grow. In the present work, we identified three hypoxia-responsive ERF (StHRE) genes whose expression is regulated by the gradual decrease in oxygen tensions that occur when potato tubers grow larger. Increasing the external oxygen concentration counteracted the modification of StHRE expression during tuber growth, supporting the idea that the actual oxygen levels inside the organs, rather than development itself, are responsible for the regulation of StHRE genes. We identified several sugar metabolism-related genes co-regulated with StHRE genes during tuber development and possibly involved in starch accumulation. All together, our data suggest a possible role for low oxygen in the regulation of sugar metabolism in the potato tuber, similar to what happens in storage tissues during seed development.
植物缺氧的发生不仅代表了一种胁迫条件，还与许多器官的正常发育和生长有关，导致代谢和生长的适应性变化，以防止内部缺氧。由于马铃薯块茎的新陈代谢活跃，且随着块茎的生长其对气体扩散的抵抗力增加，因此其内部的氧气浓度会降低。在本工作中，我们鉴定了三个缺氧响应 ERF（StHRE）基因，其表达受马铃薯块茎生长过程中氧气分压逐渐降低的调控。增加外部氧气浓度可以抵消在块茎生长过程中 StHRE 表达的改变，这支持了这样一种观点，即器官内的实际氧气水平而不是发育本身负责调控 StHRE 基因。我们在块茎发育过程中鉴定了与 StHRE 基因共同调控的几个与糖代谢相关的基因，这些基因可能参与淀粉积累。总的来说，我们的数据表明，低氧可能在调节马铃薯块茎的糖代谢中起作用，这与种子发育过程中储存组织中的情况类似。
