Here, we explored the mutual regulation of radical oxygen species (ROS) and autophagy in wheat (Triticum aestivum L.) roots under hypoxia stress. We also analyzed differences between the responses of the stele and the cortex in the two wheat cultivars Huamai 8 (waterlogging-tolerant) and Huamai 9 (waterlogging-sensitive) to hypoxia stress. In situ detection and ultracytochemical localization analysis in wheat roots showed that hypoxia stress caused greater increases in ROS levels and the expression levels of alternative oxidase (AOX) and antioxidant enzymes in the stele than in the cortex. The analysis of exogenous ROS addition and the inhibition of its production revealed the pivotal roles played by ROS in autophagy. Moreover, transmission electron microscopy and qRT-PCR analysis indicated that the stele had a higher level of autophagy than the cortex and that the two wheat cultivars primarily differed in the type and number of autophagosomes. Additional research revealed that autophagy could remove excess ROS, as pre-treatment with the autophagy inhibitor 3-methyladenine increased ROS levels in roots and the addition of the autophagy inducer rapamycin reduced root ROS levels. In conclusion, hypoxia stress induced ROS accumulation in wheat roots where ROS acted as an autophagy signal. Furthermore, higher levels of autophagy and antioxidant enzyme expression in the stele facilitated the elimination of oxidative damage caused by excessive ROS and thereby increased cell survival; in the cortex, a large number of cells died and formed aerenchyma.

在这里，我们探索了在缺氧胁迫下小麦（Triticum aestivum L.）根中自由基氧物种（ROS）和自噬的相互调节。我们还分析了两个小麦品种华麦8号（耐涝）和华麦9号（耐涝）对缺氧胁迫的响应。小麦根系的原位检测和超细胞化学定位分析表明，低氧胁迫引起ROS水平和交替氧化酶（AOX）表达水平的更大增加。）和碑皮中的抗氧化酶比皮质中的抗氧化酶高。对外源性ROS添加及其抑制作用的分析揭示了ROS在自噬中的关键作用。此外，透射电镜和qRT-PCR分析表明，碑林的自噬水平高于皮层，并且两个小麦品种的自噬体类型和数量主要不同。进一步的研究表明，自噬可以清除过量的ROS，因为用自噬抑制剂3-甲基腺嘌呤预处理可以增加根中ROS的水平，加入自噬诱导剂雷帕霉素可以降低根ROS的水平。总之，低氧胁迫诱导了小麦根中ROS的积累，其中ROS充当自噬信号。此外，石碑中较高水平的自噬和抗氧化酶表达有助于消除由过量ROS引起的氧化损伤，从而提高细胞存活率。在皮层中，大量细胞死亡并形成动脉瘤。