The relationship between ethylene-induced autophagy and reactive oxygen species in root cells during the early stages of waterlogging stress.

The response of plants to waterlogging stress is a complex process, with ethylene playing a crucial role as a signaling molecule. However, it remains unclear how ethylene is initially triggered in response to waterlogging stress when plants are continuously waterlogged for less than 12 hours. Here, we have shown that ethylene-induced autophagy leads to the degradation of damaged mitochondria (the main organelles producing reactive oxygen species (ROS)) to reduce ROS production during oxidative stress in , which improves the survival rate of root cells in the early stages of waterlogging stress. Waterlogging stress activated ethylene-related genes, including , , , , and , and ethylene content of plants increased significantly within 24 h of continuous waterlogging. As stress duration increased, increased amounts of ROS accumulated in roots, and the activity of antioxidant enzymes initially increased and then decreased. Concurrently, the level of ethylene-induced autophagy, which participates in antioxidant defense, is higher in wild-type plants than in the octuple mutant (). Exogenous application of 1-aminocyclopropanecarboxylic acid (ACC), resulted in a more pronounced manifestation of autophagy in the stele of roots. Compared with the waterlogging treatment group or the ACC treatment group, the waterlogging + ACC treatment can induce autophagy to occur earlier and expand the autophagic range to the epidermis of roots. Overall, our results provide insight into the important role of ethylene-induced autophagy in enhancing the antioxidative capacity of during the early stages of waterlogging stress. Furthermore, we suggest ethylene as a potential candidate for mitigating the deleterious effects caused by waterlogging in .