H₂O₂ repurposes plant O₂ sensing to regulate post-hypoxia responses.

Area of Science:

• Plant biology
• Molecular responses to environmental stress

Background:

• Flooding tolerance requires understanding plant molecular responses to low oxygen (hypoxia).
• Group VII ethylene response factors (ERFVIIs) regulate acclimation to hypoxia by stabilizing in response to decreased plant cysteine oxidase (PCO) activity.
• Post-hypoxic reoxygenation triggers reactive oxygen species (ROS) bursts, but recovery mechanisms remain unclear.

Purpose of the Study:

• To investigate the role of ERFVIIs in plant recovery after submergence and reoxygenation.
• To elucidate the molecular mechanisms underlying ERFVII stability and function during post-hypoxic stress.

Main Methods:

• Analysis of ERFVII stability and localization under reoxygenation conditions.
• Investigating the interaction between ROS, PCOs, and ERFVIIs.
• Gene expression analysis of hypoxia-responsive genes and ROS homeostasis genes.

Main Results:

• ERFVIIs remain stable upon reoxygenation, mediated by ROS-induced PCO inhibition.
• Stabilized ERFVIIs bind to hypoxia-responsive promoters, repressing typical hypoxia genes.
• ERFVIIs upregulate genes involved in ROS homeostasis and oxidative stress protection during recovery.

Conclusions:

• ERFVIIs play a critical role in post-submergence recovery by managing ROS levels.
• PCOs and ERFVIIs act as an integrated signaling module responding to both oxygen and ROS.
• This signaling pathway is crucial for coordinating ERFVII stability and promoting plant survival and recovery from flooding stress.