Multi-stress resilience in plants recovering from submergence

Abstract

Submergence limits plants' access to oxygen and light, causing massive changes in metabolism; after submergence, plants experience additional stresses, including reoxygenation, dehydration, photoinhibition and accelerated senescence. Plant responses to waterlogging and partial or complete submergence have been well studied, but our understanding of plant responses during post-submergence recovery remains limited. During post-submergence recovery, whether a plant can repair the damage caused by submergence and reoxygenation and re-activate key processes to continue to grow, determines whether the plant survives. Here, we summarize the challenges plants face when recovering from submergence, primarily focusing on studies of Arabidopsis thaliana and rice (Oryza sativa). We also highlight recent progress in elucidating the interplay among various regulatory pathways, compare post-hypoxia reoxygenation between plants and animals and provide new perspectives for future studies.

Keywords: flooding; metabolic homeostasis; multi-stress resilience; post-submergence recovery; regulatory network.

Figure 1

Hormones and transcription factors that regulate Arabidopsis and rice post‐submergence stress responses. Black arrows indicate positive regulation and blue lines ending with perpendicular bars represent negative regulation. The blue dashed line ending with the vertical bar indicates a relationship that has not been fully elucidated.

Figure 2

Comparison of post‐hypoxic reoxygenation in plants and mammals. Excessive ROS production is a common feature of reoxygenation in plants and animals. The conserved antioxidant systems of animals and plants inhibit damage during cellular reoxygenation. Impaired recovery of mitochondrial function occurs in plants and mammals, activating downstream MAPK cascade signalling. Activation of autophagy protects recovering cells in mammals, but to date, little research has focused on autophagy in plant responses to reoxygenation. Positive and negative effects are illustrated by black arrows and red blunt‐ended bars, respectively, and grey dashed arrows and red question marks indicate cases where the regulatory function is unknown at present.