Flooding Tolerance Mechanisms in Plant Systems

Plants exposed to prolonged flooding face impaired gas exchange, leading to oxygen deprivation and accumulation of toxic compounds. To cope, many species deploy a suite of morphological, physiological and molecular strategies. Morphological adaptations include the formation of aerenchyma and development of barriers to radial oxygen loss, which ensure internal aeration and limit loss of root-derived oxygen to anoxic soil. At the molecular level, oxygen-sensing mechanisms involving group VII ethylene response factors integrate signals from oxygen, ethylene and nitric oxide to orchestrate transcriptional reprogramming under hypoxia. Proteolytic control via the N-degron pathway modulates stability of these transcription factors, while proteases such as RHOMBOID-LIKE 2 enable swift activation of hypoxia-responsive genes. Metabolic reconfiguration towards fermentation and selective senescence of older tissues preserve resources and sustain growth. Insights from model species such as Arabidopsis and crops like rice underpin breeding and biotechnological strategies to enhance flood resilience and secure food production under climate change.

Research from Nature Portfolio

Recent studies have elucidated key components of oxygen-sensing and transcriptional control under flooding stress. Analysis of group VII ERF transcription factors in Arabidopsis has defined their non-autonomous activation of root hypoxia tolerance and detailed the role of the PLANT CYSTEINE OXIDASE N-degron pathway in regulating ERFVII stability through oxygen-dependent cysteine oxidation. Complementary work has revealed that early ethylene entrapment upon submergence elevates levels of a haem-based nitric oxide scavenger, stabilising ERFVIIs prior to hypoxia and pre-adapting plants for subsequent low-oxygen stress. These findings collectively refine our mechanistic understanding of gaseous signal integration and identify targets for manipulating flood tolerance in plants.

Flooding Tolerance Mechanisms in Plant Systems publication trend

The graph below shows the total number of articles in flooding tolerance mechanisms in plant systems across all publications each year (not limited to Nature Index journals).

Technical terms

Hypoxia: A state of reduced oxygen availability in plant tissues resulting from waterlogging or complete submergence.

Aerenchyma: Gas-filled channels formed within root or shoot tissues to facilitate internal oxygen diffusion under flooded conditions.

Ethylene Response Factor (ERFVII): A subgroup of transcription factors whose stability is controlled by oxygen and nitric oxide levels, central to initiating hypoxia-responsive gene expression.

N-degron pathway: A proteolytic mechanism that recognises destabilising N-terminal amino acids, directing proteins such as ERFVIIs for degradation under normoxic conditions.

Root barrier to radial oxygen loss (ROL barrier): A suberised or lignified outer tissue layer in roots that prevents oxygen leakage into anoxic soil and blocks entry of toxic solutes.

References

1. ERFVII action and modulation through oxygen-sensing in Arabidopsis thaliana. Nature Communications (2023).
2. Differential leaf flooding resilience in Arabidopsis thaliana is controlled by ethylene signaling-activated and age-dependent phosphorylation of ORESARA1. Plant Communications (2024).
3. Endoplasmic reticulum–bound ANAC013 factor is cleaved by RHOMBOID-LIKE 2 during the initial response to hypoxia in Arabidopsis thaliana. Proceedings of the National Academy of Sciences of the United States of America (2023).
4. The barrier to radial oxygen loss protects roots against hydrogen sulphide intrusion and its toxic effect. New Phytologist (2023).
5. Ethylene-mediated nitric oxide depletion pre-adapts plants to hypoxia stress. Nature Communications (2019).
6. Plant cysteine oxidases are dioxygenases that directly enable arginyl transferase-catalysed arginylation of N-end rule targets. Nature Communications (2017).