Redox Signaling in Plant Stress Responses

Plants are continually exposed to environmental challenges such as high light, drought, salinity and pathogen attack that perturb cellular homeostasis. Central to the adaptive response is redox signalling, in which changes in the balance of oxidants and reductants serve as information conduits that modulate gene expression, protein activity and metabolic pathways. Reactive oxygen species (ROS), including hydrogen peroxide and superoxide, constitute both damaging by‐products of aerobic metabolism and purposeful messengers that trigger tolerance mechanisms. These species arise in discrete subcellular compartments—chloroplasts, mitochondria, peroxisomes and the apoplast—and are finely regulated by antioxidant enzymes and low‐molecular‐weight redox buffers such as glutathione and ascorbate. Sensor proteins such as thioredoxins and glutaredoxins transduce redox changes into conformational shifts that influence transcription factors and other signalling components. At the cellular level, redox cues underpin processes ranging from stomatal closure to cell cycle progression, while at the tissue and whole‐plant levels they coordinate developmental acclimation and systemic immunity. Recent advances in live‐cell imaging and genetically encoded biosensors have provided unprecedented insight into the spatial and temporal dynamics of redox networks under stress. The elucidation of these pathways is critical for breeding and engineering more resilient crops in the face of climate change.

Research from Nature Portfolio

Recent studies have introduced innovative genetically encoded biosensors to monitor cellular redox status in real time. One such sensor exploits a fusion of a redox‐sensitive green fluorescent protein with an enzymatic module specific for NADP(H), enabling in vivo quantification of the NADP(H) redox poise within chloroplasts and mitochondria under stress conditions. This tool has revealed rapid fluctuations in reducing power during oxidative challenges, offering a direct window into metabolic adjustments. In parallel, investigations into light‐stress signalling have demonstrated that hydrogen peroxide produced in chloroplasts can be channelled directly to adjacent nuclei, bypassing the bulk cytosol. This compartmentalised transfer modulates nuclear gene expression in response to high‐light exposure, underscoring a precise organelle‐to‐nucleus communication route that refines the plant’s acclimation strategy.

Redox Signaling in Plant Stress Responses publication trend

The graph below shows the total number of articles in redox signaling in plant stress responses across all publications each year (not limited to Nature Index journals).

Technical terms

Reactive oxygen species (ROS): Partially reduced oxygen derivatives that act as both damaging agents and signalling molecules.

Redox signalling: Communication via changes in oxidation–reduction status of molecules that modulate biological responses.

Glutaredoxin: Thiol–disulfide oxidoreductase that catalyses reversible protein glutathionylation.

Thioredoxin: Small oxidoreductase that regulates target proteins through thiol–disulfide exchange.

NADP(H) redox status: Ratio of oxidized NADP⁺ to reduced NADPH reflecting cellular reducing power.

Retrograde signalling: Transmission of information from organelles (chloroplasts, mitochondria) to the nucleus.

Antioxidant enzymes: Proteins such as peroxidases and superoxide dismutases that remove reactive species.

Genetically encoded biosensor: Fluorescent reporter protein engineered to measure specific biochemical parameters in vivo.

References

1. NERNST: a genetically-encoded ratiometric non-destructive sensing tool to estimate NADP(H) redox status in bacterial, plant and animal systems. Nature Communications (2023).
2. Photosynthesis-dependent H2O2 transfer from chloroplasts to nuclei provides a high-light signalling mechanism. Nature Communications (2017).
3. Mechanisms of ROS Regulation of Plant Development and Stress Responses. Frontiers in Plant Science (2019).
4. Reactive Oxygen Species in Plants: From Source to Sink. Antioxidants (2022).