Reactive Oxygen Species Signaling in Plant Stress and Defense Responses

Reactive oxygen species (ROS) are highly reactive oxygen derivatives that serve dual roles as potential stressors and as essential signalling molecules in plants. Under biotic or abiotic stress such as pathogen attack, drought, salinity, high light or temperature extremes, ROS accumulate in organelles including chloroplasts, mitochondria and the apoplast, triggering signal cascades that coordinate defence and acclimation. Upon stress perception, specialised enzymes such as NADPH oxidases generate an early oxidative burst in the apoplast, leading to changes in cytosolic Ca2+ concentration, activation of kinases and transcriptional reprogramming of defence genes. Concurrently, chloroplast-derived ROS function as retrograde signals, adjusting nuclear gene expression to maintain redox homeostasis and promote photoprotection. Crosstalk among multiple ROS species—singlet oxygen, superoxide and hydrogen peroxide—ensures specificity of downstream responses, with differential effects on photosystem repair, stomatal closure and systemic acquired resistance. Emerging studies reveal intricate spatial and temporal patterns of ROS waves that underlie local and systemic responses, offering new opportunities to enhance crop resilience through targeted manipulation of redox networks.

Research from Nature Portfolio

Recent work has elucidated how plastid-derived oxidative signals intersect with light-sensing pathways to fine-tune photomorphogenesis and defence. A seminal study demonstrated that singlet oxygen generated under excess light activates a retrograde pathway that represses the GLK1 transcription factor independently of phytochrome-interacting factors, thereby preventing photo-oxidative damage by modulating chloroplast development and nuclear gene expression. This finding establishes a mechanistic link between chloroplast stress signals and nuclear-encoded regulators of growth, highlighting ROS as central mediators of organelle crosstalk and developmental plasticity.

Reactive Oxygen Species Signaling in Plant Stress and Defense Responses publication trend

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

Technical terms

Reactive oxygen species (ROS): Highly reactive molecules derived from oxygen (e.g. singlet oxygen, superoxide, hydrogen peroxide) that function as signalling cues and stressors in plants.

NADPH oxidase: Plasma membrane-associated enzyme complex that produces superoxide by transferring electrons from NADPH to oxygen, initiating the apoplastic oxidative burst.

Retrograde signalling: Communication pathway by which organelles (chloroplasts, mitochondria) send signals to the nucleus to regulate gene expression in response to functional or developmental changes.

Photomorphogenesis: Developmental programme in plants triggered by light, involving transcriptional networks that control chloroplast biogenesis, leaf expansion and stem elongation.

References

1. Bilirubin is produced nonenzymatically in plants to maintain chloroplast redox status. Science Advances (2023).
2. Plastid retrograde signaling: A developmental perspective. The Plant Cell (2024).
3. Reactive oxygen species, oxidative signaling and the regulation of photosynthesis. Environmental and Experimental Botany (2018).
4. Phytochrome and retrograde signalling pathways converge to antagonistically regulate a light-induced transcriptional network. Nature Communications (2016).