Autophagy Mechanisms in Plant Stress Responses

Autophagy is a conserved cellular process by which plants degrade and recycle cytoplasmic constituents, including damaged proteins and organelles, through vacuolar delivery. Under stress conditions such as drought, heat, salinity or pathogen attack, autophagic activity is upregulated to maintain cellular homeostasis. The core machinery involves AUTOPHAGY‐RELATED (ATG) proteins that coordinate phagophore initiation, autophagosome formation and fusion with the vacuole. Beyond bulk degradation, selective autophagy employs cargo receptors to target specific substrates, including ubiquitinated protein aggregates and organelle‐derived bodies.

Activation of autophagy underpins multiple stress‐response pathways. During abiotic stress, enhanced autophagy limits oxidative damage by removing oxidised proteins, preserving photosynthetic capacity and supporting energy balance. In biotic contexts, autophagy intersects with hormone signalling networks to reinforce defence. Coordinated regulation by transcription factors and kinases ensures that autophagic flux is matched to the intensity and duration of environmental challenges. The global significance of these mechanisms spans improved crop resilience, sustainable resource use and mitigation of yield losses under climate extremes.

Research from Nature Portfolio

Recent studies have revealed that autophagy promotes jasmonate‐mediated defence against root‐knot nematodes in tomato. Infection by Meloidogyne incognita induces formation of autophagosomes and triggers selective degradation of JASMONATE‐ASSOCIATED MYC2‐LIKE repressors via ATG8 interaction motifs. Removal of these negative regulators releases an ETHYLENE RESPONSE FACTOR 1–MEDIATOR 25 transcriptional complex that amplifies jasmonate‐responsive gene expression. In turn, ERF1 enhances transcription of ATG genes, establishing a positive feedback loop that links autophagic turnover to hormone‐driven immunity. This work exemplifies how selective autophagy fine‐tunes phytohormone circuits to bolster biotic stress tolerance.

Autophagy Mechanisms in Plant Stress Responses publication trend

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

Technical terms

Autophagy: A cellular degradation pathway in which cytoplasmic material is sequestered in double‐membrane vesicles (autophagosomes) and delivered to the vacuole for recycling.

Autophagosome: A double‐membrane vesicle that encapsulates cytosolic cargo, including damaged organelles or protein aggregates, en route to the vacuole.

ATG proteins: A family of conserved proteins essential for autophagosome formation, cargo recognition and membrane fusion during autophagy.

Selective autophagy: A targeted form of autophagy in which specific cargo receptors recognise and deliver particular substrates, such as ubiquitinated proteins, to autophagosomes.

Cargo receptor: A specialised adaptor protein (for example NBR1) that binds both the substrate to be degraded and ATG8 on the forming autophagosome membrane.

Jasmonate: A class of plant signalling molecules (phytohormones) involved in defence against pests and pathogens and in responses to abiotic stress.

References

1. Autophagy promotes jasmonate-mediated defense against nematodes. Nature Communications (2023).
2. Improvement of drought tolerance by overexpressing MdATG18a is mediated by modified antioxidant system and activated autophagy in transgenic apple. Plant Biotechnology Journal (2017).
3. NBR1-Mediated Selective Autophagy Targets Insoluble Ubiquitinated Protein Aggregates in Plant Stress Responses. PLOS Genetics (2013).
4. Degradation of Oxidized Proteins by Autophagy during Oxidative Stress in Arabidopsis. Plant Physiology (2006).
5. Role and regulation of autophagy in heat stress responses of tomato plants. Frontiers in Plant Science (2014).