GO:0009751 response to salicylic acid: Signaling Pathway, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0009751 response to salicylic acid describes any cellular or organismal change triggered by salicylic acid (SA), a key plant hormone involved in defense and stress responses.
• SA signaling is central to plant immunity, mediating resistance to biotrophic pathogens and influencing responses to abiotic stresses such as heat and low CO2.
• The transcriptional response to SA involves massive reprogramming of gene expression, including pathogenesis-related (PR) genes and defense regulators.
• NPR1 is a master regulator of SA signaling; its condensation into nuclear bodies is essential for cell survival during immune activation.
• SA interacts with other hormones like jasmonic acid (JA) and ethylene, forming a complex network that fine-tunes defense and symbiotic responses.
• Research tools such as RNA-seq, ChIP-seq, and CRISPR knockout models are widely used to dissect SA signaling components and their functions.
Description
Salicylic acid (SA) is a phenolic phytohormone that plays a critical role in plant defense against pathogens and in responses to abiotic stresses. The Gene Ontology term GO:0009751, response to salicylic acid, captures any process that results in a change in state or activity of a cell or organism as a result of an SA stimulus. This includes changes in gene expression, enzyme production, and secretion, as well as movement and other physiological adjustments. Understanding this process is fundamental for plant biologists studying immunity, stress tolerance, and hormone crosstalk. SA signaling is not only vital for resistance to biotrophic pathogens but also modulates responses to environmental factors such as elevated CO2 and low CO2. Moreover, SA interacts with other hormones like jasmonic acid and ethylene, creating a sophisticated regulatory network that balances growth, defense, and symbiosis. The importance of SA extends to agricultural crops, where manipulating SA pathways can enhance disease resistance and stress resilience. This article provides a comprehensive overview of the molecular mechanisms, key genes, and experimental approaches used to study response to salicylic acid, based on authoritative QuickGO data and verified PubMed literature.
response to salicylic acid At A Glance
| GO ID | GO:0009751 |
|---|---|
| GO term | response to salicylic acid |
| Ontology | biological_process |
| Synonym | response to salicylate; response to salicylic acid stimulus |
| Major function | Mediates cellular and organismal responses to salicylic acid, including defense gene activation, stress tolerance, and hormone crosstalk |
| Key regulators | NPR1, TGA transcription factors, WRKY transcription factors, PR proteins |
| Associated processes | Plant immunity, systemic acquired resistance, abiotic stress response, hormone signaling |
| Taxonomic range | Primarily studied in plants, but also observed in fungi and other organisms |
What Is GO:0009751?
According to the Gene Ontology, GO:0009751 response to salicylic acid is defined as any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a salicylic acid stimulus. This term encompasses the immediate and long-term cellular responses triggered when salicylic acid is perceived, including signal transduction, transcriptional reprogramming, and metabolic adjustments.
Why Is response to salicylic acid Important in Cell Biology?
The response to salicylic acid is a cornerstone of plant biology because it governs the activation of systemic acquired resistance (SAR), a broad-spectrum immune response that protects plants against a wide range of pathogens. Beyond immunity, SA signaling integrates environmental cues such as elevated CO2 and low CO2, influencing plant growth and stress adaptation. Dysregulation of SA pathways can lead to increased susceptibility to diseases or impaired stress tolerance, making it a prime target for crop improvement. Additionally, SA crosstalk with jasmonic acid and ethylene pathways determines the outcome of plant-microbe interactions, including symbiotic associations. Thus, understanding GO:0009751 is essential for both fundamental plant science and applied agricultural biotechnology.
• SA signaling is required for resistance to biotrophic pathogens such as Pseudomonas syringae and Fusarium species.
• It mediates systemic acquired resistance (SAR), a long-lasting immune response in plants.
• SA modulates responses to abiotic stresses, including heat stress and low CO2.
• SA interacts with jasmonic acid and ethylene to fine-tune defense and symbiotic pathways.
• The transcriptional response to SA involves hundreds of genes, including PR proteins and transcription factors.
• NPR1 condensate formation is critical for cell survival during immune activation.
• SA treatment can alleviate heat stress by reducing ROS and increasing trehalose in fungi.
• Extracellular vesicles in the leaf apoplast carry stress-response proteins, some of which are SA-related.
• SA cooperates with small molecules to control biotic and abiotic stress responses.
• Manipulating SA signaling offers potential for engineering disease-resistant crops.
What Happens During response to salicylic acid?
Perception and Early Signaling
In simple terms: The plant detects salicylic acid and starts a signaling cascade.
Upon SA accumulation, likely mediated by pathogen attack or stress, SA is perceived by receptors such as NPR1 and NPR3/NPR4, leading to changes in cellular redox state and activation of downstream signaling components. This early phase involves calcium fluxes, MAP kinase cascades, and production of reactive oxygen species (ROS), which further amplify the signal.
Transcriptional Reprogramming
In simple terms: The plant turns many defense genes on or off.
SA signaling activates transcription factors such as TGA and WRKY families, which bind to promoter elements (e.g., as-1) of SA-responsive genes, including pathogenesis-related (PR) genes. This leads to massive transcriptional reprogramming, with upregulation of PR-1, PR-2, PR-5, and other defense-related genes. The transcriptional response to SA is a hallmark of the process and is often used as a readout in experiments.
NPR1 Condensate Formation and Cell Survival
In simple terms: A key protein clumps together to protect cells during defense.
NPR1, a master regulator of SA signaling, forms condensates in the nucleus upon SA perception. These condensates are essential for promoting cell survival during the plant immune response, as they sequester and regulate transcription factors and cell death regulators. Disruption of NPR1 condensation leads to uncontrolled cell death and compromised immunity.
Hormone Crosstalk and Systemic Acquired Resistance
In simple terms: SA talks to other hormones to spread immunity throughout the plant.
SA signaling antagonizes jasmonic acid (JA) and ethylene pathways, prioritizing defense against biotrophs over necrotrophs. It also induces systemic acquired resistance (SAR), a long-distance signal that primes distal tissues for enhanced defense. This crosstalk is context-dependent and influenced by environmental factors such as elevated CO2.
Abiotic Stress Integration
In simple terms: SA also helps plants cope with heat, cold, and other stresses.
Beyond biotic stress, SA modulates abiotic stress responses. For example, SA treatment alleviates heat stress in Pleurotus ostreatus by reducing intracellular ROS and increasing cytosolic trehalose. In Arabidopsis, SA plays a role in low CO2 responses, linking SA signaling to photosynthetic regulation. SA also cooperates with small molecules to control both biotic and abiotic stress responses.
Key Genes Involved in GO:0009751 response to salicylic acid
The following genes and proteins are central to the response to salicylic acid, as supported by published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| NPR1 | Master regulator of SA signaling; forms nuclear condensates for cell survival | Key target for studying SA-mediated immunity and cell death control |
| TGA transcription factors | Bind SA-responsive promoters to activate PR genes | Used to dissect transcriptional regulation of SA responses |
| WRKY transcription factors | Modulate SA-dependent defense gene expression | Frequently studied in plant immunity and stress responses |
| PR-1 | Pathogenesis-related protein; marker of SA signaling activation | Common readout for SA pathway activity |
| PR-2 | Beta-1,3-glucanase; defense against pathogens | Used as marker for SAR and SA response |
| PR-5 | Thaumatin-like protein; antifungal activity | Indicator of SA-mediated defense |
| ICS1 | Isochorismate synthase; key enzyme in SA biosynthesis | Target for manipulating SA levels |
| PAL | Phenylalanine ammonia-lyase; involved in SA biosynthesis | Studied for SA production and stress response |
| EDS1 | Regulates SA accumulation and defense signaling | Important for SA pathway activation |
| PAD4 | Phytoalexin deficient 4; involved in SA signaling | Used to study SA-dependent defense |
| NPR3/NPR4 | SA receptors that negatively regulate SA signaling | Targets for understanding SA perception |
| JAZ proteins | Jasmonate ZIM-domain proteins; mediate JA-SA crosstalk | Studied for hormone antagonism |
| EIN2 | Ethylene signaling component; interacts with SA pathway | Used to study SA-ethylene crosstalk |
| RBOHD | Respiratory burst oxidase homolog D; produces ROS in SA signaling | Key for early SA signaling and oxidative burst |
| MAPK3/6 | Mitogen-activated protein kinases; transduce SA signals | Studied for SA signal transduction |
| WRKY70 | Integrates SA and JA signaling | Model for hormone crosstalk |
| SIZ1 | SUMO E3 ligase; regulates SA accumulation | Involved in SA-dependent stress responses |
How Is response to salicylic acid Regulated?
The response to salicylic acid is tightly regulated at multiple levels. SA biosynthesis is controlled by enzymes such as ICS1 and PAL, which are induced upon pathogen attack. SA perception involves NPR1 and NPR3/NPR4, with NPR1 condensate formation acting as a critical regulatory switch for cell survival. Negative regulators like NPR3/NPR4 prevent inappropriate activation in the absence of SA. Additionally, SA signaling is modulated by crosstalk with jasmonic acid and ethylene pathways, which can antagonize or synergize depending on the context. Environmental factors such as elevated CO2 and low CO2 also influence SA-mediated responses, adding another layer of regulation. Post-translational modifications, including SUMOylation by SIZ1, further fine-tune SA signaling.
response to salicylic acid and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| NPR1 | Plant immunity and cell survival | Arabidopsis npr1 knockout mutants |
| ICS1 | SA biosynthesis and defense | Arabidopsis ics1 mutants |
| PR-1 | Fusarium yellows resistance | Brassica rapa cultivars |
| SIZ1 | Abiotic stress response | Arabidopsis siz1 mutants |
| RBOHD | Oxidative burst in immunity | Arabidopsis rbohd mutants |
Fusarium Yellows Resistance in Brassica rapa
The transcriptional response to salicylic acid plays a crucial role in resistance to Fusarium yellows in Brassica rapa. Studies have shown that SA-responsive genes are differentially expressed in resistant versus susceptible cultivars, highlighting the importance of SA signaling in crop disease resistance.
Plant Immunity and Cell Survival
NPR1 condensate formation is essential for cell survival during the plant immune response. Dysregulation of this process can lead to uncontrolled cell death, underscoring the link between SA signaling and cell death regulation in plants.
Heat Stress Alleviation in Fungi
In the fungus Pleurotus ostreatus, salicylic acid treatment alleviates heat stress by reducing intracellular ROS and increasing cytosolic trehalose content. This demonstrates that SA responses are not limited to plants and can modulate stress tolerance in fungi.
Low CO2 Response in Arabidopsis
Salicylic acid is involved in the low CO2 response in Arabidopsis, linking SA signaling to photosynthetic regulation and environmental adaptation. This suggests that SA pathways may be relevant for understanding plant responses to climate change.
From response to salicylic acid-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does gene X regulate SA-induced immunity? | CRISPR knockout in Arabidopsis or crop species |
| Does a point mutation in NPR1 affect condensate formation? | Point-mutation knock-in in Arabidopsis |
| Can overexpression of ICS1 increase SA levels and resistance? | Overexpression lines in Arabidopsis or tobacco |
| How does SA signaling affect heat stress tolerance? | Pleurotus ostreatus treated with SA |
| What is the role of SA in low CO2 response? | Arabidopsis mutants in SA pathway |
| How do SA and JA interact in defense? | Double mutants or hormone treatments in Arabidopsis |
How to Study the response to salicylic acid Process
| Method | What It Measures | Typical Application |
|---|---|---|
| RNA-seq | Global gene expression changes | Identifying SA-responsive genes in crops |
| ChIP-seq | Transcription factor binding sites | Mapping TGA/WRKY targets in SA signaling |
| Proteomics | Protein abundance and modifications | Analyzing apoplastic vesicles during SA response |
| Live-cell imaging | Subcellular localization and dynamics | Visualizing NPR1 condensates |
| qRT-PCR | Expression of specific genes | Validating PR gene induction by SA |
| Western blot | Protein levels and modifications | Detecting NPR1 oligomerization |
| ROS assays | Reactive oxygen species levels | Measuring oxidative burst upon SA treatment |
| Trehalose quantification | Cytosolic trehalose content | Assessing SA-mediated heat stress alleviation |
Transcriptomics (RNA-seq)
RNA-seq is widely used to profile the transcriptional response to salicylic acid. Studies in Brassica rapa have identified hundreds of SA-responsive genes, including PR proteins and transcription factors, providing insights into the genetic basis of disease resistance. This method allows global assessment of gene expression changes upon SA treatment or pathogen infection.
Chromatin Immunoprecipitation (ChIP-seq)
ChIP-seq can identify genome-wide binding sites of transcription factors such as TGA and WRKY that mediate SA-responsive gene expression. This helps elucidate the regulatory networks downstream of SA perception.
Proteomics and Extracellular Vesicle Analysis
Proteomic analysis of extracellular vesicles isolated from the leaf apoplast has revealed that they carry stress-response proteins, some of which are involved in SA signaling. This method provides insights into intercellular communication during SA responses.
Live-cell Imaging of NPR1 Condensates
Advanced imaging techniques, such as fluorescence microscopy, have been used to visualize NPR1 condensate formation in living cells. This approach demonstrated that condensates are dynamic and essential for cell survival during immune activation.
How CRISPR Can Be Used to Study GO:0009751 response to salicylic acid
Knockout
CRISPR knockout is used to generate loss-of-function mutants for genes involved in SA signaling, such as NPR1, ICS1, and TGA transcription factors. These mutants help determine the causal role of candidate genes in SA-mediated immunity and stress responses. For example, npr1 knockout plants exhibit compromised SAR and increased susceptibility to pathogens.
Point Mutation
Point mutations can be introduced to study specific amino acid residues critical for protein function, such as those required for NPR1 condensation or SA binding. This approach allows fine-tuning of SA signaling without completely abolishing gene function.
Knock-in
Knock-in of tagged versions of SA pathway genes (e.g., GFP-NPR1) enables live-cell imaging and biochemical studies. This helps track protein localization, interactions, and dynamics during SA responses.
Overexpression
Overexpression of SA biosynthesis genes like ICS1 or signaling components can elevate SA levels and enhance defense responses. This strategy is used to engineer disease-resistant crops and to study the effects of constitutive SA signaling.
How EDITGENE Supports response to salicylic acid Research
Researchers studying response to salicylic acid-related genes often need to determine whether a candidate gene is causally involved in SA signaling, and to dissect its precise function using targeted genetic models. EDITGENE provides a comprehensive suite of CRISPR-based services to accelerate this research.
Contact EDITGENE today to design your custom CRISPR model for response to salicylic acid research.
Frequently Asked Questions About response to salicylic acid
What is GO:0009751 response to salicylic acid?
GO:0009751 is a Gene Ontology biological process term defined as any process that results in a change in state or activity of a cell or organism as a result of a salicylic acid stimulus, including changes in gene expression, enzyme production, and secretion.
What genes are involved in response to salicylic acid?
Key genes include NPR1, ICS1, PAL, TGA and WRKY transcription factors, and PR genes such as PR-1, PR-2, and PR-5.
How does salicylic acid signaling work in plants?
Salicylic acid is perceived by receptors like NPR1 and NPR3/NPR4, leading to transcriptional reprogramming via TGA and WRKY factors, and formation of NPR1 condensates that promote cell survival during immunity.
Why is salicylic acid important for plant immunity?
Salicylic acid is essential for systemic acquired resistance (SAR) and defense against biotrophic pathogens, and it coordinates crosstalk with jasmonic acid and ethylene pathways.
What is the role of NPR1 in salicylic acid response?
NPR1 is a master regulator that forms nuclear condensates upon SA perception, which are required for cell survival and activation of defense genes during the immune response.
How is the response to salicylic acid studied experimentally?
Common methods include RNA-seq, ChIP-seq, proteomics, live-cell imaging of NPR1 condensates, and CRISPR knockout models in plants.
Does salicylic acid help with abiotic stress?
Yes, SA treatment can alleviate heat stress by reducing ROS and increasing trehalose in fungi, and it is involved in low CO2 responses in Arabidopsis.
What is the difference between salicylic acid and jasmonic acid signaling?
SA primarily defends against biotrophic pathogens and promotes SAR, while JA defends against necrotrophs and herbivores; they often antagonize each other.
Can CRISPR be used to study salicylic acid signaling?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression are powerful tools to dissect gene function in SA pathways.
What are the synonyms for response to salicylic acid?
Synonyms include response to salicylate and response to salicylic acid stimulus.
Conclusion
The response to salicylic acid (GO:0009751) is a fundamental biological process that underpins plant immunity, stress tolerance, and hormone crosstalk. Research over the past decades has elucidated key components such as NPR1, TGA/WRKY transcription factors, and PR proteins, revealing intricate regulatory mechanisms including condensate formation and hormone antagonism. Understanding this process has broad implications for agriculture, where manipulating SA signaling can enhance disease resistance and abiotic stress resilience. Continued exploration using advanced CRISPR models and multi-omics approaches will further unravel the complexities of SA biology and translate findings into crop improvement.
References
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- 2. Yoneda K et al.. 2025. Role of salicylic acid in low CO2 response in Arabidopsis.. Plant Cell Physiol 66(7):1005-1019 PMID: 40391867
- 3. Miyaji N et al.. 2021. The transcriptional response to salicylic acid plays a role in Fusarium yellows resistance in Brassica rapa L.. Plant Cell Rep 40(4):605-619 PMID: 33459838
- 4. Zavaliev R et al.. 2020. Formation of NPR1 Condensates Promotes Cell Survival during the Plant Immune Response.. Cell 182(5):1093-1108.e18 PMID: 32810437
- 5. Ngom M et al.. 2020. Establishment of Actinorhizal Symbiosis in Response to Ethylene, Salicylic Acid, and Jasmonate.. Methods Mol Biol 2085:117-130 PMID: 31734921
- 6. Rutter BD et al.. 2017. Extracellular Vesicles Isolated from the Leaf Apoplast Carry Stress-Response Proteins.. Plant Physiol 173(1):728-741 PMID: 27837092
- 7. Zhang G et al.. 2023. Salicylic Acid Treatment Alleviates the Heat Stress Response by Reducing the Intracellular ROS Level and Increasing the Cytosolic Trehalose Content in Pleurotus ostreatus.. Microbiol Spectr 11(1):e0311322 PMID: 36507658
- 8. Xin K et al.. 2025. Salicylic acid cooperates with different small molecules to control biotic and abiotic stress responses.. J Plant Physiol 304:154406 PMID: 39700900
