scholarly journals Ciboria carunculoides Suppresses Mulberry Immune Responses Through Regulation of Salicylic Acid Signaling

2021 ◽  
Vol 12 ◽  
Author(s):  
Zhiyuan Lv ◽  
Lijuan Hao ◽  
Bi Ma ◽  
Ziwen He ◽  
Yiwei Luo ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Systemic Acquired Resistance ◽  
Acquired Resistance ◽  
Antimicrobial Properties ◽  
Defense Responses ◽  
Narrow Host Range ◽  
Mulberry Fruit ◽  
Pathogenesis Related Protein ◽  
Ja Signaling ◽  
Sa Signaling

Ciboria carunculoides is the dominant causal agent of mulberry sclerotial disease, and it is a necrotrophic fungal pathogen with a narrow host range that causes devastating diseases in mulberry fruit. However, little is known about the interaction between C. carunculoides and mulberry. Here, our transcriptome sequencing results showed that the transcription of genes in the secondary metabolism and defense-related hormone pathways were significantly altered in infected mulberry fruit. Due to the antimicrobial properties of proanthocyanidins (PAs), the activation of PA biosynthetic pathways contributes to defense against pathogens. Salicylic acid (SA) and jasmonic acid (JA) are major plant defense hormones. However, SA signaling and JA signaling are antagonistic to each other. Our results showed that SA signaling was activated, while JA signaling was inhibited, in mulberry fruit infected with C. carunculoides. Yet SA mediated responses are double-edged sword against necrotrophic pathogens, as SA not only activates systemic acquired resistance (SAR) but also suppresses JA signaling. We also show here that the small secreted protein CcSSP1 of C. carunculoides activates SA signaling by targeting pathogenesis-related protein 1 (PR1). These findings reveal that the infection strategy of C. carunculoides functions by regulating SA signaling to inhibit host defense responses.

scholarly journals Signaling Crosstalk between Salicylic Acid and Ethylene/Jasmonate in Plant Defense: Do We Understand What They Are Whispering?

2019 ◽  
Vol 20 (3) ◽  
pp. 671 ◽  
Author(s):  
Ning Li ◽  
Xiao Han ◽  
Dan Feng ◽  
Deyi Yuan ◽  
Li-Jun Huang
Keyword(s):  
Salicylic Acid ◽  
Signaling Pathways ◽  
Pseudomonas Syringae ◽  
Defense Response ◽  
Systemic Acquired Resistance ◽  
Acquired Resistance ◽  
Defense Responses ◽  
Host Cells ◽  
Defense Gene Expression ◽  
Signaling Crosstalk

During their lifetime, plants encounter numerous biotic and abiotic stresses with diverse modes of attack. Phytohormones, including salicylic acid (SA), ethylene (ET), jasmonate (JA), abscisic acid (ABA), auxin (AUX), brassinosteroid (BR), gibberellic acid (GA), cytokinin (CK) and the recently identified strigolactones (SLs), orchestrate effective defense responses by activating defense gene expression. Genetic analysis of the model plant Arabidopsis thaliana has advanced our understanding of the function of these hormones. The SA- and ET/JA-mediated signaling pathways were thought to be the backbone of plant immune responses against biotic invaders, whereas ABA, auxin, BR, GA, CK and SL were considered to be involved in the plant immune response through modulating the SA-ET/JA signaling pathways. In general, the SA-mediated defense response plays a central role in local and systemic-acquired resistance (SAR) against biotrophic pathogens, such as Pseudomonas syringae, which colonize between the host cells by producing nutrient-absorbing structures while keeping the host alive. The ET/JA-mediated response contributes to the defense against necrotrophic pathogens, such as Botrytis cinerea, which invade and kill hosts to extract their nutrients. Increasing evidence indicates that the SA- and ET/JA-mediated defense response pathways are mutually antagonistic.

scholarly journals Arabidopsis thaliana EDS4 Contributes to Salicylic Acid (SA)-Dependent Expression of Defense Responses: Evidence for Inhibition of Jasmonic Acid Signaling by SA

2000 ◽  
Vol 13 (5) ◽  
pp. 503-511 ◽  
Author(s):  
Vaijayanti Gupta ◽  
Michael G. Willits ◽  
Jane Glazebrook
Keyword(s):  
Gene Expression ◽  
Salicylic Acid ◽  
Jasmonic Acid ◽  
Pseudomonas Syringae ◽  
Systemic Acquired Resistance ◽  
Acquired Resistance ◽  
Defense Responses ◽  
Avirulence Gene ◽  
Signal Molecule ◽  
Resistance Response

The Arabidopsis enhanced disease susceptibility 4 (eds4) mutation causes enhanced susceptibility to infection by the bacterial pathogen Pseudomonas syringae pv. Maculicola ES4326 (Psm ES4326). Gene-for-gene resistance to bacteria carrying the avirulence gene avrRpt2 is not significantly affected by eds4. Plants homozygous for eds4 exhibit reduced expression of the pathogenesis-related gene PR-1 after infection by Psm ES4326, weakened responses to treatment with the signal molecule salicylic acid (SA), impairment of the systemic acquired resistance response, and reduced accumulation of SA after infection with Psm ES4326. These phenotypes indicate that EDS4 plays a role in SA-dependent signaling. SA has been shown to have a negative effect on activation of gene expression by the signal molecule jasmonic acid (JA). Two mutations that cause reduced SA levels, eds4 and pad4, cause heightened responses to inducers of JA-dependent gene expression, providing genetic evidence to support the idea that SA interferes with JA-dependent signaling. Two possible working models of the role of EDS4 in governing activation of defense responses are presented.

scholarly journals Involvement of Salicylate and Jasmonate Signaling Pathways in Arabidopsis Interaction with Fusarium graminearum

2010 ◽  
Vol 23 (7) ◽  
pp. 861-870 ◽  
Author(s):  
Ragiba Makandar ◽  
Vamsi Nalam ◽  
Ratnesh Chaturvedi ◽  
Richard Jeannotte ◽  
Alexis A. Sparks ◽  
...  
Keyword(s):  
Fusarium Graminearum ◽  
Systemic Acquired Resistance ◽  
Acquired Resistance ◽  
Head Blight ◽  
Pathogenesis Related ◽  
Ja Signaling ◽  
Arabidopsis Defense ◽  
Sa Signaling ◽  
Dependent Mechanism

Fusarium graminearum is the principal causative agent of Fusarium head blight (FHB), a devastating disease of wheat and barley. This fungus can also colonize Arabidopsis thaliana. Disease resistance was enhanced in transgenic wheat and Arabidopsis plants that constitutively overexpress the NONEXPRESSOR OF PATHOGENESIS-RELATED GENES 1 (NPR1) gene, which regulates salicylic acid (SA) signaling and modulates the activation of jasmonic acid (JA)-dependent defenses. Here, we provide several lines of evidence that reveal an important role for SA and JA signaling in Arabidopsis defense against F. graminearum. SA level was elevated in fungus-inoculated leaves, and SA application and biologically activated systemic acquired resistance enhanced resistance. Furthermore, the disruption of SA accumulation and signaling in the sid2 mutant and NahG transgenic plant, and the npr1 and wrky18 mutants, respectively, resulted in heightened susceptibility to this fungus in leaves and inflorescence. JA signaling was activated in parallel with SA signaling in the fungus-challenged plants. However, the hyperresistance of the JA pathway mutants opr3, coi1, and jar1 indicates that this pathway contributes to susceptibility. Genetic and biochemical experiments indicate that the JA pathway promotes disease by attenuating the activation of SA signaling in fungus-inoculated plants. However, the hypersusceptibility of the jar1 npr1 double mutant compared with the npr1 mutant suggests that JAR1 also contributes to defense, signifying a dichotomous role of JA and a JAR1-dependent mechanism in this interaction.

scholarly journals Spatial and temporal regulation of biosynthesis of the plant immune signal salicylic acid

2015 ◽  
Vol 112 (30) ◽  
pp. 9166-9173 ◽  
Author(s):  
Xiao-yu Zheng ◽  
Mian Zhou ◽  
Heejin Yoo ◽  
Jose L. Pruneda-Paz ◽  
Natalie Weaver Spivey ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Systemic Acquired Resistance ◽  
Acquired Resistance ◽  
Signal Transduction Pathway ◽  
Temporal Regulation ◽  
Calmodulin Binding ◽  
Regulation Of Biosynthesis ◽  
Pathogen Entry ◽  
Transcription Activators ◽  
Transcriptional Induction

The plant hormone salicylic acid (SA) is essential for local defense and systemic acquired resistance (SAR). When plants, such as Arabidopsis, are challenged by different pathogens, an increase in SA biosynthesis generally occurs through transcriptional induction of the key synthetic enzyme isochorismate synthase 1 (ICS1). However, the regulatory mechanism for this induction is poorly understood. Using a yeast one-hybrid screen, we identified two transcription factors (TFs), NTM1-LIKE 9 (NTL9) and CCA1 HIKING EXPEDITION (CHE), as activators of ICS1 during specific immune responses. NTL9 is essential for inducing ICS1 and two other SA synthesis-related genes, PHYTOALEXIN-DEFICIENT 4 (PAD4) and ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1), in guard cells that form stomata. Stomata can quickly close upon challenge to block pathogen entry. This stomatal immunity requires ICS1 and the SA signaling pathway. In the ntl9 mutant, this response is defective and can be rescued by exogenous application of SA, indicating that NTL9-mediated SA synthesis is essential for stomatal immunity. CHE, the second identified TF, is a central circadian clock oscillator and is required not only for the daily oscillation in SA levels but also for the pathogen-induced SA synthesis in systemic tissues during SAR. CHE may also regulate ICS1 through the known transcription activators CALMODULIN BINDING PROTEIN 60g (CBP60g) and SYSTEMIC ACQUIRED RESISTANCE DEFICIENT 1 (SARD1) because induction of these TF genes is compromised in the che-2 mutant. Our study shows that SA biosynthesis is regulated by multiple TFs in a spatial and temporal manner and therefore fills a gap in the signal transduction pathway between pathogen recognition and SA production.

scholarly journals Systemic Acquired Resistance in Canola Is Linked with Pathogenesis-Related Gene Expression and Requires Salicylic Acid

2007 ◽  
Vol 97 (7) ◽  
pp. 794-802 ◽  
Author(s):  
Shobha D. Potlakayala ◽  
Darwin W. Reed ◽  
Patrick S. Covello ◽  
Pierre R. Fobert
Keyword(s):  
Salicylic Acid ◽  
Pseudomonas Syringae ◽  
Systemic Acquired Resistance ◽  
Induced Defense ◽  
Acquired Resistance ◽  
Microbial Pathogens ◽  
Broad Host Range ◽  
Avirulent Strain ◽  
Enhanced Resistance ◽  
Pathogenesis Related

Systemic acquired resistance (SAR) is an induced defense response that confers long-lasting protection against a broad range of microbial pathogens. Here we show that treatment of Brassica napus plants with the SAR-inducing chemical benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH) significantly enhanced resistance against virulent strains of the bacterial pathogen Pseudomonas syringae pv. maculicola and the fungal pathogen Leptosphaeria maculans. Localized preinoculation of plants with an avirulent strain of P. syringae pv. maculicola also enhanced resistance to these pathogens but was not as effective as BTH treatment. Single applications of either SAR-inducing pretreatment were effective against P. syringae pv. maculicola, even when given more than 3 weeks prior to the secondary challenge. The pretreatments also led to the accumulation of pathogenesis-related (PR) genes, including BnPR-1 and BnPR-2, with higher levels of transcripts observed in the BTH-treatment material. B. napus plants expressing a bacterial salicylate hydroxylase transgene (NahG) that metabolizes salicylic acid to catechol were substantially compromised in SAR and accumulated reduced levels of PR gene transcripts when compared with untransformed controls. Thus, SAR in B. napus displays many of the hallmarks of classical SAR including long lasting and broad host range resistance, association with PR gene activation, and a requirement for salicylic acid.

scholarly journals Relationship Between Localized Acquired Resistance (LAR) and the Hypersensitive Response (HR): HR Is Necessary for LAR to Occur and Salicylic Acid Is Not Sufficient to Trigger LAR

1999 ◽  
Vol 12 (8) ◽  
pp. 655-662 ◽  
Author(s):  
Laurent Costet ◽  
Sylvain Cordelier ◽  
Stéphan Dorey ◽  
Fabienne Baillieul ◽  
Bernard Fritig ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Hypersensitive Response ◽  
Acquired Resistance ◽  
Defense Responses ◽  
Pr Proteins ◽  
Tobacco Plants ◽  
Tobacco Leaves ◽  
Pathogenesis Related ◽  
Tobacco Mosaic Virus Infection ◽  
Mosaic Virus Infection

In tobacco plants reacting hypersensitively to pathogen infection, localized acquired resistance (LAR) is induced in a sharp zone surrounding hypersensitive response (HR) lesions. Using a fungal glycoprotein inducing HR and LAR when infiltrated at 50 nM into tobacco leaves, we have shown previously that a plant signal(s) is released by HR cells and diffuses to induce LAR. Here we address two questions: does LAR occur when HR is not induced, and is salicylic acid the (or one of the) mobile LAR signal? We found that application to tobacco leaves of 0.25 nM glycoprotein triggered defense responses without HR and without an H2O2 burst. The analyzed responses include changes in expression of O-methyltransferase (OMT), 3-hydroxy-3-methylglutarylCoA reductase, pathogenesis-related (PR) proteins, and changes in levels of the signal salicylic acid. No defense responses and no increased resistance to tobacco mosaic virus infection were found beyond the elicitor-infiltrated tissue, providing strong evidence that there is no LAR without HR. Treatments of NahG tobacco leaves with 50 nM elicitor induced the HR and, in the sharp zone surrounding the HR lesion, a strong activation of OMT and of basic PR proteins, but not of acidic PR-1 proteins. This indicates that a signal different from salicylic acid is diffusing.

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