scholarly journals Tobacco Class I and II Catalases Are Differentially Expressed During Elicitor-Induced Hypersensitive Cell Death and Localized Acquired Resistance

1998 ◽  
Vol 11 (11) ◽  
pp. 1102-1109 ◽  
Author(s):  
Stéphan Dorey ◽  
Fabienne Baillieul ◽  
Patrick Saindrenan ◽  
Bernard Fritig ◽  
Serge Kauffmann
Keyword(s):  
Salicylic Acid ◽  
Catalase Activity ◽  
Induced Defense ◽  
Acquired Resistance ◽  
Defense Responses ◽  
Class I ◽  
Surrounding Tissue ◽  
Oxygen Intermediates ◽  
Hypersensitive Cell Death ◽  
Tobacco Leaves

Expression of tobacco class I (CAT1) and class II (CAT2) catalases was analyzed in leaves reacting hypersensitively to tobacco mosaic virus (TMV) or to a fungal glycoprotein elicitor. In TMV-infected plants, Cat1 transcript levels declined rapidly while Cat2 transcripts accumulated strongly. The spatial and temporal changes in catalase transcripts, proteins, and activity during the hypersensitive reaction (HR) were further investigated in tobacco leaves infiltrated with a glycoprotein elicitor. Two functionally different zones were discriminated: the infiltrated tissue in which cells undergo the HR, called the HR-zone 1; and the surrounding tissue showing strong induced defense responses, called the LAR (Localized Acquired Resistance)- zone 2. Levels of Cat1 and Cat2 mRNA and proteins and catalase activity decreased in the HR-zone 1. In the LAR-zone 2, Cat1 transcripts became rapidly undetectable, but levels of Cat2 mRNA and protein and catalase activity increased. Catalase expression in elicitorinfiltrated leaves reflected that in TMV-infected leaves. A strong rise in hydrogen peroxide occurred in the HR-zone 1 and paralleled the CAT activity decline. No H2O2 increase was measured in the LAR-zone 2. There was no correlation between salicylic acid levels and catalase activity. Modulation of catalase activity in tobacco leaves undergoing the HR appeared predominantly supported by changes in catalase transcripts and proteins. We have shown that neither H2O2 nor salicylic acid can be the primary mobile signal diffusing from the HR-zone 1 to the LAR-zone 2 and inducing CAT2 expression. Furthermore, the signaling pathway responsible for decreased CAT2 expression in the HR-zone 1 does not involve reactive oxygen intermediates.

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.

scholarly journals Spatial and Temporal Induction of Cell Death, Defense Genes, and Accumulation of Salicylic Acid in Tobacco Leaves Reacting Hypersensitively to a Fungal Glycoprotein Elicitor

1997 ◽  
Vol 10 (5) ◽  
pp. 646-655 ◽  
Author(s):  
Stephan Dorey ◽  
Fabienne Baillieul ◽  
Marie-Agnès Pierrel ◽  
Patrick Saindrenan ◽  
Bernard Fritig ◽  
...  
Keyword(s):  
Cell Death ◽  
Salicylic Acid ◽  
Defense Responses ◽  
Hypersensitive Reaction ◽  
Surrounding Tissue ◽  
Defense Gene Expression ◽  
Phytophthora Megasperma ◽  
Signaling Mechanism ◽  
Tobacco Leaves ◽  
Tissue Zone

We have analyzed the spatial and temporal expression of defense responses induced in attached tobacco leaves treated with a Phytophthora megasperma glycoprotein that was previously shown to be an efficient elicitor of the hypersensitive reaction. The infiltrated tissue (zone 1), the surrounding tissue (zone 2), which is 5 mm in width, and tissue at a distance >2 cm from zone 2 (zone 3) were analyzed separately. Cell death occurred only in zone 1 and was completed by 14 h. Defense gene expression was induced in zones 1 and 2 with striking differential patterns, but not in zone 3. There was a rapid (1 to 4 h) induction of genes of the phenylpropanoid, salicylic acid, and ses-quiterpenoid pathways in zones 1 and 2. However, it was strong and transient in the former and of lesser extent but sustained in the latter. High amounts of scopoletin, a phenylpropanoid metabolite, were found synthesized in zone 2. Pathogenesis-related (PR) transcripts and the corresponding PR proteins accumulated in high amounts in zone 2 rather late after the treatment (24 h). Salicylic acid was synthesized in both zone 1 and zone 2. Using a radioactively labeled elicitor, we demonstrated that the elicitor remained strictly localized to zone 1. The results provide strong evidence that an endogenous cell-to-cell signaling mechanism was triggered and occurred between the elici-tor-treated cells (zone 1) and the surrounding cells (zone 2), where it induces strong defense responses without cell death.

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 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 Induce the plant resistance to pathogen infection

2014 ◽  
Vol 20 (1-2) ◽  
Author(s):  
A. Ezzat ◽  
Z. Szabó ◽  
J. Nyéki
Keyword(s):  
Gene Expression ◽  
Salicylic Acid ◽  
Systemic Acquired Resistance ◽  
Induced Defense ◽  
Acquired Resistance ◽  
Vital Role ◽  
Signal Molecule ◽  
Pathogenesis Related ◽  
Related Proteins ◽  
Direct Toxicity

Systemic acquired resistance (SAR) is a mechanism of induced defense that confers long-lasting protection against a broad spectrum of microorganisms. Salicylic acid (SA) is the signal molecule which is required for induce SAR and is associated with accumulation of pathogenesis-related proteins, which are thought to contribute to resistance. SA paly vital role in some related resistance gene expression in plant cell which have direct or indirect effect on pathogen growth as SA has direct toxicity for pathogen and in the same time has stimulation effect for some enzyme related to reduce the oxidative burst.

scholarly journals The Elicitor Protein AsES Induces a Systemic Acquired Resistance Response Accompanied by Systemic Microbursts and Micro–Hypersensitive Responses in Fragaria ananassa

2018 ◽  
Vol 31 (1) ◽  
pp. 46-60 ◽  
Author(s):  
Verónica Hael-Conrad ◽  
Silvia Marisa Perato ◽  
Marta Eugenia Arias ◽  
Martín Gustavo Martínez-Zamora ◽  
Pía de los Ángeles Di Peto ◽  
...  
Keyword(s):  
Cell Death ◽  
Systemic Acquired Resistance ◽  
Calcium Influx ◽  
Wide Spectrum ◽  
Acquired Resistance ◽  
Defense Responses ◽  
Death Process ◽  
Fragaria Ananassa ◽  
Hypersensitive Cell Death ◽  
Acremonium Strictum

The elicitor AsES (Acremonium strictum elicitor subtilisin) is a 34-kDa subtilisin-like protein secreted by the opportunistic fungus Acremonium strictum. AsES activates innate immunity and confers resistance against anthracnose and gray mold diseases in strawberry plants (Fragaria × ananassa Duch.) and the last disease also in Arabidopsis. In the present work, we show that, upon AsES recognition, a cascade of defense responses is activated, including: calcium influx, biphasic oxidative burst (O2⋅− and H2O2), hypersensitive cell-death response (HR), accumulation of autofluorescent compounds, cell-wall reinforcement with callose and lignin deposition, salicylic acid accumulation, and expression of defense-related genes, such as FaPR1, FaPG1, FaMYB30, FaRBOH-D, FaRBOH-F, FaCHI23, and FaFLS. All these responses occurred following a spatial and temporal program, first induced in infiltrated leaflets (local acquired resistance), spreading out to untreated lateral leaflets, and later, to distal leaves (systemic acquired resistance). After AsES treatment, macro-HR and macro–oxidative bursts were localized in infiltrated leaflets, while micro-HRs and microbursts occurred later in untreated leaves, being confined to a single cell or a cluster of a few epidermal cells that differentiated from the surrounding ones. The differentiated cells initiated a time-dependent series of physiological and anatomical changes, evolving to idioblasts accumulating H2O2 and autofluorescent compounds that blast, delivering its content into surrounding cells. This kind of systemic cell-death process in plants is described for the first time in response to a single elicitor. All data presented in this study suggest that AsES has the potential to activate a wide spectrum of biochemical and molecular defense responses in F. ananassa that may explain the induced protection toward pathogens of opposite lifestyle, like hemibiotrophic and necrotrophic fungi.

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 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 Role for Salicylic Acid in the Activation of Defense Responses in Catalase-Deficient Transgenic Tobacco

1997 ◽  
Vol 10 (7) ◽  
pp. 922-925 ◽  
Author(s):  
He Du ◽  
Daniel F. Klessig
Keyword(s):  
Salicylic Acid ◽  
Transgenic Tobacco ◽  
Catalase Activity ◽  
Defense Responses ◽  
Transgenic Tobacco Plants ◽  
Strong Light ◽  
Tobacco Plants ◽  
Enhanced Resistance ◽  
The Cross

Transgenic tobacco plants with severely reduced catalase activity were crossed with NahG plants that do not accumulate salicylic acid. Some of the progeny from the cross spontaneously developed necrosis when grown under strong light, similar to that observed on the parental severely catalase-deficient plants. However, in contrast to the parental catalase-deficient plants, these progeny plants did not constitutively express PR-1 genes or develop enhanced resistance. Thus, salicylic acid appears to be required for the induction of these defense responses in catalase-deficient tobacco plants.

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