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 The Sesquiterpene Botrydial Produced by Botrytis cinerea Induces the Hypersensitive Response on Plant Tissues and Its Action Is Modulated by Salicylic Acid and Jasmonic Acid Signaling

2011 ◽  
Vol 24 (8) ◽  
pp. 888-896 ◽  
Author(s):  
Franco Rubén Rossi ◽  
Andrés Gárriz ◽  
María Marina ◽  
Fernando Matías Romero ◽  
María Elisa Gonzalez ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Jasmonic Acid ◽  
Botrytis Cinerea ◽  
Hypersensitive Response ◽  
Defense Responses ◽  
Callose Deposition ◽  
Pathogenesis Related ◽  
Host Signaling ◽  
Related Proteins ◽  
Ja Signaling

Botrytis cinerea, as a necrotrophic fungus, kills host tissues and feeds on the remains. This fungus is able to induce the hypersensitive response (HR) on its hosts, thus taking advantage on the host's defense machinery for generating necrotic tissues. However, the identity of HR effectors produced by B. cinerea is not clear. The aim of this work was to determine whether botrydial, a phytotoxic sesquiterpene produced by B. cinerea, is able to induce the HR on plant hosts, using Arabidopsis thaliana as a model. Botrydial induced the expression of the HR marker HSR3, callose deposition, and the accumulation of reactive oxygen species and phenolic compounds. Botrydial also induced the expression of PR1 and PDF1.2, two pathogenesis-related proteins involved in defense responses regulated by salicylic acid (SA) and jasmonic acid (JA), respectively. A. thaliana and tobacco plants defective in SA signaling were more resistant to botrydial than wild-type plants, as opposed to A. thaliana plants defective in JA signaling, which were more sensitive. It can be concluded that botrydial induces the HR on its hosts and its effects are modulated by host signaling pathways mediated by SA and JA.

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 Free and Conjugated Benzoic Acid in Tobacco Plants and Cell Cultures. Induced Accumulation upon Elicitation of Defense Responses and Role as Salicylic Acid Precursors

2001 ◽  
Vol 125 (1) ◽  
pp. 318-328 ◽  
Author(s):  
Julie Chong ◽  
Marie-Agnès Pierrel ◽  
Rossitza Atanassova ◽  
Danièle Werck-Reichhart ◽  
Bernard Fritig ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Benzoic Acid ◽  
Cell Cultures ◽  
Defense Responses ◽  
Tobacco Plants

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 Effect of Yeast CTA1 Gene Expression on Response of Tobacco Plants to Tobacco Mosaic Virus Infection

2002 ◽  
Vol 129 (3) ◽  
pp. 1032-1044 ◽  
Author(s):  
Andrzej Talarczyk ◽  
Magdalena Krzymowska ◽  
Wojciech Borucki ◽  
Jacek Hennig
Keyword(s):  
Gene Expression ◽  
Virus Infection ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Tobacco Plants ◽  
Tobacco Mosaic Virus Infection ◽  
Mosaic Virus Infection
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