Nanogram Amounts of Salicylic Acid Produced by the Rhizobacterium<i>Pseudomonas aeruginosa</i>7NSK2 Activate the Systemic Acquired Resistance Pathway in Bean

Meyer, Geert De; Capieau, Kristof; Audenaert, Kris; Buchala, Antony; Métraux, Jean‐Pierre; Höfte, Monica

doi:10.1094/mpmi.1999.12.5.450

Cited by 212 publications

(98 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The requirement of SA production for resistance induction by 7NSK2 was corroborated by the loss of ISR elicitation by bacterial mutant derivatives that were no longer capable of producing SA (De Meyer and Höfte, 1997;De Meyer et al, 1999b;Audenaert et al, 2002). However, upon colonization of tomato roots, SA is required for the production of the SA-containing siderophore pyochelin that elicits ISR in conjunction with the antibiotic pyocyanin.…”

Section: 3mentioning

confidence: 96%

Induced Systemic Resistance as a Mechanism of Disease Suppression by Rhizobacteria

Loon

Bakker

2005

PGPR: Biocontrol and Biofertilization

107

View full text Add to dashboard Cite

Abstract:Plant growth-promoting rhizobacteria can suppress diseases through antagonism between the bacteria and soil-borne pathogens, as well as by inducing a systemic resistance in the plant against both root and foliar pathogens. The generally non-specific character of induced resistance constitutes an increase in the level of basal resistance to several pathogens simultaneously, which is of benefit under natural conditions where multiple pathogens may be present. Specific Pseudomonas strains induce systemic resistance in e.g. carnation, cucumber, radish, tobacco and Arabidopsis, as evidenced by an enhanced defensive capacity upon challenge inoculation. Although some bacterial strains are equally effective in inducing resistance in different plant species, others show specificity, indicating specific recognition between bacteria and plants at the root surface. In carnation, radish and Arabidopsis, the O-antigenic side chain of the bacterial outer membrane lipopolysaccharide acts as an inducing determinant, but other bacterial traits are also involved. Pseudobactin siderophores have been implicated in the induction of resistance in tobacco and Arabidopsis, and another siderophore, pseudomonine, may explain induction of resistance associated with salicylic acid (SA) in radish. Although SA induces phenotypically similar systemic acquired resistance (SAR), it is not necessary for the systemic resistance induced by most rhizobacterial strains. Instead, rhizobacteria-mediated induced systemic resistance (ISR) is dependent on jasmonic acid (JA) and ethylene signaling in the plant. Upon challenge inoculation of induced Arabidopsis plants with a pathogen, leaves expressing SAR exhibit a primed expression of SA-, but not JA/ethylene-responsive defense-related genes, whereas leaves expressing ISR are primed to express JA/ethylene-, but not SA-responsive genes. Combination of ISR and SAR can increase protection against pathogens that are resisted through both pathways, as well as extend protection to a broader spectrum of pathogens than ISR or SAR alone.

show abstract

Section: 3mentioning

confidence: 96%

Induced Systemic Resistance as a Mechanism of Disease Suppression by Rhizobacteria

Loon

Bakker

2005

PGPR: Biocontrol and Biofertilization

107

View full text Add to dashboard Cite

show abstract

“…Some rhizobacteria trigger the SA-dependent SAR pathway by producing SA on the root (De Meyer et al, 1999;Maurhofer et al, 1998). However, WCS417r induces normal levels of protection against Pst strain DC3000 in Arabidopsis genotypes that are impaired in SA accumulation (i.e.…”

Section: Introductionmentioning

confidence: 99%

Colonization of the Arabidopsis rhizosphere by fluorescent Pseudomonas spp. activates a root-specific, ethylene-responsive PR-5 gene in the vascular bundle

et al. 2005

View full text Add to dashboard Cite

Plants of which the roots are colonized by selected strains of non-pathogenic, fluorescent Pseudomonas spp. develop an enhanced defensive capacity against a broad spectrum of foliar pathogens. In Arabidopsis thaliana, this rhizobacteria-induced systemic resistance (ISR) functions independently of salicylic acid but requires responsiveness to jasmonic acid and ethylene. In contrast to pathogen-induced systemic acquired resistance (SAR), ISR is not associated with systemic changes in the expression of genes encoding pathogenesis-related (PR) proteins. To identify genes that are specifically expressed in response to colonization of the roots by ISRinducing Pseudomonas fluorescens WCS417r bacteria, we screened a collection of Arabidopsis enhancer trap and gene trap lines containing a transposable element of the Ac/Ds system and the GUS reporter gene. We identified an enhancer trap line (WET121) that specifically showed GUS activity in the root vascular bundle upon colonization of the roots by WCS417r. Fluorescent Pseudomonas spp. strains P. fluorescens WCS374r and P. putida WCS358r triggered a similar expression pattern, whereas ISR-non-inducing Escherichia coli bacteria did not. Exogenous application of the ethylene precursor 1-aminocyclopropane-1-carboxylate (ACC) mimicked the rhizobacteria-induced GUS expression pattern in the root vascular bundle, whereas methyl jasmonic acid and salicylic acid did not, indicating that the Ds element in WET121 is inserted in the vicinity of an ethylene-responsive gene. Analysis of the expression of the genes in the close vicinity of the Ds element revealed AtTLP1 as the gene responsible for the in cis activation of the GUS reporter gene in the root vascular bundle. AtTLP1 encodes a thaumatin-like protein that belongs to the PR-5 family of PR proteins, some of which possess antimicrobial properties. AtTLP1 knockout mutant plants showed normal levels of WCS417r-mediated ISR against the bacterial leaf pathogen Pseudomonas syringae pv. tomato DC3000, suggesting that expression of AtTLP1 in the roots is not required for systemic expression of ISR in the leaves. Together, these results indicate that induction of AtTLP1 is a local response of Arabidopsis roots to colonization by non-pathogenic fluorescent Pseudomonas spp. and is unlikely to play a role in systemic resistance.

show abstract

“…The potentiated responses include oxidative burst (Iriti and Faoro, 2003), cell wall reinforcements (Benhamou et al, 1996), accumulation of defense-related materials and enzymes (Chen et al, 2000), secondary metabolite production (Ongena et al, 2000), and impediment of infection processes of pathogens such as inhibition of sporangia and zoospore germination (Yan et al, 2002). Lipopolysaccharides (LPS), siderophores, or SA from rhizobacteria also are indispensable for successful disease protection (De Meyer et al, 1999; for review, see Ramamoorthy et al, 2001). In connection with ISR and PGPR, Niu et al (2011), reported that Bacillus cereus AR156 induces ISR in Arabidopsis by simultaneously activating SA-and JA/ET-dependent signaling pathways.…”

mentioning

confidence: 99%

Microbe-Associated Molecular Patterns-Triggered Root Responses Mediate Beneficial Rhizobacterial Recruitment in Arabidopsis

et al. 2012

View full text Add to dashboard Cite

This study demonstrated that foliar infection by Pseudomonas syringae pv tomato DC3000 induced malic acid (MA) transporter (ALUMINUM-ACTIVATED MALATE TRANSPORTER1 [ALMT1]) expression leading to increased MA titers in the rhizosphere of Arabidopsis (Arabidopsis thaliana). MA secretion in the rhizosphere increased beneficial rhizobacteria Bacillus subtilis FB17 (hereafter FB17) titers causing an induced systemic resistance response in plants against P. syringae pv tomato DC3000. Having shown that a live pathogen could induce an intraplant signal from shoot-to-root to recruit FB17 belowground, we hypothesized that pathogen-derived microbe-associated molecular patterns (MAMPs) may relay a similar response specific to FB17 recruitment. The involvement of MAMPs in triggering plant innate immune response is well studied in the plant's response against foliar pathogens. In contrast, MAMPs-elicited plant responses on the roots and the belowground microbial community are not well understood. It is known that pathogen-derived MAMPs suppress the root immune responses, which may facilitate pathogenicity. Plants subjected to known MAMPs such as a flagellar peptide, flagellin22 (flg22), and a pathogen-derived phytotoxin, coronatine (COR), induced a shoot-to-root signal regulating ALMT1 for recruitment of FB17. Micrografts using either a COR-insensitive mutant (coi1) or a flagellin-insensitive mutant (fls2) as the scion and ALMT1 pro :b-glucuronidase as the rootstock revealed that both COR and flg22 are required for a graft transmissible signal to recruit FB17 belowground. The data suggest that MAMPs-induced signaling to regulate ALMT1 is salicylic acid and JASMONIC ACID RESISTANT1 (JAR1)/JASMONATE INSENSITIVE1 (JIN1)/MYC2 independent. Interestingly, a cell culture filtrate of FB17 suppressed flg22-induced MAMPsactivated root defense responses, which are similar to suppression of COR-mediated MAMPs-activated root defense, revealing a diffusible bacterial component that may regulate plant immune responses. Further analysis showed that the biofilm formation in B. subtilis negates suppression of MAMPs-activated defense responses in roots. Moreover, B. subtilis suppression of MAMPs-activated root defense does require JAR1/JIN1/MYC2. The ability of FB17 to block the MAMPselicited signaling pathways related to antibiosis reflects a strategy adapted by FB17 for efficient root colonization. These experiments demonstrate a remarkable strategy adapted by beneficial rhizobacteria to suppress a host defense response, which may facilitate rhizobacterial colonization and host-mutualistic association.

show abstract

Nanogram Amounts of Salicylic Acid Produced by the RhizobacteriumPseudomonas aeruginosa7NSK2 Activate the Systemic Acquired Resistance Pathway in Bean

Cited by 212 publications

References 29 publications

Induced Systemic Resistance as a Mechanism of Disease Suppression by Rhizobacteria

Induced Systemic Resistance as a Mechanism of Disease Suppression by Rhizobacteria

Colonization of the Arabidopsis rhizosphere by fluorescent Pseudomonas spp. activates a root-specific, ethylene-responsive PR-5 gene in the vascular bundle

Microbe-Associated Molecular Patterns-Triggered Root Responses Mediate Beneficial Rhizobacterial Recruitment in Arabidopsis

Contact Info

Product

Resources

About