A major protein component of the <i>Bacillus subtilis</i> biofilm matrix

Branda, Steven S.; Chu, Frances; Kearns, Daniel B.; Losick, Richard; Kolter, Roberto

doi:10.1111/j.1365-2958.2005.05020.x

Cited by 638 publications

(752 citation statements)

References 31 publications

Supporting

Mentioning

717

Contrasting

Unclassified

Order By: Relevance

“…Plant-generated MA was also specifically induced with Pst DC3000 and positively induced the biofilm operon yqxM. The operon yqxM is a member of a three-gene operon yqxMsipW-tasA, where tasA encodes for a protein that is a major component of the biofilm matrix and yqxM is important for the proper localization of TasA to the matrix (Branda et al, 2006). In plants, increased accumulation of L-MA can be triggered by elevated biosynthesis of one or more of the tricarboxylic acid MA precursors, fumarate, oxaloacetate, or pyruvate, by fumarase, malate dehydrogenase, and malic enzyme, or by reduced MA turnover to pyruvate or oxaloacetate by malic enzyme and malate dehydrogenase, respectively (Casati et al, 1999).…”

Section: Discussionmentioning

confidence: 99%

Root-Secreted Malic Acid Recruits Beneficial Soil Bacteria

et al. 2008

View full text Add to dashboard Cite

Beneficial soil bacteria confer immunity against a wide range of foliar diseases by activating plant defenses, thereby reducing a plant's susceptibility to pathogen attack. Although bacterial signals have been identified that activate these plant defenses, plant metabolites that elicit rhizobacterial responses have not been demonstrated. Here, we provide biochemical evidence that the tricarboxylic acid cycle intermediate L-malic acid (MA) secreted from roots of Arabidopsis (Arabidopsis thaliana) selectively signals and recruits the beneficial rhizobacterium Bacillus subtilis FB17 in a dose-dependent manner. Root secretions of L-MA are induced by the foliar pathogen Pseudomonas syringae pv tomato (Pst DC3000) and elevated levels of L-MA promote binding and biofilm formation of FB17 on Arabidopsis roots. The demonstration that roots selectively secrete L-MA and effectively signal beneficial rhizobacteria establishes a regulatory role of root metabolites in recruitment of beneficial microbes, as well as underscores the breadth and sophistication of plant-microbial interactions.

show abstract

Section: Discussionmentioning

confidence: 99%

Root-Secreted Malic Acid Recruits Beneficial Soil Bacteria

et al. 2008

View full text Add to dashboard Cite

show abstract

“…A defining step in the formation of B. subtilis biofilms is the synthesis of an extracellular matrix that holds the constituent cells together (16)(17)(18)(19). The regulatory circuit controlling the synthesis of the extracellular matrix in this bacterium has been well-characterized ( Fig.…”

Section: Surfactin and Nystatin Activate The Regulatory Circuitry Thamentioning

confidence: 99%

Structurally diverse natural products that cause potassium leakage trigger multicellularity in Bacillus subtilis

López

Fischbach²,

Chu³

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

357

394

View full text Add to dashboard Cite

We report a previously undescribed quorum-sensing mechanism for triggering multicellularity in Bacillus subtilis. B. subtilis forms communities of cells known as biofilms in response to an unknown signal. We discovered that biofilm formation is stimulated by a variety of small molecules produced by bacteria-including the B. subtilis nonribosomal peptide surfactin-that share the ability to induce potassium leakage. Natural products that do not cause potassium leakage failed to induce multicellularity. Small-molecule-induced multicellularity was prevented by the addition of potassium, but not sodium or lithium. Evidence is presented that potassium leakage stimulates the activity of a membrane protein kinase, KinC, which governs the expression of genes involved in biofilm formation. We propose that KinC responds to lowered intracellular potassium concentration and that this is a quorum-sensing mechanism that enables B. subtilis to respond to related and unrelated bacteria.biofilm ͉ quorum sensing

show abstract

“…It is known that the biofilm formation and colonization ability of Bacillus spp. and other endospore-forming Grampositive bacteria is dependent on extracellular matrix and TasA (Branda et al, 2006). We hypothesized that TasA protein may play a role in the suppression of root defense genes in Arabidopsis.…”

Section: B Subtilis Suppression Of Mamps-triggered Root Defense Respmentioning

confidence: 99%

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

et al. 2012

Self Cite

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

A major protein component of the Bacillus subtilis biofilm matrix

Cited by 638 publications

References 31 publications

Root-Secreted Malic Acid Recruits Beneficial Soil Bacteria

Root-Secreted Malic Acid Recruits Beneficial Soil Bacteria

Structurally diverse natural products that cause potassium leakage trigger multicellularity in Bacillus subtilis

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

Contact Info

Product

Resources

About