Identification and analysis of a siderophore biosynthetic gene cluster from Agrobacterium tumefaciens C58

Rondon, Michelle R.; Ballering, Katie S.; Thomas, Michael G.

doi:10.1099/mic.0.27319-0

Cited by 50 publications

(47 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One mechanism that bacteria use to regulate siderophore production is by controlling expression of the siderophore production genes via an extracytoplasmic function (ECF) factor (39,67). The siderophore produced by A. tumefaciens (a polyketide/nonribosomal peptide molecule encoded by a large gene cluster of almost 53 kb) is controlled by such a factor, which we have designated I (54). The expression of sigI is regulated by RirA and indirectly by Irr through its control of rirA expression, thus tightly linking siderophore production to iron availability (Fig.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Antiparallel and Interlinked Control of Cellular Iron Levels by the Irr and RirA Regulators of Agrobacterium tumefaciens

Hibbing

Fuqua

2011

J Bacteriol

View full text Add to dashboard Cite

The plant pathogen Agrobacterium tumefaciens encodes predicted iron-responsive regulators, Irr and RirA, that function in several other bacteria to control the response to environmental iron levels. Deletion mutations of irr and rirA, alone and in combination, were evaluated for their impact on cellular iron response. Growth was severely diminished in the ⌬irr mutant under iron-limiting conditions, but reversed to wild-type levels in an ⌬irr ⌬rirA mutant. The level of uncomplexed iron in the ⌬irr mutant was decreased, whereas the ⌬rirA mutant exhibited elevated iron levels. Sensitivity of the ⌬irr and ⌬rirA mutants to iron-activated antimicrobial compounds generally reflected their uncomplexed-iron levels. Expression of genes that encode iron uptake systems was decreased in the ⌬irr mutant, whereas that of iron utilization genes was increased. Irr function required a trihistidine repeat likely to mediate interactions with heme. Iron uptake genes were derepressed in the ⌬rirA mutant. In the ⌬irr ⌬rirA mutant, iron uptake and utilization genes were derepressed, roughly combining the phenotypes of the single mutants. Siderophore production was elevated in the rirA mutant, but most strongly regulated by an RirA-controlled sigma factor. Expression of rirA itself was regulated by Irr, RirA, and iron availability, in contrast to irr expression, which was relatively stable in the different mutants. These studies suggest that in A. tumefaciens, the Irr protein is most active under low-iron conditions, inhibiting iron utilization and activating iron acquisition, while the RirA protein is active under high-iron conditions, repressing iron uptake.

show abstract

Section: Discussionmentioning

confidence: 99%

“…tumefaciens encodes homologues of fur, rirA, and irr, as well as a large cluster of genes that directs the synthesis of a siderophore (20,54,72). The A. tumefaciens fur homologue is reported to primarily regulate manganese uptake and plays only a minor role in response to iron levels (33,53).…”

mentioning

confidence: 99%

Antiparallel and Interlinked Control of Cellular Iron Levels by the Irr and RirA Regulators of Agrobacterium tumefaciens

Hibbing

Fuqua

2011

J Bacteriol

View full text Add to dashboard Cite

show abstract

“…syringae B301D, a pathogen of stone fruit trees such as wet cherry (Prunus avium L.), does not require Pvd for virulence on immature sweet cherry fruits (19). Similarly, virulence of Agrobacterium tumefaciens B6 and C58 strains, which cause crown gall disease, was not significantly compromised by the inability to produce either agrobactin (47) or an uncharacterized high-affinity siderophore (65). There are a number of possible reasons for the lack of virulence phenotype for these siderophore mutant strains, including the compensatory action of another high-affinity siderophore and/or the plant growth environment or particulars of the infection assay.…”

mentioning

confidence: 95%

Salicylic Acid, Yersiniabactin, and Pyoverdin Production by the Model PhytopathogenPseudomonas syringaepv. tomato DC3000: Synthesis, Regulation, and Impact on Tomato andArabidopsisHost Plants

2007

View full text Add to dashboard Cite

A genetically tractable model plant pathosystem, Pseudomonas syringae pv. tomato DC3000 on tomato and Arabidopsis thaliana hosts, was used to investigate the role of salicylic acid (SA) and iron acquisition via siderophores in bacterial virulence. Pathogen-induced SA accumulation mediates defense in these plants, and DC3000 contains the genes required for the synthesis of SA, the SA-incorporated siderophore yersiniabactin (Ybt), and the fluorescent siderophore pyoverdin (Pvd). We found that DC3000 synthesizes SA, Ybt, and Pvd under iron-limiting conditions in culture. Synthesis of SA and Ybt by DC3000 requires pchA, an isochorismate synthase gene in the Ybt genomic cluster, and exogenous SA can restore Ybt production by the pchA mutant. Ybt was also produced by DC3000 in planta, suggesting that Ybt plays a role in DC3000 pathogenesis. However, the pchA mutant did not exhibit any growth defect or altered virulence in plants. This lack of phenotype was not attributable to plant-produced SA restoring Ybt production, as the pchA mutant grew similarly to DC3000 in an Arabidopsis SA biosynthetic mutant, and in planta Ybt was not detected in pchA-infected wild-type plants. In culture, no growth defect was observed for the pchA mutant versus DC3000 for any condition tested. Instead, enhanced growth of the pchA mutant was observed under stringent iron limitation and additional stresses. This suggests that SA and Ybt production by DC3000 is costly and that Pvd is sufficient for iron acquisition. Further exploration of the comparative synthesis and utility of Ybt versus Pvd production by DC3000 found siderophore-dependent amplification of ybt gene expression to be absent, suggesting that Ybt may play a yet unknown role in DC3000 pathogenesis.

show abstract

“…For instance, siderophore-deficient mutants of Erwinia amylovora, E. chrysanthemi strain 3937, Erwinia carotovora subsp. carotovora, Ralstonia solanacearum and Agrobacterium tumefaciens are virulence deficient on its host plants (Dellagi et al, 1998;Franza et al, 2005;Bhatt and Denny, 2004;Bull et al, 1996;Rondon et al, 2004). However, P. syringae pv.…”

Section: Introductionmentioning

confidence: 99%

Hemin transported protein of Xanthomonas axonopodis pv. glycines functions on leaf colonization and virulence on soybean

Prathuangwong¹,

Athinuwat²,

Chuaboon³

et al. 2013

Afr. J. Microbiol. Res.

View full text Add to dashboard Cite

Xanthomonas axonopodis pv. glycines (Xag) causes bacterial pustule disease on soybean. This bacterium is present worldwide around hot and humid growing regions such as Southeast Asia. To understand if the gene coding for hemin transport protein (hem) is involved in virulence of the pathogen in soybean, we generated a hem mutant in Xag by overlapping PCR mutagenesis. Disruption of hem significantly reduced the population size and the disease incidence when sprayed on soybean but not when injected directly to soybean. The hem mutant caused the hypersensitive response induction on tobacco as an Xag wildtype. Interestingly, the hem expression was also reduced when the Xag wildtype grow in planta. The hemin transporter protein involved in the production of extracellular polysaccharide, biofilm formation, motility and attachment but not for extracellular enzymes. This confirmed that epiphytic fitness of Xag strongly required hem functions. These results suggest that hem gene is essential for virulence of Xag on soybean during the infection process.

show abstract

Identification and analysis of a siderophore biosynthetic gene cluster from Agrobacterium tumefaciens C58

Cited by 50 publications

References 49 publications

Antiparallel and Interlinked Control of Cellular Iron Levels by the Irr and RirA Regulators of Agrobacterium tumefaciens

Antiparallel and Interlinked Control of Cellular Iron Levels by the Irr and RirA Regulators of Agrobacterium tumefaciens

Salicylic Acid, Yersiniabactin, and Pyoverdin Production by the Model PhytopathogenPseudomonas syringaepv. tomato DC3000: Synthesis, Regulation, and Impact on Tomato andArabidopsisHost Plants

Hemin transported protein of Xanthomonas axonopodis pv. glycines functions on leaf colonization and virulence on soybean

Contact Info

Product

Resources

About