scholarly journals Azorhizobium caulinodans Transmembrane Chemoreceptor TlpA1 Involved in Host Colonization and Nodulation on Roots and Stems

2017 ◽  
Vol 8 ◽  
Author(s):  
Wei Liu ◽  
Jinbao Yang ◽  
Yu Sun ◽  
Xiaolin Liu ◽  
Yan Li ◽  
...  
Keyword(s):  
Azorhizobium Caulinodans ◽  
Host Colonization

scholarly journals Effects of Calcium and Signal Sensing Systems on Azorhizobium caulinodans Biofilm Formation and Host Colonization

2020 ◽  
Vol 11 ◽  
Author(s):  
Xiaolin Liu ◽  
Kaiye Zhang ◽  
Yanan Liu ◽  
Desheng Zou ◽  
Dandan Wang ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Azorhizobium Caulinodans ◽  
Host Colonization ◽  
Sensing Systems

scholarly journals FixJ family regulator AcfR of Azorhizobium caulinodans is involved in symbiosis with the host plant

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Wei Liu ◽  
Xue Bai ◽  
Yan Li ◽  
Haikun Zhang ◽  
Xiaoke Hu
Keyword(s):  
Signal Transduction ◽  
Host Plant ◽  
Type Strain ◽  
Wild Type Strain ◽  
Response Regulator ◽  
Azorhizobium Caulinodans ◽  
Wild Type ◽  
Response Regulators ◽  
Free Living ◽  
Two Component

Abstract Background A wide variety of bacterial adaptative responses to environmental conditions are mediated by signal transduction pathways. Two-component signal transduction systems are one of the predominant means used by bacteria to sense the signals of the host plant and adjust their interaction behaviour. A total of seven open reading frames have been identified as putative two-component response regulators in the gram-negative nitrogen-fixing bacteria Azorhizobium caulinodans ORS571. However, the biological functions of these response regulators in the symbiotic interactions between A. caulinodans ORS571 and the host plant Sesbania rostrata have not been elucidated to date. Results In this study, we identified and investigated a two-component response regulator, AcfR, with a phosphorylatable N-terminal REC (receiver) domain and a C-terminal HTH (helix-turn-helix) LuxR DNA-binding domain in A. caulinodans ORS571. Phylogenetic analysis showed that AcfR possessed close evolutionary relationships with NarL/FixJ family regulators. In addition, six histidine kinases containing HATPase_c and HisKA domains were predicted to interact with AcfR. Furthermore, the biological function of AcfR in free-living and symbiotic conditions was elucidated by comparing the wild-type strain and the ΔacfR mutant strain. In the free-living state, the cell motility behaviour and exopolysaccharide production of the ΔacfR mutant were significantly reduced compared to those of the wild-type strain. In the symbiotic state, the ΔacfR mutant showed a competitive nodule defect on the stems and roots of the host plant, suggesting that AcfR can provide A. caulinodans with an effective competitive ability for symbiotic nodulation. Conclusions Our results showed that AcfR, as a response regulator, regulates numerous phenotypes of A. caulinodans under the free-living conditions and in symbiosis with the host plant. The results of this study help to elucidate the involvement of a REC + HTH_LuxR two-component response regulator in the Rhizobium-host plant interaction.

scholarly journals Host modification of a bacterial quorum-sensing signal induces a phenotypic switch in bacterial symbionts

2017 ◽  
Vol 114 (40) ◽  
pp. E8488-E8497 ◽  
Author(s):  
Cleo Pietschke ◽  
Christian Treitz ◽  
Sylvain Forêt ◽  
Annika Schultze ◽  
Sven Künzel ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Bacterial Communities ◽  
Homoserine Lactone ◽  
Innate Immune ◽  
Expression Data ◽  
Phenotypic Switch ◽  
Host Colonization ◽  
Bacterial Quorum Sensing ◽  
Bacterial Quorum ◽  
Quorum Sensing Signals

Bacterial communities colonize epithelial surfaces of most animals. Several factors, including the innate immune system, mucus composition, and diet, have been identified as determinants of host-associated bacterial communities. Here we show that the early branching metazoan Hydra is able to modify bacterial quorum-sensing signals. We identified a eukaryotic mechanism that enables Hydra to specifically modify long-chain 3-oxo-homoserine lactones into their 3-hydroxy-HSL counterparts. Expression data revealed that Hydra’s main bacterial colonizer, Curvibacter sp., responds differentially to N-(3-hydroxydodecanoyl)-l-homoserine lactone (3OHC12-HSL) and N-(3-oxododecanoyl)-l-homoserine lactone (3OC12-HSL). Investigating the impacts of the different N-acyl-HSLs on host colonization elucidated that 3OHC12-HSL allows and 3OC12-HSL represses host colonization of Curvibacter sp. These results show that an animal manipulates bacterial quorum-sensing signals and that this modification leads to a phenotypic switch in the bacterial colonizers. This mechanism may enable the host to manipulate the gene expression and thereby the behavior of its bacterial colonizers.

scholarly journals Pseudomonas aeruginosa PA14 biofilms produce R-bodies, extendable protein polymers with roles in host colonization and virulence

2020 ◽  
Author(s):  
Bryan Wang ◽  
Yu-Cheng Lin ◽  
Jeanyoung Jo ◽  
Alexa Price-Whelan ◽  
Shujuan Tao McDonald ◽  
...  
Keyword(s):  
Gene Expression ◽  
Pseudomonas Aeruginosa ◽  
Host Colonization ◽  
Biofilm Growth ◽  
Protein Polymers ◽  
Virulent Strains

reb genes code for R-bodies: large, extendable polymers that are known for their roles in obligate endosymbioses. In the non-endosymbiotic pathogen Pseudomonas aeruginosa, reb homologues are part of a cluster found in virulent strains. Here, we demonstrate that R-bodies are produced in abundance by P. aeruginosa PA14 subpopulations during biofilm growth, identify regulators of reb gene expression, and show that reb genes are required for full colonization and virulence in host models.

scholarly journals COLONIZATION of Rubus glaucus BENTH BY AZORHIZOBIUM CAULINODANS ORS571 USIG A FLAVONOIDE NARINGENINA

2016 ◽  
Vol 14 (2) ◽  
pp. 15
Author(s):  
Giovani Orlando Cancino Escalante ◽  
S E Cancino ◽  
Enrique Quevedo Garcia
Keyword(s):  
Bacterial Colonization ◽  
Lateral Roots ◽  
Plant Growth Promoting Bacteria ◽  
Azorhizobium Caulinodans ◽  
Intensity Parameters ◽  
Plant Growth Promoting ◽  
Measuring Frequency ◽  
Northwest Region ◽  
Azorhizobium Caulinodans Ors571

Root systems of two Andean blackberry materials (thorn and thornless) of Rubus glaucus Benth cultured in vitro in the presence of five treatments (four flavonoids and one control) were inoculated with Azorhizobium caulinodans ORS571 (pXLGD4)  (a strain carrying the lacZ reporter gene which facilitated the detection of bacterial colonization). Evaluation of colonization effectiveness for each treatment was done by means of application of experimental design measuring frequency and intensity parameters. Statistical analysis showed differences at comparing flavonoids vs. control and the overall higher effectiveness of the flavonoid naringenin. Observation of colonization was made by light and electron microscope confirming internal colonization of Andean blackberry roots by A. caulinodans. This is the first work demonstrating root colonization of R.glaucus by azorhizobia and therefore settling the basis for future investigations and scientific applications related to interaction with plant growth-promoting bacteria under the effect of flavonoids, along with possible implications of common benefit for non-legume crops in the northwest region of Colombia.  Key Words: Azorhizobium caulinodans ORS571, Andean blackberry, flavonoids, LacZ, lateral roots, naringenin. 

scholarly journals A Combination of Structural, Genetic, Phenotypic and Enzymatic Analyses Reveals the Importance of a Predicted Fucosyltransferase to Protein O-Glycosylation in the Bacteroidetes

Biomolecules ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1795
Author(s):  
Markus B. Tomek ◽  
Bettina Janesch ◽  
Matthias L. Braun ◽  
Manfred Taschner ◽  
Rudolf Figl ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Mutational Analysis ◽  
Bacteroides Fragilis ◽  
Host Colonization ◽  
Acceptor Specificity ◽  
Hexose Sugars ◽  
Full Structure ◽  
Bacteroidetes Phylum ◽  
General Protein

Diverse members of the Bacteroidetes phylum have general protein O-glycosylation systems that are essential for processes such as host colonization and pathogenesis. Here, we analyzed the function of a putative fucosyltransferase (FucT) family that is widely encoded in Bacteroidetes protein O-glycosylation genetic loci. We studied the FucT orthologs of three Bacteroidetes species—Tannerella forsythia, Bacteroides fragilis, and Pedobacter heparinus. To identify the linkage created by the FucT of B. fragilis, we elucidated the full structure of its nine-sugar O-glycan and found that l-fucose is linked β1,4 to glucose. Of the two fucose residues in the T. forsythia O-glycan, the fucose linked to the reducing-end galactose was shown by mutational analysis to be l-fucose. Despite the transfer of l-fucose to distinct hexose sugars in the B. fragilis and T. forsythia O-glycans, the FucT orthologs from B. fragilis, T. forsythia, and P. heparinus each cross-complement the B. fragilis ΔBF4306 and T. forsythia ΔTanf_01305 FucT mutants. In vitro enzymatic analyses showed relaxed acceptor specificity of the three enzymes, transferring l-fucose to various pNP-α-hexoses. Further, glycan structural analysis together with fucosidase assays indicated that the T. forsythia FucT links l-fucose α1,6 to galactose. Given the biological importance of fucosylated carbohydrates, these FucTs are promising candidates for synthetic glycobiology.

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