scholarly journals BDSF is a degradation-prone quorum-sensing signal detected by the histidine kinase RpfC of Xanthomonas campestris pv. campestris

2022 ◽  
Author(s):  
Xiu-Qi Tian ◽  
Yao Wu ◽  
Zhen Cai ◽  
Wei Qian
Keyword(s):  
Quorum Sensing ◽  
Histidine Kinase ◽  
Xanthomonas Campestris ◽  
Bacterial Species ◽  
Life Stage ◽  
Structural Analog ◽  
Fatty Acyl ◽  
Coa Ligase ◽  
Bacterial Quorum

Diffusible signal factors (DSFs) are medium-chain fatty acids that induce bacterial quorum sensing. Among these compounds, BDSF is a structural analog of DSF that is commonly detected in bacterial species (e.g., Xanthomonas, Pseudomonas, and Burkholderia). Additionally, BDSF contributes to the interkingdom communication regulating fungal life stage transitions. How BDSF is sensed in Xanthomonas spp. and the functional diversity between BDSF and DSF remain unclear. In this study, we generated genetic and biochemical evidence that BDSF is a low-active regulator of X. campestris pv. campestris quorum sensing, whereas trans-BDSF seems not a signaling compound. BDSF is detected by the sensor histidine kinase RpfC. Although BDSF has relatively low physiological activities, it binds to the RpfC sensor with a high affinity and activates RpfC autophosphorylation to a level that is similar to that induced by DSF in vitro. The inconsistency in the physiological and biochemical activities of BDSF is not due to RpfC–RpfG phosphorylation or RpfG hydrolase. Neither BDSF nor DSF controls the phosphotransferase and phosphatase activities of RpfC or the ability of RpfG hydrolase to degrade the bacterial second messenger cyclic di-GMP. We demonstrated that BDSF is prone to degradation by RpfB, a critical fatty acyl-CoA ligase involved in the turnover of DSF-family signals. rpfB mutations lead to substantial increases in BDSF-induced quorum sensing. Although DSF and BDSF are similarly detected by RpfC, our data suggest that their differential degradation in cells is the major factor responsible for the diversity in their physiological effects.

scholarly journals Multiple regulation mechanisms of bacterial quorum sensing

BIOMATH ◽  
2016 ◽  
Vol 5 (1) ◽  
pp. 1607291 ◽  
Author(s):  
Peter Kumberger ◽  
Christina Kuttler ◽  
Peter Czuppon ◽  
Burkhard A. Hense
Keyword(s):  
Quorum Sensing ◽  
Bacterial Species ◽  
Regulatory System ◽  
Interaction Patterns ◽  
Gene Regulatory System ◽  
Bacterial Quorum Sensing ◽  
Regulation Mechanisms ◽  
Bacterial Quorum ◽  
Evolutionary Consequences ◽  
Biological Outcomes

Many bacteria have developed a possibility to recognise aspects of their environment or to communicate with each other by chemical signals. The so-called Quorum sensing (QS) is a special case of this kind of communication. Such an extracellular signalling via small diffusible compounds (called autoinducers) is known for many bacterial species, including pathogenic and beneficial bacteria. Using this mechanism allows them to regulate their behaviour, e.g. virulence. We will focus on the typical QS system of Gram negative bacteria of the so-called lux type, based on a gene regulatory system with a positive feedback loop. There is increasing evidence that autoinducer systems themselves are controlled by various factors, often reflecting the cells’ nutrient or stress state. We model and analyse three possible interaction patterns. Typical aspects are e.g. the range of bistability, the activation threshold and the long term behaviour. Additionally, we aim towards understanding the differences with respect to the biological outcomes and estimating potential ecological or evolutionary consequences, respectively.

scholarly journals Identification of the functions of 4-coumarate-CoA ligase/ acyl-CoA synthetase paralogs in potato

2021 ◽  
Author(s):  
Matías Ariel Valiñas ◽  
Arjen ten Have ◽  
Adriana Balbina Andreu
Keyword(s):  
3D Structure ◽  
Class Ii ◽  
Fatty Acyl ◽  
Protein Family ◽  
Class I ◽  
Marker Genes ◽  
Coa Ligase ◽  
Coa Transferase ◽  
Binding Cleft

Background: The 4CL/ ACS protein family is well known for its 4-coumarate-CoA ligase (4CL) enzymes but there are many aspects of this family that are still unclear or generally known. Cytosolic class I and class II 4CL enzymes control the biosynthesis of lignin/ suberin and flavonoids, respectively. Many 4CL homologs have broad substrate permissiveness in vitro and have no clear cut function. However, it has been demonstrated unequivocally that a peroxisomal 4CL-like homolog from Arabidopsis efficiently uses p-coumarate for ubiquinone biosynthesis. Another homolog has been shown to act as a fatty acyl-CoA synthetase and yet another as OPDA-CoA ligase. Hence, despite this knowledge, most homologs remain annotated as 4CL-like whereas other researches study the ACS protein family. Results: We set out identify the specific functions of 4CL/ ACS homologs, specifically in order to study the 4CL family in Solanum tuberosum. An in depth phylogenetic analysis was done. Using clustering techniques, functional annotation and taxonomic signals, three major clades were depicted. Clade 1 is composed of class I from monocotyledons, class I from dicotyledons and class II canonical 4CL enzymes subclades. Specificity determining positions and 3D structure analysis shows that clade 2 cytosolic 4CL-like enzymes show a rather different binding cleft and presumably use medium- to long-chain fatty acids. Clade 3 is composed of five subclades, four of which have a broad taxonomic contribution and a similar binding cleft as 4CLs whereas a fifth, specific for dicotyledons shows a significantly different binding pocket. The potato 4CL family comprises four class I (St4CL-I(A-D)) and one class II (St4CL-II) members. Transcript levels of St4CLs and of marker genes of the flavonoid (chalcone synthase, CHS) and suberin (feruloyl-CoA transferase, FHT) pathways were determined by qRT-PCR in flesh and skin from Andean varieties. St4CL-IA was barely detected in the skin of some varieties whereas St4CL-IB did not show a clear pattern. St4CL-IC and St4CL-ID could not be detected. St4CL-II expression pattern was similar to CHS. St4CL-IA and St4CL-IB were induced by wounding as did FHT whereas St4CL-II and CHS expression was repressed. Constitutive and wound-induced expression suggests that St4CL-IA and St4CL-IB isoforms are likely involved in soluble and/ or suberin-bound phenolic compounds while St4CL-II appears to be involved in flavonoid biosynthesis.

scholarly journals Shiitake Mycelial Leachate Suppresses Growth of Some Bacterial Species and Symptoms of Bacterial Wilt of Tomato and Lima Bean in vitro

Plant Disease ◽  
1999 ◽  
Vol 83 (1) ◽  
pp. 20-23 ◽  
Author(s):  
R. P. Pacumbaba ◽  
Caula A. Beyl ◽  
R. O. Pacumbaba
Keyword(s):  
Pseudomonas Syringae ◽  
Bacterial Wilt ◽  
Xanthomonas Campestris ◽  
Erwinia Amylovora ◽  
Bacterial Species ◽  
Lima Bean ◽  
Symptom Expression ◽  
Shiitake Mushroom ◽  
And Staphylococcus Aureus

Mycelial leachate of shiitake mushroom inhibited growth of Pseudomonas syringae pv. glycinea, P. syringae pv. tabaci, Xanthomonas campestris pv. glycines, X. campestris pv. campestris, Erwinia amylovora, Ralstonia solanacearum, Curtobacterium flaccumfaciens pv. flaccumfaciens, Bacillus cereus, Escherichia coli, Listeria monocytogenes, Salmonella typhimurium, and Staphylococcus aureus. The mycelial leachate applied as soil drench prevented symptom expression of bacterial wilt of tomato and lima bean in the laboratory. The results suggested that the shiitake mycelia leachate contained an antibiotic ingredient.

scholarly journals Rapid Screening of Quorum-Sensing Signal N-Acyl Homoserine Lactones by an In Vitro Cell-Free Assay

2008 ◽  
Vol 74 (12) ◽  
pp. 3667-3671 ◽  
Author(s):  
Tomohiro Kawaguchi ◽  
Yung Pin Chen ◽  
R. Sean Norman ◽  
Alan W. Decho
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Quorum Sensing ◽  
High Sensitivity ◽  
Homoserine Lactone ◽  
Assay System ◽  
Rapid Screening ◽  
Whole Cell ◽  
Bacterial Quorum ◽  
Whole Cell Biosensor

ABSTRACT A simple, sensitive, and rapid cell-free assay system was developed for detection of N-acyl homoserine lactone (AHL) autoinducers involved in bacterial quorum sensing (QS). The present approach improves upon previous whole-cell biosensor-based approaches in its utilization of a cell-free assay approach to conduct bioassays. The cell-free assay was derived from the AHL biosensor bacterium Agrobacterium tumefaciens NTL4(pCF218)(pCF372), allowing the expression of β-galactosidase upon addition of exogenous AHLs. We have shown that β-galactosidase expression is possible in cell-free solution [lysate from Agrobacterium tumefaciens NTL4(pCF218)(pCF372) culture]. Assay detection limits with the use of chromogenic substrate X-Gal (5-bromo-4-chloro-3-indolyl-β-d-galactopyranoside) ranged from approximately 100 nM to 300 nM depending on the specific AHL. Replacement (of X-Gal) with the luminescent substrate Beta-Glo increased sensitivity to AHLs by 10-fold. A major advantage of the cell-free assay system is elimination of time-consuming steps for biosensor cell culture conditioning, which are required prior to whole-cell bioassays. This significantly reduced assay times from greater than 24 h to less than 3 h, while maintaining high sensitivity. Assay lysate may be prepared in bulk and stored (−80°C) over 6 months for future use. Finally, the present protocol may be adapted for use with other biosensor strains and be used in high-throughput AHL screening of bacteria or metagenomic libraries.

scholarly journals SMb20651 is another acyl carrier protein from Sinorhizobium meliloti

Microbiology ◽  
2009 ◽  
Vol 155 (1) ◽  
pp. 257-267 ◽  
Author(s):  
Ana Laura Ramos-Vega ◽  
Yadira Dávila-Martínez ◽  
Christian Sohlenkamp ◽  
Sandra Contreras-Martínez ◽  
Sergio Encarnación ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Sinorhizobium Meliloti ◽  
Fatty Acid Biosynthesis ◽  
Acyl Carrier Protein ◽  
Fatty Acyl ◽  
Acyl Carrier Proteins ◽  
Coa Ligase ◽  
Acyl Chains

Acyl carrier proteins (ACPs) are small acidic proteins that carry growing acyl chains during fatty acid or polyketide synthesis. In rhizobia, there are four different and well-characterized ACPs: AcpP, NodF, AcpXL and RkpF. The genome sequence of Sinorhizobium meliloti 1021 reveals two additional ORFs that possibly encode additional ACPs. One of these, smb20651, is located on the plasmid pSymB as part of an operon. The genes of the operon encode a putative asparagine synthetase (AsnB), the predicted ACP (SMb20651), a putative long-chain fatty acyl-CoA ligase (SMb20650) and a putative ammonium-dependent NAD+ synthetase (NadE1). When SMb20651 was overexpressed in Escherichia coli, [3H]β-alanine, a biosynthetic building block of 4′-phosphopantetheine, was incorporated into the protein in vivo. The purified SMb20651 was modified with 4′-phosphopantetheine in the presence of S. meliloti holo-ACP synthase (AcpS). Also, holo-SMb20651 was modified in vitro with a malonyl group by malonyl CoA-ACP transacylase. In E. coli, coexpression of SMb20651 together with other proteins such as AcpS and SMb20650 led to the formation of additional forms of SMb20651. In this bacterium, acylation of SMb20651 with C12 : 0 or C18 : 0 fatty acids was detected, demonstrating that this protein is involved in fatty acid biosynthesis or transfer. Expression of SMb20651 was detected in S. meliloti as holo-SMb20651 and acyl-SMb20651.

scholarly journals Priming winter wheat seeds with the bacterial quorum sensing signal N-hexanoyl-L-homoserine lactone (C6-HSL) shows potential to improve plant growth and seed yield

2018 ◽  
Author(s):  
Olena Moshynets ◽  
Lidia M. Babenko ◽  
Sergiy P. Rogalsky ◽  
Olga S. Iungin ◽  
Jessica Foster ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Winter Wheat ◽  
Seed Priming ◽  
Homoserine Lactone ◽  
Field Trials ◽  
Growth And Yield ◽  
Cereal Crop ◽  
Bacterial Quorum Sensing ◽  
Bacterial Quorum

Several model plants are known to respond to bacterial quorum sensing molecules with altered root growth and gene expression patterns and induced resistance to plant pathogens. These compounds may represent novel elicitors that could be applied as seed primers to enhance cereal crop resistance to pathogens and abiotic stress and to improve yields. We investigated whether the acyl-homoserine lactone N-hexanoyl-L-homoserine lactone (C6-HSL) impacted winter wheat (Triticum aestivum L.) seed germination, plant development and productivity, using two Ukrainian varieties, Volodarka and Yatran 60, in both in vitro experiments and field trials. In vitro germination experiments indicated that C6-HSL seed priming had a small but significant positive impact on germination levels (1.2x increase, p < 0.0001), coleoptile and radicle development (1.4x increase, p < 0.0001). Field trials over two growing seasons (2015-16 and 2016-17) also demonstrated significant improvements in biomass at the tillering stage (1.4x increase, p < 0.0001), and crop structure and productivity at maturity including grain yield (1.4 – 1.5x increase, p < 0.0007) and quality (1.3x increase in good grain, p < 0.0001). In some cases variety effects were observed (p ≤ 0.05) suggesting that the effect of C6-HSL seed priming might depend on plant genetics, and some benefits of priming were also evident in F1 plants grown from seeds collected the previous season (p ≤ 0.05). These field-scale findings suggest that bacterial acyl-homoserine lactones such as C6-HSL could be used to improve cereal crop growth and yield and reduce reliance on fungicides and fertilisers to combat pathogens and stress.

scholarly journals In Vitro, Controlling the Establishment of Xanthomonas Campestris with different Bacterial Bioagents

2016 ◽  
Vol 29 (1) ◽  
pp. 37-40
Author(s):  
Amna Ali ◽  
M Saleem Haider ◽  
Sobia Mushtaq ◽  
Ibatsam Khokhar ◽  
Irum Mukhtar ◽  
...  
Keyword(s):  
Xanthomonas Campestris ◽  
Fruits And Vegetables ◽  
Antimicrobial Agents ◽  
Bacterial Species ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Diffusion Technique

The antimicrobial agents of bacteria isolated from different rhizosphere of fruits and vegetables soil in Lahore. Of ten species, five were gram-negative (Escherichia coli, Pseudomonas fluorescence, Klebsiella pneumoniae, Salmonella typhii, Brachybacterium faecium); other five were gram positive and identified as Bacillus farraginis, Kurthia gibsonii, Aureobacterium liquefaciens, Curtobacterium albidum, Micrococcus lylae. The antagonistic potential of bacterial strains was assessed by the well diffusion technique and results indicating varying degree of biocontrol activity against pathogenic strain of X. campestris. Out of ten bacterial species, E. coli (gram negative) and C. albidum (gram positive) showed a high prevalence of resistance with reduction of 4.2cm and 4.1cm zone diameter respectively. The minimum inhibitory volume (MIV) to two bio-agents was determined for X. campestris from range 10-100 ?L. E. coli (volume required to inhibit < 20 ?L) and C. albidum (volume required to inhibit < 40 ?L) exhibited good activity against pathogen. These results provide information on the prevalence of resistant bacterial strains with the MIV of organisms and indicate the possibility of using these bacterial species as bio-agent against X. campestris.Bangladesh J Microbiol, Volume 29, Number 1, June 2012, pp 37-40

scholarly journals The bacterial quorum sensing signal DSF hijacks Arabidopsis thaliana sterol biosynthesis to suppress plant innate immunity

2020 ◽  
Vol 3 (10) ◽  
pp. e202000720
Author(s):  
Tuan Minh Tran ◽  
Zhiming Ma ◽  
Alexander Triebl ◽  
Sangeeta Nath ◽  
Yingying Cheng ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Arabidopsis Thaliana ◽  
Plasma Membrane ◽  
Quorum Sensing ◽  
Xanthomonas Campestris ◽  
Pathogenic Bacteria ◽  
Specific Effect ◽  
Molecular Pattern ◽  
Pathogen Associated Molecular Pattern ◽  
Bacterial Quorum

Quorum sensing (QS) is a recognized phenomenon that is crucial for regulating population-related behaviors in bacteria. However, the direct specific effect of QS molecules on host biology is largely understudied. In this work, we show that the QS molecule DSF (cis-11-methyl-dodecenoic acid) produced by Xanthomonas campestris pv. campestris can suppress pathogen-associated molecular pattern–triggered immunity (PTI) in Arabidopsis thaliana, mediated by flagellin-induced activation of flagellin receptor FLS2. The DSF-mediated attenuation of innate immunity results from the alteration of FLS2 nanoclusters and endocytic internalization of plasma membrane FLS2. DSF altered the lipid profile of Arabidopsis, with a particular increase in the phytosterol species, which impairs the general endocytosis pathway mediated by clathrin and FLS2 nano-clustering on the plasma membrane. The DSF effect on receptor dynamics and host immune responses could be entirely reversed by sterol removal. Together, our results highlighted the importance of sterol homeostasis to plasma membrane organization and demonstrate a novel mechanism by which pathogenic bacteria use their communicating molecule to manipulate pathogen-associated molecular pattern–triggered host immunity.

Sign in / Sign up

Export Citation Format

Share Document