The antagonistic effect of 2-phenylethanol produced by strain JS-239 against .

is a necrotrophic fungal pathogen responsible for gray mold diseases in economically significant crops. Although conventional fungicides are commonly used to control these diseases, they pose environmental hazards, such as soil and water contamination, harm to non-target organisms, and ecosystem disruption. Additionally, overuse promotes the development of fungicide-resistant strains, reducing their efficacy.

A novel transcriptional regulator, CdeR, modulates the type III secretion system via c-di-GMP signaling in .

is a bacterial pathogen that causes soft rot disease in many plant species worldwide, including temperate, subtropical, and tropical regions. This bacterium employs the type III secretion system (T3SS) to manipulate host immune responses. Although cyclic-di-GMP (c-di-GMP), a ubiquitous bacterial second messenger, negatively regulates the expression of T3SS genes in , the underlying mechanism remains unclear.

Dissecting the molecular dance: c-di-GMP, cAMP-CRP, and VfmH collaboration in pectate lyase regulation for -unveiling the soft rot pathogen's strategy.

Bacteria respond to environmental changes and adapt to host systems. The response regulator VfmH of the Vfm quorum sensing system regulates a crucial virulence factor, pectate lyase (Pel), in . At high c-di-GMP concentrations, VfmH binds c-di-GMP, resulting in the loss of its activation property in the Pel and virulence regulation in .

Type III Secretion System Inhibitors Reduce Fire Blight Infection Under Field Conditions.

Fire blight, caused by , is an economically important disease in apples and pears worldwide. This pathogen relies on the type III secretion system (T3SS) to cause disease. Compounds that inhibit the function of the T3SS (T3SS inhibitors) have emerged as alternative strategies for bacterial plant disease management, as they block bacterial virulence without affecting growth, unlike traditional antibiotics.

from the Fire Blight Biocontrol Product, Blossom Protect, Induces Host Resistance in Apple Flowers.

Fire blight, caused by , is a devastating disease of apple. Blossom Protect, a product that contains as the active ingredient, is one of the most effective biological controls of fire blight. It has been postulated that the mode of action of is to compete against and antagonize epiphytic growth of on flowers, but recent studies have found that flowers treated with Blossom Protect harbored similar to or only slightly reduced populations compared with nontreated flowers.

Potential reservoirs of antimicrobial resistance in livestock waste and treated wastewater that can be disseminated to agricultural land.

Livestock manure, dairy lagoon effluent, and treated wastewater are known reservoirs of antibiotic resistance genes (ARGs), antibiotic-resistant bacteria (ARB), and virulence factor genes (VFGs), and their application to agricultural farmland could be a serious public health threat. However, their dissemination to agricultural lands and impact on important geochemical pathways such as the nitrogen (N) cycle have not been jointly explored. In this study, shotgun metagenomic sequencing and analyses were performed to examine the diversity and composition of microbial communities, ARGs, VFGs, and N cycling genes in different livestock manure/lagoon and treated wastewater collected from concentrated animal feeding operations (CAFOs) and a municipal wastewater treatment plant along the west coast of the United States.

Genetic and Environmental Investigation of a Novel Phenylamino Acetamide Inhibitor of the Pseudomonas aeruginosa Type III Secretion System.

Traditional antibiotics target essential cellular components or metabolic pathways conserved in both pathogenic and nonpathogenic bacteria. Unfortunately, long-term antibiotic use often leads to antibiotic resistance and disruption of the overall microbiota. In this work, we identified a phenylamino acetamide compound, named 187R, that strongly inhibited the expression of the type III secretion system (T3SS) encoding genes and the secretion of the T3SS effector proteins in Pseudomonas aeruginosa.

The phytopathogen Dickeya dadantii 3937 cpxR locus gene participates in the regulation of virulence and the global c-di-GMP network.

Bacteria use signal transduction systems to sense and respond to their external environment. The two-component system CpxA/CpxR senses misfolded envelope protein stress and responds by up-regulating envelope protein factors and down-regulating virulence factors in several animal pathogens. Dickeya dadantii is a phytopathogen equipped with a type III secretion system (T3SS) for manipulating the host immune response.

Quorum-Sensing Master Regulator VfmE Is a c-di-GMP Effector That Controls Pectate Lyase Production in the Phytopathogen Dickeya dadantii.

Dickeya dadantii is a phytopathogenic bacterium that causes diseases on a wide range of host plants. The pathogen secretes pectate lyases (Pel) through the type II secretion system (T2SS) that degrades the cell wall in host plants. The virulence of is controlled by the second messenger cyclic diguanylate monophosphate (c-di-GMP), and the homeostasis of c-di-GMP is maintained by a number of diguanylate cyclases and phosphodiesterases.

Expression of the Type III Secretion System Genes in Epiphytic Cells on Apple Stigmas Benefits Endophytic Infection at the Hypanthium.

causes fire blight on rosaceous plants. One of the major entry points of into hosts is flowers, where proliferates epiphytically on stigmatic and hypanthium surfaces and, subsequently, causes endophytic infection at the hypanthium. The type III secretion system (T3SS) is an important virulence factor in Although the role of T3SS during endophytic infection is well characterized, its expression during epiphytic colonization and role in the subsequent infection is less understood.

Innovation and Application of the Type III Secretion System Inhibitors in Plant Pathogenic Bacteria.

Many Gram-negative pathogenic bacteria rely on a functional type III secretion system (T3SS), which injects multiple effector proteins into eukaryotic host cells, for their pathogenicity. Genetic studies conducted in different host-microbe pathosystems often revealed a sophisticated regulatory mechanism of their T3SSs, suggesting that the expression of T3SS is tightly controlled and constantly monitored by bacteria in response to the ever-changing host environment. Therefore, it is critical to understand the regulation of T3SS in pathogenic bacteria for successful disease management.

Soil salinity, pH, and indigenous bacterial community interactively influence the survival of E. coli O157:H7 revealed by multivariate statistics.

Complexities of biotic-abiotic interactions in soils result in the lack of integrated understanding of environmental variables that restrict the survival of shiga toxin-producing E. coli O157:H7. Herein, we reanalyzed previously published data and highlighted the influence of soil abiotic factors on E.

Functional relationships between aboveground and belowground spinach (Spinacia oleracea L., cv. Racoon) microbiomes impacted by salinity and drought.

Salinity is a major problem facing agriculture in arid and semiarid regions of the world. This problem may vary among seasons affecting both above- and belowground plant microbiomes. However, very few studies have been conducted to examine the influence of salinity and drought on microbiomes and on their functional relationships.

Tricarboxylic Acid (TCA) Cycle Enzymes and Intermediates Modulate Intracellular Cyclic di-GMP Levels and the Production of Plant Cell Wall-Degrading Enzymes in Soft Rot Pathogen .

is a plant-pathogenic bacterium that causes soft-rot in a wide range of plants. Although we have previously demonstrated that cyclic bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP), a bacterial secondary messenger, plays a central role in virulence regulation in , the upstream signals that modulate c-di-GMP remain enigmatic. Using a genome-wide transposon mutagenesis approach of a Δ mutant strain that has high c-di-GMP and reduced motility, we uncovered transposon mutants that recovered the c-di-GMP-mediated repression on swimming motility.

Cell-length heterogeneity: a population-level solution to growth/virulence trade-offs in the plant pathogen Dickeya dadantii.

Necrotrophic plant pathogens acquire nutrients from dead plant cells, which requires the disintegration of the plant cell wall and tissue structures by the pathogen. Infected plants lose tissue integrity and functional immunity as a result, exposing the nutrient rich, decayed tissues to the environment. One challenge for the necrotrophs to successfully cause secondary infection (infection spread from an initially infected plant to the nearby uninfected plants) is to effectively utilize nutrients released from hosts towards building up a large population before other saprophytes come.

Identification of c-di-GMP Signaling Components in and Their Orthologs in Xanthomonads Involved in Regulation of Bacterial Virulence Expression.

pv. () causes bacterial leaf blight of rice, one of the most devastating bacterial diseases of this staple crop worldwide. produces a range of virulence-related factors to facilitate its pathogenesis in rice, however, the regulatory mechanisms of virulence expression have been not fully elucidated.

Transcriptional responses of Xanthomonas oryzae pv. oryzae to type III secretion system inhibitor ortho-coumaric acid.

Background: We previously identified a plant-derived phenolic compound ortho-coumaric acid (OCA) as an inhibitor of type III secretion system (T3SS) of Xanthomonas oryzae pv. oryzae (Xoo), the pathogen causing bacterial leaf blight of rice, one of the most devastating bacterial diseases of this staple crop worldwide. However, the molecular mechanisms by which OCA suppresses T3SS and the transcriptional responses to the OCA treatments in Xoo remains unclear.

A feed-forward signalling circuit controls bacterial virulence through linking cyclic di-GMP and two mechanistically distinct sRNAs, ArcZ and RsmB.

Dickeya dadantii is a plant pathogen that causes soft rot disease on vegetable and potato crops. To successfully cause infection, this pathogen needs to coordinately modulate the expression of genes encoding several virulence determinants, including plant cell wall degrading enzymes (PCWDEs), type III secretion system (T3SS) and flagellar motility. Here, we uncover a novel feed-forward signalling circuit for controlling virulence.

pv. Response Regulator TriP Regulates Virulence and Exopolysaccharide Production Via Interacting With c-di-GMP Phosphodiesterase PdeR.

PdeR, a response regulator of the two-component system (TCS) with the cognate histidine kinase PdeK, has been shown to be an active phosphodiesterase (PDE) for intracellular cyclic dimeric guanosine monophosphate (c-di-GMP) turnover and positively regulates the virulence of pv. , the causal pathogen of bacterial blight of rice. To further reveal the key components and pathways involved in the PdeR-mediated c-di-GMP regulation of virulence, 16 PdeR-interacting proteins were identified, using the yeast two-hybrid (Y2H) assay.

The phosphotransferase system gene ptsH plays an important role in MnSOD production, biofilm formation, swarming motility, and root colonization in Bacillus cereus 905.

The rhizosphere bacterium Bacillus cereus 905 is capable of promoting plant growth through effective colonization on plant roots. The sodA2-encoding manganese-containing superoxide dismutase (MnSOD2) is important for survival of B. cereus 905 in the wheat rhizosphere.

Phosphodiesterase EdpX1 Promotes Xanthomonas oryzae pv. oryzae Virulence, Exopolysaccharide Production, and Biofilm Formation.

In pv. oryzae, the bacterial blight pathogen of rice, there are over 20 genes encoding GGDEF, EAL, and HD-GYP domains, which are potentially involved in the metabolism of second messenger c-di-GMP. In this study, we focused on the characterization of an EAL domain protein, EdpX1.

Development of a Method to Monitor Gene Expression in Single Bacterial Cells During the Interaction With Plants and Use to Study the Expression of the Type III Secretion System in Single Cells of in Potato.

is a bacterial plant pathogen that causes soft rot disease on a wide range of host plants. The type III secretion system (T3SS) is an important virulence factor in . Expression of the T3SS is induced in the plant apoplast or in -inducing minimal medium (hrp-MM), and is repressed in nutrient-rich media.

Rapid detection of single E. coli bacteria using a graphene-based field-effect transistor device.

Contamination of surface and drinking water due to the presence of Escherichia coli bacteria is a major cause of water-borne disease outbreak. To address unmet challenges for practical pathogen detection in contaminated samples, we report fabrication of thermally reduced graphene oxide-based field-effect transistor (rGO FET) passivated with an ultrathin layer of AlO for real-time detection of E. coli bacteria.

The diguanylate cyclase GcpA inhibits the production of pectate lyases via the H-NS protein and RsmB regulatory RNA in Dickeya dadantii.

Dickeya dadantii 3937 secretes pectate lyases (Pels) to degrade plant cell walls. Previously, we have demonstrated that EGcpB and EcpC function as bis-(3',5')-cyclic dimeric guanosine monophosphate (c-di-GMP)-specific phosphodiesterases (PDEs) to positively regulate Pel production. However, the diguanylate cyclase (DGC) responsible for the synthesis of c-di-GMP and the dichotomous regulation of Pel has remained a mystery.