Comparison of Prokaryotic and Eukaryotic Communities in Soil Samples with and without Tomato Bacterial Wilt Collected from Different Fields.

Biocontrol agents (BCA) effectively suppress soil-borne disease symptoms using natural antagonistic prokaryotes or eukaryotes. The main issue associated with the application of BCA is that disease reduction effects are unstable under different field conditions. In order to identify potentially effective BCA among several fields, we compared prokaryotic and eukaryotic communities in soil with and without tomato bacterial wilt from three different fields, each of which had the same field management and similar soil characteristics.

Draft Genome Sequence of Strain JCM 16806 Isolated from Soil Polluted by Crude Oil in China.

Here, we report the draft genome sequence of strain JCM 16806, which was isolated from an oil field. It is composed of 3,310,272 bp and contains 3,160 protein-coding genes, 8 5S rRNAs, 3 16S rRNAs, and 69 tRNAs.

Prokaryotic Communities at Different Depths between Soils with and without Tomato Bacterial Wilt but Pathogen-Present in a Single Greenhouse.

The characterization of microbial communities that promote or suppress soil-borne pathogens is important for controlling plant diseases. We compared prokaryotic communities in soil with or without the signs of tomato bacterial wilt caused by Ralstonia solanacearum. Soil samples were collected from a greenhouse at two different depths because this pathogen is present in deep soil.

l-Histidine Induces Resistance in Plants to the Bacterial Pathogen Ralstonia solanacearum Partially Through the Activation of Ethylene Signaling.

Wilt disease in plants, which is caused by the soil-borne bacterial pathogen Ralstonia solanacearum, is one of the most devastating plant diseases. We previously detected bacterial wilt disease-inhibiting activity in an extract from yeast cells. In the present study, we purified this activity and identified one of the substances responsible for the activity as the amino acid histidine.

Sensitive quantitative detection of Ralstonia solanacearum in soil by the most probable number-polymerase chain reaction (MPN-PCR) method.

We developed a sensitive quantitative assay for detecting Ralstonia solanacearum in soil by most probable number (MPN) analysis based on bio-PCR results. For development of the detection method, we optimized an elution buffer containing 5 g/L skim milk for extracting bacteria from soil and reducing contamination of polymerase inhibitors in soil extracts. Because R.

Transcriptional profile of tomato roots exhibiting Bacillus thuringiensis-induced resistance to Ralstonia solanacearum.

Activation of SA-dependent signaling pathway and suppression of JA-dependent signaling pathway seem to play key roles inB. thuringiensis-induced resistance toR. solanacearumin tomato plants.

Transcriptome analysis of quantitative resistance-specific response upon Ralstonia solanacearum infection in tomato.

Bacterial wilt, caused by the soil-borne bacterium Ralstonia solanacearum, is a lethal disease of tomato, but the molecular mechanisms of the host resistance responses to R. solanacearum remain unclear. In this study, we report the first work describing the transcriptome of cultivar resistance and susceptible tomato cultivar after inoculation with R.

Identification of natural diterpenes that inhibit bacterial wilt disease in tobacco, tomato and Arabidopsis.

The soil-borne bacterial pathogen Ralstonia solanacearum invades a broad range of plants through their roots, resulting in wilting of the plant, but no effective protection against this disease has been developed. Two bacterial wilt disease-inhibiting compounds were biochemically isolated from tobacco and identified as sclareol and cis-abienol, labdane-type diterpenes. When exogenously applied to their roots, sclareol and cis-abienol inhibited wilt disease in tobacco, tomato and Arabidopsis plants without exhibiting any antibacterial activity.

Enhanced defense responses in Arabidopsis induced by the cell wall protein fractions from Pythium oligandrum require SGT1, RAR1, NPR1 and JAR1.

The cell wall protein fraction (CWP) is purified from the non-pathogenic biocontrol agent Pythium oligandrum and is composed of two glycoproteins (POD-1 and POD-2), which are structurally similar to class III elicitins. In tomato plants treated with CWP, jasmonic acid (JA)- and ethylene (ET)-dependent signaling pathways are activated, and resistance to Ralstonia solanaceraum is enhanced. To dissect CWP-induced defense mechanisms, we investigated defense gene expression and resistance to bacterial pathogens in Arabidopsis thaliana ecotype Col-0 treated with CWP.

Beta-cyanoalanine synthase as a molecular marker for induced resistance by fungal glycoprotein elicitor and commercial plant activators.

ABSTRACT The biocontrol agent Pythium oligandrum produces glycoprotein elicitor in the cell wall fraction, designated CWP, and induces resistance to a broad range of pathogens. To understand the mechanism of CWP-induced resistance to pathogens, gene expression at the early stage of CWP treatment in tomato roots was analyzed using a cDNA array. At 4 h after CWP treatment, 144 genes were up-regulated and 99 genes were down-regulated.

Colonization of Pythium oligandrum in the tomato rhizosphere for biological control of bacterial wilt disease analyzed by real-time PCR and confocal laser-scanning microscopy.

It recently has been reported that the non-plant-pathogenic oomycete Pythium oligandrum suppresses bacterial wilt caused by Ralstonia solanacearum in tomato. As one approach to determine disease-suppressive mechanisms of action, we analyzed the colonization of P. oligandrum in rhizospheres of tomato using real-time polymerase chain reaction (PCR) and confocal laser-scanning microscopy.

Mutations in the lrpE gene of Ralstonia solanacearum affects Hrp pili production and virulence.

The Ralstonia solanacearum hrpB-regulated gene lrpE (hpx5/brg24) encodes a PopC-like leucine-rich repeat (LRR) protein that carries 11 tandem LRR in the central region. Defects in the lrpE gene slightly reduced the virulence of R. solanacearum on host plants and changed the bacterial morphology leading to the formation of large aggregates in a minimal medium.

Ralstonia solanacearum Race 3, Biovar 2 Strains Isolated from Geranium Are Pathogenic on Potato.

Ralstonia solanacearum race 3, biovar 2 is a soilborne bacterium that causes potato brown rot disease in temperate and subtropical climates. Recent outbreaks of this disease in Europe have caused serious losses, but the pathogen had not been identified in the United States. However, in 1999, strains of R.