scholarly journals Evaluation of the antibacterial activity of mango ginger rhizome extracts against bacterial wilt pathogen Ralstonia solanacearum

1970 ◽  
pp. 101
Author(s):  
R Karthika, D Prasath*, N K Leela, R Suseela Bhai, M Anandaraj
Keyword(s):  
Essential Oils ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Resistance Mechanism ◽  
Diffusion Method ◽  
Zone Of Inhibition ◽  
Mango Ginger ◽  
Methanol Extracts ◽  
Bacterial Wilt Disease ◽  
Ginger Rhizome

The Indian mango ginger (Curcuma amada Roxb.) is a perennial rhizomatous herb with a raw mango flavour. It is resistant to bacterial wilt disease. In order to understand the disease resistance mechanism of mango gingerthe hexane, chloroform and methanol extracts (5, 10, 25, 50 and 100mg/ml) and essential oils (1%, 5% and 10%) were tested against the bacterial wilt pathogen Ralstonia solanacearum by agar well diffusion method. The hexane, chloroform and methanol extracts showed more or less the same level of antimicrobial activity with a zone of inhibition ranging from 3-9 mm. The essential oils exhibited a zone of inhibition ranging from 3-7 mm.The major constituents of the essential oils were β-myrcene and β-pinene. The results indicated that the rhizome of mango ginger may contain compounds that are toxic to the pathogen. The extracts of mango ginger could be explored further for developing a natural bactericide against R. solanacearum.

scholarly journals Ralstonia solanacearum Needs Motility for Invasive Virulence on Tomato

2001 ◽  
Vol 183 (12) ◽  
pp. 3597-3605 ◽  
Author(s):  
Julie Tans-Kersten ◽  
Huayu Huang ◽  
Caitilyn Allen
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Soft Agar ◽  
Cell Protein ◽  
In Planta ◽  
Tomato Plants ◽  
Bacterial Wilt Disease ◽  
Virulence Assay ◽  
Flagellar Filament

ABSTRACT Ralstonia solanacearum, a widely distributed and economically important plant pathogen, invades the roots of diverse plant hosts from the soil and aggressively colonizes the xylem vessels, causing a lethal wilting known as bacterial wilt disease. By examining bacteria from the xylem vessels of infected plants, we found thatR. solanacearum is essentially nonmotile in planta, although it can be highly motile in culture. To determine the role of pathogen motility in this disease, we cloned, characterized, and mutated two genes in the R. solanacearum flagellar biosynthetic pathway. The genes for flagellin, the subunit of the flagellar filament (fliC), and for the flagellar motor switch protein (fliM) were isolated based on their resemblance to these proteins in other bacteria. As is typical for flagellins, the predicted FliC protein had well-conserved N- and C-terminal regions, separated by a divergent central domain. The predicted R. solanacearum FliM closely resembled motor switch proteins from other proteobacteria. Chromosomal mutants lackingfliC or fliM were created by replacing the genes with marked interrupted constructs. Since fliM is embedded in the fliLMNOPQR operon, the aphAcassette was used to make a nonpolar fliM mutation. Both mutants were completely nonmotile on soft agar plates, in minimal broth, and in tomato plants. The fliC mutant lacked flagella altogether; moreover, sheared-cell protein preparations from the fliC mutant lacked a 30-kDa band corresponding to flagellin. The fliM mutant was usually aflagellate, but about 10% of cells had abnormal truncated flagella. In a biologically representative soil-soak inoculation virulence assay, both nonmotile mutants were significantly reduced in the ability to cause disease on tomato plants. However, the fliC mutant had wild-type virulence when it was inoculated directly onto cut tomato petioles, an inoculation method that did not require bacteria to enter the intact host from the soil. These results suggest that swimming motility makes its most important contribution to bacterial wilt virulence in the early stages of host plant invasion and colonization.

scholarly journals ISOLASI DAN UJI KEMAMPUAN BAKTERIOFAG SEBAGAI AGENS PENGENDALI PENYAKIT LAYU BAKTERI (Ralstonia solanacearum) PADA TANAMAN TOMAT

2020 ◽  
Vol 14 (1) ◽  
pp. 8-20
Author(s):  
Fery Abdul Choliq ◽  
Mintarto Martosudiro ◽  
Istiqomah Istiqomah ◽  
Muhammad Fanhash Nijami
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Plaque Assay ◽  
Wilt Disease ◽  
Control Treatment ◽  
Lower Percentage ◽  
Bacterial Cells ◽  
Horticultural Crops ◽  
Bacterial Wilt Disease ◽  
Bacteriophage Infection

Tomato is the top priority in the development of horticultural crops. The obstacle which mostly encountered is Ralstonia solanacearum pathogen attack. Bacteriophage can cause bacterial lysis after they they develop themselves inside the bacteria. The specific of the bacteriophage can provide result quickly, accurately, and efficiently so that it can be used as an alternative to control bacterial wilt disease R. solanacearum environmentally friendly. This study aims to find out the effectiveness of bacteriophage to control the bacterial wilt disease R. solanacearum. The testing method are plaque assay, bacteriophage infections test in various dilutions, bacteriophage infection test in a liquid medium, and transmission electron microscopy test. In the greenhouse scale testing using a Completely Randomized Design (CRD) with 6 treatments and 4 replications. Quantitative data were analyzed using analysis of variance 5% error level and followed by least significant different  test level of 5%. The results showed that bacteriophages can infect R. solanacearum. Bacteriophage can infect bacteria R. solanacearum indicated by the appearance of plaques in NA media, the declining value of absorbance spectophotometer, and can lyse bacterial cells from dilutions 10-1 to 10-9. The morphology of bacteriophages that infect R. solanacearum have hexagonal head structure and it have which is with a size of 200 nm. In the greenhouse scale showed that the symptoms of R. solanacearum appear at 29 days after inoculation. Application of bacteriophages can control R. solanacearum with lower percentage than the control treatment.

scholarly journals Streptomyces sp.: Characterization, Identification and Its Potential as a Ralstonia solanacearum Biological Control Agent in vitro

2019 ◽  
Vol 2 (3) ◽  
pp. 89-96 ◽  
Author(s):  
Rachmad Saputra ◽  
Triwidodo Arwiyanto ◽  
Arif Wibowo
Keyword(s):  
Biological Control ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Biological Control Agent ◽  
Wilt Disease ◽  
Molecular Characteristics ◽  
Streptomyces Sp ◽  
Bacterial Wilt Disease ◽  
Wide Range

Streptomyces sp. bacteria have the potential to produce antibiotic compounds, which are one of the mechanisms that are widely used in biological control. However, in general, biological control mechanisms also occur through competition, cell wall degradation and induced resistance. This study was aimed to determine the physiological, biochemical and molecular characteristics of two isolates of Streptomyces sp. (S-4 and S16 isolates) isolated from the tomatoes roots, and to find out their ability to control Ralstonia solanacearum, which causes bacterial wilt disease on a wide range of hosts. The results showed both Streptomyces sp. isolates had several different physiological and biochemical characteristics and had a different ability to inhibit R. solanacearum in vitro. Streptomyces sp. S-16 isolate had a high similarity with Streptomyces diastaticus subsp. ardesiacus strain NRRL B-1773T based on the molecular identification results. Further research needs to be done to see the potential inhibition of the two Streptomyces isolates in inhibiting the development of bacterial wilt disease in tomato plants caused by R. solanacearum.

scholarly journals The plant-based chimeric antimicrobial protein SlP14a-PPC20 protects tomato against bacterial wilt disease caused by Ralstonia solanacearum

Plant Science ◽  
2019 ◽  
Vol 280 ◽  
pp. 197-205 ◽  
Author(s):  
Tâmara P. Morais ◽  
Paulo A. Zaini ◽  
Sandeep Chakraborty ◽  
Hossein Gouran ◽  
Camila P. Carvalho ◽  
...  
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Wilt Disease ◽  
Antimicrobial Protein ◽  
Bacterial Wilt Disease

scholarly journals A cbb3-Type Cytochrome C Oxidase Contributes to Ralstonia solanacearum R3bv2 Growth in Microaerobic Environments and to Bacterial Wilt Disease Development in Tomato

2010 ◽  
Vol 23 (8) ◽  
pp. 1042-1052 ◽  
Author(s):  
Jennifer Colburn-Clifford ◽  
Caitilyn Allen
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Wilt Disease ◽  
Wild Type ◽  
Low Oxygen ◽  
Tomato Root ◽  
Bacterial Wilt Disease ◽  
Oxygen Conditions

Ralstonia solanacearum race 3 biovar 2 (R3bv2) is an economically important soilborne plant pathogen that causes bacterial wilt disease by infecting host plant roots and colonizing the xylem vessels. Little is known about R3bv2 behavior in the host rhizosphere and early in bacterial wilt pathogenesis. To explore this part of the disease cycle, we used a novel taxis-based promoter-trapping strategy to identify pathogen genes induced in the plant rhizosphere. This screen identified several rex (root exudate expressed) genes whose promoters were upregulated in the presence of tomato root exudates. One rex gene encodes an assembly protein for a high affinity cbb3-type cytochrome c oxidase (cbb3-cco) that enables respiration in low-oxygen conditions in other bacteria. R3bv2 cbb3-cco gene expression increased under low-oxygen conditions, and a cbb3-cco mutant strain grew more slowly in a microaerobic environment (0.5% O2). Although the cco mutant could still wilt tomato plants, symptom onset was significantly delayed relative to the wild-type parent strain. Further, the cco mutant did not colonize host stems or adhere to roots as effectively as wild type. These results suggest that R3bv2 encounters low-oxygen environments during its interactions with host plants and that the pathogen depends on this oxidase to help it succeed in planta.

scholarly journals Four bottlenecks restrict colonization and invasion by the pathogen Ralstonia solanacearum in resistant tomato

2019 ◽  
Vol 71 (6) ◽  
pp. 2157-2171 ◽  
Author(s):  
Marc Planas-Marquès ◽  
Jonathan P Kressin ◽  
Anurag Kashyap ◽  
Dilip R Panthee ◽  
Frank J Louws ◽  
...  
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Molecular Mechanisms ◽  
Temporal Dynamics ◽  
Bacterial Colonization ◽  
Resistance Mechanism ◽  
Vertical Movement ◽  
Field Resistance ◽  
Structural Constraints ◽  
Tomato Root

Abstract Ralstonia solanacearum is a bacterial vascular pathogen causing devastating bacterial wilt. In the field, resistance against this pathogen is quantitative and is available for breeders only in tomato and eggplant. To understand the basis of resistance to R. solanacearum in tomato, we investigated the spatio-temporal dynamics of bacterial colonization using non-invasive live monitoring techniques coupled to grafting of susceptible and resistant varieties. We found four ‘bottlenecks’ that limit the bacterium in resistant tomato: root colonization, vertical movement from roots to shoots, circular vascular bundle invasion, and radial apoplastic spread in the cortex. Radial invasion of cortical extracellular spaces occurred mostly at late disease stages but was observed throughout plant infection. This study shows that resistance is expressed in both root and shoot tissues, and highlights the importance of structural constraints to bacterial spread as a resistance mechanism. It also shows that R. solanacearum is not only a vascular pathogen but spreads out of the xylem, occupying the plant apoplast niche. Our work will help elucidate the complex genetic determinants of resistance, setting the foundations to decipher the molecular mechanisms that limit pathogen colonization, which may provide new precision tools to fight bacterial wilt in the field.

Disease Resistance Against a Broad-Host-Range Pathogen

2013 ◽  
Vol 14 (1) ◽  
pp. 32
Author(s):  
Jonathan M. Jacobs ◽  
Caitilyn Allen
Keyword(s):  
Disease Resistance ◽  
Host Range ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Pathogenic Bacteria ◽  
Resistance Breeding ◽  
Wilt Disease ◽  
Family Type ◽  
Broad Host Range ◽  
Bacterial Wilt Disease

The bacterial wilt pathogen Ralstonia solanacearum causes major agricultural losses on many crop hosts worldwide. Resistance breeding is the best way to control bacterial wilt disease, but the biological basis for bacterial wilt resistance is unknown. We found that R. solanacearum uses an AvrE-family, Type III-secreted effector called PopS to overcome plant defenses and cause disease on tomato. Orthologs of PopS are widely conserved across distinct classes of plant pathogenic bacteria and could provide novel, durable targets for resistance. Accepted for publication 25 September 2013. Published 25 November 2013.

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