scholarly journals Induced ligno-suberin vascular coating and tyramine-derived hydroxycinnamic acid amides restrict Ralstonia solanacearum colonization in resistant tomato roots

2021 ◽  
Author(s):  
Anurag Kashyap ◽  
Montserrat Capellades ◽  
Weiqi Zhang ◽  
Sumithra Srinivasan ◽  
Anna Laromaine ◽  
...  
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Structural Changes ◽  
De Novo ◽  
Susceptible Variety ◽  
Hydroxycinnamic Acid ◽  
Physico Chemical ◽  
Tomato Roots ◽  
Hydroxycinnamic Acid Amides ◽  
Susceptible Tomato

The soil borne pathogen Ralstonia solanacearum is the causing agent of bacterial wilt, a devastating disease affecting major agricultural crops. R. solanacearum enters plants through the roots and reaches the vasculature, causing rapid wilting. We recently showed that tomato varieties resistant to bacterial wilt restrict bacterial movement in the plant. In the present work we go a step forward by identifying the physico-chemical nature of the barriers induced in resistant tomato roots in response to R. solanacearum. We describe that resistant tomato specifically responds to infection by assembling de novo a structural barrier at the vasculature formed by a ligno-suberin coating and tyramine-derived hydroxycinnamic acid amides (HCAAs). On the contrary, susceptible tomato does not form these reinforcements in response to the pathogen but instead displays lignin structural changes compatible with its degradation. Further, we show that overexpressing genes of the ligno-suberin pathway in a commercial susceptible variety of tomato restricts R. solanacearum movement inside the plant and slows disease progression, enhancing resistance to the pathogen. We thus propose that the induced barrier in resistant plants does not only restrict the movement of the pathogen, but may also prevent cell wall degradation by the pathogen and confer anti-microbial properties.

scholarly journals Biovar Differentiation and Variation in Virulence of Ralstonia solanacearum Isolates Infecting Solanaceous Vegetables

2016 ◽  
Vol 2 ◽  
pp. 22-26 ◽  
Author(s):  
Ram Devi Timila ◽  
Shrinkhala Manandhar
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Negative Impact ◽  
Virulent Strain ◽  
Solanum Melongena ◽  
Susceptible Variety ◽  
Resistant Variety ◽  
Slight Variation ◽  
Solanaceae Family ◽  
Moderately Resistant

Bacterial wilt caused by Ralstonia solanacearum E.F. Smith is one of the destructive diseases of solanaceous vegetables specially tomato (Lycopersicon esculentum L.) and eggplant (Solanum melongena L.). Experiments were conducted to determine biovar types existing among the strains or isolates of Nepal and variation in virulence in some vegetables belonging to solanaceae family. A total of 39 isolates infecting tomato, eggplant, chilli and potato collected from different parts of Nepal were analyzed for biovar types on the basis of 3 disaccharides and 3 hexose alcohols oxidation test.  Experiments were conducted to determine variation in virulence or aggressiveness of some of the  isolates under  screen house conditions using three host differentials such as Pusa Ruby (susceptible), Bishesh (moderately resistant) and Srijana (resistant) tomato cultivars. Of the 39 isolates, 23 were biovar III, three biovar II, three biovar IV, and one was biovar I. Nine isolates could not be differentiated into any of the five biovars. For breeding and epidemiological purposes it is very important to analyze the variability of aggressiveness. A total of 5 isolates collected from different places were included in the test. Isolates from Bhaktapur was found the most virulent causing wilt in the variety Bishesh (moderately resistant). Other isolates had the negative impact with zero wilt on the differentials used. Isolates from Jungekhola of Dhading district did not induce wilt even on susceptible variety (Pusa Ruby), but exhibited only senescence reaction. The result indicated that there is some slight variation among the isolates tested. Some effective management tactics might be needed in those locations where highly aggressive or virulent strain of bacterial wilt is prevalent, because resistant variety may not be stable in such locations.

scholarly journals Characterizations of endophytic Bacillus strains from tomato roots as growth promoter and biocontrol of Ralstonia solanacearum

2018 ◽  
Vol 19 (3) ◽  
pp. 906-911 ◽  
Author(s):  
YULMIRA YANTI ◽  
WARNITA WARNITA ◽  
REFLIN REFLIN ◽  
CHAINUR RAHMAN NASUTION
Keyword(s):  
16S Rrna ◽  
Plant Growth ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Plant Diseases ◽  
Growth Promoter ◽  
Good Ability ◽  
Tomato Roots ◽  
Bacillus Spp ◽  
Bacillus Strains

Yanti Y, Warnita, Reflin, Nasution CR. 2018. Characterizations of endophytic Bacillus strains from tomato roots as growth promoter and biocontrol of Ralstonia solanacearum. Biodiversitas 19: 906-911. Bacterial wilt caused by Ralstonia solanacearum is the most damaging vascular pathogens in tomato and many other crops in tropical, subtropical and warm temperate areas of the world limiting its production. Biological agents such as Plant growth Promoting Rhizobacteria (PGPR) is considered as a potential biological control agent for the suppression of plant diseases such as bacterial wilt. Bacillus spp. are one of the most potential genera of PGPR group used for controlling pathogens and promoting plant growth because of their spore-forming ability which increases their adaptation to the environment. The aims of the research were to isolate Endophytic Bacillus isolates, to characterize its ability as plant growth promoter and pathogen controller, and to identify its molecular genetic using 16S rRNA. Bacillus strains were isolated from healthy tomato roots. All Bacillus spp. strains acquired from isolation were then screened directly on plants in completely randomized design experiments with 3 replications. All potential strains were screened and identified using 16S rRNA with 27F and 1492R primers. Results showed that out of 15 obtained isolates, 6 of them showed a good ability to both promote growth and control R. solanacearum. All isolates were identified as B. Pseudomycoides strain NBRC 101232, B. cereus strain CCM 2010, B. toyonensis strain BCT-7112, B. anthracis strain ATCC 14578, B. cereus strain JCM 2152 and B. cereus ATCC 14579.

scholarly journals Viability, Stability and Biocontrol Activity in Planta of Specific Ralstonia Solanacearum Bacteriophages After Their Conservation Prior to Commercialization and Use

2021 ◽  
Author(s):  
Belén Álvarez ◽  
Laura Gadea-Pallás ◽  
Alejandro Rodríguez ◽  
Begonya Vicedo ◽  
Àngela Figàs-Segura ◽  
...  
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Reference Strain ◽  
Specific Activity ◽  
Experimental Period ◽  
In Planta ◽  
Tomato Plants ◽  
Preservation Method ◽  
Biocontrol Activity ◽  
Susceptible Tomato

Ralstonia solanacearum is a pathogen that causes bacterial wilt producing severe damage in staple solanaceous crops. Traditional control has low efficacy and/or environmental impact. Recently, the bases of a new biotechnological method by lytic bacteriophages vRsoP-WF2, vRsoP-WM2 and vRsoP-WR2 with specific activity against R. solanacearum were established. However, some aspects remain unknown, such as the survival and maintenance of the lytic activity after submission to a preservation method as the lyophilization. To this end, viability and stability of lyophilized vRsoP-WF2, vRsoP-WM2 and vRsoP-WR2 and their capacity for bacterial wilt biocontrol have been determined against one pathogenic Spanish reference strain of R. solanacearum in susceptible tomato plants in different conditions and making use of various cryoprotectants. The assays carried out have shown satisfactory results with respect to the viability and stability of the bacteriophages after the lyophilization process, maintaining high titres throughout the experimental period, also with respect to the capacity of the bacteriophages for the biological control of bacterial wilt, controlling this disease in more than 50% of the plants. The results offer good prospects for the use of lyophilization as a conservation method for the lytic bacteriophages of R. solanacearum in view of their commercialization as biocontrol agents.

scholarly journals Hydroxycinnamic Acid Degradation, a Broadly Conserved Trait, Protects Ralstonia solanacearum from Chemical Plant Defenses and Contributes to Root Colonization and Virulence

2015 ◽  
Vol 28 (3) ◽  
pp. 286-297 ◽  
Author(s):  
Tiffany M. Lowe ◽  
Florent Ailloud ◽  
Caitilyn Allen
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Root Colonization ◽  
Xylem Sap ◽  
Hydroxycinnamic Acid ◽  
Plant Colonization ◽  
In Planta ◽  
Acetyl Bromide ◽  
Defense Compounds

Plants produce hydroxycinnamic acid (HCA) defense compounds to combat pathogens, such as the bacterium Ralstonia solanacearum. We showed that an HCA degradation pathway is genetically and functionally conserved across diverse R. solanacearum strains. Further, a feruloyl-CoA synthetase (Δfcs) mutant that cannot degrade HCA was less virulent on tomato plants. To understand the role of HCA degradation in bacterial wilt disease, we tested the following hypotheses: HCA degradation helps the pathogen i) grow, as a carbon source; ii) spread, by reducing HCA-derived physical barriers; and iii) survive plant antimicrobial compounds. Although HCA degradation enabled R. solanacearum growth on HCA in vitro, HCA degradation was dispensable for growth in xylem sap and root exudate, suggesting that HCA are not significant carbon sources in planta. Acetyl-bromide quantification of lignin demonstrated that R. solanacearum infections did not affect the gross quantity or distribution of stem lignin. However, the Δfcs mutant was significantly more susceptible to inhibition by two HCA, namely, caffeate and p-coumarate. Finally, plant colonization assays suggested that HCA degradation facilitates early stages of infection and root colonization. Together, these results indicated that ability to degrade HCA contributes to bacterial wilt virulence by facilitating root entry and by protecting the pathogen from HCA toxicity.

scholarly journals Efficacy of Plant Growth-Promoting Rhizobacteria, Acibenzolar-S-Methyl, and Soil Amendment for Integrated Management of Bacterial Wilt on Tomato

Plant Disease ◽  
2004 ◽  
Vol 88 (6) ◽  
pp. 669-673 ◽  
Author(s):  
K. N. Anith ◽  
M. T. Momol ◽  
J. W. Kloepper ◽  
J. J. Marois ◽  
S. M. Olson ◽  
...  
Keyword(s):  
Plant Growth ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Untreated Control ◽  
Soil Amendment ◽  
Plant Growth Promoting Rhizobacteria ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Susceptible Tomato ◽  
Wilt Incidence

Greenhouse experiments were conducted to study the effect of plant growth promoting rhizobacteria (PGPR; Bacillus pumilus SE 34, Pseudomonas putida 89B61, BioYield, and Equity), acibenzolar-S-methyl (Actigard), and a soil amendment with S-H mixture (contains agricultural and industrial wastes such as bagasse, rice husk, oyster shell powder, urea, potassium nitrate, calcium super phosphate, and mineral ash) on bacterial wilt incidence caused by Ralstonia solanacearum (race 1, biovar 1) in susceptible tomato (Lycopersicon esculentum cv. Solar Set). In experiments with PGPR, Pseudomonas putida 89B61 significantly reduced bacterial wilt incidence when applied to the transplants at the time of seeding and 1 week prior to inoculation with Ralstonia solanacearum. BioYield, a formulated PGPR that contained two Bacillus strains, decreased disease significantly in three experiments. Equity, a formulation containing more than 40 different microbial strains, did not reduced wilt incidence compared with the untreated control. With inoculum at low pathogen densities of 1 × 105 and 1 × 106 CFU/ml, disease incidence of Actigard-treated plants was significantly less than with nontreated plants. This is the first report of Actigard-mediated reduction of bacterial wilt incidence in a susceptible tomato cultivar. When PGPR and Actigard applications were combined, Actigard plus P. putida 89B61 or BioYield reduced bacterial wilt incidence compared with the untreated control. Incorporation of S-H mixture into infested soil 2 weeks before transplanting reduced bacterial wilt incidence in one experiment. Combination of Actigard with the S-H mixture significantly reduced bacterial wilt incidence in tomato in two experiments.

scholarly journals Compatibility and performance of susceptible tomato cultivars grafted onto bacterial wilt (Ralstonia solanacearum) resistant rootstock

2020 ◽  
Vol 147 ◽  
pp. 15100-15107
Author(s):  
Kanyua Stella ◽  
Mwangi Maina ◽  
Mbaka Jesca
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Economic Damage ◽  
Vegetable Crops ◽  
Subsequent Increase ◽  
Wide Range ◽  
Tomato Cultivars ◽  
Sodom Apple ◽  
And Performance ◽  
Susceptible Tomato

Objective: Tomato (Solanum lycopersicum L.) belongs to the Solanaceae family and currently is one of the most important vegetable crops. Bacterial wilt, caused by Ralstonia solanacearum is a soil borne disease of tomato causing significant economic damage on tomatoes, tobacco and potatoes. Bacterial wilt is difficult to manage because the pathogen can survive in soil for long periods in association with a wide range of crops such as pepper, potato, capsicum, eggplants and weeds such as Jimson weed and nightshade. The objective of this study was to determine compatibility and performance of susceptible tomato cultivars grafted onto bacterial wilt resistant rootstocks. Methodology: Scions from susceptible tomato commercial cultivars (Anna F1 and Cal J) were grafted onto rootstocks of Eggplant, Sodom apple and tomato cultivar Mt56 that were determined to be resistant to bacterial wilt in a previous study. Cleft grafting technique was used in the experiment. Data on compatibility was assessed daily to check on the healing of the graft union and number of established plants. The grafted plants were considered compatible if 67% of the grafted plants had healed and growth established fourteen days after grafting. Data were subjected to ANOVA using GenStat version 15 and significantly different treatment means separated using LSD at P < 0.05. Results and application: The grafted plants were compatible at varying rates, that is Mt56 + Anna F1 (93.30%), Mt56 + Cal J (76.7%), S. melongena + Anna F1 (96.7%), S. melongena + Cal J (83.3%), S. incarnum + Anna F1 (73.3% ), and S. incarnum + Cal J (100%). It was concluded that tomato scions and the botanically related wilt resistant rootstocks are compatible. All the grafted plants performed well except those on Sodom apple rootstock whose stem did not expand at the rate as the scion stem. It is recommended that the proven resistant rootstocks be deployed to tomato farmers for use in tomato grafting and subsequent increase in their production. Key words: Grafting, Compatibility, Performance, Bacterial wilt

scholarly journals Tomato root transformation followed by inoculation with Ralstonia solanacearum for straightforward genetic analysis of bacterial wilt disease

2019 ◽  
Author(s):  
Rafael J. L. Morcillo ◽  
Achen Zhao ◽  
María I. Tamayo-Navarrete ◽  
José M. García-Garrido ◽  
Alberto P. Macho
Keyword(s):  
Genetic Analysis ◽  
Pseudomonas Syringae ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Wilt Disease ◽  
Tomato Root ◽  
Sustainable Solutions ◽  
Bacterial Wilt Disease ◽  
Tomato Roots ◽  
Root Transformation

ABSTRACTRalstonia solanacearum is a devastating soil borne vascular pathogen that is able to infect a large range of plant species, causing an important threat to agriculture. However, the Ralstonia model is considerably under-explored in comparison to other models involving bacterial plant pathogens, such as Pseudomonas syringae in Arabidopsis. Research targeted to understanding the interaction between Ralstonia and crop plants is essential to develop sustainable solutions to fight against bacterial wilt disease, but is currently hindered by the lack of straightforward experimental assays to characterize the different components of the interaction in native host plants. In this scenario, we have developed an easy method to perform genetic analysis of Ralstonia infection of tomato, a natural host of Ralstonia. This method is based on Agrobacterium rhizogenes-mediated transformation of tomato roots, followed by Ralstonia soil-drenching inoculation of the resulting plants, containing transformed roots expressing the construct of interest. The versatility of the root transformation assay allows performing either gene overexpression or gene silencing mediated by RNAi. As a proof of concept, we used this method to show that RNAi-mediated silencing of SlCESA6 of tomato roots conferred resistance to Ralstonia. Here, we describe this method in detail, enabling genetic approaches to understand bacterial wilt disease in a relative short time and with small requirements of equipment and plant growth space.SUMMARYA versatile method for tomato root transformation followed by inoculation with Ralstonia solanacearum to perform straightforward genetic analysis for the study of bacterial wilt disease.

scholarly journals Identification of Ralstonia solanacearum resistant rootstocks for tomato grafting

2020 ◽  
Vol 43.3 ◽  
pp. 7452-7457
Author(s):  
Kanyua Stella ◽  
Mwangi Maina ◽  
Mbaka Jesca
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Solanum Melongena ◽  
Tomato Cultivar ◽  
Solanum Lycopersicum L ◽  
Management Measures ◽  
Tomato Cultivars ◽  
Sodom Apple ◽  
Solanaceae Family ◽  
Susceptible Tomato

Bacterial wilt, caused by Ralstonia solanacearum, causes severe losses to tomato (Solanum lycopersicum L). Current management measures are not fully effective. Grafting with resistant rootstocks may be an effective strategy for managing the disease. However, R. solanacearum populations maintain considerable diversity, and little information is known regarding the efficacy of available rootstocks for use in grafting to reduce bacterial wilt incidence and subsequent crop loss. Tomato belongs to family Solanaceae which includes other well-known species, such as eggplant (aubergine), peppers, tobacco and potato. The objective of this study was to identify bacterial wilt resistant germplasm that can be used as rootstocks in tomato grafting. The potential candidates for the study included species that belong to solanaceae family. Rootstocks included tomato cultivar Mt56, Eggplant (Solanum melongena), Capsicum and Sodom apple (Solanum incarnum). Tomato cultivars Anna F1 and Cal J were used as sources of scions. Diseased plants were collected from farmers’ fields and bacterial inoculum isolated using CPG Medium with TZC used to identify distinct colonies of R.solanacearum. The inoculum was applied on the test plants by injecting into the soil planted with tomatoes. Disease severity data was recorded using 0 to 5 scoring scale. Data was subjected to ANOVA using Genstat version 15 and significantly different treatment means separated using LSD at P < 0.05. Solanum melongena, Solanum incarnum and tomato cultivar (Mt56) did not develop infection while tomato cultivar Anna F1 and Cal J (used as positive controls) and Capsicum developed infection. It was concluded that resistant germplasm to bacterial wilt exists and can be utilized to graft susceptible tomato cultivars and contribute to management of bacterial wilt.

scholarly journals Spatial-Temporal and Quantitative Analysis of Growth and EPS I Production by Ralstonia solanacearum in Resistant and Susceptible Tomato Cultivars

1999 ◽  
Vol 89 (12) ◽  
pp. 1233-1239 ◽  
Author(s):  
J. A. McGarvey ◽  
T. P. Denny ◽  
M. A. Schell
Keyword(s):  
Ralstonia Solanacearum ◽  
Antimicrobial Activities ◽  
Enzyme Linked Immunosorbent Assay ◽  
Vascular Bundles ◽  
Susceptible Cultivar ◽  
Bacterial Populations ◽  
Resistant Cultivars ◽  
Cell Densities ◽  
Almost All ◽  
Susceptible Tomato

One susceptible and two resistant cultivars of tomato were tested for differences in infection by Ralstonia solanacearum and for the subsequent multiplication, colonization, and production of the wilt-inducing virulence factor, exopolysaccharide I (EPS I). Bacterial ingress into the taproot was fastest in the susceptible cv. Marion, followed by the resistant cvs. L285 (fivefold slower) and Hawaii 7996 (15-fold slower). Once inside the taproot, R. solanacearum colonized, to some extent, almost all regions of the resistant and susceptible plants. However, colonization occurred sooner in the susceptible than in the resistant cultivars, as measured by viablecell counts of bacteria in the midstems. Rates of multiplication and maximum bacterial cell densities were also greater in the susceptible than in the resistant cultivars. Growth experiments utilizing xylem fluid from infected and uninfected plants indicated that neither antimicrobial activities nor reduced levels of growth-supporting nutrients in the xylem fluids were responsible for the reduced bacterial multiplication in the resistant cultivars. Quantification of EPS I in the infected plants, using an enzyme-linked immunosorbent assay, revealed that the bacterial populations in the susceptible cultivar produced greater amounts of EPS I per plant than those in the resistant cultivars. Immunofluorescence microscopy using antibodies against either EPS I or R. solanacearum cells revealed that bacteria and EPS I were distributed throughout the vascular bundles and intercellular spaces of the pith in the susceptible cultivar, whereas in the resistant cultivars, bacteria and EPS I were restricted to the vascular tissues.

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.

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