Leaf-to-Whole Plant Spread Bioassay for Pepper and Ralstonia solanacearum Interaction Determines Inheritance of Resistance to Bacterial Wilt for Further Breeding

Bacterial wilt (BW) disease from Ralstonia solanacearum is a serious disease and causes severe yield losses in chili peppers worldwide. Resistant cultivar breeding is the most effective in controlling BW. Thus, a simple and reliable evaluation method is required to assess disease severity and to investigate the inheritance of resistance for further breeding programs. Here, we developed a reliable leaf-to-whole plant spread bioassay for evaluating BW disease and then, using this, determined the inheritance of resistance to R. solanacearum in peppers. Capsicum annuum ‘MC4′ displayed a completely resistant response with fewer disease symptoms, a low level of bacterial cell growth, and significant up-regulations of defense genes in infected leaves compared to those in susceptible ‘Subicho’. We also observed the spreading of wilt symptoms from the leaves to the whole susceptible plant, which denotes the normal BW wilt symptoms, similar to the drenching method. Through this, we optimized the evaluation method of the resistance to BW. Additionally, we performed genetic analysis for resistance inheritance. The parents, F1 and 90 F2 progenies, were evaluated, and the two major complementary genes involved in the BW resistance trait were confirmed. These could provide an accurate evaluation to improve resistant pepper breeding efficiency against BW.

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Leaf-to-whole plant spread bioassay for pepper and Ralstonia solanacearum interaction determines inheritance of resistance to bacterial wilt for further breeding

10.1101/2021.01.27.428365 ◽

2021 ◽

Author(s):

Ji-Su Kwon ◽

Jae-Young Nam ◽

Seon-In Yeom ◽

Won-Hee Kang

Keyword(s):

Bacterial Wilt ◽

Ralstonia Solanacearum ◽

Evaluation Method ◽

Inheritance Of Resistance ◽

Breeding Programs ◽

Whole Plant ◽

Resistance Trait ◽

Breeding Efficiency ◽

Serious Disease ◽

Chili Peppers

AbstractBacterial wilt (BW) disease by Ralstonia solanacearum is a serious disease and causes severe yield losses in chili peppers worldwide. Resistant cultivar breeding is the most effective in controlling BW. Thus, a simple and reliable evaluation method is required to assess disease severity and to investigate the inheritance of resistance for further breeding programs. Here, we developed a reliable leaf-to-whole plant spread bioassay for evaluating BW disease and then, using this, determined the inheritance of resistance to R. solanacearum in peppers. Capsicum annuum ‘MC4’ displayed a completely resistant response with fewer disease symptoms, a low level of bacterial cell growth, and significant up-regulations of defense genes in infected leaves compared to those in susceptible ‘Subicho’. We also observed the spreading of wilt symptoms from the leaves to the whole susceptible plant, which denotes the normal BW wilt symptoms, similar to the drenching method. Through this, we optimized the evaluation method of the resistance to BW. Additionally, we performed genetic analysis for resistance inheritance. The parents, F1 and 90 F2 progenies, were evaluated, and the two major complementary genes involved in the BW resistance trait were confirmed. These could provide an accurate evaluation to improve resistant pepper breeding efficiency against BW.

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A Novel, Sensitive Method to Evaluate Potato Germplasm for Bacterial Wilt Resistance Using a Luminescent Ralstonia solanacearum Reporter Strain

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-10-13-0303-fi ◽

2014 ◽

Vol 27 (3) ◽

pp. 277-285 ◽

Cited By ~ 29

Author(s):

Andrea Paola Zuluaga Cruz ◽

Virginia Ferreira ◽

María Julia Pianzzola ◽

María Inés Siri ◽

Núria S. Coll ◽

...

Keyword(s):

Bacterial Wilt ◽

Ralstonia Solanacearum ◽

Accurate Method ◽

Quantitative Detection ◽

Screening Methods ◽

Reporter Strain ◽

In Planta ◽

Breeding Programs ◽

Potato Germplasm ◽

Pathogen Colonization

Several breeding programs are under way to introduce resistance to bacterial wilt caused by Ralstonia solanacearum in solanaceous crops. The lack of screening methods allowing easy measurement of pathogen colonization and the inability to detect latent (i.e., symptomless) infections are major limitations when evaluating resistance to this disease in plant germplasm. We describe a new method to study the interaction between R. solanacearum and potato germplasm that overcomes these restrictions. The R. solanacearum UY031 was genetically modified to constitutively generate light from a synthetic luxCDABE operon stably inserted in its chromosome. Colonization of this reporter strain on different potato accessions was followed using life imaging. Bacterial detection in planta by this nondisruptive system correlated with the development of wilting symptoms. In addition, we demonstrated that quantitative detection of the recombinant strain using a luminometer can identify latent infections on symptomless potato plants. We have developed a novel, unsophisticated, and accurate method for high-throughput evaluation of pathogen colonization in plant populations. We applied this method to compare the behavior of potato accessions with contrasting resistance to R. solanacearum. This new system will be especially useful to detect latency in symptomless parental lines before their inclusion in long-term breeding programs for disease resistance.

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Evaluation of Resistance Sources of Tomato (Solanum lycopersicum L.) to Phylotype I Strains of Ralstonia solanacearum Species Complex in Benin

Agronomy ◽

10.3390/agronomy11081513 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1513

Author(s):

Herbaud Zohoungbogbo ◽

Adonis Quenum ◽

Judith Honfoga ◽

Jaw-Rong Chen ◽

Enoch Achigan-Dako ◽

...

Keyword(s):

Bacterial Wilt ◽

Ralstonia Solanacearum ◽

Species Complex ◽

Block Design ◽

Agricultural System ◽

Sources Of Resistance ◽

Breeding Programs ◽

Solanum Lycopersicum L ◽

The University ◽

Phylotype I

Finding sources of resistance to bacterial wilt (BW) caused by Ralstonia solanacearum species complex is a crucial step toward the development of improved bacterial wilt-resistant tomato varieties. Here, we evaluated new sources of bacterial wilt-tolerant/resistant tomato lines and identified associated phylotype/sequevar of R. solanacearum strains in Benin. Eighteen F5 lines and five checks were evaluated in two hotspots: the experimental site of the World Vegetable Center, Cotonou Benin, and the Laboratory of Genetics, Biotechnology and Seed Science of the University of Abomey-Calavi. Experiments were laid out in a randomized complete block design with four replicates. Data were collected on bacterial wilt incidence, horticultural and fruit traits and yield components. Across the two experiments, the F5 lines showed no wilting, while the local variety ‘Tounvi’ used as susceptible check showed 57.64% wilting. The wilting was due to BW and was associated with sequevars I-14, I-18 and I-31 of phylotype I. AVTO1803, AVTO1955-6 and H7996 were the highest yielding lines with 20.29 t·ha−1, 17.66 t·ha−1 and 17.07 t/ha, respectively. The sources of resistance to BW can be recommended to national agricultural system for dissemination or used in tomato breeding programs.

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A Single Locus Leads to Resistance of Arabidopsis thaliana to Bacterial Wilt Caused by Ralstonia solanacearum Through a Hypersensitive-like Response

Phytopathology ◽

10.1094/phyto.1999.89.8.673 ◽

1999 ◽

Vol 89 (8) ◽

pp. 673-678 ◽

Cited By ~ 11

Author(s):

Gan-Der Ho ◽

Chang-Hsien Yang

Keyword(s):

Arabidopsis Thaliana ◽

Bacterial Wilt ◽

Ralstonia Solanacearum ◽

Northern Blot Analysis ◽

Plant Diseases ◽

Glutathione S Transferase ◽

Solanacearum Strain ◽

Whole Plant ◽

Pathogenesis Related Protein ◽

Pathogenesis Related

Strains of Ralstonia solanacearum have been shown to cause bacterial wilt in some, but not all, ecotypes of Arabidopsis thaliana. We demonstrate here that after inoculation of the leaves of resistant ecotype S96 with R. solanacearum strain Ps95 necrosis around the inoculation site rapidly appeared and no further symptoms developed in the plant. Leaves of susceptible ecotype N913 completely wilted 7 days after inoculation with Ps95, and symptoms spread systemically throughout the whole plant within 2 weeks after inoculation. These results suggest that the resistance of Arabidopsis S96 to R. solanacearum is due to a response similar to the hypersensitive response (HR) observed in other plant diseases. Northern blot analysis of the expression of defense-related genes, known to be differentially induced during the HR in Arabidopsis, indicated that pathogenesis-related protein PR-1, glutathione S-transferase (GST1), and Cu, Zn superoxide dismutase (SOD) mRNAs increased significantly in S96 leaves between 3 to 12 h after infiltration with Ps95. The induction of these genes in susceptible ecotype N913 by Ps95 was clearly delayed. Genetic analysis of crosses between resistant ecotype S96 and susceptible ecotype N913 indicated that resistance to Ps95 is due to a single dominant locus.

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Simplified Evaluation Method for Suppressing Bacterial Wilt Disease by Treating Non-pathogenic Ralstonia solanacearum Mutant Selection in Eggplant

Horticultural Research (Japan) ◽

10.2503/hrj.11.393 ◽

2012 ◽

Vol 11 (3) ◽

pp. 393-398 ◽

Cited By ~ 2

Author(s):

Koichiro Ogawa ◽

Taro Mori ◽

Hiromi Matsusaki ◽

Naotaka Matsuzoe

Keyword(s):

Bacterial Wilt ◽

Ralstonia Solanacearum ◽

Evaluation Method ◽

Wilt Disease ◽

Mutant Selection ◽

Bacterial Wilt Disease

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Ralstonia solanacearum Needs Motility for Invasive Virulence on Tomato

Journal of Bacteriology ◽

10.1128/jb.183.12.3597-3605.2001 ◽

2001 ◽

Vol 183 (12) ◽

pp. 3597-3605 ◽

Cited By ~ 201

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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