Dataset Information

Complete Genome Sequence of Ralstonia solanacearum FJAT-91, a High-Virulence Pathogen of Tomato Wilt.

ABSTRACT: Ralstonia solanacearum FJAT-91, which displays higher virulence toward plants belonging to the family Solanaceae, was isolated from a wilted tomato plant vessel in Fujian province, southeast China. Here, we report the complete genome sequence of R. solanacearum FJAT-91 using long-read single-molecule PacBio sequencing technology. The genome comprises a 3,873,214-bp circular chromosome and a 2,000,873-bp circular megaplasmid with an overall G+C content of 66.85%.

SUBMITTER: Chen D

PROVIDER: S-EPMC5597756 | biostudies-literature | 2017 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Complete Genome Sequence of Ralstonia solanacearum FJAT-91, a High-Virulence Pathogen of Tomato Wilt.

Chen Deju D Liu Bo B Zhu Yujing Y Zhang Haifeng H Chen Zheng Z Zheng Xuefang X Xiao Rongfeng R Chen Yanping Y

Genome announcements 20170914 37

Ralstonia solanacearum FJAT-91, which displays higher virulence toward plants belonging to the family Solanaceae, was isolated from a wilted tomato plant vessel in Fujian province, southeast China. Here, we report the complete genome sequence of R. solanacearum FJAT-91 using long-read single-molecule PacBio sequencing technology. The genome comprises a 3,873,214-bp circular chromosome and a 2,000,873-bp circular megaplasmid with an overall G+C content of 66.85%. ...[more]

PMID: 28912315

Similar Datasets

Project description:Plant xylem fluid is considered a nutrient-poor environment, but the bacterial wilt pathogen Ralstonia solanacearum is well adapted to it, growing to 10(8) to 10(9) CFU/g tomato stem. To better understand how R. solanacearum succeeds in this habitat, we analyzed the transcriptomes of two phylogenetically distinct R. solanacearum strains that both wilt tomato, strains UW551 (phylotype II) and GMI1000 (phylotype I). We profiled bacterial gene expression at ~6 × 10(8) CFU/ml in culture or in plant xylem during early tomato bacterial wilt pathogenesis. Despite phylogenetic differences, these two strains expressed their 3,477 common orthologous genes in generally similar patterns, with about 12% of their transcriptomes significantly altered in planta versus in rich medium. Several primary metabolic pathways were highly expressed during pathogenesis. These pathways included sucrose uptake and catabolism, and components of these pathways were encoded by genes in the scrABY cluster. A UW551 scrA mutant was significantly reduced in virulence on resistant and susceptible tomato as well as on potato and the epidemiologically important weed host Solanum dulcamara. Functional scrA contributed to pathogen competitive fitness during colonization of tomato xylem, which contained ~300 µM sucrose. scrA expression was induced by sucrose, but to a much greater degree by growth in planta. Unexpectedly, 45% of the genes directly regulated by HrpB, the transcriptional activator of the type 3 secretion system (T3SS), were upregulated in planta at high cell densities. This result modifies a regulatory model based on bacterial behavior in culture, where this key virulence factor is repressed at high cell densities. The active transcription of these genes in wilting plants suggests that T3SS has a biological role throughout the disease cycle. IMPORTANCE Ralstonia solanacearum is a widespread plant pathogen that causes bacterial wilt disease. It inflicts serious crop losses on tropical farmers, with major economic and human consequences. It is also a model for the many destructive microbes that colonize the water-conducting plant xylem tissue, which is low in nutrients and oxygen. We extracted bacteria from infected tomato plants and globally identified the biological functions that R. solanacearum expresses during plant pathogenesis. This revealed the unexpected presence of sucrose in tomato xylem fluid and the pathogen's dependence on host sucrose for virulence on tomato, potato, and the common weed bittersweet nightshade. Further, R. solanacearum was highly responsive to the plant environment, expressing several metabolic and virulence functions quite differently in the plant than in pure culture. These results reinforce the utility of studying pathogens in interaction with hosts and suggest that selecting for reduced sucrose levels could generate wilt-resistant crops.

Project description: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 that R. 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 lacking fliC or fliM were created by replacing the genes with marked interrupted constructs. Since fliM is embedded in the fliLMNOPQR operon, the aphA cassette 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.

Dataset Information

Complete Genome Sequence of Ralstonia solanacearum FJAT-91, a High-Virulence Pathogen of Tomato Wilt.

Publications

Complete Genome Sequence of <i>Ralstonia solanacearum</i> FJAT-91, a High-Virulence Pathogen of Tomato Wilt.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets