The bacterium Ralstonia solanacearum is a widely accepted model organism for the study of pathogenicity in plants [1]. This soil-borne bacterium, which belongs to the betaproteobacteria, is responsible for bacterial wilt on more than 200 plant species from 50 botanical families, including important crops such as potato, tomato, eggplant, pepper, tobacco and banana. In fact, bacterial wilt is co...

This study aims to isolate and identify the causal pathogen of tomato bacterial wilt in Egypt. In 2008, tomato plants showing typical symptoms of bacterial wilt disease with no foliar yellowing were observed in Minia, Assiut and Sohag governorates, Egypt. When cut stems of symptomatic plants were submerged in water, whitish ooze was evident and longitudinal sections showed a brown discoloration...

Most strains of the bacterial wilt pathogen Ralstonia solanacearum are tropical, but race 3 biovar 2 (R3bv2) strains can attack plants in temperate zones and tropical highlands. The basis of this distinctive ecological trait is not understood. We compared the survival of tropical, R3bv2, and warm-temperate North American strains of R. solanacearum under different conditions. In water at 4 degre...

Some phages from genus Inovirus use host or bacteriophage-encoded site-specific integrases or recombinases establish a prophage state. During integration or excision, a superinfective form can be produced. The three states (free, prophage, and superinfective) of such phages exert different effects on host bacterial phenotypes. In Ralstonia solanacearum, the causative agent of bacterial wilt dis...

Phytopathogenic strains of Burkholderia cepacia (synonym Pseudomonas cepacia) produce endopolygalacturonase, whereas strains of clinical and soil origin do not. Growth of a phytopathogenic strain (ATCC25416) at elevated temperatures resulted in nonpectolytic derivatives that were either cured of a resident plasmid or contained a plasmid of reduced mass. The resident 200-kb plasmid (pPEC320) in ...

Bacillus subtilis JW-1 was isolated from rhizosphere soil as a potential biocontrol agent of bacterial wilt caused by Ralstonia solanacearum. Seed treatment followed by a soil drench application with this strain resulted in >80% reduction in bacterial wilt disease compared with that in the untreated control under greenhouse conditions. The antibacterial compound produced by strain JW-1 was puri...

The current bacterial wilt infestation level in the potato fields in the Peruvian Andes was investigated by collecting stem samples from wilted plants and detecting Ralstonia solanacearum. In total 39 farmers' fields located in the central and northern Peru between the altitudes 2111 and 3742 m above sea level were sampled. R. solanacearum was detected in 19 fields, and in 153 out of the 358 sa...

Ralstonia eutropha JMP134(pJP4) and several other species of motile bacteria can degrade the herbicide 2,4-dichlorophenoxyacetate (2,4-D), but it was not known if bacteria could sense and swim towards 2,4-D by the process of chemotaxis. Wild-type R. eutropha cells were chemotactically attracted to 2,4-D in swarm plate assays and qualitative capillary assays. The chemotactic response was induced...

Ralstonia solanacearum is the causal agent of bacterial wilt of many agriculturally important crops. Exopolysaccharide synthesized by products of the epsI operon is the major virulence factor for R. solanacearum. Expression of epsI has been demonstrated to be under the control of several proteins, including several two-component regulators. Overexpression of EpsR was found previously to reduce ...

The biosynthesis of [NiFe] hydrogenases is a complex process that requires the function of the Hyp proteins HypA, HypB, HypC, HypD, HypE, HypF, and HypX for assembly of the H(2)-activating [NiFe] site. In this study we examined the maturation of the regulatory hydrogenase (RH) of Ralstonia eutropha. The RH is a H(2)-sensing [NiFe] hydrogenase and is required as a constituent of a signal transdu...