Bacterial community dynamics of tomato hydroponic greenhouses infested with hairy root disease.

The rhizosphere is a complex ecosystem consisting of microbes in the interface between growth medium and plant roots, which affects plant productivity and health. This is one of the few studies analysing bacterial communities present in the rhizosphere of hydroponically grown plants. Tomato grown under hydroponic conditions is prone to hairy root disease (HRD) that is caused by rhizogenic Agrobacterium biovar 1 strains.

Potential for Biocontrol of Hairy Root Disease by a Clade.

Rhizogenic biovar 1 is the causative agent of hairy root disease (HRD) in the hydroponic cultivation of tomato and cucumber causing significant losses in marketable yield. In order to prevent and control the disease chemical disinfectants such as hydrogen peroxide or hypochlorite are generally applied to sanitize the hydroponic system and/or hydroponic solution. However, effective control of HRD sometimes requires high disinfectant doses that may have phytotoxic effects.

Assessment of the genetic and phenotypic diversity among rhizogenic Agrobacterium biovar 1 strains infecting solanaceous and cucurbit crops.

Rhizogenic Agrobacterium biovar 1 strains have been found to cause extensive root proliferation on hydroponically grown Cucurbitaceae and Solanaceae crops, resulting in substantial economic losses. As these agrobacteria live under similar ecological conditions, infecting a limited number of crops, it may be hypothesized that genetic and phenotypic variation among such strains is relatively low. In this study we assessed the phenotypic diversity as well as the phylogenetic and evolutionary relationships of several rhizogenic Agrobacterium biovar 1 strains from cucurbit and solanaceous crops.

Genome-Wide Characterization of ISR Induced in Arabidopsis thaliana by Trichoderma hamatum T382 Against Botrytis cinerea Infection.

In this study, the molecular basis of the induced systemic resistance (ISR) in Arabidopsis thaliana by the biocontrol fungus Trichoderma hamatum T382 against the phytopathogen Botrytis cinerea B05-10 was unraveled by microarray analysis both before (ISR-prime) and after (ISR-boost) additional pathogen inoculation. The observed high numbers of differentially expressed genes allowed us to classify them according to the biological pathways in which they are involved. By focusing on pathways instead of genes, a holistic picture of the mechanisms underlying ISR emerged.

From extensive clone libraries to comprehensive DNA arrays for the efficient and simultaneous detection and identification of orchid mycorrhizal fungi.

A DNA array was developed from extensive clone library sequence data sets for the assessment of dominant members of mycorrhizal fungi that associate with terrestrial orchid species. As a-proof-of-concept, the array was developed for the basidiomycetous mycorrhizal partners from three closely related perennial Orchis species, including Orchis anthropophora, O. militaris and O.

Evolutionary relationships between Fusarium oxysporum f. sp. lycopersici and F. oxysporum f. sp. radicis-lycopersici isolates inferred from mating type, elongation factor-1alpha and exopolygalacturonase sequences.

Fusarium oxysporum is a ubiquitous species complex of soilborne plant pathogens that comprises many different formae speciales, each characterized by a high degree of host specificity. In this study, the evolutionary relationships between different isolates of the F. oxysporum species complex have been examined, with a special emphasis on the formae speciales lycopersici and radicis-lycopersici, sharing tomato as host while causing different symptoms.