Genomic insights into a Pseudomonas amygdali isolate from Hibiscus rosa-sinensis.

The taxonomy of Pseudomonas has been extensively studied, yet the determination of species is currently difficult because of recent taxonomic changes and the lack of complete genomic sequence data. We isolated a bacterium causing a leaf spot disease on hibiscus (Hibiscus rosa-sinensis). Whole genome sequencing revealed similarity to Pseudomonas amygdali pv.

Virulence of oomycete pathogens from Phragmites australis-invaded and noninvaded soils to seedlings of wetland plant species.

Soil pathogens affect plant community structure and function through negative plant-soil feedbacks that may contribute to the invasiveness of non-native plant species. Our understanding of these pathogen-induced soil feedbacks has relied largely on observations of the collective impact of the soil biota on plant populations, with few observations of accompanying changes in populations of specific soil pathogens and their impacts on invasive and noninvasive species. As a result, the roles of specific soil pathogens in plant invasions remain unknown.

Soil pathogen communities associated with native and non-native Phragmites australis populations in freshwater wetlands.

Soil pathogens are believed to be major contributors to negative plant-soil feedbacks that regulate plant community dynamics and plant invasions. While the theoretical basis for pathogen regulation of plant communities is well established within the plant-soil feedback framework, direct experimental evidence for pathogen community responses to plants has been limited, often relying largely on indirect evidence based on above-ground plant responses. As a result, specific soil pathogen responses accompanying above-ground plant community dynamics are largely unknown.

Diversity of peronosporomycete (oomycete) communities associated with the rhizosphere of different plant species.

Peronosporomycete (oomycete) communities inhabiting the rhizospheres of three plant species were characterized and compared to determine whether communities obtained by direct soil DNA extractions (soil communities) differ from those obtained using baiting techniques (bait communities). Using two sets of Peronosporomycete-specific primers, a portion of the 5' region of the large subunit (28S) rRNA gene was amplified from DNA extracted either directly from rhizosphere soil or from hempseed baits floated for 48 h over rhizosphere soil. Amplicons were cloned, sequenced, and then subjected to phylogenetic and diversity analyses.