Complete genome sequences of strains GM1 and GM2, isolated from the leaves of garlic mustard.

We report the complete genomes of two strains, GM1 and GM2, isolated from garlic mustard plants. strain GM1 was found to carry a HiVir pantaphos biosynthetic gene cluster, which causes onion necrosis.

Pantailocins: phage-derived bacteriocins from and subsp. .

Phage-derived bacteriocins (tailocins) are ribosomally synthesized structures produced by bacteria in order to provide advantages against competing strains under natural conditions. Tailocins are highly specific in their target range and have proven to be effective for the prevention and/or treatment of bacterial diseases under clinical and agricultural settings. We describe the discovery and characterization of a new tailocin locus encoded within genomes of and subsp.

Draft genome sequences for ATCC 35400 and subspecies ICMP 10132.

Here, we describe draft genome sequences for two bacterial isolates from the genus . ATCC 35400 was originally isolated from honeydew melon and was obtained from the American Type Culture Collection. subspecies ICMP 10132 was originally isolated from sugarcane and classified as , but average nucleotide identity and discriminatory PCR support species reclassification.

Genome-wide association and dissociation studies in reveal potential virulence factors affecting and × hybrid.

is a member of a species complex that causes center rot of bulb onions () and also infects other crops like leeks (), chives (), bunching onion or Welsh onion (), and garlic (). This pathogen relies on a chromosomal phosphonate biosynthetic gene cluster (HiVir) and a plasmid-borne thiosulfinate tolerance cluster () for onion pathogenicity and virulence, respectively. However, pathogenicity and virulence factors associated with other species remain unknown.

The Genetic Requirements for HiVir-Mediated Onion Necrosis by , a Necrotrophic Plant Pathogen.

is an unusual bacterial pathogen that lacks typical virulence determinants yet causes extensive necrosis in onion foliage and bulb tissues. The onion necrosis phenotype is dependent on the expression of the phosphonate toxin, pantaphos, which is synthesized by putative enzymes encoded by the HiVir (high virulence) gene cluster. The genetic contributions of individual genes in HiVir-mediated onion necrosis remain largely unknown, except for the first gene, (phosphoenolpyruvate mutase, ), whose deletion resulted in the loss of onion pathogenicity.

Evaluating Options to Increase the Efficacy of Biocontrol Agents for the Management of spp. Under Field Conditions.

Center rot of onion is caused by a complex of plant pathogenic species, which can lead to significant yield losses in the field and during storage. Conventional growers use foliar protectants such as a mixture of copper bactericides and an ethylene-bis-dithiocarbamate (EBDC) fungicide to manage the disease; however, organic growers have limited management options besides copper-protectants. Biocontrol agents (BCAs) provide an alternative; however, their efficacy could be compromised due in part to their inability to colonize the foliage.

A Novel Biosynthetic Gene Cluster Across the Species Complex Is Important for Pathogenicity in Onion.

Onion center rot is caused by at least four species of genus (, , , and subsp). Critical onion pathogenicity determinants for were recently described, but whether those determinants are common among other onion-pathogenic species remains unknown. In this work, we report onion pathogenicity determinants in subsp and We identified two distinct secondary metabolite biosynthetic gene clusters present separately in different strains of onion-pathogenic subsp.

Validation of Species-Specific PCR Assays for the Detection of , , , and .

Species of represent a group of plant pathogenic bacteria that infect a variety of agro-economically important plant species. Among these, a complex of , , , and subsp. cause center rot in onion, resulting in significant economic losses.

The Distribution of Onion Virulence Gene Clusters Among spp.

is a gram-negative bacterium and the primary causal agent of center rot of onions in Georgia. Previous genomic studies identified two virulence gene clusters, HiVir and , associated with center rot. The HiVir gene cluster is required to induce necrosis on onion tissues via synthesis of pantaphos, (2-hydroxy[phosphono-methyl)maleate), a phosphonate phytotoxin.

Functional Characterization of a Global Virulence Regulator Hfq and Identification of Hfq-Dependent sRNAs in the Plant Pathogen .

To successfully infect plant hosts, the collective regulation of virulence factors in a bacterial pathogen is crucial. Hfq is an RNA chaperone protein that facilitates the small RNA (sRNA) regulation of global gene expression at the post-transcriptional level. In this study, the functional role of Hfq in a broad host range phytopathogen was determined.