Blueberry stem galls in Pacific Northwest are often attributed to Agrobacterium tumefaciens. The disease also is associated with indole-3-acetic-acid (IAA) producing bacteria, as described on cranberry stem gall. Lack of studies makes it difficult to conclude whether these two types of bacteria could be the causal agent of stem gall...
Erwinia amylovora is a plant pathogenic bacterium that causes the destructive disease fire blight of apple and pear. We examined the plasmid content of a collection of 305 isolates of E. amylovora from Washington and Oregon with PCR assays and RFLP. Nearly all isolates of E. amylovora carried plasmid pEA29,...
Fire blight is a serious disease of apple and pear trees caused by the bacterium, Erwinia amylovora. This bacterium harbors a pathogenesis mechanism known as the Hrp secretory operon which induces some resistance genes and suppresses other resistance genes in the host plant following invasion. While previous researchers analyzed expression...
Pantoea vagans C9-1 (C9-1) is a biological control agent sprayed onto apple and pear trees during bloom for suppression of fire blight, a devastating bacterial disease caused by Erwinia amylovora. Prior bioinformatics studies of C9-1 focused on predicted phenotypes associated with the three native megaplasmids, pPag1, pPag2, and pPag3, and...
Competitive exclusion has been the mechanism hypothesized to account for the biological control of fire blight disease of pear and apple by the bacterium Pseudomonas fluorescens A506 (A506). Recent laboratory assays demonstrated, however, that A506 produces an antibiotic that is toxic to the fire blight pathogen, Erwinia amylovora, when cultured...
Thiamin is an essential nutrient in the human diet. Severe thiamin deficiency leads to beriberi, a lethal disease which is common in developing countries. Thiamin biofortification of staple food crops is a possible strategy to alleviate thiamin deficiency-related diseases. In plants, thiamin plays a role in the response to abiotic...
Succinate dehydrogenase (Sdh) inhibitor fungicides, such as boscalid, are effective for the management of gray mold caused by the fungal pathogen Botrytis cinerea. Unfortunately, resistance to boscalid was common among isolates of the pathogen from small fruits grown in Oregon. Boscalid-resistance is commonly associated with mutations in Sdh, especially in...
Cotoneaster is a genus of ornamental landscape plants commonly affected by fire blight. Fire blight is a disease caused by the bacterial pathogen, Erwinia amylovora (Burrill) Winslow et al. that attacks a wide range of taxa in the apple subfamily (Maloideae; Rosaceae). To assess susceptibility of species and identify potential...
Bacterial blight (Xanthomonas arboricola pv. corylina) (Xac) of hazelnut (Corylus avellana L.) was described first in Oregon in 1915 and is now recognized as a damaging disease of young hazelnut trees worldwide. Stressed hazelnut trees in conditions such as planting on marginal sites, and trees between 1 and 4-years-old are...
Corylus avellana L. is a global commodity and a valuable crop for the U.S. Pacific Northwest. A tremendous amount of work has been put into the development of healthy disease free, high yielding and tasty hazelnuts for the in-shell and confectionary markets. Clonal propagation is required to provide nursery trees...
The leaf surface is a stark environment for bacterial colonists with limited
availability of nutrients, water and protected niches. Despite these limitations, a
plethora of bacteria appear to have adapted ways to survive and flourish on leaf
surfaces. One mechanism of survival is the formation of biofilms. Biofilms are a...
Landscape plants are highly diverse and nursery producers often grow thousands of taxa to satisfy the varied needs and aesthetic tastes of consumers. Related to this diversity, ornamental plant breeders must be nimble and diverse in their approach. Two seemingly disparate studies were conducted to investigate improving ornamental shrubs –...
Cotoneaster is an ornamental shrub valued for showy flowers, berries and architecture as well as the ability tolerate adverse conditions under which other taxa fail. Cotoneaster is a highly diverse genus of over 400 species, of which few are available in the US nursery trade. Some species commercially available have...
Pseudomonas is a diverse genus of Gram-negative bacteria that includes pathogens of plants, insects, and humans as well as environmental strains with no known pathogenicity. Pseudomonas fluorescens itself encompasses a heterologous group of bacteria that are prevalent in soil and on foliar and root surfaces of plants. Some strains of...
Antibiotics are essential for control of bacterial diseases of plants, especially fire blight of pear and apple and bacterial spot of peach. Streptomycin is used in several countries; the use of oxytetracycline, oxolinic acid and gentamicin is limited to only a few countries. Springtime antibiotic sprays suppress pathogen growth on...
Conjugative plasmids are known to facilitate the acquisition and dispersal of genes contributing to the fitness of Pseudomonas spp. Here, we report the characterization of pA506, the 57-kb conjugative plasmid of Pseudomonas fluorescens A506, a plant epiphyte used in the United States for the biological control of fire blight disease...
Virginia Woolf was a self-proclaimed atheist, yet her fictional and personal writing
reveal her ecstatic consciousness. Characters in Woolf s novels experience ecstasy, and
her letters and diaries support the theory that she herself had experienced ecstatic
consciousness. Major figures in the philosophy of religion assert that ecstatic
consciousness is...
Secondary metabolites are synthesized by many microorganisms and provide a fitness benefit in the presence of competitors and predators. Secondary metabolism also can be costly, as it shunts energy and intermediates from primary metabolism. In Pseudomonas spp., secondary metabolism is controlled by the GacS-GacA global regulatory system. Intriguingly, spontaneous mutations...
Cnidarians, such as corals and sea anemones serve as hosts to a variety of organisms including symbiotic dinoflagellates, bacteria, virus, and apicomplexans. As corals are vital to the health and productivity of the reef ecosystem it is important to understand how these organisms interact with each component of the holobiont....