Oregon State University

About: Oregon State University is a education organization based out in Corvallis, Oregon, United States. It is known for research contribution in the topics: Population & Gene. The organization has 28192 authors who have published 64044 publications receiving 2634108 citations. The organization is also known as: Oregon Agricultural College & OSU.

Use of multiline cultivars and cultivar mixtures for disease management

Abstract: The usefulness of mixtures (multiline cultivars and cultivar mixtures) for disease management has been well demonstrated for rusts and powdery mildews of small grain crops. Such mixtures are more useful under some epidemiological conditions than under others, and experimental methodology, especially problems of scale, may be crucial in evaluating the potential efficacy of mixtures on disease. There are now examples of mixtures providing both low and high degrees of disease control for a wide range of pathosystems, including crops with large plants, and pathogens that demonstrate low host specificity, or are splash dispersed, soilborne, or insect vectored. Though most analyses of pathogen evolution in mixtures consider static costs of virulence to be the main mechanism countering selection for pathogen complexity, many other potential mechanisms need to be investigated. Agronomic and marketing considerations must be carefully evaluated when implementing mixture approaches to crop management. Practical difficulties associated with mixtures have often been overestimated, however, and mixtures will likely play an increasingly important role as we develop more sustainable agricultural systems.

Carcinogenic polycyclic aromatic hydrocarbon-DNA adducts and mechanism of action.

Abstract: Polycyclic aromatic hydrocarbons (PAHs) are a class of widespread environmental carcinogens. Most of our knowledge of their mechanisms of metabolic activation to DNA-binding "ultimate carcinogenic" metabolites has come from analysis of the DNA interaction products formed by these highly reactive intermediates. Studies of their role in forming DNA-binding intermediates identical to those formed in vivo from the PAH itself have also allowed identification of the particular cytochrome P450 enzymes involved in activating various structural classes of carcinogenic PAHs. It has been established that PAHs, after metabolic activation in vivo, are capable of inducing mutations in oncogenes and, by inducing multiple mutations, may result in tumors. PAHs also cause changes in cellular gap-junction communication similar to those caused by the tumor promoter 12-O-tetradecanoylphorbol-13-acetate. Thus, PAHs may also act through a promotional mechanism in addition to serving as tumor initiators. Previous studies on these mechanisms are described and summarized.

Nutrient enrichment can increase the severity of coral diseases

Abstract: John F. Bruno*, Laura E. Petes, C. Drew Harvell and Annaliese Hettinger Department of Marine Sciences, The University of North Carolina, Chapel Hill, NC 27599-3300, USA Department of Zoology, Oregon State University, Corvallis, OR 97331, USA Section of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA Department of Biology, California State University, Northridge, CA 91330, USA *Correspondence: E-mail: jbruno@unc.edu Abstract The prevalence and severity of marine diseases have increased over the last 20 years, significantly impacting a variety of foundation and keystone species. One explanation is that changes in the environment caused by human activities have impaired host resistance and/or have increased pathogen virulence. Here, we report evidence from field experiments that nutrient enrichment can significantly increase the severity of two important Caribbean coral epizootics: aspergillosis of the common gorgonian sea fan Gorgonia ventalina and yellow band disease of the reef-building corals Montastraea annularis and M. franksii. Experimentally increasing nutrient concentrations by 2–5· nearly doubled host tissue loss caused by yellow band disease. In a separate experiment, nutrient enrichment significantly increased two measures of sea fan aspergillosis severity. Our results may help explain the conspicuous patchiness of coral disease severity, besides suggesting that minimizing nutrient pollution could be an important management tool for controlling coral epizootics.