The kinetic mechanism of the unidirectional
H2-oxidizing hydrogenase from soybean nodule bacteroids has
been investigated with highly purified enzyme. Measurements
of the K, for H2 vary from 0.97 to 2.6 pM, and the K,,, for
methylene blue varies from 6 to 17 pM. With H2 and
methylene blue as substrates,...
Published July 1981. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Carbonyl sulfide (COS) has been investigated as a rapid-equilibrium inhibitor of CO oxidation
by the CO dehydrogenase purified from Rhodospirillum rubrum. The kinetic evidence suggests that the
inhibition by COS is largely competitive versus CO (Ki = 2.3 pM) and uncompetitive versus methylviologen
as electron acceptor (Ki = 15.8 pM)....
The virus-encoded proteins of tobacco etch virus (TEV), a plant potyvirus, arise by proteolytic processing of
a large polyprotein precursor. The TEV genome codes for two proteinases, a 49-kilodalton proteinase and
helper component proteinase (HC-Pro), which cleave the polyprotein at specific sites. The only known cleavage
event catalyzed by HC-Pro...
This scanned article is provided to correct an error on the publisher’s website. The online version has incorrectly given the first author name as “Listen, Aaron” rather than the correct, “Liston, Aaron.” If using this article, please cite the first author correctly.
The RNA genome of tobacco etch virus (TEV), a plant potyvirus, functions as an mRNA for synthesis of a
346-kilodalton polyprotein that undergoes extensive proteolytic processing. The RNA lacks a normal 5' cap
structure at its terminus, which suggests that the mechanism of translational initiation differs from that of a...
Climatic conditions in southern Oregon are unique among the wine-growing regions of the Pacific Northwest. Previous experience has shown that one strength of this region lies in the production of warm-climate cultivars which may not mature properly in other regions of Oregon. The current selection of such cultivars with known...
Gray mold of grape, caused by Botrytis cinerea, can be a serious problem in Oregon vineyards. Disease control has been achieved primarily through the application of foliar fungicides. For a time, the fungicide benomyl provided outstanding control of this disease; however, by the late-1970's, strains of B. cinerea resistant to...
The immediate objective of this project is to establish a vineyard at the Southern Oregon Experiment Station in which previously untested wine grape cultivars will be evaluated. The ultimate goal is to characterize the production and wine qualitypotential of these cultivars in southern Oregon.
To determine if the distribution and frequency of dicarboximide resistance in the Botrytis population in vineyards in western Oregon is rapidly changing or remaining relatively stable. 2. To determine the relationship between fungicide use and the frequency of dicarboximide-resistant strains of Botrytis cinerea in grape, raspberry, snap bean, and strawberry...
The effects of nitric oxide (NO) on the individual components of Azotobacter vinelandii
nitrogenase have been examined by kinetic and spectroscopic methods. Incubation of the Fe protein (Av2)
for 1 h with stoichiometries of 4- and 8-fold molar excesses of NO to Av2 dimer resulted in a complete
loss of...
Acetylene is a slow-binding inhibitor of the Ni- and Fe-containing dimeric hydrogenase isolated
from Azotobacter vinelandii. Acetylene was released from hydrogenase during the recovery from inhibition.
This indicates that no transformation of acetylene to another compound occurred as a result of the interaction
with hydrogenase. However, the release of C2H2...
To characterize the cultural aspects, maturation, production, and wine quality of several untested Italian, French, and Spanish wine cultivars in southern Oregon.
Four year old vines of 18 varieties were cane pruned, trained to a Scott Henry, thinned before veraison, and harvested in October and November 1993. Two of the varieties, Chardonnay and Cabernet Sauvignon, were used as standards. Only four varieties were spur pruned to reduce cropping or cluster size: Dolcetto,...
Objectives: 1. Survey Oregon vineyards for the presence, identity and abundance of plant parasitic nematodes. 2. Document seasonal changes in abundance of species of important plant parasites in order to identify optimum times for sampling. 3. Evaluate the efficacy of Nemacur for reducing populations of plant parasitic nematodes.
Since phylloxera's discovery in a commercial vineyard in August of 1990, nine infestations have been verified in Oregon. With over 95% of Oregon's vineyards planted with ownrooted, Vitis vinifera, non-resistant vines, understanding the insect's biology under our conditions has become important for determining management strategies that minimize rate of spread....
Seed size, abundance, viability, dormancy, and germination requirements strongly influence plant establishment and therefore are important considerations in restoration of native vegetation. These characteristics provide criteria for selection of suitable species, development of collection and pretreatment methods, and determination of seeding densities. The first set of objectives of this study...
Objectives 1. Survey Oregon vineyards for the presence, identity and abundance of plant-parasitic nematodes. 2. Relate the distribution and abundance of potentially pathogenic species to viticultural practices and site characteristics. 3. Evaluate the efficacy of Nemacur for reducing populations of plant-parasitic nematodes. 4. Document seasonal changes in the abundance of...
The objectives of this study are to isolate and characterize pathogenic agrobacteria that cause crown gall in grapevines and test hot water dips as a method for eradicating the infectious bacteria . Crown gall is commonly found among Oregon vineyards and the causative agent, Agrobacterium vitis, is known to be...
A genetic complementation system was developed
in which tobacco etch virus (TEV) polymerase (NIb)-
expressing transgenic plants or protoplasts were inoculated
with NIb-defective TEV mutants. A β-glucuronidase (GUS)
reporter gene integrated into the genomes of parental and four
mutant viruses was used to assay RNA amplification. Two
mutants (termed VNN...
Tobacco etch virus (TEV) encodes three proteinases that catalyze processing of the genome-encoded polyprotein.
The P1 proteinase originates from the N terminus of the polyprotein and catalyzes proteolysis between
itself and the helper component proteinase (HC-Pro). Mutations resulting in substitution of a single amino
acid, small insertions, or deletions were...
Erigeron decumbens var. decumbens, the Willamette Daisy, is endemic to the Willamette Valley of Oregon. This taxon is a Category 1 Candidate for listing under the federal Endangered Species Act (U.S. Fish and Wildlife Service 1990) and is listed as Endangered under Oregon state law. Herbarium records indicate that E....
Erigeron decumbens var. decumbens, the Willamette daisy, is known only from the Willamette Valley of Oregon. Herbarium records, from the 1800's until 1934, indicate that the Willamette daisy was once common and widely distributed throughout the Willamette Valley (Clark et al. 1993). However, between 1934 and 1980, this taxon was...
The tobacco etch potyvirus (TEV) polyprotein is proteolytically processed by three viral proteinases (NIa,
HC-Pro, and P1). While the NIa and HC-Pro proteinases each provide multiple functions essential for viral
infectivity, the role of the P1 proteinase beyond its autoproteolytic activity is understood poorly. To determine
if P1 is necessary...
We report first-year results from two field experiments evaluating the effectiveness of various techniques for the control of pest plants in Fender's blue butterfly habitat. In the woody-plant study, we monitored the effects of mowing, mowing and herbicides, and burning on woody plants and key native and non-native grasses and...
Oregon is a leader in production of premium wines in the United States and the industry has been expanding rapidly over the past few years. However, continued production and expansion of vineyards are threatened by infestation of phylloxera, Daktulospaira vitifoliae, an insect that feeds on roots. Most grapevines in Oregon...
Objectives 1. Survey Oregon vineyards for the presence, identity and abundance of plant-parasitic nematodes. 2. Relate the distribution and abundance of potentially pathogenic species to viticultural practices and site characteristics. 3. Evaluate the efficacy of Nemacur for reducing populations of plant-parasitic nematodes. 4. Document seasonal changes in the abundance of...
The septoria diseases of winter wheat are a limiting factor to wheat production in the Willamette Valley. This publication will describe the symptoms and development of the septoria diseases, including the influence of environmental conditions, the reactions of different cultivars to Septoria, the impact of Septoria on yield, and control...
One goal of this environmental education curriculum is that students will gain an appreciation of Willamette Valley wetland prairies, a threatened ecosystem, and will gain an understanding of the importance of protecting these wetlands. A second goal is that students will see first-hand the processes involved in conducting scientific field...
A mutational analysis was conducted to investigate the functions of the tobacco etch potyvirus VPgproteinase
(NIa) protein in vivo. The NIa N-terminal domain contains the VPg attachment site, whereas the
C-terminal domain contains a picornavirus 3C-like proteinase. Cleavage at an internal site separating the two
domains occurs in a subset...
We report results from a field experiment evaluating the effectiveness of mowing, mowing and herbicides, and burning on woody plants, key native and non-native grasses and forbs, and the Fender's blue butterfly. The goal was to find a technique that controlled woody pest plants without harming native species or promoting...
Survey data compiled in 1995 showed that plant-pathogenic nematodes that cause yield loss in California and European vineyards are found in over 85% of Oregon vineyards. In over 37% of the samples collected, population densities of Xiphinema wnericanwn (dagger nematode) and Criconenw1la xenoplax (ring nematode) were greater than levels known...
Three forecasting programs for scheduling fungicide applications were selected for comparison with the standard Oregon phenology based program. The UCDavis (California) program used leaf wetness and temperature early in the year and only temperature during the summer. The New York program was based on rainfall and temperature. The German Oi...
The nng nematode, Cnconenwlla xenoplax, has been reported to depress the vigor and yields of grapevines in Europe, California, Washington, and Michigan. Population densities of 500 C. xenoplax per kg of soil have reported to reduce vine yield 10-25% in California. A survey of Oregon vineyards found C. xenoplax in...
Crown gall can develop on grapevines wounded by freezing temperatures, mechanical damage or grafting. Increased demand for grape varieties grafted to phylloxera resistant rootstocks has led to increased incidence of crown gall at graft unions. Therefore a search for plant material that is resistant to crown gall has been undertaken....
Strobilus production, growth, and morphology of Pacific yew (Taxus brevifolia Nutt.) were examined at three sites in the Cascade Mountains and one site in the Willamette Valley of western Oregon. Strobilus production on branch segments was positively associated with overstory openness for male and female trees at all four sites...
We report results from a field experiment evaluating the effectiveness of mowing, mowing and herbicides, and burning on woody plants, key native and non-native grasses and forbs, and the Fender’s blue butterfly. The goal was to find a technique that controlled woody pest plants without harming native species or promoting...
Native prairies, which once dominated the landscape of the Willamette Valley, are considered among the rarest of Oregon's ecosystems. Even though only remnants remain today, they harbor rare and endangered species such as the Fender's blue butterfly (Icaricia icariodes fenderi) and its preferred host plant, Kincaid's lupine (Lupinus sulphureus ssp....
Develop a cost-effective system for identifying potential biological control agents of powdery mildew on grape that are efficacious in the Pacific Northwest. 2. Begin a primary screening program to develop biological control agents specifically adapted to the Pacific Northwest.
Three forecasting programs for scheduling fungicide applications were selected for comparison with the standard Oregon phenology based program. The California (Gubler-Thomas, UC-Davis) program used leaf wetness and temperature early in the year to predict ascospore infection periods and only temperature during the summer to predict conidial infection periods. The New...
Native upland prairies, which once dominated the landscape of the Willamette Valley, are considered among the rarest of Oregon's ecosystems. Even though only remnants remain today, they harbor many rare and endangered species such as the Fender's blue butterfly and its host plant, Kincaid’s lupine. Invasion of remnant prairies by...
Plant-pathogenic nematodes that cause yield loss in California and European vineyards are found in over 85 % of Oregon vineyards. Population densities of Xiphinema americanun (dagger nematode) and Criconemella xenoplax (ring nematode) were found in 37% of vineyards at levels reported to cause > 10-25% loss in California vineyards. However,...
Crown gall can develop on grapevines wounded by freezing temperatures, mechanical damage or grafting. Pathogenic agrobacteria residing within the vascular system are able to initiate tumor growth in damaged plant cells. Sampling from 21 sites in Oregon vineyards and nurseries yielded diverse populations of pathogenic agrobacteria. Most of the pathogenic...