90 results match your criteria: "Beltsville Agricultural Research Center-west[Affiliation]"

Parallel reductions in phenolic constituents resulting from the domestication of eggplant.

Phytochemistry

July 2015

The New York Botanical Garden, 2900 Southern Blvd, Bronx, NY 10458, United States.

Crop domestication is often accompanied by changes in metabolite compositions that alter traits such as flavor, color, or other beneficial properties. Fruits of eggplants (Solanum melongena L.) and related species are abundant and diverse in pharmacologically interesting phenolic compounds, particularly hydroxycinnamic acid (HCA) conjugates such as the antioxidant caffeoylquinic acids (CQA) and HCA-polyamine amides (HCAA).

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Trypanosomatids are increasingly recognized as prevalent in European honey bees (Apis mellifera) and by default are attributed to one recognized species, Crithidia mellificae Langridge and McGhee, 1967. We provide reference genetic and ultrastructural data for type isolates of C. mellificae (ATCC 30254 and 30862) in comparison with two recent isolates from A.

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Frosty pod rot (FPR) of Theobroma cacao (cacao) is caused by the hemibiotrophic fungus Moniliophthora roreri. Cacao clones tolerant to FPR are being planted throughout Central America. To determine whether M.

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Background: The basidiomycete Moniliophthora roreri is the causal agent of Frosty pod rot (FPR) disease of cacao (Theobroma cacao), the source of chocolate, and FPR is one of the most destructive diseases of this important perennial crop in the Americas. This hemibiotroph infects only cacao pods and has an extended biotrophic phase lasting up to sixty days, culminating in plant necrosis and sporulation of the fungus without the formation of a basidiocarp.

Results: We sequenced and assembled 52.

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Article Synopsis
  • Understanding the tolerance mechanisms of Theobroma cacao against the frosty pod rot fungus Moniliophthora roreri is crucial for developing disease-resistant clones.
  • RNA-Seq analysis identified 3009 transcripts with different expression levels between tolerant and susceptible cacao clones, revealing major shifts in 152 metabolic pathways.
  • Tolerant clones showed increased expression of defense-related genes at low levels of infection, indicating a proactive immune response, while susceptible clones exhibited a delayed response as infection progressed.
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Isolongifolenone: a novel sesquiterpene repellent of ticks and mosquitoes.

J Med Entomol

January 2009

USDA-ARS, Invasive Insect Biocontrol and Behavior Laboratory, Beltsville Agricultural Research Center-West, Beltsville, MD 20705, USA.

A naturally occurring sesquiterpene, isolongifolenone, derivatives of which have been used extensively as ingredients in the cosmetics industry, was discovered to effectively repel blood-feeding arthropods that are important disease vectors. We show that (-)-isolongifolenone deters the biting of the mosquitoes, Aedes aegypti (L.) and Anopheles stephensi Liston, more effectively than the widely used synthetic chemical repellent, N,N-diethyl-3-methyl benzamide (DEET), in laboratory bioassays.

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Activity evaluation of cocoa pod borer sex pheromone in cacao fields.

Environ Entomol

June 2008

USDA-ARS, Invasive Insect Biocontrol and Behavior Laboratory, Beltsville Agricultural Research Center-West, Beltsville, MD 20705, USA.

The previously identified female sex pheromone of cocoa pod borer, Conopomorpha cramerella, was re-evaluated for its attractive activity in different field conditions. It was found that lures containing 100-mug of synthetic sex pheromone blend, (E,Z,Z)- and (E,E,Z)-4,6,10-hexadecatrienyl acetates, and the corresponding alcohols in a ratio of 40:60:4:6 in a polyethylene vial attracted male C. cramerella moths in Sabah and peninsular Malaysia and in Sumatra and Sulawesi, Indonesia, suggesting that the same pheromone strain existed in a wide stretch of the Indo-Malayan archipelago.

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Phvytophthora megakarya is a devastating oomycete pathogen that causes black pod disease in cacao. Phytophthora species produce a protein that has a similar sequence to the necrosis and ethylene inducing protein (Nep1) of Fusarium oxysporum. Multiple copies of NEP1 orthologs (PmegNEP) have been identified in P.

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Tolerance of a field grown soybean cultivar to elevated ozone level is concurrent with higher leaflet ascorbic acid level, higher ascorbate-dehydroascorbate redox status, and long term photosynthetic productivity.

Photosynth Res

January 2000

USDA, Agricultural Research Service, Beltsville Agricultural Research Center-West, Natural Resources Institute, Climate Stress Laboratory, Building 046A, Beltsville, MD, 20705-2350, USA.

We examined the characteristics of ascorbic acid (ASC) level, dehydroascorbate (DHA) level, and the ASC-DHA redox status in the leaflets of two soybean cultivars grown in a field environment and exposed to elevated ozone (O(3)) levels. These two cultivars, one that preliminary evidence indicated to be O(3)-tolerant (cv Essex), and one that was indicated to be O(3)-sensitive (cv Forrest), were grown in open-top chambers during the summer of 1997. The plants were exposed daily to a controlled, moderately high O(3) level ( approximately 58 nl l(-1) air) in the light, beginning at the seedling stage and continuing to bean maturity.

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Sex pheromone of the dogwood borer, Synanthedon scitula.

J Chem Ecol

October 2005

Chemicals Affecting Insect Behavior Laboratory, Beltsville Agricultural Research Center-West, USDA Agricultural Research Services, Beltsville, MD 20705, USA.

The sex pheromone of female dogwood borers (DWB) Synanthedon scitula (Harris) (Lepidoptera: Sesiidae) was determined to be an 88:6:6 ternary blend of (Z,Z)-3,13-octadecadienyl acetate (Z,Z-3,13-ODDA), (E,Z)-2,13-octadecadienyl acetate (E,Z-2,13-ODDA), and (Z,E)-3,13-octadecadienyl acetate (Z,E-3,13-ODDA) by gas chromatography-electroantennographic detection (GC-EAD) and gas chromatography-mass spectrometry (GC-MS). The major sex pheromone component, Z,Z-3,13-ODDA, was attractive as a single component. A blend of Z,Z-3,13-ODDA with 1-3% of E,Z-2,13-ODDA (binary blend) was more attractive than the single component.

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Developmental expression of stress response genes in Theobroma cacao leaves and their response to Nep1 and a compatible infection by Phytophthora megakarya were studied. Ten genes were selected to represent genes involved in defense (TcCaf-1, TcGlu1,3, TcChiB, TcCou-1, and TcPer-1), gene regulation (TcWRKY-1 and TcORFX-1), cell wall development (TcCou-1, TcPer-1, and TcGlu-1), or energy production (TcLhca-1 and TcrbcS). Leaf development was separated into unexpanded (UE), young red (YR), immature green (IG), and mature green (MG).

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Cross-contamination of lettuce (Lactuca sativa L.) with Escherichia coli O157:H7 via contaminated ground beef.

J Food Prot

July 2003

U.S. Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center-West, Plant Sciences Institute, Produce Quality and Safety Laboratory, Building 002, Room 117, 10300 Baltimore Avenue, Beltsville, Maryland 20705, USA.

A lettuce outbreak strain of E. coli O157:H7 was used to quantitate the pathogen's survival in ground beef and its transfer to hands, cutting board surfaces, and lettuce. Overnight storage of inoculated beef at 4 degrees C resulted in no pathogen growth, while room-temperature storage allowed multiplication.

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Phosphorylation of the D1 photosystem II reaction center protein is controlled by an endogenous circadian rhythm.

Plant Physiol

December 2002

Vegetable Laboratory, The Henry A Wallace Beltsville Agricultural Research Center-West, United States Department of Agriculture-Agricultural Research Service, Beltsville, Maryland 20705-2350, USA.

The light dependence of D1 phosphorylation is unique to higher plants, being constitutive in cyanobacteria and algae. In a photoautotrophic higher plant, Spirodela oligorrhiza, grown in greenhouse conditions under natural diurnal cycles of solar irradiation, the ratio of phosphorylated versus total D1 protein (D1-P index: [D1-P]/[D1] + [D1-P]) of photosystem II is shown to undergo reproducible diurnal oscillation. These oscillations were clearly out of phase with the period of maximum in light intensity.

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Site-directed mutagenesis was used to identify cis-acting elements that control hormonal and abscission-specific expression of the bean (Phaseolus vulgaris) abscission cellulase (BAC) promoter. Auxin inhibition of BAC promoter expression is at least in part controlled by a negatively regulated element and ethylene induction by a positively regulated element. One of a series of 15 different 10-bp mutations created in a 2.

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Volatile compounds emitted by sclerotia of Sclerotinia minor, Sclerotinia sclerotiorum, and Sclerotium rolfsii.

J Agric Food Chem

June 2002

Building 010A Room 238, Henry A. Wallace Beltsville Agricultural Research Center-West, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland 20705, USA.

Volatile compounds emitted by sclerotia of Sclerotinia minor, Sclerotinia sclerotiorum, and Sclerotium rolfsii were identified by solid phase microextraction followed by gas chromatography and mass spectometry. Both S. minor and S.

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Adjustments of net photosynthesis in Solanum tuberosum in response to reciprocal changes in ambient and elevated growth CO2 partial pressures.

Physiol Plant

May 2001

U.S.D.A., Agricultural Research Service, Climate Stress Laboratory, Bldg. 046-A, 10300 Baltimore Avenue, Beltsville Agricultural Research Center - West, Beltsville, MD 20705-2350, USA.

Single leaf photosynthetic rates and various leaf components of potato (Solanum tuberosum L.) were studied 1-3 days after reciprocally transferring plants between the ambient and elevated growth CO2 treatments. Plants were raised from individual tuber sections in controlled environment chambers at either ambient (36 Pa) or elevated (72 Pa) CO2.

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Analysis of gene promoters for two tomato polygalacturonases expressed in abscission zones and the stigma.

Plant Physiol

July 2000

Soybean and Alfalfa Research Laboratory, United States Department of Agriculture-Agricultural Research Service, Building 006, Beltsville Agricultural Research Center-West, 10300 Baltimore Avenue, Beltsville, Maryland 20705, USA.

The tomato (Lycopersicon esculentum cv Ailsa Craig) polygalacturonase genes TAPG1 (LYCes;Pga1;2) and TAPG4 (LYCes;Pga1;5) are abundantly expressed in both abscission zones and the pistils of mature flowers. To further investigate the spatial and temporal expression patterns for these genes, the TAPG gene promoters were ligated to beta-glucuronidase (GUS) reporter genes and transformed into tomato. GUS expression with both constructs was similar and entirely consistent with the expression patterns of the native gene transcripts.

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A number of photosystem II (PSII) associated proteins, including core proteins D1, D2 and CP43, and several proteins of the LHCII complex, are phosphorylated by a thylakoid-bound, redox-regulated kinase(s). We demonstrate here that the compound propyl gallate is an effective inhibitor of LHCII phosphorylation in vivo while having little effect on PSII core protein phosphorylation. Using this inhibitor, we demonstrate that LHCII dephosphorylation is insensitive to light in vivo.

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Phytoremediation of soil metals.

Curr Opin Biotechnol

June 1997

United States Department of Agriculture, Beltsville Agricultural Research Center West, MD 20705, USA.

The phytoremediation of metal-contaminated soils offers a low-cost method for soil remediation and some extracted metals may be recycled for value. Both the phytoextraction of metals and the phytovolatilization of Se or Hg by plants offer great promise for commercial development. Natural metal hyperaccumulator phenotype is much more important than high-yield ability when using plants to remove metals from contaminated soils.

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Third-stage infective larvae of Onchocerca volvulus were examined to elucidate the ultrastructure and the interrelations of the stoma, esophagus, intestine, and nervous system. The alimentary canal involves a cuticularized stoma with a triradiate lumen that is continuous with a similar triradiate lumen in the muscular region of the esophagus. The lumen wall may be laterally appressed or opened into a stellate form in the glandular region.

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Carbohydrate and carbon metabolite accumulation responses in leaves of ozone tolerant and ozone susceptible spinach plants after acute ozone exposure.

Photosynth Res

November 1996

Agricultural Research Service, Beltsville Agricultural Research Center-West, Climate Stress Laboratory, Natural Resources Institute, USDA, Building 046A, 20705-2350, Beltsville, MD, USA.

The objective of this study was to determine whether exposure of plants to ozone (O3) increased the foliar levels of glucose, glucose sources, e.g., sucrose and starch, and glucose-6-phosphate (G6P), because in leaf cells, glucose is the precursor of the antioxidant, L-ascorbate, and glucose-6-phosphate is a source of NADPH needed to support antioxidant capacity.

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Integrated control of ectoparasites.

Rev Sci Tech

December 1994

United States Department of Agriculture, Beltsville Agricultural Research Center-West, Maryland 20705.

Integrated control of ectoparasites of veterinary importance is being implemented on a limited basis at present. However, several forces are accelerating a global shift to integrated pest management (IPM). These accelerating forces include the following: reduction in new chemical compounds registered for use on livestock and poultry universal development of resistance to pesticides heightened environmental sensitivities to exclusive dependence on pesticide-based control need for strategies which increase profits for the producer while decreasing costs to the consumer.

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The unconjugated N-glycans (UNGs) Man3(Xyl)GlcNAc(Fuc)GlcNAc and Man5GlcNAc influence tomato (Lycopersicon esculentum cv 'Rutgers') fruit ripening at nanomolar concentrations. In addition, we have shown a delaying effect on ripening of tomato pericarp discs by 10 ng per g fresh weight Man5GlcNAc, one of 10 UNGs purified from mature green tomato pericarp. In the present study, oligomannosidic UNGs from tomato fruit exhibited activity similar to Man5GlcNAc.

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1-Aminocyclopropane-1-carboxylic acid (ACC) synthase is a key enzyme regulating biosynthesis of the plant hormone ethylene. The expression of an enzymatically active, wound-inducible tomato (Lycopersicon esculentum L. cv Pik-Red) ACC synthase (485 amino acids long) in a heterologous Escherichia coli system allowed us to study the importance of hypervariable COOH terminus in enzymatic activity and protein conformation.

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Cellulase activity was measured in soybean (Glycine max) leaf abscission zones, flower abscission zones, pod abscission zones, apical buds, and adventitious rooting hypocotyls. Immunoprecipitation data showed that a cellulase immunologically similar to the bean abscission cellulase (isoelectric point 9.5) is present in soybean leaf, flower, and pod abscission zones, but is not present in soybean apical buds or rooting hypocotyls.

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