Effect of Diaporthe RNA virus 1 (DRV1) on growth and pathogenicity of different <Emphasis Type="Italic">Diaporthe</Emphasis> species     

Ntsane Moleleki  Michael J. Wingfield  Brenda D. Wingfield  Oliver Preisig 《European journal of plant pathology / European Foundation for Plant Pathology》2011,131(2):261-268

A 4.1 kbp positive-strand RNA virus known as Diaporthe RNA virus 1 (DRV1) occurs in hypovirulent, non-sporulating isolates of the fungal pathogen Diaporthe perjuncta. A full-length cDNA clone of DRV1 was developed and RNA transcribed from the cDNA clone used to transfect different Diaporthe spp. The transfected species included three D. ambigua isolates and an unidentified Phomopsis asexual state of a Diaporthe sp. Successful transfections were confirmed using RT-PCR. Although the in vitro-transcribed positive sense single-stranded RNA used for transfection included vector sequences at both ends, the genomes of progeny virus from DRV1-transfected isolates were free of the vector sequences. Transfection resulted in morphological changes in these fungal pathogens. However, the presence of DRV1 did not reduce growth rate in two of the three D. ambigua or the Phomopsis sp. significantly. Pathogenicity studies showed that the transfected isolates have reduced aggresiveness.  相似文献   

Polygenetic development of the Mormon Mesa,NV petrocalcic horizons: Geomorphic and paleoenvironmental interpretations     

Amy L. Brock  Brenda J. Buck 《CATENA》2009

Mormon Mesa, Nevada, USA is of one of Earth's rare and unique landforms. Regionally, Mormon Mesa is important because of its relationship to the lower Colorado River and its connection to stream incision. Petrocalcic horizons at Mormon Mesa developed from multiple exposure, erosion, and sedimentation events driven by variations in paleoclimate since the early Pliocene. This study utilizes pedogenic features at Mormon Mesa to construct a sequence of development for the soil profile. We sampled and described seven profiles at Mormon Mesa to determine the soil and geomorphic processes that have influenced the development of this geomorphically important soil. The Mormon Mesa soil profile generally consists of four petrocalcic soil horizons from the base upward (transitional, laminar, massive, and brecciated) and an additional set of horizons that formed in unconsolidated surficial eolian sediments. The transitional horizon formed after cessation of Muddy Creek Fm. deposition (~ 5 to 4 Ma) and accumulated calcium carbonate to a stage II–III morphology (maybe IV in some locations). After a period of landform stability, the upper portion of the transitional horizon was exposed and eroded (~ 2.8 Ma). Petrocalcic fragments and stage II pendants that formed in the transitional horizon were exposed on the surface and later mixed with aggrading eolian sediments. After the surface re-stabilized, calcium carbonate accumulated along the underlying discontinuity with the transitional horizon and formed a laminar horizon. Shallower accumulations of calcium carbonate formed pendants on the undersides of the rotated petrocalcic fragments and pendants that had previously been eroded from the transitional horizon. Continued rooting and bioturbation caused rotation and multiple directions of pendant formation. Today, in plan view, these pendants appear concentric and are the pisoliths described by Bachman and Machette [Bachman, G.O., Machette, M.N., 1977. Calcic Soils and Calcretes in the Southwestern United States., USGS: Open-File Report 77–797]. Continued calcium carbonate precipitation eventually plugged the horizon (massive horizon). After the massive horizon became indurated, the upper portion was exposed, fractured, eroded, and mixed with aggrading eolian sediments. These brecciated fragments experienced erosion/brecciation and soil stabilization/cementation with pedogenic calcite multiple times, probably as a result of the Pleistocene glacial/interglacial climate cycles. All of the features described in this study are interpreted to have formed in response to climatic changes that caused either soil erosion with concurrent eolian deposition, or soil development and pedogenic carbonate accumulation.  相似文献   

Insurance data for research in companion animals: benefits and limitations     

Agneta Egenvall  Ane N?dtvedt  Johanna Penell  Lotta Gunnarsson  Brenda N Bonnett 《Acta veterinaria Scandinavica》2009,51(1):42

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抗重金属植物根际细菌的植物促生长特征以及它们对黑芥种子萌发的影响     

Brenda ROMÁN-PONCE  Diana Miryel REZA-VÁZQUEZ  Sonia GUTIÉRREZ-PAREDES  María de Jes&#;s DE HARO-CRUZ  Jessica MALDONADO-HERNÁNDEZ  Yanely BAHENA-OSORIO  Paulina ESTRADA-DE LOS SANTOS  En Tao WANG  María Soledad VÁSQUEZ-MURRIETA 《土壤圈》2017,27(3):511-526

Phytoremediation is an emerging technology that uses plants and their associated microbes to clean up pollutants from the soil, water, and air. In order to select the plant growth-promoting rhizobacteria(PGPR) for phytoremediation of heavy metal contamination, 60 bacterial strains were isolated from the rhizosphere of two endemic plants, Prosopis laevigata and Spharealcea angustifolia, in a heavy metal-contaminated zone in Mexico. These rhizobacterial strains were characterized for the growth at different pH and salinity, extracellular enzyme production, solubilization of phosphate, heavy metal resistance, and plant growth-promoting(PGP) traits, including production of siderophores and indol-3-acetic acid(IAA). Overall, the obtained rhizobacteria presented multiple PGP traits. These rhizobacteria were also resistant to high levels of heavy metals(including As as a metalloid)(up to 480 mmol L(-1)As(V), 24 mmol L(-1)Pb(Ⅱ), 21 mmol L(-1)Cu(Ⅱ), and 4.5 mmol L(-1)Zn(Ⅱ)). Seven rhizobacterial strains with the best PGP traits were identified as members of Alcaligenes, Bacillus, Curtobacterium, and Microbacterium, and were selected for further bioassay.The inoculation of Brassica nigra seeds with Microbacterium sp. CE3R2, Microbacterium sp. NE1R5, Curtobacterium sp. NM1R1,and Microbacterium sp. NM3E9 facilitated the root development; they significantly improved the B. nigra seed germination and root growth in the presence of heavy metals such as 2.2 mmol L(-1)Zn(Ⅱ). The rhizobacterial strains isolated in the present study had the potential to be used as efficient bioinoculants in phytorremediation of soils contaminated with multiple heavy metals.  相似文献   

Population structure of <Emphasis Type="Italic">Cylindrocladium parasiticum</Emphasis> infecting peanuts (<Emphasis Type="Italic">Arachis hypogaea</Emphasis>) in Georgia,USA     

Louwrance P. Wright  Andrew J. Davis  Brenda D. Wingfield  Pedro W. Crous  Tim Brenneman  Michael J. Wingfield 《European journal of plant pathology / European Foundation for Plant Pathology》2010,127(2):199-206

Cylindrocladium parasiticum is an important pathogen of peanut (Arachis hypogaea) causing the disease Cylindrocladium black rot. The genetic structure of this haploid pathogen was determined for populations associated with peanut in Georgia, USA. Ten polymorphic microsatellite markers were used to determine genetic and genotypic diversity among three sub-populations representing the geographic distribution of peanut production in Georgia. Among 200 isolates collected, only 10 unique multilocus haplotypes were identified, with one multilocus haplotype occurring 176 times. Although no evidence for random mating was observed, the existence of loops in a constructed haplotype network hint at the possibility of recombination events. The absence of random mating might therefore be attributed to the homothallic nature of C. parasiticum as well as the clonality of the population, without excluding the possible occurrence of recombination. Cylindrocladium parasiticum thus appears to consist of a genetically homogeneous population throughout Georgia with mainly clonal reproduction or inbreeding contributing to the observed population genetic structure.  相似文献   

Trait dissection of maize kernel weight: Towards integrating hierarchical scales using a plant growth approach   总被引：1，自引：0，他引：1  

Lucas Borrás  Brenda L. Gambín 《Field Crops Research》2010

Maize (Zea mays L.) yield is a function of the number harvested kernels per unit land area and the individual kernel weight (KW). Kernel weight and its development show a wide variability due to the genotype, the environment, the crop management, and all possible interactions. Commercial maize hybrids differ markedly in the patterns (rate and duration of kernel growth) behind differences in final KW. The same can be observed when public or elite proprietary maize inbred lines are analyzed. To progress in our understanding of KW variability, we reviewed and discussed current knowledge for analyzing kernel growth as an integrated system, modulated by processes linking different levels of organization (the different kernel tissues, the whole kernel, the plant, the canopy). Ideas on how to integrate this knowledge towards the development of a multi-hierarchical scale framework for predicting KW under different growth environments are currently needed, as they have high relevance for dissecting the genetic basis of kernel growth and maize yield definition at the canopy level.  相似文献   

Clonality and phenotyping of canine lymphomas before chemotherapy and during remission using polymerase chain reaction (PCR) on lymph node cytologic smears and peripheral blood     

Dilini N. Thilakaratne  Monique N. Mayer  Valerie S. MacDonald  Marion L. Jackson  Brenda R. Trask  Beverly A. Kidney 《The Canadian veterinary journal. La revue veterinaire canadienne》2010,51(1):79-84

Polymerase chain reaction (PCR) assays for the immunoglobulin and T-cell receptor genes were utilized to determine phenotype and clonality from lymph node cytologic smears and peripheral blood lymphocytes from 10 dogs with lymphoma, before chemotherapy and during remission. Results were compared with those from 13 dogs with a cytologic diagnosis of lymph node hyperplasia. Clonality was identified in 7 of the lymphomas on the basis of either lymph node cytology or peripheral blood lymphocytes before treatment. No lymph node hyperplasia samples were clonal. In 6 of the dogs with lymphoma, clonality was demonstrated during clinical remission. Detection of PCR clonality during clinical remission is an effective means of identifying minimal residual disease in canine lymphoma and thus additional work is warranted to determine if molecular remission is prognostic or predictive for outcome in well-controlled and well-defined lymphoma subtypes.  相似文献   

Effect of Antibiotic-containing Extenders on Taylorella equigenitalis Contaminated Semen     

Bettina T. Olivieri  Brenda C. Love  Grant B. Rezabek  Catherine G. Lamm  Dickson D. Varner  Mark E. Payton  G. Reed Holyoak 《Journal of Equine Veterinary Science》2011,31(11):655-660

Taylorella equigenitalis is a gram-negative coccobacillus and the causative agent of a transmissible venereal disease in horses known as contagious equine metritis. Outbreaks of contagious equine metritis have been documented in various countries since 1977, with the most recent discovery in the United States in December 2008. During disease occurrences, culturing semen samples for T equigenitalis before breeding may help to prevent transmission of this disease; however, little is known about the antimicrobial activity of equine semen extenders against the organism. The purpose of this study was to investigate the infectivity levels of T equigenitalis in three equine semen extenders inoculated with known concentrations of the organism. The semen extenders used for this study included INRA 96, E-Z Mixin BF, and VMDZ. In addition, Timentin was added to INRA 96 at three different concentrations (0.5, 1.0, and 1.5 mg/mL) to investigate possible synergistic effects of antibiotic supplementation of extenders. Results were based on the visual counting of the colonies on chocolate Eugon agar plates. Both INRA 96 (with added Timentin) and VMDZ (as supplied by the manufacturer) significantly reduced the numbers of T equigenitalis isolated from semen extenders as compared with INRA 96 (as supplied by the manufacturer) or the antibiotic free E-Z Mixin BF. Our findings indicate that INRA 96 (with added Timentin) or VMDZ may significantly decrease the growth of T equigenitalis in extended semen; however, it is also important to consider the possible effects of antibiotic supplemented extenders on sperm longevity and fertility in addition to eliminating specific pathogens in semen.  相似文献   

Arsenic and chromium resistance mechanisms in the Micrococcus luteus group     

Ivan ARROYO-HERRERA  Brenda ROM&#;N-PONCE  Rafael BUSTAMANTE-BRITO  Joseph GUEVARA-LUNA  Erika Yanet TAPIA-GARC&#;A  Violeta LARIOS-SERRATO  Nannan ZHANG  Paulina ESTRADA-DE LOS SANTOS  En Tao WANG  Mar&#;a Soledad V&#;SQUEZ-MURRIETA 《土壤圈》2023,33(4):600-611

High arsenic (As) and chromium (Cr) concentrations are currently receiving attention because of their negative effects on the environment and human health. Microorganisms inhabiting contaminated environments have developed resistance mechanisms against the toxicity of these pollutants. Indeed, members of the bacterial genus Micrococcus have been isolated from different toxic metal-contaminated environments; however, knowledge concerning its resistance mechanisms to As and Cr toxicity remains lim...  相似文献   

Eucalyptus scab and shoot malformation: A new and serious foliar disease of Eucalyptus caused by Elsinoe necatrix sp. nov.     

Nam Q. Pham  Seonju Marincowitz  Myriam Solís  Tuan A. Duong  Brenda D. Wingfield  Irene Barnes  Bernard Slippers  Jupiter I. Muro Abad  Alvaro Durán  Michael J. Wingfield 《Plant pathology》2021,70(5):1230-1242

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