843 research outputs found

    De novo Analysis of the Epiphytic Transcriptome of the Cucurbit Powdery Mildew Fungus Podosphaera xanthii and Identification of Candidate Secreted Effector Proteins.

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    The cucurbit powdery mildew fungus Podosphaera xanthii is a major limiting factor for cucurbit production worldwide. Despite the fungus's agronomic and economic importance, very little is known about fundamental aspects of P. xanthii biology, such as obligate biotrophy or pathogenesis. To design more durable control strategies, genomic information about P. xanthii is needed. Powdery mildews are fungal pathogens with large genomes compared with those of other fungi, which contain vast amounts of repetitive DNA sequences, much of which is composed of retrotransposons. To reduce genome complexity, in this work we aimed to obtain and analyse the epiphytic transcriptome of P. xanthii as a starting point for genomic research. Total RNA was isolated from epiphytic fungal material, and the corresponding cDNA library was sequenced using a 454 GS FLX platform. Over 676,562 reads were obtained and assembled into 37,241 contigs. Annotation data identified 8,798 putative genes with different orthologues. As described for other powdery mildew fungi, a similar set of missing core ascomycete genes was found, which may explain obligate biotrophy. To gain insight into the plant-pathogen relationships, special attention was focused on the analysis of the secretome. After this analysis, 137 putative secreted proteins were identified, including 53 candidate secreted effector proteins (CSEPs). Consistent with a putative role in pathogenesis, the expression profile observed for some of these CSEPs showed expression maxima at the beginning of the infection process at 24 h after inoculation, when the primary appressoria are mostly formed. Our data mark the onset of genomics research into this very important pathogen of cucurbits and shed some light on the intimate relationship between this pathogen and its host plant

    Small-signal modeling of phase-shifted full-bridge converter considering the delay associated to the leakage inductance

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    This paper demonstrates that in the Phase-Shifted Full-Bridge (PSFB) buck-derived converter, there is a random delay associated with the blanking time produced by the leakage inductance. This random delay predicts the additional phase drop that is present in the frequency response of the open-loop audio-susceptibility transfer function when the converter shows a significant blanking time. The existing models of the PSFB converter do not contemplate the delay and gain differences associated to voltage drop produced in the leakage inductor of the transformer. The small-signal model proposed in this paper is based on the combination of two types of analysis: the first analysis consists of obtaining a small-signal model using the average modeling technique and the second analysis consists of studying the natural response of the power converter. The dynamic modeling of the Phase-Shifted Full-Bridge converter, including the random delay, has been validated by simulations and experimental test.This research was funded by the European Regional Development Fund, the Ministry of Science, Innovation and Universities and the State Research Agency, grant number DPI2017-84572-C2-2-R

    An Asp376Glu substitution in ALS gene and enhanced metabolism confers high tribenuron-methyl resistance in Sinapis alba

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    Acetolactate synthase (ALS) inhibiting herbicides (group 2) have been widely applied for the last 20 years to control Sinapis alba in cereal crops from southern Spain. In 2008, a tribenuron-methyl (TM) resistant (R) S. alba population was first reported in a cereal field in Malaga (southern Spain). In 2018, three suspected R S. alba populations (R1, R2 and R3) to TM were collected from three different fields in Granada (southern Spain, 100 km away from Malaga). The present work aims to confirm the putative resistance of these populations to TM and explore their resistance mechanisms. Dose–response assays showed that the R1, R2 and R3 populations ranging between 57.4, 44.4 and 57.1 times more resistance to TM than the susceptible population (S). A mutation in the ALS gene (Asp376Glu) was detected in the Rs S. alba populations. 14C-metabolism studies show that metabolites and TM were changing significantly faster in the R than in the S plants. Alternative chemical control trials showed that 2,4-D and MCPA (auxin mimics), glyphosate (enolpyruvyl shikimate phosphate synthase,EPSPS, inhibitor-group 9), metribuzin (PSII inhibitors/Serine 264 Binders, -group 5) and mesotrione (hydroxyphenyl pyruvate dioxygenase, HPPD, inhibitor-group 27) presented a high control of the four populations of S. alba tested, both S and R. Based on these results, it is the first case described where the Asp376Glu mutation and P450-mediated metabolism participates in resistance to TM in S. alba. Comparing these results with those found in the S. alba population in Malaga in 2008, where the resistance was TSR type (Pro197Ser), we can suggest that despite the geographical proximity (over 100 km), the resistance in these cases was due to different evolutionary events

    Handgrip and knee extension strength as predictors of cancer mortality: A systematic review and metaâ analysis

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145272/1/sms13206.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145272/2/sms13206_am.pd

    FOOTHILL COLOMBIAN PLAIN, HYDRODYNAMIC AND HYDROGEOCHEMICAL PATHWAY HYPOTHESIS, HYDROGEOLOGIC METHODS.

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      La nueva información de presión de formación, fisicoquímica e isotopía ambiental, permitieron la elaboración de hipótesis preeliminares sobre el origen y movimiento del agua de formación asociada a hidrocarburos en Piedemonte y parte central de los Llanos Orientales. En Piedemonte, se sugiere la presencia de sistemas hidráulicos individuales sobrepresionados, asociados a cada estilo estructural; encontrándose un sistema levemente subpresionado al sur de Cupiagua. El origen de las aguas de formación es confuso, encontrándose aguas connatas con bajas salinidades, aguas empobrecidas isotópicamente con altas salinidades y aguas con desviaciones en las trayectorias isotópicas, sugiriendo la acción de procesos de mezcla y/o interacción roca-fluido. Se determinó flujo SW, con una anomalía de flujo W-SW (Cusiana), favorecida por canales permeables originados por la yuxtaposición de litologías permeables.   En Llanos, se sugieren sistemas hidráulicos levemente sobrepresionados (menos que en Piedemonte), con zonas de subpresión para campos paralelos y adyacentes al frente de deformación. La isotopía sugiere la acción de procesos de mezcla y/o interacción roca fluido. Anomalías de presión y fisicoquímica, sugieren mezcla de fluidos en forma ascendente, con plumas dispuestas paralelamente y adyacentemente al frente de deformación. El flujo es N-NW desde el SE, hacia zonas subpresionadas al centro de la cuenca.   Palabras Claves: Hidrodinámica, Hidrogeoquímica, Migración, Piedemonte, Llanos Orientales      New information of formation pressure, groundwater physicochemical and environmental isotopes, allowed to carry out hypothesis on the origin and movement of formation water associated to hydrocarbons in Foothill and central part of the Llanos Orientales basin. In Piedemonte, overpressured individual hydraulic systems are suggested, associated to each structural style; founding a slightly subpressured system to the south of Cupiagua. The formation water origin in not clear, founding cognate waters with low salinities, waters with isotopic impoverishment and high salinities, and waters with deviations in the isotopic trajectories, that suggest action of mixture processes and/or interaction rock-fluid. It has been established a SW flow, with a W-SW anomaly (Cusiana), which is favoured by permeable channels originated by juxtaposition of permeable lythologies.   In Llanos, slightly overpressured hydraulic systems are suggested (less than in Piedemonte), with subpressured zones for field parallel and adjacent to the deformation front. Isotopic analysis suggests the action of mixture processes and/or interaction fluid-rock. Pressure and physicochemical anomalies, suggest mixture of fluid in ascending form, with plumes parallel and adjacent to the deformation front. The flow is N-NW from SE, towards subpressured zones in the basin.   Key words: Hydrodynamic, Hidrogeochemical, Migration, Piedemonte, Llanos Orientale

    FOOTHILL COLOMBIAN PLAIN, HYDRODYNAMIC AND HYDROGEOCHEMICAL PATHWAY HYPOTHESIS, HYDROGEOLOGIC METHODS.

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      La nueva información de presión de formación, fisicoquímica e isotopía ambiental, permitieron la elaboración de hipótesis preeliminares sobre el origen y movimiento del agua de formación asociada a hidrocarburos en Piedemonte y parte central de los Llanos Orientales. En Piedemonte, se sugiere la presencia de sistemas hidráulicos individuales sobrepresionados, asociados a cada estilo estructural; encontrándose un sistema levemente subpresionado al sur de Cupiagua. El origen de las aguas de formación es confuso, encontrándose aguas connatas con bajas salinidades, aguas empobrecidas isotópicamente con altas salinidades y aguas con desviaciones en las trayectorias isotópicas, sugiriendo la acción de procesos de mezcla y/o interacción roca-fluido. Se determinó flujo SW, con una anomalía de flujo W-SW (Cusiana), favorecida por canales permeables originados por la yuxtaposición de litologías permeables.   En Llanos, se sugieren sistemas hidráulicos levemente sobrepresionados (menos que en Piedemonte), con zonas de subpresión para campos paralelos y adyacentes al frente de deformación. La isotopía sugiere la acción de procesos de mezcla y/o interacción roca fluido. Anomalías de presión y fisicoquímica, sugieren mezcla de fluidos en forma ascendente, con plumas dispuestas paralelamente y adyacentemente al frente de deformación. El flujo es N-NW desde el SE, hacia zonas subpresionadas al centro de la cuenca.   Palabras Claves: Hidrodinámica, Hidrogeoquímica, Migración, Piedemonte, Llanos Orientales      New information of formation pressure, groundwater physicochemical and environmental isotopes, allowed to carry out hypothesis on the origin and movement of formation water associated to hydrocarbons in Foothill and central part of the Llanos Orientales basin. In Piedemonte, overpressured individual hydraulic systems are suggested, associated to each structural style; founding a slightly subpressured system to the south of Cupiagua. The formation water origin in not clear, founding cognate waters with low salinities, waters with isotopic impoverishment and high salinities, and waters with deviations in the isotopic trajectories, that suggest action of mixture processes and/or interaction rock-fluid. It has been established a SW flow, with a W-SW anomaly (Cusiana), which is favoured by permeable channels originated by juxtaposition of permeable lythologies.   In Llanos, slightly overpressured hydraulic systems are suggested (less than in Piedemonte), with subpressured zones for field parallel and adjacent to the deformation front. Isotopic analysis suggests the action of mixture processes and/or interaction fluid-rock. Pressure and physicochemical anomalies, suggest mixture of fluid in ascending form, with plumes parallel and adjacent to the deformation front. The flow is N-NW from SE, towards subpressured zones in the basin.   Key words: Hydrodynamic, Hidrogeochemical, Migration, Piedemonte, Llanos Orientale

    Tribenuron-methyl metabolism and the rare Pro197Phe double mutation together with 2,4-D metabolism and reduced absorption can evolve in Papaver rhoeas with multiple and cross herbicide resistance to ALS inhibitors and auxin mimics

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    Multiple resistance mechanisms to ALS inhibitors and auxin mimics in two Papaver rhoeas populations were investigated in wheat fields from Portugal. Dose-response trials, also with malathion (a cytochrome P450 inhibitor), cross-resistance patterns for ALS inhibitors and auxin mimics, alternative herbicides tests, 2,4-D and tribenuron-methyl absorption, translocation and metabolism experiments, together with ALS activity, gene sequencing and enzyme modelling and ligand docking were carried out. Results revealed two different resistant profiles: one population (R1) multiple resistant to tribenuron-methyl and 2,4-D, the second (R2) only resistant to 2,4-D. In R1, several target-site mutations in Pro197 and enhanced metabolism (cytochrome P450-mediated) were responsible of tribenuron-methyl resistance. For 2,4-D, reduced transport was observed in both populations, while cytochrome P450-mediated metabolism was also present in R1 population. Moreover, this is the first P. rhoeas population with enhanced tribenuron-methyl metabolism. This study reports the first case for P. rhoeas of the amino acid substitution Pro197Phe due to a double nucleotide change. This double mutation could cause reduced enzyme sensitivity to most ALS inhibitors according to protein modelling and ligand docking. In addition, this study reports a P. rhoeas population resistant to 2,4-D, apparently, with reduced transport as the sole resistance mechanism.This work has been supported by the Asociacion de Agroquimicos y Medio Ambiente, Spain. Joel Torra acknowledges support from the Spanish Ministry of Science, Innovation, and Universities (grant Ramon y Cajal RYC2018–023866-I) and by the Spanish State Research Agency, Spain (AEI) and the European Regional Development Fund, EU (ERDF) through the projects AGL2017-83325-C4-2-R and PID2020-113229RB- C42. The field surveys made in Portugal were supported by Foundation for Science and Technology through the project UIDB/05064/2020 (VALORIZA). Jorge Lozano-Juste group is funded by grants RYC2020- 029097-I and PID2021-128826OA-I00 from Ministerio de Ciencia e Innovaci ́on (MCIN, Spain), AEI and the ERDF

    Enhanced detoxification via Cyt-P450 governs cross-tolerance to ALS-inhibiting herbicides in weed species of centaurea

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    Centaurea is a genus of winter weeds with a similar life cycle and competitive traits, which occurs in small-grains production fields in the central-southern of the Iberian Peninsula. However, most of herbicides recommended for weed management in wheat show poor control of Centaurea species. This study summarizes the biology, herbicide tolerance to acetolactate synthase (ALS) inhibitors, and recommended chemical alternatives for the control of Centaurea species. Four species (C. cyanus L., C. diluta Aiton, C. melitensis L. and C. pullata L. subsp. baetica Talavera), taxonomically characterized, were found as the main important broadleaf weeds in small- grains production fields of the Iberian Peninsula. These species showed innate tolerance to tribenuron-methyl (TM), showing LD50 values (mortality of 50% of a population) higher than the field dose of TM (20 g ai ha 1). The order of tolerance was C. diluta (LD50 =702 g ha 1) ≫ C. pullata (LD50 =180 g ha 1) ≫ C. cyanus (LD50 =65 g ha 1) >C. melitensis (LD50 =32 g ha 1). Centaurea cyanus and C. melitensis presented higher foliar retention (150–180 μL herbicide solution), absorption (14–28%) and subsequent translocation (7–12%) of TM with respect to the other two species. Centaurea spp. plants were able to metabolize 14C-TM into non-toxic forms (hydroxylated OH-metsulfuron-methyl and conjugated-metsulfuron-methyl), with cytochrome P450 (Cyt-P450) monooxygenases being responsible for herbicide detoxification. Centaurea cyanus and C. mellitensis metabolized up to 25% of TM, while C. diluta and C. pullata metabolized more than 50% of the herbicide. Centaurea species showed 80–100% survival when treated with of florasulam, imazamox and/or metsulfuron-methyl, i.e., these weeds present cross-tolerance to ALS inhibitors. In contrast, auxin mimics herbicides (2,4-D, clopyralid, dicamba, fluroxypir and MCPA) efficiently controlled the four Centaurea species. In addition, the mixture of ALS-inhibitors and auxin mimics also proved to be an interesting alternative for the control of Centaurea. These results show that plants of the genus Centaurea found in the winter cereal fields of the Iberian Peninsula have an innate tolerance to TM and cross-resistance to other ALS-inhibiting herbicides, governed by reduced absorption and translocation, but mainly by the metabolization of the herbicide via Cyt-P450
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