227 research outputs found

    Role of Antioxidant Enzymes, Hydrogen Peroxide and PRProteins in the Compatible and Incompatible Interactions of Cowpea (Vigna unguiculata) Genotypes with the Fungus Colletotrichum gloeosporioides.

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    This work was conducted to measured the time-course activities and evaluate the possible roles of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and hydrogen peroxide (H2 O2 ), and the pathogenesis-related proteins (PR-proteins), peroxidase (POX), β-1,3-glucanase (GLU) and chitinase (CHI), in the resistant (TE97) and susceptible (BR3) cowpea genotypes in response to C. gloeosporioides infection

    Host defense responses restricts the growth of the fungus Colletotrichum lindemuthianum in cowpea, TE 97 411-1E resistant genotype.

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    Cowpea is the main subsistence crop in the semiarid North-east of Brazil. However, very few is known concerning to its defense mechanisms against fungi. The objective of this present work was to evaluate the infection strategies of the hemibiotrophic fungi Colletotrichum lindemuthianum and the associated cytological defense responses of two cowpea genotypes, TE 97-411-1E (resistant) and BR 3 Tracuateua (susceptible). The infection process of the fungi in both genotypes occurred preferentially through the leaf epidermal cells by penetration tubes emerged from appressoria. The resistant cowpea genotype, TE 97-411-1E, showed enhanced penetration resistance to C. lindemuthianum associated with higher epidermal H2O2 accumulation, papilla formation, and increase in phenylalanine ammonialyase activity, possibly related to accumulation of phenolic compounds and host cell wall lignification. Macroscopic examination of the primary leaves revealed the presence of shrunken necrotic lesions characteristic of anthracnose in infected BR 3 Tracuateua, whereas in TE 97-411-1E cell death was also observed but only in a reduced percentage of the infection sites. In summary the results obtained in the present study suggested that TE 97-411-1E genotype is more resistant to C. lindemuthianum compared to BR 3 Tracuateua, as it developed more effective defense responses against the establishment of the pathogen

    Respostas de defesa da planta impedem o crescimento do fungo Colletotrichum gloeosporioides no genótipo de feijão-caupi BR 3 Tracuateua.

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    O feijão-caupi [Vigna unguiculata (L.) Walp.] é uma das culturas mais importantes no semiárido do Nordeste do Brasil. Embora tolerante às condições climáticas adversas, esta espécie é constantemente atacada por patógenos, ocasionando perdas na produção. Assim, o presente trabalho foi conduzido para avaliar que estratégias de infecção o patógeno Colletotrichum gloeosporioides utiliza para infectar e se desenvolver nos genótipos de feijão-caupi BR 3 Tracuateua e TE 97-411-1E e para verificar as respostas citológicas de defesa do feijão-caupi, como também o papel da fenilalanina amônia liase (PAL) no processo de infecção. Exame macroscópico mostrou um alto número de folhas primárias com lesões necróticas em TE 97-411-1E comparado com BR 3-Tracuateua. O processo de infecção foi iniciado indiretamente, via abertura dos estômatos, por tubos germinativos, sem formação de apressório. A atividade da PAL nas folhas de feijão-caupi aumentou em dois diferentes tempos após inoculação em ambos os genótipos. O primeiro pico pode estar associado a biossíntese inicial de compostos fenólicos e o segundo ao acúmulo posterior de compostos fenólicos e lignificação da parede celular do hospedeiro. O presente trabalho fornece evidências que a PAL tem um importante papel nas estratégias de defesa que o feijão-caupi emprega para se defender contra o fungo C. gloeosporioides. O crescimento do patógeno foi mais evidente no genótipo TE 97-411-1E, sugerindo que este é mais suscetível ao fungo do que BR 3-Tracuateua

    Infection process and host defense responses in compatible and incompatible interactions between Cowpea (Vigna unguiculata) and Colletotrichum gloeosporioides.

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    The infection process of Colletotrichum gloeosporioides was examined by light microscopy on two cowpea genotypes, BR 3 Tracuateua and TE 97-411. In the susceptible genotype BR 3 Tracuateua, the pathogen acted as an intracellular hemibiotroph. Invasion of cowpea primary leaves occurred preferentially through the leaf epidermal cells by penetration tubes that emerged from appressoria. The penetration tube swelled within 48 h to form a spherical infection vesicle inside the epidermal cell in a biotrophic interaction. Subsequently, it became multilobed and multiseptated. By 4 d after inoculation, one or more large primary hyphae emerged from the lateral lobes and grew intracellularly and further colonized several adjacent epidermal host cells, characterizing the necrotrophic phase of infection. Primary leaves of the resistant cowpea genotype, TE 97-411, showed enhanced penetration resistance to C. gloeosporioides associated with higher epidermal H2O2 accumulation beneath appressoria and primary germ tubes, papilla formation, and increased phenylalanine ammonia-lyase activity, possibly related to accumulation of phenolic compounds and host cell wall lignification. Macroscopic examination of the primary leaves revealed the presence of shrunken necrotic lesions characteristic of anthracnose in infected BR 3 Tracuateua, whereas in the genotype TE 97-411, cell death was also observed but only in a reduced percentage of the infection sites. In summary, the results obtained in this study suggested that TE 97-411 is the resistant genotype to C. gloeosporioides compared with BR 3 Tracuateua because it developed more effective defense responses against the establishment of the pathogen

    Soroprevalência das enfermidades infecciosas de importância em ovinos e caprinos de corte do polo produtivo da Bacia do Jacuípe, Bahia.

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    Objetivou-se realizar uma avaliação prospectiva de relevantes enfermidades infecciosas de ovinos e caprinos ligados à agroindústria da carne na Bacia do Jacuípe, BA. Para tanto, foi realizado o diagnóstico sorológico de sete doenças: Agalaxia contagiosa (AC); Artrite-encefalite caprina (CAE); Brucelose ovina; Clamidiose; Maedi-visna; Paratuberculose; Toxoplasmose.Agenda-2030; ODS 1; ODS 2; ODS 12

    Degradation of MONOCULM 1 by APC/CTAD1 regulates rice tillering

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    A rice tiller is a specialized grain-bearing branch that contributes greatly to grain yield. The MONOCULM 1 (MOC1) gene is the first identified key regulator controlling rice tiller number; however, the underlying mechanism remains to be elucidated. Here we report a novel rice gene, Tillering and Dwarf 1 (TAD1), which encodes a co-activator of the anaphase-promoting complex (APC/C), a multi-subunit E3 ligase. Although the elucidation of co-activators and individual subunits of plant APC/C involved in regulating plant development have emerged recently, the understanding of whether and how this large cell-cycle machinery controls plant development is still very limited. Our study demonstrates that TAD1 interacts with MOC1, forms a complex with OsAPC10 and functions as a co-activator of APC/C to target MOC1 for degradation in a cell-cycle-dependent manner. Our findings uncovered a new mechanism underlying shoot branching and shed light on the understanding of how the cell-cycle machinery regulates plant architecture

    An international survey on the pragmatic management of epistaxis

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    Epistaxis is one of the most common ear, nose and throat emergencies. The management of epistaxis has evolved significantly in recent years, including the use of nasal cautery and packs. However, a correct treatment requires the knowledge of nasal anatomy, potential risks, and complications of treatment. Epistaxis is often a simple and readily treatable condition, even though a significant bleed may have potentially severe consequences. At present, there are very few guidelines concerning this topic. The current Survey explored the pragmatic approach in managing epistaxis. A questionnaire, including 7 practical questions has been used. The current International Survey on epistaxis management reported a relevant prevalence (21.7%), mainly during childhood and senescence, an important hospitalization rate (11.8%), the common use of anterior packing and electrocoagulation, and the popular prescription of a vitamin supplement and intranasal creams

    A candidate super-Earth planet orbiting near the snow line of Barnard’s star

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    Barnard’s star is a red dwarf, and has the largest proper motion (apparent motion across the sky) of all known stars. At a distance of 1.8 parsecs, it is the closest single star to the Sun; only the three stars in the α Centauri system are closer. Barnard’s star is also among the least magnetically active red dwarfs known and has an estimated age older than the Solar System. Its properties make it a prime target for planetary searches; various techniques with different sensitivity limits have been used previously, including radial-velocity imaging, astrometry and direct imaging, but all ultimately led to negative or null results. Here we combine numerous measurements from high-precision radial-velocity instruments, revealing the presence of a low-amplitude periodic signal with a period of 233 days. Independent photometric and spectroscopic monitoring, as well as an analysis of instrumental systematic effects, suggest that this signal is best explained as arising from a planetary companion. The candidate planet around Barnard’s star is a cold super-Earth, with a minimum mass of 3.2 times that of Earth, orbiting near its snow line (the minimum distance from the star at which volatile compounds could condense). The combination of all radial-velocity datasets spanning 20 years of measurements additionally reveals a long-term modulation that could arise from a stellar magnetic-activity cycle or from a more distant planetary object. Because of its proximity to the Sun, the candidate planet has a maximum angular separation of 220 milliarcseconds from Barnard’s star, making it an excellent target for direct imaging and astrometric observations in the future. © 2018, Springer Nature Limited.The results are based on observations made with the CARMENES instrument at the 3.5-m telescope of the Centro Astronomico Hispano-Aleman de Calar Alto (CAHA, Almeria, Spain), funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de Investigaciones Cientificas (CSIC), the European Union and the CARMENES Consortium members; the 90-cm telescope at the Sierra Nevada Observatory (Granada, Spain) and the 40-cm robotic telescope at the SPACEOBS observatory (San Pedro de Atacama, Chile), both operated by the Instituto de Astrofisica de Andalucia (IAA); and the 80-cm Joan Oro Telescope (TJO) of the Montsec Astronomical Observatory (OAdM), owned by the Generalitat de Catalunya and operated by the Institute of Space Studies of Catalonia (IEEC). This research was supported by the following institutions, grants and fellowships: Spanish MINECO ESP2016-80435-C2-1-R, ESP2016-80435-C2-2-R, AYA2016-79425-C3-1-P, AYA2016-79245-C3-2-P, AYA2016-79425-C3-3-P, AYA2015-69350-C3-2-P, ESP2014-54362-P, AYA2014-56359-P, RYC-2013-14875; Generalitat de Catalunya/CERCA programme; Fondo Europeo de Desarrollo Regional (FEDER); German Science Foundation (DFG) Research Unit FOR2544, project JE 701/3-1; STFC Consolidated Grants ST/P000584/1, ST/P000592/1, ST/M001008/1; NSF AST-0307493; Queen Mary University of London Scholarship; Perren foundation grant; CONICYT-FONDECYT 1161218, 3180405; Swiss National Science Foundation (SNSF); Koshland Foundation and McDonald-Leapman grant; and NASA Hubble Fellowship grant HST-HF2-51399.001. J.T. is a Hubble Fellow

    A C19MC-LIN28A-MYCN Oncogenic Circuit Driven by Hijacked Super-enhancers Is a Distinct Therapeutic Vulnerability in ETMRs: A Lethal Brain Tumor

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    © 2019 Elsevier Inc. Embryonal tumors with multilayered rosettes (ETMRs) are highly lethal infant brain cancers with characteristic amplification of Chr19q13.41 miRNA cluster (C19MC) and enrichment of pluripotency factor LIN28A. Here we investigated C19MC oncogenic mechanisms and discovered a C19MC-LIN28A-MYCN circuit fueled by multiple complex regulatory loops including an MYCN core transcriptional network and super-enhancers resulting from long-range MYCN DNA interactions and C19MC gene fusions. Our data show that this powerful oncogenic circuit, which entraps an early neural lineage network, is potently abrogated by bromodomain inhibitor JQ1, leading to ETMR cell death. Sin-Chan et al. uncover a C19MC-LIN28A-MYCN super-enhancer-dependent oncogenic circuit in embryonal tumors with multilayered rosettes (ETMRs). The circuit entraps an early neural lineage network to sustain embryonic epigenetic programming and is vulnerable to bromodomain inhibition, which promotes ETMR cell death
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