RESUMEN
The Neurospora crassa genome has a gene cluster for the synthesis of galactosaminogalactan (GAG). The gene cluster includes the following: (1) UDP-glucose-4-epimerase to convert UDP-glucose and UDP-N-acetylglucosamine to UDP-galactose and UDP-N-acetylgalactosamine (NCU05133), (2) GAG synthase for the synthesis of an acetylated GAG (NCU05132), (3) GAG deacetylase (/NCW-1/NCU05137), (4) GH135-1, a GAG hydrolase with specificity for N-acetylgalactosamine-containing GAG (NCU05135), and (5) GH114-1, a galactosaminidase with specificity for galactosamine-containing GAG (NCU05136). The deacetylase was previously shown to be a major cell wall glycoprotein and given the name of NCW-1 (non-GPI anchored cell wall protein-1). Characterization of the polysaccharides found in the growth medium from the wild type and the GAG synthase mutant demonstrates that there is a major reduction in the levels of polysaccharides containing galactosamine and N-acetylgalactosamine in the mutant growth medium, providing evidence that the synthase is responsible for the production of a GAG. The analysis also indicates that there are other galactose-containing polysaccharides produced by the fungus. Phenotypic characterization of wild-type and mutant isolates showed that deacetylated GAG from the wild type can function as an adhesin to a glass surface and provides the fungal mat with tensile strength, demonstrating that the deacetylated GAG functions as an intercellular adhesive. The acetylated GAG produced by the deacetylase mutant was found to function as an adhesive for chitin, alumina, celite (diatomaceous earth), activated charcoal, and wheat leaf particulates.
RESUMEN
Leishmaniasis presents different types of clinical manifestations that can be divided into cutaneous leishmaniasis and visceral leishmaniasis. The host's immune system, associated with genetic and nutritional factors, is strongly involved in the evolution of the disease or parasite escape. Humoral immunity is characterized by the production of antibodies capable of promoting neutralization, opsonization, and activation of the complement system. In this scenario, B lymphocytes produce antibodies that play an important role in Leishmania infection although neglected for a long time. Thus, relevant aspects in the establishment of Leishmania infection will be addressed, highlighting the importance of humoral immunity during the entire process of Leishmania infection.
Asunto(s)
Leishmaniasis Cutánea , Leishmaniasis Visceral , Leishmaniasis , Humanos , Inmunidad Humoral , AnticuerposRESUMEN
The elastic properties of cell membranes, particularly the membrane tension and bending modulus, are known to be key regulators of cellular functions. Here, we present a correlative and integrated tool based on optical tweezers and scanning electron microscopy to accurately determine these properties in a variety of cell types. Although there are intrinsic difficulties associated with correlative experiments, we believe that the methods presented can be considered a suitable protocol for determining the elastic properties of cell membranes. For complete details on the use and execution of this protocol, please refer to Soares et al. (2020).
Asunto(s)
Membrana Celular , Microscopía Electrónica de Rastreo , Pinzas Ópticas , Animales , Membrana Celular/metabolismo , Membrana Celular/ultraestructura , Elasticidad , HumanosRESUMEN
The objective of this study was to evaluate the Holopothrips fulvus Morgan (Thysanoptera: Phlaeothripidae) population dynamics and to identify dwarf cashew genotypes less infested by the pest in 2015 and 2016, under field conditions. H. fulvus population evaluations were carried out by monthly observations in the plants and using a score scale varying from 0 to 4. H. fulvus infestation occurred from October to December, and in the cashew genotypes CAP 112/8, CAP 121/1, CAP 131/2, CAP 145/2, CAP 145/7, CAP 128/2, CAP 120/4, CAP 123/6, CAP 130/1, and CAP 157/2 was dependent on the flowering period of the crop in 2015. In 2016, there was dependence in all evaluated genotypes between H. fulvus infestation and the cashew flowering period. In 2015, no significant differences were observed between the evaluated genotypes regarding H. fulvus infestation. In 2016, genotypes CAP 105/5, CAP 143/7, CAP 150/3, CAP 155/2, CAP 158/8, CAP 161/7, CAP 163/8, CAP 31, CAP 71, CAP 92, CAP 113, CAP 120, CAP 155, CAP 165, CAP 106/1, CAP 111/2, CAP 127/3, CAP 157/2, and BRS 226 were less infested. H. fulvus occurs from October to December and we could identify the dwarf cashew genotypes less infested by the pest.
Asunto(s)
Anacardium/genética , Anacardium/parasitología , Thysanoptera/fisiología , Animales , Genotipo , Dinámica Poblacional , Estaciones del AñoRESUMEN
Abstract Cashew, Anacardium occidentale L. (Anacardiaceae), is one of the most important sources of agricultural income in northeastern Brazil, but many of the arthropods associated with the crop have yet to be identified. We describe here for the first time the damage caused by Holopothrips fulvus (Morgan) (Thysanoptera: Phlaeothripidae) to dwarf-cashew trees cultivated in the municipality of Pacajús, Ceará, Brazil. Leaf tissue injuries were caused by the sucking mouthparts of the insect and were characterized by dark necrotic spots on the epidermis that resulted in yellowing, wilting and, ultimately, abscission of the leaves. H. fulvus also fed on developing kernels and pseudofruits producing injuries that manifested in the form of chlorotic specks. Additional information is given on the pest status and important aspects of the morphology of the insect, including sexual dimorphism, redescription of the adults and description of the second instar larvae.
RESUMEN
Cucurbits cultivation has great importance in the food industry. However, in the main producing regions of curcubits, the increase of cultivation areas has been limited by viral infections. Among the most prevalent viruses there is the Watermelon Mosaic Virus (WMV), Papaya Ringspot Virus (PRSV-W) and Zucchini Yellow Mosaic Virus (ZYMV). The aim of this study was to evaluate the reaction of watermelon genotypes (Crimson sweet and Charleston Gray) and pumpkin (Jacarezinho and Caserta) to isolate watermelon strains in the following cities: Palmas (PYP-12), Gurupi (PYG-14 and PYG-19), Formoso do Araguaia (PYF-6), and Porto Nacional (PyPn-36 and PyPn-39). The experiment was performed in a greenhouse, in a completely randomized design, with 5 testing plants for each repetition to measure the response of these strains to cucurbit genotypes. The inoculated strains were obtained from leaves of watermelon cv Crinson sweet with symptoms The plants were rated by severity of viral symptoms in intervals of four days during 32 days. It was verified that the cucurbit genotypes showed different susceptibility to the viral strains. However, Caserta and Charleston gray were the ones which had greater sensitivity due to their high severity variation among the tested strains. Thus, it can be observed that the reaction among strains depends on the host and this reaction can be antagonistic or synergistic, depending on the mixed infection. Charleston gray watermelon was the most susceptible to most of the viral strains. Thus, this cultivar should be avoided in these regions.
O cultivo de cucurbitáceas tem grande importância no que diz respeito à alimentação, mas o aumento das áreas de plantio tem sido limitado por infecções virais nos principais pólos produtores de cucurbitáceas. Entre os mais prevalentes destacam-se o vírus do mosaico da melancia (WMV), o vírus da mancha anelar do mamoeiro estirpe melancia (PRSV-W) e o vírus do mosaico amarelo da abobora (ZYMV). Este estudo teve como objetivo avaliar a reação dos genótipos de cucurbitácea Melancia Crimson sweet e Charleston gray; Abóbora: Jacarezinho e Caserta, para isolar variedades de safra de melancia nas cidades de Palmas (PYP-12), Gurupi (PYG-14 e PYG-19), Formoso do Araguaia (PYF-6) e Porto Nacional (PyPn-36 e PyPn-39). O experimento delineamento inteiramente casualizado (DIC), foi conduzido em estufa e foram utilizadas 5 plantas de teste para cada repetição para medir a resposta dessas cepas aos genótipos de cucurbitáceas. A inoculação dos vírus em plantas realizada a partir de folhas com a infecção de melancia Crimson sweet. As plantas inoculadas foram avaliadas por graus de severidade em quatro dias de intervalo durante 32 dias após a inoculação. Verificou-se que os genótipos de cucurbitaceas analisadas apresentaram susceptibilidade diferente às cepas virais testadas. No entanto, o genótipo de abóbora de Caserta e Charleston gray foram as que apresentou maior sensibilidade, devido à sua alta variação de severidade entre as cepas. Assim, podemos ver que a reação entre as estirpes depende do hospedeiro e a reação pode ser antagonista ou sinérgica dependendo da infecção mista. A melancia Charleston gray foi o mais suscetível à maioria das cepas virais. Assim, esta cultivar deve ser evitada nessas regiões.
Asunto(s)
Virosis , Potyvirus , Citrullus , Cucurbita , GenotipoRESUMEN
Banana is the most consumed fruit in the world as it is a delicious and aromatic fruit. However, its production is limited mainly due post-harvest problems such as diseases, especially anthracnose, which accelerates senescence and causes early fall. The aim of this work was to evaluate the agronomic traits and the resistance of banana genotypes (Fhia 18, Fhia 01, Thap Mae, Caipira, Prata (control) and Maçã (control)) to the fungus Colletotrichum musae. The weight of bunch (Wb), fruit length (Fl), fruit diameter (Fd), the number of fruits per bunch (Nfc), number of hands per bunch (Nhb), yield (Yd), pH, total sugars (Brix) and finger detachment were evaluated. The AUDPC (area under the disease progress curve) showed that the genotypes Fhia 01, Maçã and Prata (15.77, 15.55 and 11.60 respectively) are more susceptible to the fungus C. musae than Caipira, Fhia 18 and Thap maeo (6.66, 7.29 and 8.76 respectively). The experiment with Fhias 18 and Thap Maeo genotypes showed lower finger detachment of 18 and 15%, and Thap maeo, Fhia18 and Caipira were resistant to C musae and presented the best agronomic characteristics.
A banana é fruta mais consumida no mundo, tradicionalmente exploradas em várias regiões do mundo, pois é uma fruta de muito saborosa e aromática. Contudo sua produção é limitada principalmente por problemas pós-colheita que mais acometem o fruto, dentre elas aparecimento de doenças principalmente a antracnose que acelera a senescência e o despencamento precoce. O objetivo desde trabalho foram avaliadas as características agronômicas e a resistência dos genótipos de banana Fhia 18, Fhia 01, Thap Mae, Caipira, Prata (controle) e Maçã (Controle), ao fungo Colletotrichum musae. A avaliação das características agronômicas como; peso do cacho (PC), comprimento dos frutos (CF), diâmetro do fruto (DF), número de frutos por cacho (NFC), número de pencas por cacho (NPC), Produtividade (Pd), pH, açúcares totais (Brix) e despencamento. A AACPD Área abaixo da curva da progressão da doença nos genótipos Fhia 01, Maçã e Prata (15,77, 15,55 e 11,60 respectivamente) mostraram se mais suscetível ao fungo C. musae que os demais genótipos Caipira, Fhia 18 e Thap maeo (6,66, 7,29 e 8,76 respectivamente), enquanto que para o experimento de despencamento genótipos Fhias 18 e Thap Maeo foram os que tiveram menor despencamento 18 e 15%, e a Os genótipos Thap maeo Fhia18 e Caipira foram resistentes a C musae e tiveram as melhores características agronômicas.
Asunto(s)
Productos Agrícolas , Colletotrichum , Musa , Hongos , GenotipoRESUMEN
Although several methods for the analysis of nitrogen compounds in diesel fuel have been described in the literature, the demand for rapid, sensitive, and robust analyses has increased in recent years. In this study, a comprehensive two-dimensional gas chromatographic method was developed for the identification and quantification of nitrogen compounds in diesel fuel samples. The quantification was performed using the standard addition method and the analysis was conducted using comprehensive two-dimensional gas chromatography coupled with fast quadrupole mass spectrometry. This study is the first to report quantification of nitrogen compounds in diesel fuel samples using the standard addition method without fractionation. This type of analysis was previously performed using many laborious separation steps, which can lead to errors and losses. The proposed method shows good linearity for target nitrogen compounds evaluated (m-toluidine, 4-ethylaniline, indole, 7-methylindole, 7-ethylindole, carbazole, isoquinoline, 4-methylquinoline, benzo[h]quinolone, and acridine) over a range from 0.05 to 2.0 mg/L, and limits of detection and quantification of <0.06 and 0.16 mg/L, respectively, for all nitrogen compounds studied.
RESUMEN
Comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC/TOFMS) has shown great skill in analyzing complex mixtures such as fossil fuels, especially for compounds at low concentrations. The analysis of N-polyaromatic compounds (NPAC) in coal and crude oil is a great challenge for analytical chemistry due to its environmental and technological importance, and also its diversity of concentration in the matrix. This study is the first report in the applicability of GC×GC/TOFMS for detection of NPAC in a coal tar sample with no fractionation. Normally these compounds are analyzed after sample treatment, making the process expensive and time consuming. However, the higher separation power of GC×GC/TOFMS, compared to 1D-GC, produces cleaner mass spectra in complex samples, which helps in identification of analytes with no pre-fractionation. In this paper, the main objectives were to demonstrate the applicability of GC×GC/TOFMS in the speciation and separation between basic and neutral NPAC from coal tar sample derived from fast pyrolysis, without prior sample fractionation. The methodology used here consisted of chromatographic injection of the diluted sample using a conventional columns set and data analysis by ChromaTOF/Excel™ software. Some basic compounds (pyridines and quinolines) and neutral ones (carbazoles and indoles) were detected with good chromatographic separation and spectral similarity. Tools like spectral deconvolution, extracted ion chromatogram (EIC) and dispersion graphics allowed greater security on the identification and separation of NPAC in this complex sample of coal tar, with no pre-treatment.
Asunto(s)
Alquitrán/química , Cromatografía de Gases y Espectrometría de Masas/métodos , Compuestos de Nitrógeno/análisisRESUMEN
In this paper it is studied the most polar fractions of bio-oil produced by fast pyrolysis of Lignocel BK40-90 (sawdust from forest timber). The biomass was submitted to the pyrolysis in an existing FCC pilot plant that was adapted for this procedure. The equipment consists of a fluidized bed reactor with nitrogen injection. The unit operates with continuous biomass feeding and continuous solids circulation. The produced bio-oil was submitted to an aqueous alkaline extraction, isolating the acidic compounds that were analyzed by one-dimensional gas chromatography and comprehensive two-dimensional gas chromatography with quadrupole mass spectrometry detection (qMS). One hundred and thirty compounds (mainly phenols and ketones) were tentatively identified in the extract, some of them by the use of retention indexes. The main differences between chromatographic techniques were the substantial increasing in the peak capacity of GC×GC and the resolution of some co-elutions that occurred in GC/qMS. It is also possible to conclude that this extract is rich in important raw materials for the chemical industry and can be used for this end.