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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
591

Molecular characterisation of glycine-N-acyltransferase from two primates : the vervet monkey and the chacma baboon / Cornelius Mthiuzimele Mahlanza

Mahlanza, Mthiuzimele Cornelius January 2011 (has links)
Glycine-N-acyltransferase (GLYAT, EC 2.3.1.13) has been characterised in a number of species including: humans, chimpanzees, rhesus monkeys and bovines. The characterisation of GLYAT from various species contributes to a better understanding of the diversity of the enzyme which in turn might help improve the current understanding of detoxification in mammals. The GLYAT enzyme of both the chacma baboon and vervet monkey has not been characterised. In this project, tissue samples were obtained from a chacma baboon (Papio ursinus) and a vervet monkey (Chlorocebus pygerythrus) to determine the nucleic acid sequence that encodes GLYAT in these two species to broaden our current understanding on the diversity of GLYAT in primates. A liver of a chacma baboon was used to extract total RNA. Complementary DNA (cDNA) was synthesised using an oligo (dT) primer. An open reading frame (ORF) encoding GLYAT of the chacma baboon was amplified with a PCR (polymerase chain reaction) using primers designed from a human GLYAT transcript. The PCR product containing an ORF encoding GLYAT of the chacma baboon was cloned, sequenced and expressed. The recombinant GLYAT of the chacma baboon expressed well in bacteria, but was insoluble and did not have enzyme activity. A crude cytoplasmic extract was prepared from the liver of a chacma baboon. The objective was to compare enzyme activity between the native and recombinant GLYAT. The prepared liver extract from the chacma baboon was assayed for enzyme activity and compared to the activity in a liver extract from bovine, previously prepared by Ms M Snyders. Both the chacma baboon and bovine liver extracts had GLYAT enzyme activity. To obtain sequence information on vervet monkey GLYAT, leukocytes were isolated from blood obtained from a living vervet monkey. A human GLYAT gene sequence was used as a reference DNA sequence in the design of PCR primers that were used to amplify the exons of GLYAT of the vervet monkey. All six GLYAT exons were individually amplified and PCR products were sequenced. The sequences were combined to reconstruct an ORF encoding GLYAT of the vervet monkey. The ORFs coding the GLYAT of both chacma baboon and vervet monkey were found to be 888 bp long (excluding stop codon) and encoded a protein of 296 amino acids. A fragment of 1256 bp of the chacma baboon GLYAT transcript was sequenced. The two GLYAT ORF sequences were translated to amino acid sequences and aligned to that of GLYAT of primates obtained from the Ensembl sequence database. The GLYAT amino acid sequences of the chacma baboon, vervet monkey and rhesus monkey formed a related group, distinct from other primates. The chacma baboon and vervet monkey sequences were 99 % identical to the rhesus monkey sequence and 92.6 % identical to the human sequence. There were 4 new variations introduced by GLYAT amino acid sequences from the chacma baboon and the vervet monkey. The vervet monkey introduced an isoleucine in place of a valine at position 32 and an arginine in place of a histidine or glutamine at position 224. The chacma baboon introduced a tyrosine in place of isoleucine at position 201 and an arginine in place of histidine or glutamine at position 240. The knowledge generated in this project will broaden the understanding of GLYAT diversity relating to GLYAT in primates. / Thesis (M.Sc. (Biochemistry))--North-West University, Potchefstroom Campus, 2011
592

Investigation into the Molecular Pharmacology of α1 and α3 Glycine Receptors

Xuebin Chen Unknown Date (has links)
The glycine receptor (GlyR) mediates fast inhibitory neurotransmission in the central nervous system (CNS). Although GlyR α1 subunits are widely distributed, α3 subunits are found only on spinal cord pain sensory neurons where they mediate central inflammatory pain sensitization. Thus, the α3 subunit is a potential therapeutic target for anti-inflammatory analgesia. It is yet to be understood why α3 subunits are represented in these synapses. Thus, α3 subunit-specific modulators are required both as therapeutic leads and as pharmacological probes for basic research. The Thesis, which consists of three independent studies, investigated the molecular pharmacology of three classes of compounds at GlyRs, especially those containing the α3 subunit. The dihydropyridines (DHPs), nifedipine and nicardipine, modulate native GlyRs at micromolar concentrations. Nicardipine has a biphasic potentiating and inhibitory effect, whereas nifedipine causes inhibition only. The first study investigated the molecular mechanism by which these compounds inhibit recombinant GlyRs. The rate of onset of inhibition in the open state was accelerated by pre-application of DHP in the closed state, with the degree of acceleration proportional to the concentration of pre-applied DHP. This implies a non-inhibitory binding site close to the DHP inhibitory site. DHP inhibition was use-dependent and independent of glycine concentration, consistent with a pore-blocking mode of action. DHP sensitivity was abolished by the G2’A mutation, providing a strong case for DHP binding site in the pore. Nifedipine exhibited an approximately 10-fold higher inhibitory potency at α1-containing relative to α3-containing receptors, whereas nicardipine was only weakly selective for α1-containing GlyRs. The differential sensitivities of nifedipine and nicardipine for different GlyR isoforms suggest that DHPs may be a useful resource to screen as pharmacological tools for selectively inhibiting different synaptic GlyR isoforms. To date there are few compounds known to pharmacologically discriminate between α1 and α3 subunit-containing GlyRs. The second study stemmed from an observation that β-alanine and taurine act as weak partial agonists of α3 GlyRs but as strong partial agonists at α1 GlyRs. Using chimeras of α1 and α3 subunits, we identified the relatively structurally divergent M4 transmembrane domain and C-terminal tail as a specific determinant of the efficacy difference. As mutation of individual non-conserved M4 residues had little influence on agonist efficacies, the reduced efficacy of α3 GlyRs is most likely a distributed effect of all non-conserved M4 residues. Given the lack of contact between M4 and other transmembrane domains, the efficacy differences are probably mediated by differential interactions between the respective M4 domains and the surrounding lipid environment. The strong influence of M4 primary structure on partial agonist efficacy suggests that the relatively poorly conserved α3 GlyR M4 domain may be a promising domain to target in the search for α3 GlyR-specific modulators. β-carbolines have recently been shown to inhibit glycine receptors in a subunit-specific manner. The third study screened four structurally similar β-carbolines, harmane (HM), tryptoline (TP), norharmane (NHM) and 6-methoxyharmalan (MH) at recombinantly expressed α1, α1β, α2 and α3 glycine receptors. The four compounds exhibited only weak subunit-specificity, rendering them unsuitable as pharmacological probes. Because they displayed competitive antagonist activity, we investigated the roles of known glycine binding residues in coordinating the four compounds. The structural similarity of the compounds, coupled with the differential effects of C-loop mutations (T204A, F207Y) on compound potency, implied direct interactions between variable β-carboline groups and mutated residues. Mutant cycle analysis employing HM and NHM revealed a strong pairwise interaction between the HM methyl group and the C-loop in the region T204 and F207. These results, which define the orientation of the bound β-carbolines, were supported by molecular docking simulations. The information may also be relevant to understanding the mechanism of β-carboline binding to GABAAR where they are potent pharmacological probes. The identification of compounds that specifically abolish α3 GlyR-mediated currents should provide a useful means to investigate the physiological roles of this subunit. Drugs that potently and selectively enhance α3-subtype GlyR function may potentially serve as lead compounds since α3-subtype GlyRs have emerged as a potential therapeutic target for pain treatment. Results from studies forming the Thesis have identified several structural elements that might be useful for developing novel α3 subunit-specific drugs in the future.
593

Regulation of protein degradation by virus derived repeated amino acid sequences /

Leonchiks, Ainars, January 2002 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / Härtill 6 uppsatser.
594

GABA-, glycine- and glutamate-induced currents in rat medial preoptic neurons : functional interactions and modulation by capsaicin /

Karlsson, Urban, January 2007 (has links)
Diss. (sammanfattning) Umeå : Univ., 2007. / Härtill 4 uppsatser.
595

The role of strychnine-sensitive nACHRS in rabbit retinal OFF ganglion cells

Renna, Jordan Michael. January 2008 (has links) (PDF)
Thesis (Ph. D.)--University of Alabama at Birmingham, 2008. / Title from first page of PDF file (viewed Feb. 13, 2009). Includes bibliographical references.
596

Combinações de fósforo mineral e composto orgânico granulado no sitema milho/soja/milho /

Pereira, Julio Cesar dos Reis. January 2018 (has links)
Orientador: Salatiér Buzetti / Resumo: Solos localizados em regiões de clima tropical apresentam, predominantemente, teores baixos de fósforo disponível (P), em função da sua mineralogia que tem alta capacidade de ser fixado por oxihidróxidos de Fe e Al. Portanto, é necessário o aporte de P nos sistemas de produção, além de estudos voltados para manutenção, ou aumento da disponibilidade do nutriente nestes solos. As tecnologias visando a utilização de fontes minerais de P, combinadas à fertilizantes orgânicos compostos, oriundos de resíduos agroindustriais, torna-se uma alternativa aos sistemas produtivos em condição de clima tropical. Neste trabalho objetivou-se, verificar o efeito da aplicação fertilizante superfosfato triplo (SFT), aplicado no sulco de semeadura, combinado ao fertilizante composto orgânico (FOC) granulado, com a seguinte composição: N total (15 g kg-1); P2O5 total (25 g kg-1); K2O (10 g kg-1); Ca (40 g kg-1); Mg (10 g kg-1); M.O. (400 g kg-1); CTC (450 mmolc dm-3); carbono orgânico (150 g kg-1); pH CaCl2 (7,0) e umidade (30 g kg-1) na base seca (65ºC), aplicado no sulco de semeadura, ou a lanço em área total, na cultura do milho, safra 2012/13, avaliou-se também o seu efeito na sucessão milho/soja/milho. O delineamento experimental adotado foi de blocos casualizados, com quatro repetições. Os tratamentos foram: SFT nas doses de 0; 37,5; 75; 112,5 e 150 kg ha-1 de P2O5 combinadas ao FOC granulado nas doses de 6,0; 4,5; 3,0; 1,5; Mg ha-1, respectivamente, mais o tratamento controle, avaliando seu... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Soils located in tropical climate regions present, predominantly, low available phosphorus content (P), depending on their facility to be fixed by Oxyhydroxide de Fe and Al. Therefore, it is necessary P input on soil to contribute to the production systems, in addition to studies for maintenance, or increase availability of the nutrient in these soils. Technologies aiming the use of P mineral sources, combined with organic fertilizers, originating from agro residues, become an alternative to production systems in tropical climate conditions. In this sense, it was intended, with this work, to evaluate the triple superphosphate fertilizer (SFT), applied at sowing furrow, combined to the granulated organic compound fertilizer (FOC), with the following composition: N (15 g kg-1); P205 (25 g kg-1); K20 (10 g kg-1); Ca (40 g kg-1); Mg (10 g kg-1); M. O. (400 g kg-1); CTC (450 mmolc dry matter (DM = 400 g kg-3); Organic carbon (150 g kg-1); pH CaCl2 (7.0) and humidity (30 g kg-1) on dry base (65ºC), applied in the furrow at sowing, or spread in total area, in corn crop, harvest 2012/13, aiming to evaluate also its effect on the succession of maize/soybean/maize. The experimental design adopted was randomized blocks, with four repetitions. The treatments were: SFT in the doses of 0; 37.5; 75; 112 and 150 kg ha-1 of P2O5 combined with granulated FOC in doses of 6.0; 4.5; 3.0; 1.5; 0 Mg ha-1, respectively, evaluating its residual effect in the soybean succession, harvest 2013/14, on a ... (Complete abstract click electronic access below) / Doutor
597

Manejo intercalar de leguminosas perenes na cultura do café em produção / Intercropping and perennial legume management on producing coffee

Cunha, Aquiles Junior da 26 September 2012 (has links)
Intercropped legumes in coffee rows perform as green manure, providing good soil coverage and reducing weed infestation. This study evaluated soil coverage and interference of forage peanuts and perennial soybean on weed infestation and phytosociology, and on growth and yield of coffee plants. The experiment was done in Patrocínio/MG, in a 11 years old producing coffee orchard, cultivar Catuaí Vermelho IAC-99, spaced by 3.80 x 0.70 m. Nine treatments were evaluated as a 23+1 factorial, in randomized blocks, with 4 repetitions, with two perennial legumes: forage peanuts (Arachis pintoi) and perennial soybean (Glycine wightii); two types of side management: with no side management, or with side management with glyphosate at 50 cm from canopy projection; two types of vertical management: no vertical management, or with legume vertical management at 5 cm above soil level. The additional treatment, the control, was done with the herbicide glyphosate (1.0 kg ha-1 of acid equivalent) between the rows. The two legume species resulted in good soil coverage, reducing weed infestation. Bidens pilosa and Spermacoce latifolia were the weed species with the greatest index of importance value. Perennial soybean, regardless of management, reduced the average number of nodes and coffee yield. Legume growth with no side management also affected coffee yield negatively, with greater interference during the high yield year. Forage peanut, with side management, did not affect the vegetative and yield characteristics of coffee. / As leguminosas intercaladas nas ruas do cafezal servem de adubo verde, proporcionam uma boa cobertura do solo e podem diminuir a infestação de plantas daninhas. O objetivo desse estudo foi avaliar a cobertura do solo e a interferência do amendoim-forrageiro e da soja-perene sobre a infestação e a fitossociologia de plantas daninhas e sobre as características vegetativas e produtivas do cafeeiro. O experimento foi instalado no município de Patrocínio/MG, em uma lavoura de café em produção da cultivar Catuaí Vermelho, linhagem IAC-99, no espaçamento de 3,80 x 0,70 m com 11 anos de idade. Utilizou-se nove tratamentos em esquema fatorial 23+1, no delineamento em blocos casualizados com 4 repetições, sendo duas espécies de leguminosas perenes: amendoim-forrageiro (Arachis pintoi) e soja-perene (Glycine wightii); dois tipos de manejo lateral: sem manejo lateral e com manejo lateral com glyphosate a 50 cm da projeção da saia; dois tipos de manejo vertical: sem manejo vertical e com manejo vertical das leguminosas a 5 cm do solo. O tratamento adicional, correspondente à testemunha, foi realizado com a aplicação do herbicida glyphosate (1,0 kg ha-1 de equivalente ácido) nas entrelinhas da parcela. As duas espécies de leguminosas proporcionaram boa cobertura do solo, diminuindo a infestação de plantas daninhas. O picão-preto (Bidens pilosa) e a erva-quente (Spermacoce latifolia) foram as espécies de plantas daninhas com maior índice de valor de importância. A soja-perene, independente do manejo, diminuiu o número médio de nós e a produtividade de café. O cultivo de leguminosas sem o manejo lateral também prejudicou a produtividade de café, sendo a interferência maior no ano de carga alta. O amendoim-forrageiro manejado lateralmente não causou interferência nas características vegetativas e produtivas do cafeeiro. / Doutor em Agronomia
598

Influência do glyphosate em cultivares de soja rr e do herbicida nicosulfuron aplicado em híbridos de milho-pipoca em três estádios de desenvolvimento

Cavalieri, Sidnei Douglas [UNESP] 10 September 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-09-10Bitstream added on 2014-06-13T21:01:04Z : No. of bitstreams: 1 cavalieri_sd_dr_botfca.pdf: 541032 bytes, checksum: 35c98291dc7bcdb9b1ec86f4f88d72ba (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O estudo da seletividade e dos efeitos secundários dos herbicidas nas culturas agrícolas é de extrema importância para o sucesso da agricultura. No presente trabalho, três experimentos foram realizados. O primeiro, conduzido em casa-de-vegetação localizada na Faculdade de Ciências Agronômicas, UNESP, Campus de Botucatu (SP), teve como objetivo avaliar o efeito de formulações comerciais de glyphosate em parâmetros nutricionais e acúmulo de matéria seca de duas cultivares de soja RR resistentes ao glyphosate. Os tratamentos avaliados resultaram do arranjo fatorial entre formulações de glyphosate (Roundup Original®, Roundup Ready®, Roundup Transorb®, Roundup WG®, Roundup Ultra® e Zapp Qi®), mais uma testemunha e cultivares de soja RR (CD 225 RR e V Max RR), conduzidos em delineamento de blocos completos casualizados com seis repetições. As aplicações dos herbicidas ocorreram quando as plantas de soja apresentavam-se no estádio V3 (25 dias após a emergência), na dosagem de 960 g e.a. ha-1. Transcorridos 15 dias após o tratamento, a parte aérea das plantas de soja foi colhida e seca em estufa. Depois de secas, obtiveram-se os dados de massa da matéria seca de hastes, folhas e parte aérea (hastes + folhas), sendo em seguida o material triturado e enviado para laboratório para análise dos teores de macronutrientes (N, P, K, Ca, Mg e S) e micronutrientes (Cu, Fe, Mn, Zn e B). Após isso, de posse dos resultados das análises laboratoriais, calculou-se o acúmulo de nutrientes na parte aérea de cada planta presente nos vasos. De forma geral, o acúmulo de macronutrientes, micronutrientes e matéria seca na parte aérea das plantas de soja sempre foi maior na cultivar V Max RR em relação à CD 225 RR. As formulações Roundup Ready® e Roundup Ultra®, não apresentaram problemas no que diz respeito ao acúmulo de nutrientes e matéria seca na parte aérea... / The study of selectivity and secondary effects of herbicides on crops is extremely important to the success of agriculture. In this study, three experiments were conducted. The first one, carried out in a greenhouse located at the College of Agronomic Sciences, UNESP, Botucatu (SP), aimed to evaluate the effect of commercial formulations of glyphosate on nutritional status and dry matter accumulations in two glyphosate-resistant soybeans cultivars (GR). The treatments were arranged in a factorial arrangement involving six commercial formulations of glyphosate Roundup Original®, Roundup Ready®, Roundup Transorb®, Roundup WG®, Roundup Ultra® and Zapp Qi® plus a control treatment, and two soybean cultivars (CD 225 RR and V Max RR), arranged in a randomized complete block design replicated six times. The herbicide applications occurred when the soybean plants were at V3 growth stage (25 days after emergence) using a dose of 960 g a.e. ha-1. After 15 days after application, the shoot of soybeans was harvested and dried in an oven. Once dried, we obtained data of dry matter of stems, leaves and shoots (stems + leaves), and then the plants were crushed and sent to the laboratory for analysis of macronutrients (N, P, K, Ca, Mg and S) and micronutrients (Cu, Fe, Mn, Zn and B). After that, ownership of the results of nutritional analysis, we calculated the accumulation of nutrients in the shoots in each plant of the pots. In general, the accumulation of macronutrients, micronutrients and dry matter in the shoot of soybean plants was always greater in V Max RR cultivar than CD 225 RR cultivar. The formulations Roundup Ready®, Roundup Ultra® and Zapp QI® showed no problems in regard to the accumulation of nutrients in shoots of cultivars. Furthermore, the Roundup Original®, Roundup Transorb® and Roundup WG® formulations caused the greatest damage to the nutrition provided the cultivars... (Complete abstract click electronic access below)
599

Resistência de genótipos de soja Glycine max (L.) a Nezara viridula (L. ,1758) (Hemiptera: Pentatomidae)

Souza, Efrain de Santana [UNESP] 05 February 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-05Bitstream added on 2014-06-13T19:37:23Z : No. of bitstreams: 1 souza_es_me_botfca.pdf: 441338 bytes, checksum: ea2c42d17d75e649a7553a96a791b3e0 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Visando avaliar a resistência de diferentes genótipos de soja [Glycine max (L.)] frente ao ataque do percevejo Nezara viridula (L.) (Hemiptera: Pentatomidae), foram conduzidos ensaios em laboratório sob condições controladas (T= 25  2º C, U.R.= 70  10% e fotoperíodo= 12 h). Foram realizados testes de atratividade e preferência para alimentação com grãos maduros e vagens verdes dos genótipos de soja „Conquista‟, „IAC-17‟, „IAC-19‟, „IAC-24‟, „PI-227687‟, „TMG-103‟, „TMG-117‟, „TMG-121‟, „BRS-242‟ e „IAC-PL1‟, avaliando-se o número de insetos atraídos aos 15, 30, 45, 60, 120 e 180 minutos após a liberação. No teste com vagens verdes, contou-se também o número de picadas e o tempo médio de alimentação por picada. Visando associar a preferência do inseto com as características físicas dos genótipos, realizou-se a contagem do número de tricomas em vagens verdes (densidade/área) e a medição da textura nestas mesmas vagens. Estudos de antibiose também foram realizados utilizando-se os mesmos genótipos, acompanhando-se diariamente o desenvolvimento dos insetos confinados a cada material (25 ninfas/genótipo). Nesta fase avaliou-se: a duração de cada estádio e a duração total da fase ninfal; a mortalidade por estádio e total da fase ninfal; o peso de ninfas (N5) e adultos recém-emergidos (24 h) e o período de desenvolvimento de ovo a adulto. Em teste com chance de escolha, os grãos maduros de „TMG-117‟ e „TMG-121‟ foram menos atrativos aos adultos de N. viridula. Com relação às vagens, „IAC-17‟ e „PI-227687‟ foram os menos atrativos; „IAC-17‟ e „IAC-PL1‟ foram pouco consumidos, indicando a expressão de resistência por não-preferência para alimentação. As vagens dos genótipos „IAC-17‟, „TMG-117‟ e „PI-227687‟ apresentaram elevada densidade de tricomas; em „IAC-17‟... / Aiming to evaluate the resistance of different genotypes of soybean Glycine max L. against the attack of stink bug Nezara viridula (L., 1758) (Hemiptera: Pentatomidae), experiments were conducted in laboratory under controlled conditions (T= 25  2 ° C, R.H= 70  10% and photoperiod= 12 h). Tests of attractiveness and preference were conducted in mature grain and green pods of soybean genotypes „Conquista‟, „IAC-17‟, „IAC-19‟, „IAC-24‟, „PI-227687‟, „TMG-103‟, „TMG -117‟, „TMG -121‟, „BRS-242‟ and „IAC-PL1‟, evaluating the number of insects attracted to the 15, 30, 45, 60, 120 and 180 minutes after release. In the test with green pods, also counted the number of pricks and the average time of feeding per prick. Aiming to the preference of the insect with the physical characteristics of the genotypes, there was a count of the number of trichomes in green pods (density / area) and the measurement of texture in these same pods. Antibiosis studies were also conducted using the same genotypes, following the daily development of insects confined in each material (25 insects / genotype). At this stage it was evaluated: the duration of each stage and total duration of the nymphal stage; the mortality per stage and total nymphal stage; the weight of nymphs (N5) and newly emerged adults (24 h) and the development period from egg to adult. In test-choice, the mature grains of „TMG-117‟ and „TMG-121‟ were less attractive to adults of N. viridula. Regarding the pods, „IAC-17‟ and „PI-227687‟ were the least attractive, „IAC-17‟ and „IAC-PL1‟ were little consumed, indicating the expression of resistance by non-preference for feeding. The pods of the genotypes „IAC-17‟, „TMG-117‟ and „PI-227687‟ showed high density of trichomes; in „IAC-17‟ this structure was considered the main factor of resistance. In biology tests... (Complete abstract click electronic access below)
600

Efeito do aumento da concentração de co2 atmosférico sobre o oídio, a ferrugem e o desenvolvimento de plantas de soja

Lessin, Ricardo Contreira [UNESP] 18 August 2008 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-08-18Bitstream added on 2014-06-13T19:37:27Z : No. of bitstreams: 1 lessin_rc_me_botfca.pdf: 518732 bytes, checksum: 7e4d555398ff650c409d95422bc6f7ea (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os níveis de concentração de CO2 atmosférico estão se elevando nas últimas décadas devido principalmente à queima de combustíveis fósseis. Essa alteração atmosférica, além de intensificar o fenômeno do efeito estufa, pode afetar o comportamento de algumas plantas e microrganismos de interesse agrícola. O CO2, por ser um componente básico da fotossíntese, em alta concentração, pode causar alterações na morfologia e nos processos fisiológicos das plantas, assim como na interação destas com fitopatógenos. Sendo assim, o presente estudo teve por objetivo avaliar o efeito da alta concentração de CO2 atmosférico na severidade do oídio, causado por Microsphaera diffusa, e da ferrugem asiática, causado por Phakopsora pachyrhizi, na soja e também em alguns fatores relacionados ao desenvolvimento da planta que podem exercer influência na doença, como o crescimento, peso da matéria seca e nodulação. Foram realizados três ensaios em estufas de topo aberto com (E+CO2) ou sem (E) injeção de CO2 e sem estufa (T), correspondendo às concentrações de, aproximadamente, 647 ppm, 474 ppm e 453 ppm, respectivamente. No primeiro ensaio, foram avaliadas características de desenvolvimento da planta; no segundo, a severidade da ferrugem asiática, que ocorreu de forma espontânea; e no terceiro, a severidade do oídio em quatro cultivares com diferentes níveis de resistência. As cultivares foram: FT-Estrela, altamente suscetível (AS); Embrapa 48, suscetível (S); FT-Cometa, moderadamente resistente (MR) e FT-5 (Formosa), resistente (R). Nos resultados obtidos, foi verificado um aumento significativo na severidade do oídio, no tratamento com injeção de CO2,em folhas primárias e na planta inteira das cultivares analisadas em conjunto, mas não houve alteração na expressão de resistência das cultivares. Para a ferrugem asiática, houve redução da severidade... / The concentration of atmospheric CO2 is increasing in recent decades, mainly due to burning of fossil fuels. This atmospheric change can intensify the phenomenon of the greenhouse effect, and can affect the behavior of important agricultural plants and microorganisms. The CO2, as a basic component of photosynthesis, in high concentrations, can cause changes in morphological and physiological processes of plants, as well as interaction with plant pathogens. Therefore, this study aimed to assess the effect of high concentrations of atmospheric CO2 on the severity of powdery mildew in soybean, caused by Microsphaera diffusa, and also in some characteristics related to the development of the plant that may influence the disease, such as growth, weight of dry matter and nodulation. Three trials were developed under open-top chambers with (E+CO2) or without (E) injection of CO2 and without greenhouse (T), with the approximate concentrations of 647 ppm, 474 ppm, and 453 ppm, respectively. On the first trial, growth characteristics were evaluated, on the second, the severity of rust, caused by Phakopsora pachyrhizi, which occurred spontaneously; on the third, the severity of powdery mildew on four cultivars with different levels of resistance: FT-Estrela, highly susceptible (AS); Embrapa 48, ...(Complete abstract click electronic access below)

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