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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.
31

Compreendendo a via de desenvolvimento de tricoma glandular em tomateiro (Solanum lycopersicum) utilizando mutantes e variações genéticas naturais / Understanding the glandular trichomes development pathway in tomato (Solanum lycopersicum) using mutants and natural genetic variations

Eloisa Vendemiatti 04 September 2015 (has links)
Os tricomas são estruturas de origem epidérmicas que podem ser classificados em dois tipos: glandulares e não glandulares (tectores) e estão relacionados, principalmente, com estratégias de defesas de plantas. Pouco se conhece sobre a via de desenvolvimento dos tricomas glandulares, já que a maior parte dos estudos é em Arabidopsis thaliana, modelo no qual os tricomas glandulares são ausentes. O gênero Solanum possui uma grande diversidade de tricomas, em especial glandulares (tipos I, IV, VI e VII). O estudo de tais estruturas vem ganhando cada vez mais destaque, já que são fontes de diversos metabólitos secundários de importância econômica e ecológica. Espécies selvagens são consideradas recursos genéticos para o tomateiro (S. lycopersicum), tais como S. galapagense, a qual possui variações genéticas naturais que lhe confere maior resistência ao ataque de herbívoros. Entre essas variações está a presença de tricomas glandulares do tipo IV, uma fonte do aleloquimico acilaçúcar. A ausência de tricomas glandulares do tipo IV é considerada uma das causas da suscetibilidade do tomateiro cultivado a insetos. No presente trabalho, foi demonstrado que o tomateiro cultivado na verdade forma tricomas do tipo IV, mas estas estruturas estão presentes somente até o primeiro par de folhas, além dos cotilédones. Desse modo, a presença de tricomas tipo IV em espécies selvagens seria considerada uma neotenia, ou seja, a manutenção de estruturas juvenis na fase adulta. Além de se determinar que mutantes de tomateiro afetando a juvenilidade (e.g. Mouse ears e fasciated) apresentam tricomas tipo IV na fase adulta, a formação dessas estruturas correlacionou se com a expressão de miR156, sendo também presentes em grandes quantidades em uma linhagem transgênica superexpressando esse micro RNA relacionado à juvenilidade. Quanto à base genética da presença de tricomas tipo IV nas espécies selvagens, no presente trabalho foi criada uma linhagem quase isogênica ao modelo genética Micro-Tom (MT) contendo a variação genética natural por nós denominada Galapagos enhanced trichomes (Get). Tal variação é derivada de S. galapagense e condiciona a presença de tricomas tipo IV em folhas adultas, quando introgredida em tomateiro cultivado (cv. Micro-Tom). O mapeamento preliminar de Get no cromossomo 2 de tomateiro também foi realizado através do mapa de \"single nucleotide polymorphism\" (SNPs) entre MT e a linhagem MT-Get. A eventual clonagem de GET irá contribuir não somente para se desvendar a base genética da formação de tricomas glandulares, como também contribuir para se criar variedades resistentes a insetos, reduzindo o uso de agrotóxicos. / Trichomes are epidermal structures that can be classified into two types: glandular or non-glandular, and they are mainly related to plant defense strategies. Little is known about the glandular trichome development pathway, since most of the studies are in Arabidopsis thaliana, a model in which this kind of trichome is absent. The Solanum genus has a wide variety of trichomes, especially glandular ones (Types I, IV, VI and VII). The study of these structures are gaining more prominence, since they are sources of several secondary metabolites of economic and ecological importance. Wild species are considered genetic resources for tomato (S. lycopersicum), such as S. galapagense which has natural genetic variations that gives resistance to herbivores attack. Among these variations is the presence of type IV glandular trichomes, a source of the acyl sugar allelochemical. The absence of type IV glandular trichomes is considered to be one of the causes of tomato susceptibility to insects. In this study, it was determined that tomato actually has type IV trichomes, but these structures are present only in the cotyledons and the first pair of leaves. Thus, the presence of type IV trichomes in wild species would be considered a neotenic feature, i.e. the maintenance of juvenile structures in adulthood. In addition, it was determined that tomato mutants affecting youthfulness (e.g. Mouse ears and fasciated) have type IV trichomes in adulthood. Moreover, the presence of these structures was correlated with the expression of miR156, besides the increased formation of type IV trichomes in a transgenic line overexpressing this micro RNA related to youthfulness. On the genetic basis of type IV trichomes presence in wild species, in this work it was created a near isogenic line (NIL) containing the natural genetic variation here named Galapagos enhanced trichomes (Get). This variation is derived from S. galapagense and harbors type IV trichomes in adult leaves, when introgressed in cultivated tomato (cv. Micro-Tom). The preliminary genetic map of Get in the tomato chromosome 2 was conducted through the analysis of \"single nucleotide polymorphism\" (SNPs) between MT and MT-Get. The eventual cloning of GET will contribute not only to unravel the genetic basis of glandular trichomes formation, but will also contribute to create varieties resistant to insects, reducing the pesticides use.
32

Obtenção e uso de linhagens quase isogênicas de tomateiro (Solanum lycopersicum L. cv Micro-Tom) afetando a composição de carotenoides: uma ferramenta para o estudo da nutracêutica / Obtainment and application of tomato (solanum lycopersicum l. cv micro-tom) near isogenic lines affecting carotenoid content: a nutraceutical study tool

Stevan Ricardo Bordignon 02 September 2015 (has links)
A incidência de doenças crônicas atinge índices epidêmicos, sendo responsável por mais de 60% da mortalidade mundial. Medidas preventivas são adotadas e, entre elas, uma alimentação balanceada. Nesta inclui-se o consumo de frutos e vegetais, especialmente os de coloração vermelha e laranja, ricos em carotenoides, fitonutrientes que muitas vezes assumem papel de antioxidantes, prevenindo a incidência destas doenças. No presente trabalho foram obtidas linhagens quase isogênicas (NILs) de tomateiro contendo os alelos at, B, Del, gf, og, r, t e y, os quais afetam a composição de carotenoides. Tais linhagens constituem uma importante ferramenta para estudos de nutracêutica, como os testes de biodisponibilidade de diferentes tipos de carotenoides no plasma sanguíneo, após ingestão, o que foi testado no presente trabalho através do emprego de HPLC e ratos da linhagem Wistar. Além disso, frente às diferentes ofertas de cores e composições metabólicas de tomates disponíveis no mercado, as NILs permitiram o ajuste de parâmetros de colorimetria como um método rápido para identificar os principais mutantes da via de biossíntese de carotenoides presentes em linhagens comerciais. Ressalta-se que, muitas vezes as cores podem enganar e não trazer vantagens nutricionais, como é o caso do consumo de linhagens comerciais contendo a mutação yellow flesh (r). Por fim, as NILs foram utilizadas para verificar se as mutações alterando a composição de carotenoides possuíam alguma penalidade em termos de produtividade ou outros parâmetros de qualidade de fruto (Teor de Sólidos Solúveis, acidez). Os resultados mostraram-se de aplicabilidade e geraram um banco de dados passível de expansão, para novos mutantes que alterem a cor do tomate e fazendo uso de outros backgrounds. Tais dados podem ser usados tanto para programas de melhoramento visando a qualidade nutricional, quanto para o comércio atacado, beneficiando o consumidor final. / The incidence of chronic disease reaches epidemic levels, accounting for over 60% of global mortality. Preventive measures are adopted, and among them, a balanced diet. This includes the fruits and vegetables consumption, especially the red and orange ones, rich in carotenoids, phytonutrients which often assumes the role of antioxidants preventing these diseases incidence. In this study, tomato near isogenic lines (NILS) containing the alleles B, Del, gf, og, r, t and y, were obtained, affecting the carotenoid fruit content. Such lines are an important tool for nutraceutical studies, like different carotenoids bioavailability tests in blood plasma after ingestion, which was tested in this work by HPLC employment and Wistar rats. Moreover, in the face of different colors and metabolic contents offerings of tomatoes available at the market, NILs allowed the adjustment of colorimetric parameters as a fast way to identify carotenoids biosynthetic pathway key mutants present in commercial strains. It is highlighted that many times colors can mislead and not bring nutritional benefits, like the consumption of commercial strains containing the mutation yellow flesh (r). At the end, NILs were used to verify if the carotenoid content mutations had some penalty in terms of productivity or other fruit quality parameters (Soluble Solids Content, acidity). The results showed relevant and generated a database capable of expansion to new fruit color tomato mutants even in other genetic backgrounds. Such data can be used both for nutritional quality breeding programs, both for the wholesale trade, benefiting the end user.
33

Messianisme, mysticisme et monothéisme : le RSI dans les œuvres de Tom Robbins / Messianism, Mysticism and Monotheism : RSI in Tom Robbins' works

Buckwalter, Elvis 05 May 2009 (has links)
Dans le contexte d’une société américaine où la religion occupe une place primordiale, une approche lacanienne des romans de Tom Robbins s’avère particulièrement utile pour dégager les thèmes directeurs de ses œuvres : le messianisme, le mysticisme et le monothéisme. Non seulement ces manifestations religieuses jouent un rôle central dans son œuvre romanesque, mais elles servent aussi à mieux exploiter les outils psychanalytiques développés par Jacques Lacan, et en particulier le Symbolique, l’Imaginaire et le Réel. Comment le RSI peut-il éclaircir le débat religieux dans les œuvres de Tom Robbins ou dans d’autres œuvres postmodernes ? Cette étude multidisciplinaire répond à cette problématique en se portant sur trois axes principaux. Premièrement, l’envergure de la messianité dans la société américaine donne lieu au phénomène littéraire que nous appelons « le sujet messianique », se caractérisant par son ancrage topologique dans le Symbolique lacanien. Ensuite, la prévalence d’une approche mystique de la spiritualité dans les œuvres robbinsiennes s’exprime par une relation mystique entre un être divin d’une part, et le croyant d’autre part – rapport symbiotique propre à l’instance Imaginaire. Enfin, le Réel lacanien met en exergue l’impossibilité de la réconciliation structurale entre ces deux instances en explorant le thème du monothéisme dans les œuvres de Tom Robbins. Cette thèse a l’ambition non seulement de faire connaître un écrivain américain peu connu du public francophone, mais aussi de mieux définir l’articulation entre la religion, la psychanalyse et les romans de Tom Robbins / In the context of an American society where the importance of religion takes on epic proportions, a Lacanian approach to analyzing Tom Robbins’ novels is particularly useful in the identification of his works’ major themes: messianism, mysticism and monotheism. Not only do these particular religious events play a central role in his fiction, but they also serve to put psychoanalytic tools to use, such tools as the Symbolic, the Imaginary and the Real developed by Jacques Lacan. How can RSI define the religious debate in the works of Tom Robbins? This multidisciplinary study addresses this problem by focusing on three main areas. First of all, American society’s infatuation with messianism has given rise to a literary phenomenon that I have termed « the messianic subject », characterized by its topological anchorage in the Symbolic order. Moreover, the prevalence of mystical approaches to spirituality in Robbins’ novels – expressed by a mystical relationship between a divine being on the one hand, and believers on the other – constitute a symbiotic relationship present in Lacan’s Imaginary order. Finally, the realm of the Lacanian Real highlights the impossibility of reconciliation between these two structural instances by exploring the theme of monotheism in the works of Tom Robbins. This dissertation aims not only to make a little-known American writer known to Francophone audiences, but also to better define the relationship between religion and psychoanalysis in the novels of Tom Robbins
34

The Aesthetics and Ethics of the Absent Subject in the Novels of Tom McCarthy / L'esthétique et l'éthique du sujet absent dans les romans de Tom McCarthy

Staunton, Benjamin 16 November 2018 (has links)
Résumé en français : Ce projet s’intéresse à la fois aux œuvres et à la théorie de l’écrivain-artiste Tom McCarthy, précisément en analysant ses livres Remainder (2005), Men in Space (2007), C (2010), et Satin Island (2015), ainsi que ses œuvres théoriques, Tintin and the Secret of Literature (2006) et Typewriters, Bombs, Jellyfish : Essays (2017). Son rapport avec certains styles littéraires d’avant-garde et de modernisme a provoqué des analyses qui l’ont rendu explicit à travers les accueils critiques au sein de et en dehors du monde universitaire, et également a travers ses propres œuvres de théorie. Toutefois, cette analyse de McCarthy prend comme point de vue l’angle de Jean Baudrillard et son regard postmoderne et critique culturel. On a suggéré que les œuvres de McCarthy rejettent le sujet traditionnel du roman moderne et de ce fait éviter les résolutions de l’ordre idéologique ou structurelle, ce qui permet l’émergence de nouvelles façons subjectives. C’est l’affirmation de ce travail que l’éthique et l’esthétique du choix de McCarthy, le refus et l’absence du sujet, sont en fait des expressions d’une positivité et passivité relevant de leurs origines d’une idéologie qui est purement bourgeoise. La première partie s’engage à explorer les conditions du temps, de l’espace, et du destin individuel dans les romans, afin de les lier aux conditions postmodernes. Ces conditions-ci facilitent l’analyse, dans la deuxième partie de ce mémoire, d’une série des styles littéraires et « formalisms », ce qui simule la présence d’un sujet « absent » dans les romans. Avec un regard visé sur la notion de Symbolisme, de l’« a-signification » et de la mélancolie en tant que repère littéraire d’une subjectivité absente, cette deuxième partie élabore l’esthétique de l’absence (d’un perspectif linguistique et technologique), développant l’essentiel de la notion d’une présence simulée. La troisième partie réunit, a travers l’ironie et le personnage mythique du farceur, les conditions et l’esthétique de ce sujet absent sous la formed’une vision d’éthique cyclique, plutôt qu’infini ou discriminatoire, et c’est cette éthique qui produit à la fois la capacite d’un défi mortel et le plaisir de la conformité en même temps.Mots-clés en français : Tom McCarthy, roman, Baudrillard, éthique, esthétique, communication de masse, le postmoderne, absence / Résumé en anglais : This study engages with the novels and theory of the English author and artist Tom McCarthy, specifically the novels Remainder (2005), Men in Space (2007), C (2010) and Satin Island (2015), as well as his works of theory, Tintin and the Secret of Literature (2006) and Typewriters, Bombs, Jellyfish: Essays (2017). McCarthy’s literary connection to certain brands of avant-garde modernism has been analysed and made explicit both through their critical reception inside and outside of academia, and through McCarthy’s own works of theory. However, in this study McCarthy’s literary oeuvre is engaged with through the lens of Jean Baudrillard’s particular brand of postmodernity and cultural criticism. It has been suggested that McCarthy’s novels reject the traditional subject of the modern novel, and as such avoid turning to ideological or structural resolutions, leaving open the space for new modes of subjectivity to emerge. It is the contention of this study that the ethics and aesthetics of this refusal and absence are in fact expressions of a specifically bourgeois ideological positivity and passivity. The first section serves to approach the conditions of time, space and individual destiny in the novels, relating these to the conditions of postmodernity. These conditions serve to foster, in the second section of the study, a series of literary modes and formalisms that simulate the presence of the ‘absent subject’ in the novels. Looking specifically at Symbolism, a-signification and melancholy as literary markers of an absent subjectivity, this second section elaborates on the aesthetics of absence (linguistic and technological) that are essential to this mode of simulated presence. The third section brings together, through the figure of irony and the mythic trickster figure, the conditions and aesthetics of this absent subject in the form of a mode of ethics that is cyclical, as opposed to infinite or discriminatory, and which produces both the capacity for fatal challenge and the pleasure of conformity at once.Mots-clés en anglais: Tom McCarthy, the novel, Baudrillard, ethics, aesthetics, mass communication, postmodernity, absence.
35

Etude du mécanisme de translocation de l'ARNtLys dans les mitochondries de Saccharomyces cerevisiae / Studying the mechanisms of tRNALys(CUU) translocation into mitochondria of Saccharomyces cerevisiae

Schirtz, Tom 12 October 2012 (has links)
L’import d’ARN dans les mitochondries est un processus ubiquitaire chez les eucaryotes. Dans Saccharomyces cerevisiae un isoaccepteur cytosolique de l’ARNtLys, l’ARNtLys(CUU) (tRK1), est partiellement importé dans les mitochondries. L’adressage vers la surface mitochondriale a été étudié en détail mais l’étape de translocation dans les mitochondries reste toujours à démontrer. L’objectif principal de ce travail de thèse était l’identification et la caractérisation des protéines qui participent dans ce processus. Deux protéines de la membranes externe capables de former des canaux, Tom40 et VDAC1, ont été identifiées et leur rôle dans l’étape de translocation a été évalué in vitro et in vivo en utilisant des souches mutantes appropriées ou des agents capables de bloquer de manière spécifique les canaux formés par les protéines Tom40 et VDAC1. Ainsi il a été démontré que la délétion de VDAC1 ou l’inhibition du canal VDAC1 a conduit à une inhibition importante, néanmoins pas complète, de l’import de tRK1. Le blocage simultané des canaux Tom40 et VDAC1 par contre a causé un arrêt complet de l’import de tRK1 in vitro. Vu ces résultats, nous proposons que la translocation de tRK1 à travers la membrane mitochondriale externe puisse suivre deux chemins alternatifs. / RNA import into mitochondria is a ubiquitous process in eukaryotic cells. In Saccharomyces cerevisiae one cytosolic isoacceptor of tRNALys, tRNALys(CUU) (tRK1), is partially imported into mitochondria. Targeting of tRK1 to the mitochondrial surface is well described but the translocation of tRK1 into mitochondria is still poorly understood. This PhD work aimed to study this translocation step and the main objective was the identification and characterization of mitochondrial membrane proteins participating in this process. The two channel-forming proteins of the mitochondrial outer membrane, Tom40 and VDAC1, were identified and their role in tRK1 translocation further investigated with the help of in vitro and in vivo import studies using appropriate mutant strains or specific agents capable of blocking Tom40 and VDAC1. In this way, it could be demonstrated that deletion of the VDAC1 gene or inhibition of VDAC1 led to an important yet not complete inhibition of tRK1 import into mitochondria. Simultaneous blocking of the two channels formed by Tom40 and VDAC1, however, resulted in a complete inhibition of tRK1 import in vitro. Regarding these results we propose that tRK1 translocation through the mitochondrial outer membrane can use two alternative pathways.
36

Cognitive Development Of Turkish Children On The Relation Of Evidentiality And Theory Of Mind

Ozoran, Dincer 01 January 2010 (has links) (PDF)
For the first time a representative Theory of Mind (ToM) scale (Wellman &amp / Liu, 2004) has been cast into three different linguistic forms in order to show the impact of evidential markers on ToM understanding. With Turkish children, we studied (i) a control form without explicit evidential markers, as conducted by Bayramoglu &amp / Hohenberger (2007), (ii) a verbal form with &ndash / DI (marking factuality in the past ) and (iii) a verbal form with &ndash / MIS (marking hearsay in the past). To predict ToM performance of children, we also conducted a working memory task and two language tasks for complex syntax understanding. Our analysis showed that Turkish children, ranging from 4 to 7 years of age, performed significantly better with the form &ndash / DI than the control form. Also one of the language tasks which measures relative clause understanding was found to be a significant predictor of ToM performance. We conclude that evidential markers may help Turkish children in their online reasoning of ToM. We think that the relation between evidentiality and ToM may be understood clearer with cross-linguistic studies by varying the presence of evidentials and also their linguistic properties (i.e. lexical or morphological) while controlling the materials across languages. Theory of Mind (ToM), Evidentiality, ToM scale, Cognitive Development, Language.
37

"The true male animals" changing representations of masculinity in Lonesome Dove, Bonfire of the Vanities, Fight Club, and A Man in Full /

Player, Bailey. Edwards, Leigh H. January 2006 (has links)
Thesis (M.A.)--Florida State University, 2006. / Advisor: Leigh Edwards, Florida State University, College of Arts and Sciences, Dept. of English. Title and description from dissertation home page (viewed Sept. 22, 2006) Document formatted into pages; contains vi, 107 pages. Includes bibliographical references.
38

Da universidade livre à escola oficial: um estudo sobre o imaginário do Centro Tom Jobim / From one free university to an official school: a study of imaginary of the Centro Tom Jobim (Brazil).

Tiago Lazzarin Ferreira 12 November 2012 (has links)
O presente estudo tem o objetivo de fornecer pistas sobre o imaginário de dois períodos distintos de uma mesma instituição: a antiga Universidade Livre de Música Tom Jobim (ULM) e a atual Escola de Música do Estado de São Paulo Tom Jobim (EMESP). Pretende compreender e caracterizar os fundamentos pedagógicos de um projeto educacional de Música utilizando-se das teorias de Gilbert Durand, Edgar Morin e José Carlos de Paula Carvalho. O interesse se deve à mudança do modelo de ensino livre e acessível a todas as idades para o modelo de ensino oficial acompanhado da padronização do perfil dos estudantes. Por meio da teoria do Imaginário de Durand, pretende-se identificar os mitos relativos às duas propostas de ensino e situá-las no panorama político que as engendrou. A pesquisa se baseou no estudo dos documentos publicados pela gestão da Organização Social Santa Marcelina, Diário Oficial do Estado de São Paulo e nas observações feitas em campo. / The present research had as objective to investigate the imaginary of two distinct periods of one same institution: the former Universidade Livre de Música-TomJobim (ULM) and the current Escola de Música do Estado de São Paulo Tom Jobim(EMESP). The aim of this study is to understand and characterize the pedagogical principles of that Music-centered educational project through the theories of Gilbert Durand, Edgar Morinand José Carlos de Paula Carvalho. This interest was awakened by the change (undergone by the institution),from a free education model accessible to all ages, to an official teaching model followed by standardization of students profiles. Through Durands theory of the Imaginary this study seeks to identify miths regarding each of the two educational proposals, and to place them in the respective political scenes that engendered them. Research was based on the study of documents published by (the administration of)the Organização Social Santa Marcelina, study of the Diário Oficial do Estado de São Paulo, and field observations.
39

Genômica funcional da interação cacaueiro (Theobroma cacao L.) x Moniliophthora perniciosa por meio do sistema modelo Micro-Tom (Solanum lycopersicum L.) / Functional genomics of the interaction cocoa (Theobroma cacao L.) x Moniliophthora perniciosa by means of the model system Micro-Tom (Solanum lycopersicum L)

Danielle Camargo Scotton 21 September 2012 (has links)
A cultura do cacaueiro (Theobroma cacao L.) na região sul da Bahia foi dizimada com a introdução do fungo Moniliophthora perniciosa. Novas fontes de resistência têm sido buscadas e alternativas são necessárias para assegurar a produção de cultivares considerando a variabilidade genética do patógeno. A descoberta de genes de resistência e de defesa presumíveis a partir de abordagens genômicas impõe a necessidade de estabelecimento de uma plataforma de análise funcional para comprovar a função dos genes identificados e/ou esclarecimento dos mecanismos envolvidos; isto requer o desenvolvimento de métodos de manipulação e/ou inserção de genes, permitindo a superexpressão ou silenciamento de genes de interesse. Os primeiros cacaueiros transgênicos só foram desenvolvidos a poucos anos, e a eficiência do processo ainda é limitada. Há grande influência genotípica na capacidade embriogênica, que reduz a eficiência de obtenção de transgênicos. Micro-Tom tem sido considerado um modelo para pesquisas em tomateiro, sendo uma cultivar miniatura, ciclo de vida curto, porte reduzido e de fácil transformação. MT pode ser usada no estudo da interação com o fungo M. perniciosa, visto a disponibilidade de isolados do biótipo-S que infectam o tomateiro, assim disponibilizando informações dos mecanismos de defesa do T. cacao a M. perniciosa em um menor tempo, suprindo alguns obstáculos encontrados nas características biológicas do cacaueiro. Considerando que durante a patogênese do cacaueiro, M. perniciosa é capaz de desencadear a morte celular programada no tecido infectado, foi analisada a hipótese de que a expressão de genes anti-apoptóticos diminuiria ou minimizaria os efeitos da infecção, permitindo uma menor susceptibilidade. Para tal, foi clonado o gene da proteína Bax-inhibitor-1, que atua como atenuador basal para a progressão da morte celular, e desenvolvida uma construção. Esse gene havia sido detectado numa biblioteca da interação M. perniciosa x T. cacao e identificado com sequência completa, e foi re-introduzido em tomateiro e cacaueiro sob controle de promotor constitutivo. Para o modelo genético MT, plantas transgênicas contendo Bax-inhibitor-1, SKP1 e Cafeína sintase foram obtidas. Plantas transgênicas de tomateiro contendo o gene Bax-inhibitor-1 foram inoculadas com M. perniciosa e demonstraram redução no número de plantas sintomáticas (40%), quando comparadas as plantas de MT inoculadas com o mesmo patógeno (83%). Esses dados corroboram com resultados das inoculações com os fungos necrotróficos B. cinerea, S. sclerotium e S. rolfsii, sendo que as plantas transgênicas inoculadas também apresentaram contenção dos sintomas dessas doenças, uma redução de 40% da área de infecção em comparação as plantas de MT infectadas. Desse modo, pode-se concluir que o gene Bax-inhibitor-1 em MT agiu de forma basal na atenuação da progressão da morte celular, reduzindo os sintomas da vassoura-de-bruxa, da mesma forma que esse transgene contribuiu na redução dos sintomas do mofo cinza, mofo branco e murcha-de-esclerócio, por conter o crescimento e desenvolvimento dos fungos inoculados em tomateiro. Foi possível otimizar o protocolo de embriogênese somática e de transformação genética de cacaueiro, o que levou a obtenção de plantas transgênicas contendo a construção Bax-inhibitor-1, confirmadas por RTqPCR. Indicando que a abordagem de transformação de cacaueiro está implementada no laboratório, porém a baixa eficiência do processo e o tempo necessário ainda impedem seu uso em larga escala para análise funcional / The cultivation of cocoa (Theobroma cacao L.) in south Bahia was decimated by the introduction of the fungus Moniliophthora perniciosa. New sources of resistance have been sought and alternatives are needed to ensure the production of cultivars considering the genetic variability of the pathogen. The discovery of genes for resistance and defense presumed from genomic approaches makes it necessary the establishment of a platform to verify the function of identified genes and/or the elucidation of the mechanisms involved; this requires the development of methods for manipulating and/or insertion of genes, allowing overexpressing or silencing of genes of interest. The first transgenic cocoa were only developed a few years ago, and the efficiency of the process is still limited. There is an expressive influence of the embryogenic capacity, which reduces the efficiency of obtaining transgenic plants. The cultivar Micro-Tom (MT) is considered a model for research on tomato, since it has a miniature size, short life cycle, and facile genetic transformation. MT can be used to study the interaction with the fungus M. perniciosa, since isolates of biotype-S are able to infect tomato, thus provinding inferences about defense mechanisms of T. cacao to M. perniciosa in a short time, providing some obstacles encountered in biological characteristics of cocoa. Since during the pathogenesis of cocoa, M. perniciosa is able to trigger programmed cell death in infected tissue, it was analyzed the hypothesis that the expression of anti-apoptotic genes diminish or minimize the effects of infection, allowing less susceptibility. To this end, was cloned the protein Bax-inhibitor-1, which acts as a basal attenuator for the progression of cell death, was cloned engineered in a vector for genetic transformation. This gene was detected in a library of interaction M. perniciosa x T. cacao and identified with the complete sequence, and was re-introduced into tomato and cocoa under the control of a constitutive promoter. For the genetic model MT, transgenic plants containing Bax-inhibitor-1, SKP1 and Caffeine synthase were obtained. Transgenic tomato plants containing the gene Bax-inhibitor-1 were inoculated with M. perniciosa and demonstrated a reduction in the number of symptomatic plants (40%) compared MT plants inoculated with the same pathogen (83%). These data corroborate results of inoculations with the necrotroph fungi B. cinerea, S. sclerotium e S. rolfsii. Thus, when transgenic plants were inoculated, it was observed a reduction of 40% in the area of infection, compared to infected MT plants. Taken together, the results indicate that the gene Bax-inhibitor-1 acted in the basal attenuation of progression of cell death in MT, reducing the symptoms of the witches\' broom disease, as well as the symptoms of gray mold, white mold and wilt esclerotia. Moreover it was possible to optimize the protocol for somatic embryogenesis and genetic transformation of cocoa, which led to the production of transgenic plants containing the construct Baxinhibitor- 1, confirmed by RT-qPCR. Although, a protocol for cocoa transformation was implemented in the laboratory, its the low efficiency and the time required still prevent its widespread use for functional analysis
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Variações alélicas que afetam a carotenogênese em tomateiro alteram o amadurecimento e a suscetibilidade dos frutos ao fungo Botrytis cinerea / Allelic variations affecting tomato carotenogenesis alter ripening and susceptibility of fruits to Botrytis cinerea

Bruna Orsi 05 July 2018 (has links)
Carotenoides são pigmentos encontrados em grande abundancia em frutos do tomateiro. A capacidade de sequestro de radicais destes pigmentos faz do tomate uma excelente opção para inclusão de compostos nutricionais pela dieta. Embora a síntese de carotenoides seja reconhecida como uma das respostas da cascata de eventos que levam ao amadurecimento, pouco se sabe a respeito de sua influência neste processo. Deste modo, o objetivo deste trabalho foi determinar se o conteúdo e a composição de carotenóide nos frutos acarretam alterações na conservação e na suscetibilidade dos frutos ao fungo B. cinerea. Foram utilizadas linhagens quase isogênicas (NILs) ao Micro Tom (MT) carregando as mutações, Beta carotene (B), tangerine (t), yellow flesh (r) e Delta carotene (Del). A caracterização dessas variações alélicas revelou, não apenas alterações no conteúdo de carotenoides, mas também outros efeitos pleiotrópicos relacionados ao amadurecimento, parâmetros de qualidade, espessura da cutícula e propriedades nutricionais dos frutos. Em face disso, subsequentemente investigamos se o diferencial conteúdo e composição de carotenóides nas referidas NILs altera a suscetibilidade dos frutos ao fungo Botrytis cinerea. A caracterização do amadurecimento demonstrou que o pico climatérico dos frutos do mutante r foi antecipado, assim como a transição para o estádio breaker. De modo contrário, a alteração na coloração da epiderme do mutante t foi atrasada, reafirmando suspeitas de outros autores que sugeriram que a enzima carotenoide-isomerase é necessária para a síntese de carotenoides no escuro. O conteúdo de ácido ascórbico também foi contrastante entre estes genótipos, sendo que no mutante r a sua concentração foi elevada, enquanto em t sua concentração foi reduzida. A perda de massa dos frutos foi menor no mutante Del, no entanto, esta característica não esteve relacionada a espessura da cutícula, que foi maior em B. A inoculação com B. cinerea por meio de ferimentos na pele dos frutos revelou menor suscetibilidade do mutante t, e em menor amplitude, do mutante Del. Ainda, o mutante t também se mostrou menos suscetível à inoculação do patógeno sobre frutos intactos. A maior espessura da cutícula de B não reduziu sua suscetibilidade ao fungo, que infectou os tecidos preferencialmente através da cicatriz do pedúnculo. A interação com B. cinerea desencadeou a produção de etileno e de espécies reativas de oxigênio (EROs), assim, é provável que a capacidade de sequestro de radicais livres tenha contribuído para a redução da suscetibilidade em t e Del, que mostraram menor produção de superóxido. Juntos, estes resultados sugerem que a modulação na atividade de enzimas da carotenogênese pode servir como ferramenta para obtenção de frutos com diferente vida útil durante o armazenamento pós-colheita de tomate. / Carotenoids are pigments found in great abundance in tomato fruits. The radical sequestration capacity of these pigments makes tomato an excellent option for inclusion of nutritional compounds in diet. Although the synthesis of carotenoids is recognized as one of the cascade responses that trigger ripening, little is known about its influence in this process. Thus, the aim of this study was to determine if the content and composition of carotenoids in the fruits alters the conservation and the susceptibility of the fruits to the B. cinerea fungus. Micro Tom (MT) near-isogenic lines (NILs) harboring the mutations Beta carotene (B), tangerine (t), yellow flesh (r) and Delta carotene (Del) has been used. The characterization of these allelic variations revealed not only changes in the carotenoid content but also other pleiotropic effects related to maturation, quality parameters, cuticle thickness and nutritional properties of fruit. In this way, we subsequently investigated whether the differential content and composition of carotenoids in NILs alters fruit susceptibility to the fungus Botrytis cinerea. The ripening characterization showed that the climacteric peak of the fruits of the r mutant was anticipated, as well as the transition to the breaker stage. Conversely, the change in epidermal coloration of mutant t was delayed, reaffirming suspicions of other authors who suggested that the carotenoid-isomerase enzyme is required for the synthesis of carotenoids in the dark. The ascorbic acid content was also contrasting among these genotypes, and in the r mutant its concentration was high, while at t its concentration was reduced. The fruit mass loss was lower in Del mutant, however, this characteristic was not related to cuticle thickness, which was higher in B. Wound-inoculation with B. cinerea revealed less susceptibility of the mutant t, and in a lesser extent, the mutant Del. Further, mutant t was also less susceptible to pathogen inoculation on intact fruits. The greater thickness of the cuticle of B did not reduce its susceptibility to the fungus, which infected the tissues preferentially through the scar of the peduncle. The interaction with B. cinerea triggered the production of ethylene and reactive oxygen species (ROS), so the free radical scavenging capacity probably contributed to the reduction of t and Del susceptibility, which showed lower production of superoxide. Together, these results suggest that modulation in carotenogenesis enzyme activity may serve as a tool to obtain fruit with different shelf-life during post-harvest tomato storage.

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