Les épisodes de convection en milieu hauturier sont des processus physiques hivernaux récurrents, mais irréguliers, ayant un fort pouvoir perturbateur sur l’écosystème pélagique. Les principaux objectifs de ma thèse ont été d’étudier l’influence d’épisodes de convection en Méditerranée Nord Occidentale sur les cycles biogéochimiques (distribution et bilan des sels nutritifs) et d’évaluer leurs impacts sur le compartiment microbien (abondance, activité et diversité). Ces travaux reposent sur mon implication active dans les campagnes océanographiques CASCADE (mars 2011) et DeWEX (février et avril 2013) qui s’inscrivent dans le cadre du chantier Méditerranée Mistrals (WP3 et WP1 respectivement du programme MermEX). Nous avons estimé que les apports en sels nutritifs lors d’un seul phénomène de convection de "moyenne envergure" étaient équivalents aux apports annuels des rivières et des dépôts atmosphériques à l’échelle du golfe du Lion, et pourraient soutenir une production primaire nouvelle de l'ordre de 46 à 63 g C.m-2.a-1 (i.e. l'ordre de grandeur de la production nouvelle annuelle de la zone). Une approche satellitale nous a permis de suivre l’évolution de plusieurs épisodes de convection et de mettre en évidence un étroit couplage entre ce type de forçage physique et le développement de blooms phytoplanctoniques en Méditerranée Nord Occidentale. Pour aborder le rôle des microorganismes dans la régulation des cycles biogéochimiques en réponse à ces épisodes de convection, nous avons identifié l’influence relative des forçages physico-chimiques sur les changements de diversité des communautés microbiennes (bactéries et archées identifiées par pyroséquençage), ceci en relation avec leur activité de reminéralisation de la matière organique. Nous avons également utilisé les épisodes de convection pour évaluer la pertinence écologique des écotypes de SAR11, Marine group I et Marine group II, les 3 groupes taxonomiques les plus répandus et abondants en Méditerranée et dans tous les océans du monde. Ces travaux ont permis de proposer des scénarii cohérents de l'évolution potentielle des écosystèmes pélagiques en Méditerranée Nord Occidentale dans un contexte de changement climatique global. En effet, mon étude est une contribution à la compréhension de la réponse potentielle des écosystèmes pélagiques à la modification attendue de la fréquence et/ou de l'intensité des processus de convection. / Open-ocean convection episodes are recurrent winter physical processes, but irregular in intensity, with a strong disruptive effect on the pelagic ecosystem. My principal thesis objectives were to study the influence of the Northwestern Mediterranean convection on the biogeochemical cycles (nutrient distribution and assessment), and to evaluate their impacts on the microbial compartment (abundance, activity and diversity). This work was based on my active participation to the oceanographic cruises CASCADE (March 2011) and DeWEX (February and April 2013), which are incorporated in the framework of Mistral Mediterranean project (respectively in the WP3 and WP1 of MermEX program). We estimated that the nutrient supply by a single convection episode of “average-scale” was equivalent to the annual riverine discharges and atmospheric deposition in the golf of Lion. This could sustain a new primary production from 46 to 63 g C.m-2.a-1 (i.e. the annual new primary production rate of this area). A remote sensing approach allowed us to follow open-ocean convection episodes evolution, and to highlight the close relationship between this kind of physical forcing and the phytoplanktonic bloom development in the Northwestern Mediterranean. During the study of the impact of convection episodes on the role of microorganisms in the biogeochemical cycles regulation, we determined the influence of physical parameters and environmental factors on the modification of the microbial community diversity (pyrosequencing of Bacteria and Archaea), in relation with organic matter mineralization. Besides, we used convection mixing as a model to evaluate the ecological pertinence of SAR11, Marine group I and Marine Group II ecotypes, 3 taxonomic groups the most widespread and abundant in Mediterranean and in all the oceans. In a climate change context, my works allowed us to propose different coherent scenarios of the potential evolution of the Northwestern Mediterranean pelagic ecosystems. My study contribute to the understanding of the pelagic ecosystem evolution with the predictable modifications in frequency and/or intensity of open-ocean convection processes.

La majorité des espèces de poissons côtiers a un cycle de vie comprenant une phase juvénile et adulte démersale et une phase larvaire pélagique. Cette seconde phase représente l’unique opportunité de dispersion pour de nombreuses espèces mais est soumise à une forte mortalité. Aujourd’hui, il est toujours délicat de prédire la connectivité entre les populations car tous les processus influençant la survie et le transport des larves durant leur phase pélagique ne sont pas encore décrits. Les larves de poissons possèdent des capacités comportementales non-négligeables (de nage, d’orientation, etc.) qui pourraient leur permettre de contrôler leur dispersion au cours de leur épisode pélagique. Cependant, les observations in situ de ces comportements ont principalement été faites en milieu tropical. Elles sont nettement plus rares en milieu tempéré, notamment chez les poissons Perciformes. Dans cette thèse, nous cherchons à décrire l’écologie et les capacités comportementales des larves de poissons en Mer Méditerranée Nord-Occidentale, un milieu tempéré où elles n’ont pas encore été décrites.La première partie de cette thèse vise à décrire la distribution des jeunes stades larvaires le long d’un transect côte-large traversant un front hydrologique. Nous nous intéressons également à leurs comportements de migration nycthémérale et d’évitement des prédateurs. La méthode d’imagerie utilisée pour décrire leur distribution à microéchelle génèrant des quantités de données considérables, nous avons développé une méthode de classification automatique pour accélérer le traitement de ce type de données. La seconde partie se concentre sur la phase d’installation, c’est-à-dire lorsque les larves arrivent à la côte à la fin de leur phase pélagique. Nous avons suivi l’arrivée des larves à la côte afin de déterminer les périodes d’installation des différentes espèces ainsi que les facteurs influençant leur arrivée. Nous avons également testé in situ les capacités d’orientation des espèces les plus abondantes, en se focalisant sur les mécanismes d’orientation à large échelle. En laboratoire, nous avons mesuré les vitesses de nage de plusieurs espèces, incluant celles testées pour l’orientation. Nous avons ensuite implémenté ces comportements observés dans un modèle biophysique afin de tester leur l’influence combinée sur le taux d’installation. Pour finir, nous discutons de l’influence que peut avoir le comportement sur la survie des larves de poissons tout au long de la phase pélagique, ainsi que de l’importance de sa prise en compte dans les modèles de dispersion. / Most coastal fish species have a bipartite life history, with a demersal phase as juvenile and adult and a pelagic larval phase. Dispersal is often limited to this pelagic phase, which is also the phase experiencing the highest mortality rates. Predicting the connectivity between populations remains difficult because not all processes determining larval fish survival and transport during the pelagic phase are understood. Besides the environmental conditions that may influence the journey of fish larvae in the open ocean, these tiny organisms possess high behavioural abilities (swimming, orientating, etc.) that have the potential to shape their dispersal. However, the vast majority of in situ observations of these behaviours have been conducted in tropical environments and very little data exists on temperate Perciformes fish larvae. In this dissertation, we aim to describe the ecology and behavioural abilities of fish larvae from the Mediterranean Sea, a temperate environment where they have never been studied.The first part of this dissertation describes the distribution of young fish larvae along an inshore-offshore transect crossing an hydrological front. We also describe their diel vertical migration and predatoravoidance behaviour. The high-frequency imaging techniques used to capture their distribution at miscroscale generated huge amount of data. It lead us to modify an automatic classification method to reduce the time required to processes these kind of data. The second part focuses on the settlement phase, when fish larvae come back to the coast at the end of their pelagic journey. To shed light on the factors influencing the settlement process, we monitored the supply of fish larvae to a coastal habitat, on a weekly basis for three years and at higher frequency over shorter periods of time. Additionally, we tested the in situ orientation abilities of the most abundant species, focusing on large scale orientation mechanisms. In the laboratory, we measured the swimming speeds of several species, including the ones tested for orientation. Then, we implemented these observed behaviours in a biophysical model to explore their combined influence on settlement rate. To finish, we discuss on how larval fish behaviour may influence survival throughout the pelagic larval phase and insist on the importance of considering behaviour to improve larval dispersal models.

Les bactéries et microalgues marines sont acteurs clés du fonctionnement des écosystèmes océaniques et leur contribution dans les cycles biogéochimiques majeurs est largement reconnue. Dans ce contexte, il apparaît essentiel de mieux comprendre les interactions existant entre bactéries et microalgues. Dans l’environnement marin, les interactions spécifiques entre microorganismes nécessitent une forte proximité qui n’est souvent rendue possible que par un attachement cellulaire. La première partie de ce travail de thèse a consisté à sélectionner les microalgues qui présentaient des bactéries physiquement attachées. Deux diatomées appartenant aux genres Thalassiosira et Chaeoceros ont été retenues afin d’étudier leur microflore épibionte issue d’associations à long terme (culture de microalgues établies depuis plusieurs années) et à court terme (microalgues prélevées directement dans l’environnement). Ces travaux ont permis de mettre en évidence une forte ressemblance des communautés épibiontes dans les associations à long terme, qui s’opposait à la forte différence des épibiontes issus des associations à court terme. Les communautés d’épibiontes bactériens étaient majoritairement composées d’alpha- et gammaprotéobactéries, mais aussi de Bacteroidetes et d’actinobactéries. Cette étude a également permis de mettre en évidence que la surface des microalgues représentait un écosystème particulier puisque près de la moitié des épibiontes isolés correspondaient à de nouveaux taxons (genres et espèces). Une de ces souches qui constitue un nouveau genre a été complètement caractérisée, contribuant à l’enrichissement de la diversité bactérienne décrite. Enfin, la nature des interactions entre les deux diatomées et leurs bactéries épibiontes a été analysée par l’intermédiaire de co-cultures, afin d’identifier une interaction forte, qui pourra être examinée par transcriptomique. De très nombreuses interactions commensalismes ont été mises en évidence, reflet de la reminéralisation de la matière organique par les bactéries. Cependant, un faible impact des bactéries sur la croissance des microalgues a été observé. Les conditions expérimentales qui excluent au maximum les stress abiotiques et biotiques, masquent peut-être les interactions qui pourraient se produire dans un environnement naturel plus fluctuant. Ces résultats témoignent de la complexité des interactions biotiques, fournissent des méthodes et des organismes modèles permettant de les étudier et soulèvent de nombreuses hypothèses exaltantes pour les travaux futurs. / Marine microalgal and bacterial contribution to the global biogeochemical cycles is largely recognized and lead to define them as key actors of oceanic ecosystems. In this context, it is essential to better understand the interactions occurring between bacteria and microalgae. In the marine environment, specific interactions between microorganisms require tight physical association that is made possible by cellular attachment. In this work, we first selected microalgae with physically attached bacteria. Two diatoms belonging to the genus Thalassiosira and Chaetoceros were selected to study the epibiotic microflora from long-term (microalgae in culture) and short-term (microalgae directly collected from natural communities) associations. This work highlighted strong similarities between epibiotic assemblages from long-term associations and a higher difference for epibiotic communities from short-term associations. The bacterial epibiotic assemblages were mainly composed of Alpha- and Gammaproteobacteria but also Bacteroidetes and Actinobacteria. This study also highlighted that the surface of microalgae represented a peculiar ecosystem where nearly half isolates constituted new taxa (genera and species). One of them representing a new genus has been completely characterized, contributing to the enrichment of the described bacterial diversity. Finally, the nature of interactions between diatoms and their epibiotic bacteria was analyzed by co-culturing to identify strong interactions, to be further examined by transcriptomics. Numerous commensal interactions have been identified, corresponding to the bacterial remineralization of organic matter. However, only small effects of bacteria on microalgal growth were observed. The experimental conditions that exclude a maximum of abiotic and biotic stresses may mask potential interactions that could occur in an unstable natural environment. These results reflect the complexity of biotic interactions, provide methods and model organisms to study them, and raise many exciting hypotheses for future work.

La thèse de doctorat avec le titre “Potentiel, valorisation et perspectives de développement de l’œnotourisme en Moldavie occidentale” a comme but l’identification, l’évaluation et l’utilisation des ressources œnotouristique de la Moldavie en prenant comme exemple le modèle français alsacien d’exploiter cette forme de tourisme. La thèse est divisée en 5 chapitres, premièrement on a fait une analyse générale de tout ce que signifie l’œnotourisme et ses modèles de développement dans les Etats de nouveau monde et de l’ancien monde. Ensuite, on a présenté la place de la Moldavie dans le contexte nationale concernant la viticulture et le tourisme pour argumenter le choix de choisir cette région. La Moldavie représente la région avec la plus grande surface viticole du pays. Le troisième chapitre est la plus importante partie de la thèse contenant la comparaison entre deux régions, l’Alsace et la Moldavie pour voir l’état de développement de la Moldavie par rapport à l’Alsace. La Moldavie doit adopter ce modèle car il y a la preuve que c’est un modèle de succès. Les derniers chapitres sont axés sur les questionnaires appliqués auprès les touristes et les viticulteurs de toutes les deux régions pour mettre en évidence leurs opinions concernant le développement de l’œnotourisme. / The doctoral thesis with the title "Potential, valorisation and development prospects of wine tourism in western Moldova" has as aim the identification, evaluation and use of the wine tourism Moldova resources by taking as an example the Alsatian model to exploit this form of tourism. The thesis is divided into five chapters, first made a general discussion of everything means wine tourism and its models of development in the states of New World and Old World. Then it is presented the place of Moldova in the national context concerning viticulture and tourism to argue the choice to choose this region. Moldova is the region with the largest wine area of the country. The third chapter is the most important part of the thesis containing the comparison between the two regions, Alsace and Moldova to see the state of development of Moldova and Alsace. Moldova must adopt this model because there is evidence that it is a model of success. The last chapters are focused on the questionnaires applied to tourists and winemakers of the two regions to highlight their views on the development of wine tourism.

Cette étude vise à donner une description et une analyse de la structure de l’économie du territoire de l’actuel département de la Manche jusqu’au milieu du XIXe siècle. Une première partie reconstitue l’évolution de la population (pour chaque paroisse), des principaux prix agricoles et des salaires depuis le XIVe siècle, et elle procède à une comparaison systématique des prix et des salaires avec ceux des autres régions françaises. Elle met en évidence les cinq ou six grandes phases qu’a connues l’histoire économique de ce territoire. La seconde partie aborde successivement chacun des secteurs économiques (agriculture, industrie et artisanat, activités maritimes), depuis le début du XVIIe siècle (agriculture) ou du XVIIIe siècle (autres secteurs) jusque vers 1850. Une description aussi détaillée que possible des activités élémentaires, voire des entreprises individuelles, conduit à estimer l’évolution de la valeur de leur production, de leur valeur ajoutée (dans certains cas, de leur rentabilité) et des effectifs employés, en s’appuyant sur des modèles économétriques sectoriels simples. Une appréciation globale est enfin portée sur les forces et faiblesses de l’économie de ce territoire, dans la perspective de son insertion dans la France du XIXe siècle. / This study offers a description and analysis of the economic structure, until the mid 19th century, of the fraction of Occidental Normandy which is currently the department “La Manche”. The first part builds up the evolution of population (down to each parish or community), prices of the main agricultural products and salaries from the early 14th century; it offers detailed comparisons with corresponding elements in other French regions. It elaborates on the joint evolution of population and prices, and prices and salaries, in order to caracterise the five or six main stages of this territory’s economic history. The second part successively deals with each of the main branches of industry (agriculture, industry and craftsmanship, maritime trade), between the early 17th (agriculture) or 18th (other sectors) century and the 1850’s. A detailed description is given for each industry, or where appropriate individual companies, leading to estimated evolutions of revenues, added value (in some cases profitability) and staff over the course of the study period, with the help of simple industry-specific econometric models. The strengths and weaknesses of this economy are finally assessed, with the perspective in mind of its further integration into 19th century France.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Cette recherche vise à montrer comment le recours à l'autobiographie comme première forme littéraire utilisée largement, dans un premier temps, par les auteures sénégalaises et maliennes, répondait à un besoin de concilier leur propre itinéraire individuel avec le parcours collectif de la majorité des femmes qui avaient été les oubliées de la colonisation. Les premières femmes lettrées ont pu profiter de possibilités nouvelles grâce notamment à la scolarisation et à la pratique de métiers. Toutefois, très peu nombreuses, elles sont demeurées marginales par rapport aux lieux de pouvoir de la modernité coloniale et post-coloniale. L'analyse de leurs récits a démontré que l'écriture à caractère autobiographique leur a permis d'exprimer à la fois un vécu personnel et une vision des transformations de la condition des femmes. Tant dans leur vie que dans la prise de parole dans la sphère publique, habituellement réservée aux hommes, elles apparaissent comme des actrices historiques. Leur percée sur la scène littéraire est donc une expression créatrice mais également un acte politique. / Québec Université Laval, Bibliothèque 2013

Foi desenvolvida uma nova metodologia de análise de extratos e partes de plantas medicinais, via espectrometria de massas (MS) com infusão direta de amostra, técnica analítica denominada fingerprinting ou \"impressão digital\" química. Essa abordagem, que envolve mínimo prepraro de amostra, foi aplicada visando detectar as condições e as épocas adequadas para cultivo e/ou coleta de produtos naturais, permitindo a obtenção de uma matéria-prima vegetal com princípios ativos e concentrações padronizadas, assim como auxiliar no reconhecimento e na compreensão das interações ecológicas do vegetal com seu ambiente. A metodologia analítica envolveu MS com fonte de ionização por electrospray (ESI) nos modos positivo e negativo e experimentos de fragmentação de íons de interesse (MS/MS) por inserção direta do extrato diluído e frações ativas de Maytenus ilicifolia, de extratos de Arrabidaea chica de diferentes acessos (origens geográficas), assim como óleos de Pterodon pubescens e as amêndoas e o pedúnculo de diferentes clones de Anacardium occidentale. A caracterização das amêndoas e pedúnculos de A. occidentale, assim como de seus respectivos clones por meio do perfil de seus constituintes químicos foi realizada com sucesso. Na extração da amêndoa empregando-se éter, foi possível caracterizar o perfil de triacilgliceróis (TAG) por ESI(+) e ácidos graxos livres por ESI(-). Na extração do suco do pedúnculo empregando-se isopropanol, foram detectados íons referentes aos ácidos anacárdicos por ESI(-). Foram avaliados os principais parâmetros que possibilitam a ionização por ESI, tais como voltagens do capilar, cone e do cone extrator, e a influência de cada um destes parâmetros no perfil obtido nos espectros de ESI(-) do suco. Para A. chica a metodologia mostrou-se eficiente na bioprospecção de antocianidinas e dentre os nove acessos analisados, foi possível indicar aquele que produziu maior quantidade de material corante em relação a biomassa. Também foram avaliadas metodologias de extração por tratamento enzimático, o qual ocasionou aumento da intensidade de agliconas, provavelmente devido à hidrólise das antocianinas. A ocorrência de hidrólise também foi observada na em diferentes metodologias de secagem das folhas, principalmente na secagem realizada ao sol com borrifação de água. Houve variação sazonal na produção de metabólitos secundários, como pudemos observar nos experimentos realizados com amostras coletadas de 2007 a 2009. Para M. ilicifolia, foi possível caracterizar uma série de compostos relacionados à atividade antiúlcera já conhecidos da literatura, como dulcitol, catequina e derivados e flavonóides glicosilados. A metodologia proposta foi aplicada ainda na avaliação do melhoramento agrícola de M. ilicifolia por comparação dos perfis dos compostos identificados. A metodologia desenvolvida para análise direta de P. pubescens mostrou-se eficiente na detecção e identificação de compostos bioativos, possibilitando a caracterização rápida e sem preparo de amostra do óleo da semente. Em conclusão, a técnica de fingerprinting MS permite de maneira rápida, informativa e com mínimo preparo que amostras, que produtos naturais sejam caracterizados e tenham sua qualidade monitorada. / A new analytical methodology for the analysis of medicinal plant parts and extracts via direct infusion mass spectrometry (MS) has been developed. This analytical approach, named chemical fingerprinting, involves minimal sample preparation and was applied in this work with the aim to detect optimal culture conditions, culture periods and harvest times for obtaining raw natural products with highest active principle and concentrations, as well as to understand and recognizing ecological interactions between plant and its surrounding environment. The analytical methodology included MS with electrospray ionization (ESI) in the positive (+) and negative (-) modes, as well as fragmentation of ions of interest (MS/MS) experiments. The diluted extract and active fractions of Maytenus ilicifolia, extracts of Arrabidaea chica from diverse geographic origins (accesses), as well as the oil from Pterodon pubescens and nuts of various clones of Anacardium occidentale were introduced by direct injection. Characterization of nuts and stems from A. occidentale, as well as of its respective clones by their chemical constituents has been successfully performed. After ether extraction of nuts, it was possible to characterize the triacylglycerols (TAG) by ESI(+) and free fatty acids by ESI (-). After extraction of stem juice with isopropanol, diverse ions were identified as anacardic acids by ESI(-). Also, parameters influencing to the ionization process, such as capillary voltage, cone voltage and cone extraction voltage, have been evaluated for the stem juice at ESI(-). For A. chica, the proposed methodology has been proven to efficiently bioprospect the anthocyanins, and among the nine accesses evaluated, it has been possible to identify the one producing higher amounts of dying material proportionally to the biomass. We also evaluated the enzymatic treatment extraction methodology, which resulted in the increase of aglycones content, probably due to anthocyanins hydrolysis. The occurrence of hydrolysis has been also observed when leaves have been water-sprayed while drying in the sun. Seasonal influence on the production of secondary metabolite has been observed in the samples collected on the experiments performed from 2007 to 2009. For M. ilicifolia, it has been possible to characterize a series of compounds related to the anti ulcer activity and already reported in the literature, such as dulcitol, catechin and derivatives and flavonoid glycosides. The proposed methodology has been applied in the evaluation of genetic improvement of M. ilicifolia by comparing the identified compounds profiles. The developed methodology aimed at direct analyzing P. pubescens has successfully detected and identified bioactive compounds of the seed oil, allowing the fast characterization. In conclusion, the proposed MS fingerprinting methodology allows in an informative, straightforward and with minimal sample preparation the chemical characterization and quality control of natural products.

CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior / O presente trabalho teve por objetivo estudar as respostas fisiolÃgicas e bioquÃmicas de clones de cajueiro anÃo-precoce (Anacardium occidentale L.) ao estresse salino. Os experimentos foram conduzidos em casa de vegetaÃÃo, sendo as plÃntulas cultivadas em vasos plÃsticos contendo vermiculita. No primeiro experimento, cinco clones de cajueiro anÃo-precoce foram submetidos aos tratamentos com NaCl a 0 (controle), 8 e 16 dS.m-1 de condutividade elÃtrica e objetivou selecionar clones com tolerÃncias diferenciadas ao estresse salino. Para isso, foram estudados os efeitos da salinidade no crescimento, nas trocas gasosas, no teor de Ãgua, na suculÃncia foliar, no potencial osmÃtico, nas concentraÃÃes de prolina, N-aminossolÃveis e carboidratos solÃveis e nos teores dos Ãons inorgÃnicos (Na+, Cl- e K+). A salinidade reduziu o crescimento das plÃntulas de todos os clones estudados. Os efeitos inibitÃrios do NaCl foram mais conspÃcuos na parte aÃrea do que nas raÃzes. O clone CCP 06 foi aquele que apresentou maior reduÃÃo no crescimento foliar, enquanto os clones BRS 189 e CCP 09 foram os que apresentaram as menores reduÃÃes. A salinidade inibiu a mobilizaÃÃo das reservas cotiledonÃrias, principalmente, na dose mais elevada de sal. A reduÃÃo no crescimento, pela salinidade, correlacionou-se com a reduÃÃo na taxa de fotossÃntese lÃquida. Os clones CCP 06 e BRS 189 apresentaram, respectivamente, a maior e a menor reduÃÃo na taxa fotossintÃtica a 8 dS.m-1. Embora a salinidade tenha reduzido a condutÃncia estomÃtica dos clones de cajueiro anÃo-precoce, essa reduÃÃo nÃo foi acompanhada por mudanÃas nas concentraÃÃes internas de CO2. Os clones estudados nÃo apresentaram alteraÃÃes, em funÃÃo da salinidade, no estado hÃdrico das folhas e raÃzes, porÃm, apresentaram reduÃÃes no potencial osmÃtico, favorecendo o ajustamento osmÃtico e, consequentemente, a manutenÃÃo da turgescÃncia dos tecidos. Sob condiÃÃes de estresse salino, os clones BRS 189 e CCP 09 foram os mais eficientes na regulaÃÃo do transporte do Ãon Na+ para a parte aÃrea da plÃntula, acumulando-o nas raÃzes. Em relaÃÃo ao Cl-, o clone CCP 09 mostrou-se o mais eficiente no controle do transporte desse Ãon. PorÃm, CCP 06 foi o clone que mais acumulou ambos os Ãons tÃxicos na parte aÃrea da planta. Com o aumento da salinidade, os teores de potÃssio dos clones estudados tiveram seus valores reduzidos apenas nas raÃzes. Na dose de 8 dS.m-1, o BRS 189 foi o clone que mais aumento suas concentraÃÃes de N-aminosolÃveis e prolina no suco radicular. Nesse mesmo nÃvel de sal, a salinidade aumentou a concentraÃÃo de carboidratos apenas nos clones CCP 06 e BRS 189. De posse destes resultados, o segundo experimento foi realizado com os clones CCP 06 e BRS 189 que foram os que se mostraram, respectivamente, o menos e o mais tolerante à salinidade. Esse experimento teve por objetivo estudar os efeitos da salinidade (NaCl a 8 dS.m-1) na atividade da H+-ATPase e na composiÃÃo e peroxidaÃÃo dos lipÃdios de membrana plasmÃtica isoladas de raÃzes das plÃntulas dos dois clones contrastantes. A salinidade estimulou a atividade da H+-ATPase apenas no clone tolerante, o BRS 189, sendo esse clone o que apresentou maior conteÃdo de esterÃis totais e menor relaÃÃo fosfolipÃdios totais (PLt)/ esterÃis totais (Et), tanto em condiÃÃes controle como de estresse. Esses resultados foram concordantes com o fato de ter sido o BRS 189 o clone que melhor excluiu o Na+ da parte aÃrea. Nesse clone nÃo foram observadas alteraÃÃes nos teores de malondialdeÃdo, diferentemente do que ocorreu com o CCP 06, cujos teores aumentaram com o estresse salino. A maior proteÃÃo da membrana plasmÃtica do clone BRS 189 ao dano oxidativo està de acordo com os maiores acÃmulos de prolina e N-aminossolÃveis observados nesse clone. Os principais fosfolipÃdios da membrana plasmÃtica isolada de raÃzes do clone BRS 189 foram fosfatilglicerol (PG), fosfatidiletalonamina (PE) e fosfatilserina (PS). A salinidade provocou alteraÃÃes nas proporÃÃes relativas dos fosfolipÃdios, sendo PE e fosfatidilinositol (PI) os que apresentaram maiores aumentos em relaÃÃo ao total, enquanto que fosfatidilglicerol (PG) e Ãcido fosfatÃdico (PA) foram os que apresentaram maiores reduÃÃes. A percentagem de PS, em relaÃÃo ao total, nÃo foi afetada pela salinidade. No entanto, a relaÃÃo entre essas mudanÃas na composiÃÃo lipÃdica do BRS 189 pela salinidade e o aumento na atividade da H+-ATPase necessita ser melhor investigada. / Early-dwarf cashew seedlings (Anacardium occidentale L.) were used in order to investigate the physiological and biochemical changes induced by salt stress. The seeds (nuts) were sown in plastics pots containing vermiculite moistened with either distilled water (control treatment) or NaCl solutions at 8 and 16 dS.m-1 of electrical conductivity (saline treatment), and kept in greenhouse throughout the experimental period. Uniform 28-day-old seedlings were used for the analyses. The first experiment aimed to select, among five clones (CCP 06, CCP 09, CCP 76, Embrapa 51 and BRS 189), the ones showing contrasting salt-tolerance. The effect of salinity on the growth, gas exchange, water content, leaf succulence, osmotic potential and inorganic (Na+, Cl-, K+) and organic (proline, soluble carbohydrates, quaternary ammonium compounds) solute concentration for both salt-sensitive and salt-tolerant clones was studied. Salinity inhibited the growth of all clones studied, being the inhibitory effect on shoot growth more conspicuous than in root growth. Clone CCP 06 leaf area was the most inhibited by salt stress, while clones BRS 189 and CCP 09 leaf areas were the least affected by salinity. Salt stress caused a great decrease in the cotyledon reserve mobilization especially at 16 dS.m-1. Growth reduction was correlated to the reduction in net photosynthetic rate. CCP 06 and BRS 189 showed the greatest and the lowest reduction in photosynthetic rate at 8 dS.m-1, respectively. Although, salinity reduced stomatal conductance, this reduction was not followed by changes in CO2 internal concentration. The water status, expressed as water content in relation to dry mass, was not changed by salt-stress. Salinity induced the lowering of osmotic potential both in leaves and roots of all clones studied. This osmotic adjustment might have lead to turgor maintenance of those tissues. The concentrations of Cl- and Na+ increased with increasing salt stress. Clones BRS 189 and CCP 09 accumulated more Na+ in the roots, and this could explain their efficiency in maintaining a lower ion concentration in shoots, i.e. they regulated more efficiently the transport of Na+ from roots to shoots. The regulation of Cl- transport to shoots was more efficient in clone CCP 09 than in the others. Salinity did not induce significant changes in leaves and stems K+ concentration, but it induced a reduction of K+ concentration in roots. Salinity also induced increases of quaternary ammonium compounds and proline concentration in BRS 189 root at 8 dS.m-1. In addition, this level of salinity increased soluble carbohydrates in the root sap especially in clones BRS 189 and CCP 06. During the second experiment, the effect of salt stress (NaCl at 8 dS.m-1) on the activity of H+-ATPase, lipid composition and peroxidation of root plasma membrane of both salt-tolerant (BRS 189) and salt- sensitive (CCP 06) clones were studied. The vanadate-sensitive H+-ATPase activity was studied in plasma membrane-enriched vesicles isolated by discontinuous sucrose gradient centrifugation from roots. ATP hidrolizing activity in this fraction was mostly inhibited by vanadate and scarcely, by azide and molybdate, indicating that it was essentially enriched in plasma membrane vesicles. Salinity induced a 1.3-fold increase in the H+-ATPase specific activity in roots of BRS 189 seedlings. Salinity had no appreciable effect on the hydrolytic activity of this enzyme during the growth of CCP 06 seedlings. Likewise, clone BRS 189 roots plasma membrane showed higher sterol content and lower phospholipids/total sterol ratio than clone CCP 06. Both properties could contribute to the decrease in Na+ influx or increase in Na+ efflux or âexclusionâ from roots. This could result in less Na+ being transported to the shoot, and thus explaining the higher salt-tolerance of clone BRS 189. The higher degree of root plasma membrane lipid peroxidation of clone, and the lower proline and ammonium quaternary compounds contents of CCP 06 when compared to BRS 189 could also explain the differences in salt-tolerance between the two clones. These organic solutes could protect and stabilize plasma membrane against oxidative stress. Phosphatidylglycerol (PG), phosphatidylethanolamine (PE) and phosphatidylserine (PS) were the major phospholipids in the plasma membrane from BRS 189 roots. Salinity induced increases in the relative proportions of PE and phosphatidylinositol (PI), while PG and PA were reduced. No changes were detected in PS in relation to control plant. The importance of lipid composition changes on H+-ATPase activity must be more studied.

PIZARRO, Juan Carlos Alvarez. Caracteres fisiológicos e bioquímicos da tolerância à salinidade em clones de cajueiro anão precoce. 2006. 135 f. Dissertação (Mestrado em Bioquímica) - Universidade Federal do Ceará, Fortaleza-CE, 2006. / Submitted by Eric Santiago (erichhcl@gmail.com) on 2016-05-30T14:16:32Z No. of bitstreams: 1 2006_dis_jcapizarro.pdf: 935692 bytes, checksum: c709b8b0747f8a929112611a9c584729 (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-07-12T23:10:54Z (GMT) No. of bitstreams: 1 2006_dis_jcapizarro.pdf: 935692 bytes, checksum: c709b8b0747f8a929112611a9c584729 (MD5) / Made available in DSpace on 2016-07-12T23:10:54Z (GMT). No. of bitstreams: 1 2006_dis_jcapizarro.pdf: 935692 bytes, checksum: c709b8b0747f8a929112611a9c584729 (MD5) Previous issue date: 2006 / Early-dwarf cashew seedlings (Anacardium occidentale L.) were used in order to investigate the physiological and biochemical changes induced by salt stress. The seeds (nuts) were sown in plastics pots containing vermiculite moistened with either distilled water (control treatment) or NaCl solutions at 8 and 16 dS.m-1 of electrical conductivity (saline treatment), and kept in greenhouse throughout the experimental period. Uniform 28-day-old seedlings were used for the analyses. The first experiment aimed to select, among five clones (CCP 06, CCP 09, CCP 76, Embrapa 51 and BRS 189), the ones showing contrasting salt-tolerance. The effect of salinity on the growth, gas exchange, water content, leaf succulence, osmotic potential and inorganic (Na+, Cl-, K+) and organic (proline, soluble carbohydrates, quaternary ammonium compounds) solute concentration for both salt-sensitive and salt-tolerant clones was studied. Salinity inhibited the growth of all clones studied, being the inhibitory effect on shoot growth more conspicuous than in root growth. Clone CCP 06 leaf area was the most inhibited by salt stress, while clones BRS 189 and CCP 09 leaf areas were the least affected by salinity. Salt stress caused a great decrease in the cotyledon reserve mobilization especially at 16 dS.m-1. Growth reduction was correlated to the reduction in net photosynthetic rate. CCP 06 and BRS 189 showed the greatest and the lowest reduction in photosynthetic rate at 8 dS.m-1, respectively. Although, salinity reduced stomatal conductance, this reduction was not followed by changes in CO2 internal concentration. The water status, expressed as water content in relation to dry mass, was not changed by salt-stress. Salinity induced the lowering of osmotic potential both in leaves and roots of all clones studied. This osmotic adjustment might have lead to turgor maintenance of those tissues. The concentrations of Cl- and Na+ increased with increasing salt stress. Clones BRS 189 and CCP 09 accumulated more Na+ in the roots, and this could explain their efficiency in maintaining a lower ion concentration in shoots, i.e. they regulated more efficiently the transport of Na+ from roots to shoots. The regulation of Cl- transport to shoots was more efficient in clone CCP 09 than in the others. Salinity did not induce significant changes in leaves and stems K+ concentration, but it induced a reduction of K+ concentration in roots. Salinity also induced increases of quaternary ammonium compounds and proline concentration in BRS 189 root at 8 dS.m-1. In addition, this level of salinity increased soluble carbohydrates in the root sap especially in clones BRS 189 and CCP 06. During the second experiment, the effect of salt stress (NaCl at 8 dS.m-1) on the activity of H+-ATPase, lipid composition and peroxidation of root plasma membrane of both salt-tolerant (BRS 189) and salt- sensitive (CCP 06) clones were studied. The vanadate-sensitive H+-ATPase activity was studied in plasma membrane-enriched vesicles isolated by discontinuous sucrose gradient centrifugation from roots. ATP hidrolizing activity in this fraction was mostly inhibited by vanadate and scarcely, by azide and molybdate, indicating that it was essentially enriched in plasma membrane vesicles. Salinity induced a 1.3-fold increase in the H+-ATPase specific activity in roots of BRS 189 seedlings. Salinity had no appreciable effect on the hydrolytic activity of this enzyme during the growth of CCP 06 seedlings. Likewise, clone BRS 189 roots plasma membrane showed higher sterol content and lower phospholipids/total sterol ratio than clone CCP 06. Both properties could contribute to the decrease in Na+ influx or increase in Na+ efflux or “exclusion” from roots. This could result in less Na+ being transported to the shoot, and thus explaining the higher salt-tolerance of clone BRS 189. The higher degree of root plasma membrane lipid peroxidation of clone, and the lower proline and ammonium quaternary compounds contents of CCP 06 when compared to BRS 189 could also explain the differences in salt-tolerance between the two clones. These organic solutes could protect and stabilize plasma membrane against oxidative stress. Phosphatidylglycerol (PG), phosphatidylethanolamine (PE) and phosphatidylserine (PS) were the major phospholipids in the plasma membrane from BRS 189 roots. Salinity induced increases in the relative proportions of PE and phosphatidylinositol (PI), while PG and PA were reduced. No changes were detected in PS in relation to control plant. The importance of lipid composition changes on H+-ATPase activity must be more studied. / O presente trabalho teve por objetivo estudar as respostas fisiológicas e bioquímicas de clones de cajueiro anão-precoce (Anacardium occidentale L.) ao estresse salino. Os experimentos foram conduzidos em casa de vegetação, sendo as plântulas cultivadas em vasos plásticos contendo vermiculita. No primeiro experimento, cinco clones de cajueiro anão-precoce foram submetidos aos tratamentos com NaCl a 0 (controle), 8 e 16 dS.m-1 de condutividade elétrica e objetivou selecionar clones com tolerâncias diferenciadas ao estresse salino. Para isso, foram estudados os efeitos da salinidade no crescimento, nas trocas gasosas, no teor de água, na suculência foliar, no potencial osmótico, nas concentrações de prolina, N-aminossolúveis e carboidratos solúveis e nos teores dos íons inorgânicos (Na+, Cl- e K+). A salinidade reduziu o crescimento das plântulas de todos os clones estudados. Os efeitos inibitórios do NaCl foram mais conspícuos na parte aérea do que nas raízes. O clone CCP 06 foi aquele que apresentou maior redução no crescimento foliar, enquanto os clones BRS 189 e CCP 09 foram os que apresentaram as menores reduções. A salinidade inibiu a mobilização das reservas cotiledonárias, principalmente, na dose mais elevada de sal. A redução no crescimento, pela salinidade, correlacionou-se com a redução na taxa de fotossíntese líquida. Os clones CCP 06 e BRS 189 apresentaram, respectivamente, a maior e a menor redução na taxa fotossintética a 8 dS.m-1. Embora a salinidade tenha reduzido a condutância estomática dos clones de cajueiro anão-precoce, essa redução não foi acompanhada por mudanças nas concentrações internas de CO2. Os clones estudados não apresentaram alterações, em função da salinidade, no estado hídrico das folhas e raízes, porém, apresentaram reduções no potencial osmótico, favorecendo o ajustamento osmótico e, consequentemente, a manutenção da turgescência dos tecidos. Sob condições de estresse salino, os clones BRS 189 e CCP 09 foram os mais eficientes na regulação do transporte do íon Na+ para a parte aérea da plântula, acumulando-o nas raízes. Em relação ao Cl-, o clone CCP 09 mostrou-se o mais eficiente no controle do transporte desse íon. Porém, CCP 06 foi o clone que mais acumulou ambos os íons tóxicos na parte aérea da planta. Com o aumento da salinidade, os teores de potássio dos clones estudados tiveram seus valores reduzidos apenas nas raízes. Na dose de 8 dS.m-1, o BRS 189 foi o clone que mais aumento suas concentrações de N-aminosolúveis e prolina no suco radicular. Nesse mesmo nível de sal, a salinidade aumentou a concentração de carboidratos apenas nos clones CCP 06 e BRS 189. De posse destes resultados, o segundo experimento foi realizado com os clones CCP 06 e BRS 189 que foram os que se mostraram, respectivamente, o menos e o mais tolerante à salinidade. Esse experimento teve por objetivo estudar os efeitos da salinidade (NaCl a 8 dS.m-1) na atividade da H+-ATPase e na composição e peroxidação dos lipídios de membrana plasmática isoladas de raízes das plântulas dos dois clones contrastantes. A salinidade estimulou a atividade da H+-ATPase apenas no clone tolerante, o BRS 189, sendo esse clone o que apresentou maior conteúdo de esteróis totais e menor relação fosfolipídios totais (PLt)/ esteróis totais (Et), tanto em condições controle como de estresse. Esses resultados foram concordantes com o fato de ter sido o BRS 189 o clone que melhor excluiu o Na+ da parte aérea. Nesse clone não foram observadas alterações nos teores de malondialdeído, diferentemente do que ocorreu com o CCP 06, cujos teores aumentaram com o estresse salino. A maior proteção da membrana plasmática do clone BRS 189 ao dano oxidativo está de acordo com os maiores acúmulos de prolina e N-aminossolúveis observados nesse clone. Os principais fosfolipídios da membrana plasmática isolada de raízes do clone BRS 189 foram fosfatilglicerol (PG), fosfatidiletalonamina (PE) e fosfatilserina (PS). A salinidade provocou alterações nas proporções relativas dos fosfolipídios, sendo PE e fosfatidilinositol (PI) os que apresentaram maiores aumentos em relação ao total, enquanto que fosfatidilglicerol (PG) e ácido fosfatídico (PA) foram os que apresentaram maiores reduções. A percentagem de PS, em relação ao total, não foi afetada pela salinidade. No entanto, a relação entre essas mudanças na composição lipídica do BRS 189 pela salinidade e o aumento na atividade da H+-ATPase necessita ser melhor investigada.