Made available in DSpace on 2014-06-11T19:28:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-07-25Bitstream added on 2014-06-13T20:08:45Z : No. of bitstreams: 1 rhein_afl_me_jabo.pdf: 308367 bytes, checksum: de8b1088481af03e96f1353c48b63cbf (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / No presente trabalho verificou-se a atividade da redutase do nitrato, o acúmulo de prolina livre e o crescimento inicial em raízes de cana-de-açúcar, cv. IAC91-5155, considerada tolerante à seca, sob interação dos estresses hídrico e ácido no solo. O estudo teve o intuito de propor a utilização destes compostos como indicadores bioquímico-fisiológicos, para aferir o grau de tolerância em plantas jovens de cana-de-açúcar cultivadas sob efeito dos estresses associados. Aos 30 dias de idade, as mudas, originadas da brotação de gemas, foram transferidas para vasos com 12 dm3 de Latossolo Vermelho distrófico e submetidas à associação de três tratamentos de disponibilidade hídrica: sem estresse (70%), estresse moderado (55%) e estresse severo (40%), de acordo com a capacidade de campo, e três níveis de acidez no solo: sem estresse (55%), estresse moderado (33%) e estresse severo (23%), considerando-se o índice de saturação por bases. O delineamento experimental foi em blocos casualizados, em esquema fatorial 3x3, com quatro repetições. Aos 60 dias sob associação dos estresses foram determinados os teores de prolina livre, a atividade da redutase do nitrato e o crescimento inicial do sistema radicular de plantas jovens de cana-de-açúcar. Pelos resultados obtidos evidenciou-se que a redução da atividade da redutase do nitrato ocorreu em moderada acidez e restrição hídrica associadas à severidade dos estresses. O acúmulo de prolina livre pode ser considerado indicador fisiológico em plantas jovens de cana-de-açúcar, cv. IAC91-5155, sob condições severas de disponibilidade hídrica e acidez do solo. A deficiência hídrica reduziu o crescimento das raízes. / In the present work it was observed the nitrate reductase activity, the accumulation of free proline, and the sugarcane cv. IAC91-5155 roots initial growth, under interaction between the water and acid stress in soil. The study reasoning was to propose the use of these compounds as biochemical-physiological indicators, so as to detect the tolerance level of sugarcane seedlings grown under the effect of the stress factors. After 30 days the seedlings, originated from the shoot sprouting, were transferred to pots with 12 dm3 of dystrophic Red Latosol and submitted to three treatments of water availability: no stress (70%), moderate stress (55%) and severe stress (40%), in accordance with field capacity and three acidity treatments: no stress (55%), moderate stress (33%) and severe stress (23%), considering the base saturation index. The experimental design was in randomized blocks under factorial scheme of 3x3, with four replicates. After 60 days under the stress association, the levels of free proline, the nitrate reductase activity and the growth of the sugarcane roots system were evaluated. The results indicate that the reduction of the nitrate reductase activity took place under moderate levels of acidity and water restriction associated to the stress intensities. The accumulation of free proline can be considered as a biochemicalphysiological indicator for sugarcane cv. IAC91-5155 seedlings, when under the interaction of soil severe stress conditions. The water deficiency reduced the roots growth.

Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2018-02-23T14:35:18Z No. of bitstreams: 1 PGPV16MA192.pdf: 957637 bytes, checksum: 97f795d2bfa5bbcfdfd15778233312bb (MD5) / Made available in DSpace on 2018-02-23T14:35:18Z (GMT). No. of bitstreams: 1 PGPV16MA192.pdf: 957637 bytes, checksum: 97f795d2bfa5bbcfdfd15778233312bb (MD5) Previous issue date: 2016-07-15 / FAPESC / The main causes of reduction in bean crop productivity are the abiotic stresses such as drought stress, low availability of nutrients in the soil and unfavorable temperatures. The selection of bean cultivars with a larger root distribution is an excellent strategy to improve nutrient absorption capacity in soils with low nutrient availability, and also genotypes with more developed root system has increased tolerance to drought stress. So it is very important to analyze the distribution of the root bean system in breeding programs, as cultivars with larger root profile are more productive and resistant to biotic and abiotic factors. Thus, this study aimed to: i) estimate the phenotypic correlation and its direct and indirect effects of the aerial part of the components that are associated with root distribution, facilitating the indirect selection for this character; ii) evaluate the genetic variability and association of root distribution in relation to the growth habit in bean lines. The experiments were conducted in the experimental area of IMEGEM, arranged in a randomized block design. To evaluate the root system was used Bohm method, when the genotypes full flowering were perpendicular profiles open the line of sowing, a rectangle with dimensions of 0.5 m wide by 0.3 m high, with checkered 0 05 m side was willing and a photo was taken. The determination of the root distribution in binary (presence denomination (1) and absence (0) of the root in each square) was performed using photo analysis. The measurement of characteristic root distribution of the determination of simple events (presence = 1 and absence = 0). In addition, it evaluated the root angle through Shovelomics method and also measured the aboveground parts. The results revealed the importance of stem diameter characters, leaf area index, the first pod insertion and root angle, since it had the highest positive correlation with root distribution to assist in indirect selection of this character. The residual effect was greater than the coefficient of determination indicating that the independent characteristics are not fully influence on the root distribution and low values of correlation coefficients are attributed to the effects of environment, competition for nutrients and different physiological mechanisms that control the expression multiple genes with minor effects. The results revealed that genetic variability exists in the root system of the analyzed strains. All contrasts involving the particular growth habit showed significant difference, indicating that the habit indeterminate genotypes are promising for use in crossing blocks, when the aim is the selection of cultivars with good root distributions / As principais causas de redução na produtividade da cultura do feijão são os estresses abióticos, como deficiência hídrica, baixa disponibilidade de nutrientes no solo e temperaturas desfavoráveis. A seleção de cultivares de feijão com uma maior distribuição radicular é uma excelente estratégia para melhorar a capacidade de absorção de nutrientes, em solos com baixa disponibilidade de nutrientes, e também, genótipos com sistema radicular mais desenvolvido possuem maior tolerância ao estresse hídrico. Por isso, é de grande importância a análise da distribuição do sistema radicular do feijão em programas de melhoramento, já que cultivares com maior perfil radicular se mostram mais produtivas e com resistência a fatores bióticos e abióticos. Sendo assim, este trabalho teve como objetivos: i) estimar a correlação fenotípica e seus efeitos diretos e indiretos dos componentes da parte aérea que estão associados com a distribuição radicular; ii) avaliar a variabilidade genética e associação da distribuição radicular em relação ao hábito de crescimento em linhagens de feijão. Os experimentos foram realizados na área experimental do IMEGEM, arranjados em delineamento de blocos casualizados. Para avaliação do sistema radicular foi utilizado o método de Bohm, quando os genótipos apresentaram pleno florescimento foram abertos perfis perpendiculares a linha de semeadura, onde um retângulo com dimensões de 0,5 m de largura por 0,3 m de altura, quadriculado com 0,05 m de lado foi disposto e uma foto foi capturada. A determinação da distribuição radicular no sistema binário (denominação de presença (1) e ausência (0) das raízes em cada quadrícula) foi realizada por meio da análise da foto. A mensuração da característica distribuição radicular a partir da determinação de eventos simples (presença=1 e ausência=0). Além disso, foi avaliado o ângulo de raiz através do método de Shovelomics e também mensurado os componentes da parte aérea. Os resultados revelaram a importância dos caracteres diâmetro de caule, índice de área foliar, inserção do primeiro legume e ângulo de raiz, uma vez que apresentaram as maiores correlações positivas com a distribuição radicular, podendo auxiliar na seleção indireta desse caráter. O efeito residual foi superior ao coeficiente de determinação, indicando que as características independentes não têm total influência na distribuição radicular, e os baixos valores dos coeficientes de determinação estão atribuídos a efeitos do ambiente, competição por nutrientes e a diferentes mecanismos fisiológicos que controlam a expressão de vários genes com efeitos menores. Os resultados revelaram que existe variabilidade genética no sistema radicular das linhagens analisadas. Todos os contrastes envolvendo o hábito de crescimento determinado apresentaram diferença significativa, evidenciando que os genótipos de hábito indeterminado são promissores para utilização em blocos de cruzamentos, quando a finalidade é a seleção de cultivares com boas distribuições radiculares

Orientadora: Durvalina Maria Mathias dos Santos / Banca: Isabel Cristina Leite / Banca: Marcelo de Almeida Silva / Resumo: No presente trabalho verificou-se a atividade da redutase do nitrato, o acúmulo de prolina livre e o crescimento inicial em raízes de cana-de-açúcar, cv. IAC91-5155, considerada tolerante à seca, sob interação dos estresses hídrico e ácido no solo. O estudo teve o intuito de propor a utilização destes compostos como indicadores bioquímico-fisiológicos, para aferir o grau de tolerância em plantas jovens de cana-de-açúcar cultivadas sob efeito dos estresses associados. Aos 30 dias de idade, as mudas, originadas da brotação de gemas, foram transferidas para vasos com 12 dm3 de Latossolo Vermelho distrófico e submetidas à associação de três tratamentos de disponibilidade hídrica: sem estresse (70%), estresse moderado (55%) e estresse severo (40%), de acordo com a capacidade de campo, e três níveis de acidez no solo: sem estresse (55%), estresse moderado (33%) e estresse severo (23%), considerando-se o índice de saturação por bases. O delineamento experimental foi em blocos casualizados, em esquema fatorial 3x3, com quatro repetições. Aos 60 dias sob associação dos estresses foram determinados os teores de prolina livre, a atividade da redutase do nitrato e o crescimento inicial do sistema radicular de plantas jovens de cana-de-açúcar. Pelos resultados obtidos evidenciou-se que a redução da atividade da redutase do nitrato ocorreu em moderada acidez e restrição hídrica associadas à severidade dos estresses. O acúmulo de prolina livre pode ser considerado indicador fisiológico em plantas jovens de cana-de-açúcar, cv. IAC91-5155, sob condições severas de disponibilidade hídrica e acidez do solo. A deficiência hídrica reduziu o crescimento das raízes. / Abstract: In the present work it was observed the nitrate reductase activity, the accumulation of free proline, and the sugarcane cv. IAC91-5155 roots initial growth, under interaction between the water and acid stress in soil. The study reasoning was to propose the use of these compounds as biochemical-physiological indicators, so as to detect the tolerance level of sugarcane seedlings grown under the effect of the stress factors. After 30 days the seedlings, originated from the shoot sprouting, were transferred to pots with 12 dm3 of dystrophic Red Latosol and submitted to three treatments of water availability: no stress (70%), moderate stress (55%) and severe stress (40%), in accordance with field capacity and three acidity treatments: no stress (55%), moderate stress (33%) and severe stress (23%), considering the base saturation index. The experimental design was in randomized blocks under factorial scheme of 3x3, with four replicates. After 60 days under the stress association, the levels of free proline, the nitrate reductase activity and the growth of the sugarcane roots system were evaluated. The results indicate that the reduction of the nitrate reductase activity took place under moderate levels of acidity and water restriction associated to the stress intensities. The accumulation of free proline can be considered as a biochemicalphysiological indicator for sugarcane cv. IAC91-5155 seedlings, when under the interaction of soil severe stress conditions. The water deficiency reduced the roots growth. / Mestre

Cyclodipeptides (CDPs) are the smallest, most stable cyclic peptides that are synthesized as secondary metabolites by bacteria. The aim of this study was to investigate the effect of the Pseudomonas argentinensis (SA190) and four (CDPs), named as cis-cyclo-(Pro-Phe) (Cyclo2), cis-cyclo-(Pro-Leu) (Cyclo3), cis-cyclo-(Pro-Tyr) (Cyclo4) and cis-cyclo-(Pro-Val) (Cyclo5), with three concentrations (1µM, 100nM, and 10nM), on the growth of Arabidopsis thaliana under normal plant growth conditions [1/2MS media], salt conditions [125 mM NaCl] and drought conditions [25% PEG]. Moreover, we determined the most effective CDPs with optimal concentration. It was found that cis-cyclo-(Pro-Tyr) (Cyclo4) at a concentration of 100nM had an effect on the plant growth and can mimic the effect of SA190 under normal [1/2MS media] conditions. Also, cis-cyclo-(Pro-Tyr) (Cyclo4) at a concentration of 1µM can mimic the effect of SA190 under salt conditions [125mM NaCl]. Finally, cis-cyclo-(Pro-Val) (Cyclo5) at a concentration of 1µM can mimic the effect of SA190 under drought conditions [25% PEG].

Les interactions entre les contraintes environnementales sur le phénotype rendent complexe l'étude des mécanismes d'adaptation et d'évolution des plantes. Aborder une telle question nécessite une approche intégrée de l'orchestration, à différentes échelles, des réponses des plantes à des stimuli environnementaux isolés et combinés. Nous avons utilisé Arabidopsis thaliana pour évaluer les bases génétiques des réponses à deux contraintes abiotiques majeures en forte interaction au champ : la sécheresse et les hautes températures. Grâce à des outils performants pour l'analyse du phénotype, une large gamme de traits a été mesurée sur de nombreux génotypes différant dans leur plasticité. Nous avons caractérisé la croissance et des traits d'histoire de vie, la morphologie et la structure foliaire, ainsi que les capacités d'acquisition et de conservation des ressources, en particulier l'eau et le carbone. Après une description des réponses phénotypiques et de leur architecture génétique, les conséquences de ces réponses dans une perspective écologique et évolutive ont été évaluées. En particulier, nous avons analysé les variations des stratégies fonctionnelles mises en relief par les covariations phénotypiques et génétiques. De plus, les processus responsables des réponses observées ont été examinés. Les résultats ont permis de mettre en évidence des variations génétiques associées à plusieurs régions génomiques dont l'influence est probablement majeure pour les mécanismes d'adaptation des plantes. Certaines de ces régions génomiques, de par leur effet sur la performance, sont porteuses d'intérêt dans une perspective d'amélioration des espèces cultivées face aux changements climatiques actuels. / The mechanisms of plant adaptation and evolution are difficult to investigate since environmental constraints have interactive effects on plant phenotypes. Such study requires an integrated approach about the coordination, at different organizational levels, of the plant phenotypic responses to multiple environmental cues. Using the model plant Arabidopsis thaliana, we assessed the genetic bases of the integrated responses to two major abiotic constraints that strongly interact in the field: water availability and high temperature. Using powerful tools for the analysis of the phenotype, a large range of traits was measured in many genotypes that differ in their plasticity. We focused on the traits related to plant growth and life history, leaf structure and morphology, and to the acquisition and conservation of resources, specifically water and carbon. After a description of the phenotypic responses and their genetic architecture, the ecological and evolutionary consequences of these responses were evaluated. Specifically, we examined the variations in the functional strategies that are highlighted by phenotypic and genetic covariations. Moreover, the processes responsible of the observed phenotypic responses to environmental constraints were investigated. Strong genetic variability associated to particular genomic regions was identified. Such loci have presumably important influence on the mechanisms of plant adaption to fluctuating environments. Some of these genomic regions have a strong effect on plant performance in stressing conditions, and therefore offer promising avenues for crop improvement facing current global climate change.

Made available in DSpace on 2016-12-08T16:44:34Z (GMT). No. of bitstreams: 1 PGPV11MA035.pdf: 382044 bytes, checksum: 888904b44ab1d4e73c30ea19d52dffc8 (MD5) Previous issue date: 2011-02-02 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Bean production is affected by a range of abiotic stresses such as drought, low soil fertility, soil acidity and unfavorable temperatures. However, a deep root system and well distributed allows better adaptation, especially regarding the conditions of drought and low nutrient availability. Despite the advancement of research, little has been done in this line of study. Thus, this study aimed to: i) present an alternative to the measurement and statistical analysis to the root distribution, ii) measuring the character of root distribution in bean genotypes Active Germplasm Bank of UDESC (Universidade do Estado de Santa Catarina) and its relationship to other important agronomic characteristics, and iii) to evaluate the root distribution along the profile between mutant populations and select bean genotypes with higher metric values for the character. The experiments were performed in the experimental area of IMEGEM, arranged in a randomized design. The evaluation of root distribution was held in hybrids, cultivars, accessions and mutant populations of beans. For that were open profiles perpendicular to the plant rows of beans, where a rectangle with dimensions of 0.5 m wide by 0.3 m, 0.05 m grid was set aside and a photo was taken. The determination of root distribution in the binary system (name of presence (1) and absence (0) of roots in each box) was performed by analysis of the photo. It was observed that the measurement of the characteristic root distribution through the determination of simple events is a valuable tool for researchers because it allows the quantitative analysis of root distribution by means of Generalized Linear Models the GENMOD procedure of SAS. Considering the small number of genotypes, can be stated that the Active Germplasm Bank Bean has promising genotypes for the character root distribution, where BAF09 (black) and BAF35 (carioca) present the best root deep distribution (20 to 30 cm). It might still be verified the presence of significant positive correlation between root distribution and other traits of agronomic importance. The mutant populations present different performance against the mutagenic for the root distribution. Since the most promising segregating populations are derived from cultivars IPR Uirapuru and IPR Chopim, as they present a significant increase in the number of roots with increasing doses of mutagen / A produção de feijão é afetada por uma gama de estresses abióticos, como seca, baixa fertilidade do solo, acidez do solo e temperaturas desfavoráveis. No entanto, um sistema radicular profundo e bem distribuído permite melhor adaptação da cultura, principalmente no que tange as condições de deficiência hídrica e baixa disponibilidade de nutrientes. Apesar do avanço da pesquisa, pouco se tem trabalhado nessa linha de estudo. Sendo assim, este trabalho teve como objetivos: i) apresentar uma alternativa para a mensuração e a análise estatística para o caráter distribuição radicular; ii) mensurar o caráter distribuição radicular em genótipos de feijão do Banco Ativo de Germoplasma da UDESC (Universidade do Estado de Santa Catarina) e verificar a correlação com outros caracteres de importância agronômica; e iii) avaliar a distribuição radicular ao longo do perfil entre populações mutantes e selecionar genótipos de feijão com valores métricos superiores para o caráter. Os experimentos foram realizados na área experimental do IMEGEM, arranjados em delineamento inteiramente casualizado. A avaliação da distribuição radicular foi realizada em híbridos, cultivares, acessos e populações mutantes de feijão. Para isso foram abertos perfis perpendiculares alinha de semeadura, onde um retângulo com dimensões de 0,5 m de largura por 0,3 m de altura, quadriculado com 0,05 m de lado foi disposto e uma foto foi capturada. A determinação da distribuição radicular no sistema binário (denominação de presença (1) e ausência (0) das raízes em cada quadrícula) foi realizada por meio da análise da foto. A mensuração da característica distribuição radicular a partir da determinação de eventos simples (presença=1 e ausência=0) é uma valiosa ferramenta para o pesquisador, já que possibilita a análise quantitativa da distribuição radicular, por meio dos Modelos Lineares Generalizados do procedimento GENMOD do SAS. Ainda que de forma incipiente, devido ao pequeno número de genótipos avaliados pode ser afirmado que o Banco Ativo de Germoplasma de Feijão possui genótipos promissores para o caráter distribuição radicular. Sendo que BAF09 (preto) e BAF35 (carioca), por apresentarem distribuição radicular profunda e significativa (20 a 30 cm), merecem destaque. Pôde ser verificada ainda a presença de correlação positiva e significativa entre a distribuição radicular e outros caracteres de importância agronômica. As populações mutantes apresentaram desempenho diferenciado frente ao mutagênico para a distribuição radicular. As populações segregantes mais promissoras foram oriundas das cultivares IPR Uirapuru e IPR Chopim, pois apresentaram um aumento significativo na distribuição radicular o aumento das doses do agente mutagênico

Les herbicides sont des polluants suscitant de grandes inquiétudes en raison de leur ubiquité environnementale résultant de leur usage intensif dans l’agriculture moderne et de leur persistance dans les sols et les eaux. Les herbicides peuvent être dégradés par des microorganismes, des plantes ou d’autres processus naturels, produisant alors une vaste gamme de métabolites dont l’impact sur les écosystèmes reste méconnu. Dans un contexte d’évaluation des risques environnementaux, l’étude de la réponse des plantes à des mélanges complexes de xénobiotiques est importante pour estimer les effets des contaminations, notamment dans le cas de pollution résiduelle. Afin d’étudier l’impact de cette diversité de polluants, les mécanismes de réponse et les cibles impliquées, la plante modèle Arabidopsis thaliana a été confrontée à des doses variables de molécules de la famille des triazines constituant une série chimique cohérente : atrazine, herbicide encore largement utilisé au niveau mondial, déséthylatrazine, métabolite chloré de l’atrazine, et hydroxyatrazine, métabolite de déchloration de l’atrazine. Ce travail montre que l’exposition de courte durée à des doses variables d’atrazine, de déséthylatrazine et d’hydroxyatrazine, au niveau racinaire, affecte de manière spécifique et dose-dépendante la croissance précoce et le développement de la plante. La caractérisation d’effets directs et multiples sur la respiration et la croissance racinaire a permis de révéler des mécanismes d’action non-canoniques, distincts de l’action classiquement décrite des triazines sur le photosystème II. Afin d’identifier ces mécanismes, activés en absence de dommages cellulaires, une analyse transcriptomique au niveau du génome entier a été effectuée. Les trois triazines induisent des changements coordonnés et spécifiques dans l’expression des gènes. L’analyse fonctionnelle des gènes différentiellement exprimés et de leur promoteur révèle que les voies de signalisation liées à la fois aux hormones végétales, à la perception de faibles niveaux d’énergie, aux stress environnementaux ainsi qu’aux interactions biotiques sont impliquées dans la réponse aux faibles doses de triazines. Les triazines affectent, en particulier, l’expression de gènes connus pour être régulés par les cytokinines. De manière intéressante, cette famille d’hormones végétales montre des caractéristiques chimiques similaires à celles des triazines. Des études développementales utilisant différentes modalités d’exposition aux triazines et aux cytokinines ont alors été effectuées sur des génotypes sauvages et sur des mutants de la voie de signalisation des cytokinines. L’identification d’interactions spécifiques entre les triazines et les composants de la signalisation des cytokinines a alors mis en évidence des mécanismes potentiels de compétition et/ou d’antagonisme. La caractérisation de ces perturbations au niveau de la transduction du signal pourra permettre à terme d’évaluer l’efficacité des herbicides sur les cultures ainsi que l’impact des contaminations xénobiotiques sur les communautés végétales naturelles. Enfin, l’identification des interactions entre stress xénobiotique, biotique et abiotique approfondira les connaissances sur les effets croisés de la pollution chimique et des stress liés au changement climatique. / Herbicides are pollutants of high concern due to their environmental ubiquity resulting from extensive use in modern agriculture and persistence in soil and water. Degradation events on active molecules mediated by microorganisms, by plants and by natural processes give rise to a plethora of herbicide metabolites of unknown impact on ecosystems. Study of plant behavior toward such complex mixtures of xenobiotic structures is important to evaluate the effects of contaminations, especially in the context of residual pollution. In order to understand the mechanisms underlying the action of this diversity of compounds, the model plant Arabidopsis thaliana was confronted to variable doses of the widely-used triazine herbicide atrazine, and of two of its metabolites, desethylatrazine and hydroxyatrazine. Short exposure to varying concentrations of atrazine, desethylatrazine and hydroxyatrazine was found to affect early growth and development in various dose-dependent and distinct manners. These differential effects pointed out to the multiple involvement of non-canonical mechanisms, directly affecting respiration and root development. In order to identify these mechanisms, which are activated in the absence of major adverse physiological effects, a genome-wide transcriptomic analysis was carried out. All of the triazines under study induced coordinated and specific changes in gene expression. Functional analysis of differentially expressed genes and of their promoters revealed that signaling pathways related to plant hormones, low energy sensing, environmental stresses and biotic interactions were involved in low-dose triazine responses. In particular, triazines affected the expression of genes known to be regulated by cytokinins. Interestingly, this family of plant hormones shares similar chemical features with triazine compounds. Developmental studies on plants bearing mutations in cytokinin sensing and signaling pathways were then carried out under variable triazine exposures. The identification of specific interactions between triazine compounds and cytokinin-signaling components highlighted potential mechanisms of competition and/or antagonism. The characterization of such signal transduction modifications and perturbations will be useful to assess herbicide efficiency in crop systems and xenobiotic contamination impact on natural plant communities. Finally, the identification of crosstalk processes between xenobiotic, abiotic and biotic stress signaling gives novel insights into the interplay between chemical pollution and climate change stressors.