O objetivo deste trabalho foi desenvolver uma metodologia para avaliar potenciais ações visando à minimização dos custos ambientais a partir dos conceitos da Simbiose Industrial em redes horizontais de empresas. Para cumprir tal objetivo, foi realizada uma Revisão Sistêmica de Literatura (RBS) utilizando a metodologia Methodi Ordinatio, donde resultou um portfólio com 149 artigos, que foram utilizados para desenvolver a metodologia proposta. Com os resultados, foi possível identificar descrições sobre custos ambientais e simbiose industrial e, posteriormente, possibilitou a adaptação do modelo de custos ambientais com o questionário de identificação de simbiose industrial. A metodologia foi aplicada em um aglomerado de leiterias na cidade de Piraí do Sul - PR, em três etapas, sendo: a 1ª etapa, a coleta de dados através de questionário; a 2ª etapa, elaborar um novo cenário para cada empresa e, a 3ª etapa, a análise dos resultados. Contudo, foi possível identificar a relação de potenciais de Simbiose Industrial, no aglomerado, relacionando-os com os custos ambientais, possibilitando, assim, estabelecer uma redução dos referidos custos, através da colaboração e confiança dos integrantes do aglomerado. / The objective of this work was to develop a methodology to evaluate potential actions aimed at minimizing environmental costs from the concepts of Industrial Symbiosis in horizontal networks of companies. To accomplish this objective, a Systemic Literature Review (RBS) was carried out using Methodi Ordinatio methodology, which resulted in a portfolio of 149 articles, which were used to develop the proposed methodology. With the results, it was possible to identify descriptions of environmental costs and industrial symbiosis, and later allowed the adaptation of the environmental cost model with the industrial symbiosis identification questionnaire. The methodology was applied in a cluster of dairies in the city of Piraí do Sul - PR, in three stages, being: the first stage, the data collection through a questionnaire; The second stage, to elaborate a new scenario for each company and, the third stage, the analysis of the results. However, it was possible to identify the relationship of potential of Industrial Symbiosis in the cluster, relating them to the environmental costs, thus allowing a reduction of these costs through the collaboration and trust of the members of the agglomerate.

Diaphorina citri Kuwayama, 1908 (Hemiptera: Psyllidae) é um inseto exótico no Brasil, registrado desde a década de 40. Apesar dos danos diretos que pode causar, só recebeu atenção como praga em 2004, quando foi confirmada a doença Huanglonbing (HLB) em citros, a qual foi posteriormente relacionada a D. citri como inseto-vetor. Atualmente, não há cura para plantas doentes. Portanto, o manejo do HLB é baseado na retirada de árvores infectadas e no controle dos psilídeos, o qual se fundamenta no controle biológico clássico, ação natural de predadores e no controle químico. Porém, o uso contínuo e intenso de agrotóxicos é sempre problemático devido ao desequilíbrio que pode causar nos agroecossistemas. Portanto, investigar as populações de D. citri no Brasil e discutir possíveis medidas alternativas para o controle ou manejo do vetor/doença são desejáveis. Assim, este trabalho apresenta como objetivos i) avaliar a diversidade genética intra e interpopulacional de D. citri e verificar a existência de estruturação populacional no Brasil, especialmente entre as populações que se distribuem na principal região citrícola do país; ii) determinar a ocorrência e frequência de infecção por Wolbachia em diferentes populações desse psilídeo, além de caracterizar a diversidade desse simbionte e definir a relação entre os haplótipos do hospedeiro e as linhagens de Wolbachia,visando fornecer subsídios para o controle alternativo deste inseto-vetor. A análise de diversidade genética utilizou o gene da citocromo oxidase I (COI) como marcador molecular. Os cálculos dos índices de fixação F indicaram a presença de estrutura genética e os cálculos dos índices de diversidade molecular mostraram um quadro de expansão populacional recente. Já a caracterização de Wolbachia via tipagem pela análise de sequências de multilocos (multilocus sequencing typing - MLST) indicou a ocorrência de cinco STs (173, 174, 175, 225 e 236), enquanto que análises das sequências do wsp indicaram quatro tipos de Wolbachia. O ST-173 foi predominante, estando presente em todas as populações, enquanto que os demais foram populações-específicos. Análises da relação hospedeiro-simbionte não revelou a existência de relações específicas entre os haplótipos do hospedeiro e os STs de Wolbachia, nem a diminuição da diversidade nucleotídica de D. citri frente à infecção por mais de um ST do simbionte. A relação entre os STs de Wolbachia e as consequências desta diversidade na bioecologia do hospedeiro ainda permanecem desconhecidas, mas a constatação de que Wolbachia ocorre em todas as populações e de que há um ST com distribuição abrangente abre caminhos para a utilização desse simbionte no desenvolvimento de estratégias alternativas de controle de D. citri. / Diaphorina citri Kuwayama, 1908 (Hemiptera: Psyllidae) is an exotic insect in Brazil, first recorded in the 40s. Although it causes direct damage, D. citri only received attention as a pest in 2004, when the \"Huanglonbing\" (HLB) disease was confirmed infecting citrus in Brazil, and subsequently related to D. citri as vector. Currently, there is no cure for diseased plants, and the management of HLB is based on the removal of infected trees and psyllid control, which is based on classical biological control, natural predation and chemical control. However, the continuous use of pesticides is always problematic due to the imbalance it can cause in agrosystems. Therefore, investigations on the populations structure of D. citri in Brazil and possible alternative measures for vector/disease control or management are highly desired. Thus, this study was aimed to i) evaluate the intra and interpopulation genetic diversity of D. citri and verify the existence of population structuring in Brazil, especially in the main citrus producing region of the country, ii) determine the natural rate of infection and characterize the Wolbachia strains associated with different populations of D. citri and iii) investigate the relationship among host haplotypes and the strains of Wolbachia, in order to provide data for the alternative control of this vector. The analysis of genetic diversity was done using the cytochrome oxidase I (COI) gene as a molecular marker. The fixation rates F calculated indicated the presence of genetic structure, while the molecular diversity indices pointed to a recent population expansion of D. citri in Brazil. The multilocus sequence typing analysis (\"multilocus sequencing typing - MLST\") for Wolbachia demonstrated the presence of five new sequence-types (STs = 173, 174, 175, 225 and 236), while only four were identified when using the wsp sequences as markers. The ST-173 was the predominant ST associated with D. citri, being present in all populations, while others were specific to certain populations. Analysis of the hostsymbiont relationship did not reveal the existence of specific interactions between host haplotypes and the STs of Wolbachia, or the decrease of nucleotide diversity of D. citri in populations infected by more than one ST. The effects of Wolbachia diversity on the host bioecology are still unknown, but the fact that Wolbachia is fixed in all populations and that there is a ST broadly distributed throughout the D. citri populations highlights the use of Wolbachia for the development of alternative strategies to control D. citri.

Submitted by (lucia.rodrigues@ufrpe.br) on 2016-07-05T12:16:24Z No. of bitstreams: 1 Emmanuella Vila Nova da Silva.pdf: 1939037 bytes, checksum: f521d3bf721007766ec42ccf2f7454a6 (MD5) / Made available in DSpace on 2016-07-05T12:16:24Z (GMT). No. of bitstreams: 1 Emmanuella Vila Nova da Silva.pdf: 1939037 bytes, checksum: f521d3bf721007766ec42ccf2f7454a6 (MD5) Previous issue date: 2012-03-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The use of plants symbiotically associated with N2 fixing bacteria and mycorrhizal fungi (AMF) provides an efficient strategy to accelerate the recovery of impacted areas and reduces its costs considerably. The term "mycorrhiza helper bacteria” (MHB) has been introduced and discussed due to the synergistic effect that this dual combination promotes to plants. They are bacteria associated with roots and AMF that selectively promote the establishment of symbiosis with fungi. Thus, the objectives were to verify the AMF activity in the area with native vegetation in the Pernambucano semiarid, municipality of Sertânia; determine glomerospores number and the most probable number (MPN) of infective propagules; quantify the content of glomalin-related protein in the soil and determine the feasibility of bacteria (MHB) co-inoculation and AMF mixture in “sabiá” (Mimosa caesalpiniifolia Benth) aiming at obtaining combinations and compatibility of symbiotic pairs, as well as to evaluate the mycorrhizal efficiency and colonization. The experiments were conducted in greenhouse of the Agronomic Institute of Pernambuco (IPA). 10 composite soil samples were collected with points were defined at random. Samples were homogenized and analyzed for physical and chemical characteristics. Composite samples were used for direct count (DC) and propagation of AMF for indirect count (IC) of spores, using trap- cultures and sorghum (Sorghum bicolor L. Moench) and peanut (Arachis hypogea L.) as host plants (experiment I). To determine the MPN of infective propagules of AMF in the Haplic Luvisol was used a system of serial dilution: 0, 1:10, 1:100 and 1:1000 with five replicates each, with maize (Zea mays L.) as host plant (experiment II). In the experiment III were used pots with Haplic Luvisol soil (8 kg pot-1) at pH 6.0 and the plant used was the “sabiá”. On seeding, inoculation with Burkholderia sabiae (BR 3405) and co-inoculation with BR3405 + MHB were performed and each seed was inoculated with 2 mL of specific medium for each of MHB bacteria and for the BR3405 containing 108 CFU mL-1. In the inoculation with AMF mixture was used 4 g pot-1 in the form of propagule containing approximately 670 spores. Plants were harvested at 110 days after planting (DAP) and the following variables were evaluated: shoot dry mass (SDM), root (RDM), RDM/SDM ratio, plant height (PH) on periods of 45, 90 and 110 days, root length (RL), total N accumulated in SDM (Nat), strains efficiency (E) and mycorrhizal colonization. The experimental design was randomized blocks, with 9 x 2 factorial arrangement plus an absolute control (AC) - without inoculation; MHB strains and one control treatment inoculated only with Burkholderia sabiae with and without AMF (AMF mixture) with 3 blocks . The experimental results show that the MPN of AMF infective propagules found in the city of Sertânia was 23 propagules cm-3. Soil proteins related to easily extractable glomalin (PSRGFE) and soil proteins related to total glomalin (PSRGT) were approximately 0.46 and 0.26 mg g soil-1, respectively. The AMF colonization combined with the bacteria was positive, as in the case of RL, treatments with BR 3405 + Azospirillum amazonenses (Y2) and BR 3405 + Herbaspirillum seropedicae (Z67) showed significant difference by the Tukey test (p <0.05) compared to the factor with and without AMF. Thereby ensuring that, in the presence of MHB bacteria there was increase in root length of “sabiá” plants. Strains efficiency showed better results when bacteria were in the presence of AMF and the treatment BR 3405 + Paenibacillus brasilensis (24) + AMF showed the best response. The treatments that received AMF were higher compared to the others on the variables SDM, RDM, E, Nac, coming to present on average 84% of root colonization. / A utilização de plantas associadas simbioticamente, com bactérias fixadoras de N2 e fungos micorrízicos arbusculares (FMA), constitui uma estratégia eficiente para acelerar a recuperação de áreas impactadas além de reduzir consideravelmente os custos com a mesma. O conceito de “mycorrhiza helper bacteria (MHB)” tem sido introduzido e discutido devido ao efeito sinergístico que essa dupla associação promove às plantas. São bactérias associadas com raízes e FMA que, seletivamente, promovem o estabelecimento da simbiose com os fungos. Deste modo, os objetivos deste trabalho foram verificar a atividade de FMA em área com vegetação nativa do semiárido Pernambucano, no município de Sertânia; determinar o número de glomerosporos e o número mais provável (NMP) de propágulos infectivos; quantificar o teor de proteínas do solo relacionadas à glomalina; determinar a viabilidade da co-inoculação entre bactérias (MHB) e mistura de FMA em sabiá (Mimosa caesalpiniifolia Benth) visando obter combinações e compatibilidade de pares simbióticos, assim como avaliar a eficiência e colonização micorrízica. Os experimentos foram conduzidos em casa de vegetação na Sede do Instituto Agronômico de Pernambuco (IPA). Foram coletadas 10 amostras compostas de solo, sendo os pontos definidos aleatoriamente. As amostras foram homogeneizadas e analisadas quanto às características físicas e químicas. Amostras compostas foram utilizadas para contagem direta (CD) e multiplicação de FMA para contagem indireta (CI) de esporos, com o uso de culturas-armadilha, empregando sorgo granífero (Sorghum bicolor L. Moench) e amendoim (Arachis hypogea L.) como plantas hospedeiras (experimento I). Para a determinação do NMP de propágulos infectivos de FMA no Luvissolo Háplico foi utilizado um sistema de diluição em série: 0, 1:10, 1:100 e 1:1000, com 5 repetições cada e, tendo o milho (Zea mays L.) como planta hospedeira (experimento II). No experimento III foram utilizados vasos com o solo Luvissolo Háplico (8 kg vaso-1) com pH 6,0 e a planta utilizada foi a sabiá. Na semeadura, foi efetuada inoculação com Burkholderia sabiae (BR 3405) e co-inoculação com BR3405 + MHB contendo 108 UFC mL-1. Na inoculação com a mistura do FMA, foram utilizados 4 g vaso-1 em forma de propágulo, contendo aproximadamente 670 esporos. A colheita foi realizada 110 dias após plantio (DAP) e foram avaliadas as seguintes variáveis: massa seca da parte aérea (MSPA), raiz (MSR), relação MSR/MSPA, altura de planta (AP) nos períodos de 45, 90 e 110 dias, comprimento da raiz (CR), N total acumulado na MSPA (Nac), eficiência das estirpes (E%) e colonização micorrízica. O delineamento experimental adotado foi em blocos casualizados, com arranjo fatorial 9 x 2 mais uma testemunha absoluta (TA) – sem inoculação; estirpes de MHB e um tratamento controle inoculado apenas com Burkholderia sabiae com e sem FMA (mistura de FMA) com 3 blocos. Os resultados dos experimentos mostram que o NMP de propágulos infectivos de FMA encontrados no município de Sertânia foi de 23 propágulos cm-3. As proteínas do solo relacionadas à glomalina facilmente extraível (PSRGFE) e as proteínas do solo relacionadas à glomalina total (PSRGT) ficaram em torno de 0,46 e 0,26 mg g solo-1, respectivamente. A colonização dos FMA em conjunto com as bactérias foi positiva, como no caso do CR, os tratamentos com BR 3405 + Azospirillum amazonenses (Y2) e BR 3405 + Herbaspirillum seropedicae (Z67) apresentaram diferença significativa pelo teste de Tukey (p<0,05) em relação ao fator com e sem FMA. Confirmando deste modo que, na presença das bactérias MHB houve aumento no comprimento do sistema radicular das plantas de sabiá. A eficiência das estirpes obteve os melhores resultados quando as bactérias estavam em presença de FMA e o tratamento BR 3405 + Paenibacillus brasilensis (24) + FMA foi o que obteve melhor resposta. Os tratamentos que receberam os FMA foram superiores em relação aos demais nas variáveis MSPA, MSR, E, Nac, chegando a apresentar uma média em torno de 84% de colonização radicular.

Submitted by (lucia.rodrigues@ufrpe.br) on 2016-07-05T14:36:45Z No. of bitstreams: 1 Artenisa Cerqueira Rodrigues.pdf: 1487841 bytes, checksum: e529e19a4038e9e52c84b90e95264477 (MD5) / Made available in DSpace on 2016-07-05T14:36:45Z (GMT). No. of bitstreams: 1 Artenisa Cerqueira Rodrigues.pdf: 1487841 bytes, checksum: e529e19a4038e9e52c84b90e95264477 (MD5) Previous issue date: 2012-06-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / It has been a recurrent the use of plant growth-promoting bacteria (PGPB) in association with the legume-rhizobia symbiotic system to increase the biological nitrogen fixation (BNF). Thus, the search for using alternative vehicles that increase quality and efficiency of inoculum leading to reduced costs and possible environmental impacts have been investigated. The BNF change in response to biological and environmental factors and their effectiveness can be measured by the concentrations of compounds involved in this process, being an important point to evaluate biochemical indicators related to the metabolisms of nitrogen, carbon and antioxidant. In this context, this study aimed at verifying the survival of cowpea to bacterial colonization and evaluating the interrelationship of Bradyrhizobium sp. and PGPB providing better symbiotic performance and cowpea development; optimizing the BNF and cowpea development, inoculated and co-inoculated with Bradyrhizobium sp. and PGPB, as well as evaluating the activities of enzymes as indicators of efficiency, senescence and stress/oxidative protection during and after the establishment of symbiosis; and determining the efficiency of inoculation and co-inoculation of cowpea with Bradyrhizobium sp. and PGPB using variables of growth and production and, jointly, characterizing the exopolysaccharide used as a vehicle for seed inoculation. Three experiments were conducted in greenhouse of the Agronomy Institute of Pernambuco (IPA). The legume used was cowpea cv. "IPA 206" inoculated with Bradyrhizobium sp. (BR 3267) and co-inoculated with different strains of PGPB. In the first experiment, the experimental design was randomized blocks with 24 treatments one inoculated (BR 3267), and 22 co-inoculated (BR 3267 + PGPB); and an absolute control (AC), with three replications. In the experiment II, the experimental design was randomized blocks with 2x4 factorial arrangement, two harvest periods (FP, flowering point; BS, beginning of senescence) and four treatments (inoculated and co-inoculated) + AC, with four repetitions. In the experiment III, the experimental design was a randomized block with 2x6 factorial arrangement, two harvest periods (FP, flowering point; GF, grain filling) and six treatments, one inoculated (BR 3267), and three co-inoculated (BR 3267 + PGPB), and two controls (AC and NC), with four replications. In the results was found synergism between BR 3267 and PGPB in cowpea especially in combination of BR 3267 with strains Paenibacillus graminis (MC 04.21) and P. durus (C 04.50), which exhibited better symbiotic response. Pre-selected strains of PGPB were combined with BR 3267, forming two symbiotic pairs (BR 3267 + MC 04.21; BR 3267 + C 04.50) and a tripartite (BR 3267 + MC 4.21 + C 04.50) where the results showed significant differences for growth variables as well as the biochemical indicators related to the metabolisms of nitrogen, carbon and antioxidative. There was increased concentration of total soluble proteins in nodules of plants co-inoculated compared to those inoculated in isolation with BR 3267. There was intense proteolytic activity and a decline in enzyme activity in the BS, but there was delayed of the deleterious effects of aging in the tripartite co-inoculation, allowing better symbiotic performance in cowpea plants. It can be suggested the use of inoculating compounds with bacteria studied aiming at improving the BNF and delaying senescence of nodules ensuring the availability of nitrogen for a longer period of time. This response emphasizes the importance of the combination and compatibility of microorganisms introduced, in combination, to promote a better symbiotic efficiency of cowpea, especially for tripartite co-inoculation, with respect to Rhizobium native to soil, and this synergistic response resulted in improved variables of production and efficiency of N2 fixation. With respect to chemical and rheological characteristics, the EPS used as vehicle for inoculation presents as a polyanionic heteropolysaccharide with low-viscosity fluid pseudoplastic, revealing an endothremal peak by the technique of differential scanning calorimetry that represents a favorable feature considering its use on industrial scale. / Para o incremento da fixação biológica do nitrogênio (FBN) tem sido recorrente o uso de bactérias promotoras de crescimento em plantas (BPCP’s) em associação com o sistema simbiótico leguminosa-rizóbio. Desta forma, a busca da utilização de veículos alternativos que aumentem a qualidade e eficiência do inoculante levando a redução de custos e de possíveis impactos ambientais tem sido investigados. A FBN varia em resposta a fatores biológicos e ambientais e a sua efetividade pode ser mensurada através das concentrações dos compostos envolvidos neste processo, sendo um ponto relevante avaliar indicadores bioquímicos relacionados aos metabolismos do nitrogênio, do carbono e antioxidativo. Neste contexto, este trabalho teve como objetivos verificar a sobrevivência do caupi à colonização bacteriana, assim como avaliar a interrelação Bradyrhizobium sp. e BPCP’s visando uma melhor performance simbiótica e desenvolvimento do caupi; otimizar a FBN e o desenvolvimento do caupi, inoculados e co-inoculados com Bradyrhizobium sp. e BPCP’s, assim como avaliar as atividades de enzimas como indicadores de eficiência, senescência e de estresse/proteção oxidativo durante a após o estabelecimento da simbiose; e determinar a eficiência da inoculação e co-inoculação do caupi com Bradyrhizobium sp. e BPCP’s utilizando variáveis de crescimento e produção e, juntantemente, caracterizar o exopolissacarídeo utilizado como veículo de inoculação das sementes. Foram conduzidos três experimentos em casa de vegetação do Instituto Agronômico de Pernambuco (IPA). A leguminosa utilizada foi caupi cv. “IPA 206” inoculada com Bradyrhizobium sp. (BR 3267) e co-inoculadas com diferentes estirpes de BPCP’s. No experimento I, o delineamento experimental utilizado foi em blocos ao acaso com 24 tratamentos, sendo um com inoculação (BR 3267); 22 combinações (BR 3267 + BPCP’s); uma testemunha absoluta (TA), com três repetições. No experimento II, o delineamento experimental adotado foi em blocos ao acaso com arranjo fatorial 2x4, dois períodos de coleta (PF, ponto de florescimento; IS, início de senescência) e quatro tratamentos (inoculados e co-inoculados) + TA, com quatro repetições. No experimento III, o delineamento experimental utilizado foi em blocos ao acaso com arranjo fatorial 2x6, dois períodos de colheita (PF, ponto de florescimento; e EG, enchimento de grãos) e seis tratamentos, sendo um com inoculação (BR 3267), e três com co-inoculações (BR 3267 + BPCP’s); e duas testemunhas (TA e TN), com quatro repetições. Nos resultados constatou-se sinergismo entre BR 3267 e BPCP’s em caupi principalmente na combinação de BR 3267 com Paenibacillus graminis (MC 04.21) e P. durus (C 04.50), que exibiram melhor resposta simbiótica. As estirpes de BPCP’s pré-selecionadas foram combinadas com BR 3267, formando dois pares simbióticos (BR 3267 + MC 04.21; BR 3267 + C 04.50) e uma tripartite (BR 3267+ MC 04.21 + C 04.50) onde os resultados mostraram diferenças significativas para as variáveis de crescimento bem como para os indicadores bioquímicos relacionados aos metabolismos do nitrogênio, carbono e antioxidativo. Houve aumento da concentração de proteínas solúveis totais nos nódulos das plantas co-inoculadas em relação àquelas inoculadas isoladamente com a BR 3267. Ocorreu intensa atividade proteolítica e declínio na atividade das enzimas no IS, porém na co-inoculação tripartite houve retardo dos efeitos deletérios da senescência, o que permitiu uma melhor performance simbiótica na plantas de caupi. Pode-se sugerir o uso de inoculantes compostos com as bactérias estudadas visando incrementar a FBN e retardar a senescência dos nódulos assegurando a disponibilidade de nitrogênio por um maior período de tempo. Esta resposta ressalta a importância da combinação e compatibilidade de microrganismos introduzidos, em mistura, para promover uma melhor eficiência simbiótica do caupi, em especial para a co-inoculação em tripartite, com relação ao rizóbio nativo do solo, e esta resposta sinérgica resultou em melhoria nas variáveis de produção e eficiência da fixação de N2. Em relação às características químicas e reológicas do EPS, utilizado como veículo para inoculação, este se apresenta como um heteropolissacarídeo polianiônico com fluido pseudoplástico pouco viscoso, revelando-se pela técnica de calorimetria exploratória diferencial um pico endotérmico que representa uma característica favorável tendo em vista a possibilidade de seu uso em escala industrial.

No description available.

Abstract Mutualism is often conditional and the associations vary from antagonism to mutualism along environmental conditions and genotypes of interacting species. I studied antagonism-mutualism continuum hypothesis of symbiosis experimentally using two different Epichloë/Neotyphodium endophytes and their host grasses, agricultural meadow fescues and natural fine fescue, as study systems. These systemic fungal endophytes live asymptomatically within aerial tissues of grasses, and are vertically transmitted to the next grass generation via seeds. Thus, asexual endophyte strains are dependent on the growth, survival and reproduction of their hosts. Epichloë/Neotyphodium endophytes are considered plant mutualists, because they improve the resistance of the host against various stresses, e.g. herbivores. In addition to experimental approach, I examined prevalence and genetic structure of Epichloë festucae in natural grass populations. Finally, current knowledge concerning grass endophytes was reviewed and the effects of variable environment and genetic background on the ecology and the evolution of grass-endophyte symbiosis were discussed. The endophyte improved the performance of the agronomic meadow fescues, but the beneficial effects were dependent on the grass cultivar and the growth environment. The endophyte-infected (E+) meadow fescues were more susceptible to the pathogenic snow molds and they suffered increased winter damage compared to the endophyte-free (E-) plants. Many natural Festuca rubra and F. ovina populations were either endophyte-free or had low infection frequency. The highest infection frequencies were found in subarctic areas where the infection incidence differed between habitats. Twenty out of the 25 E. festucae genotypes detected were carrying multiple alleles in microsatellite loci indicating multiple infections or vegetative hybridization of the fungus. A dominant genotype (63.5% of all isolates) occurred in all populations suggesting that this fungus is mainly asexual. E+ F. ovina seedlings performed worse than endophyte-free E- seedlings. In F. rubra, the river bank originated E+ seedlings allocated fewer, but longer and heavier tillers than the other seedlings indicating possible improved performance of the endophyte infected grasses in harsh river bank conditions. In short, I detected both positive and negative effects of endophyte infection on grasses varying along species, environment and genotypic background of study subjects. The results support the antagonism-mutualism continuum hypothesis.

Among dinitrogen (N2)-fixing some cyanobacteria can establish symbiosis with a broad range of host plants from all plant lineages including bryophytes, ferns, gymnosperms, and angiosperms. In the boreal forests, the symbiosis between epiphytic cyanobacteria and feathermosses Hylocomium splendens and Pleurozium schreberi is ecologically important. The main input of biological N to the boreal forests is through these cyanobacteria, and thus, they greatly contribute to the productivity of this ecosystem. Despite the ecological relevance of the feathermoss symbiosis, our knowledge about the establishment and maintenance of cyanobacterial-plant partnerships in general is limited, and particularly our understanding of the feathermoss symbiosis is rudimentary. The first aim of this thesis was to gain insight on the genomic rearrangements that enabled cyanobacteria to form a symbiosis with feathermosses, and their genomic diversity and similarities with other plant-symbiotic cyanobacteria partnerships. Genomic comparison of the feathermoss isolates with the genomes of free-living cyanobacteria highlighted that functions such as chemotaxis and motility, the transport and metabolism of organic sulfur, and the uptake of phosphate and amino acids were enriched in the genome of plant-symbiotic cyanobacteria. The second aim of this PhD study was to identify cyanobacterial molecular pathways involved in forming the feathermoss symbiosis and the regulatory rewiring needed to maintain it. Global transcriptional and post-transcriptional regulation in cyanobacteria during the early phase of establishment of the feathermoss symbiosis, and after colonization of the moss were investigated. The results revealed that the putative symbiotic gene repertoire includes pathways never before associated with cyanobacteria-plant symbioses, such as nitric-oxide sensing and regulation, and the transport and metabolism of aliphatic sulfonate. The third aim was to explore the role of the cyanobacterial community in contributing to the temporal variability of N2-fixation activity. Results from a field-study showed that temporal variation in N2-fixation rates could be explained to a high degree by changes in cyanobacterial community composition and activity. In particular, the cyanobacteria belonging to the genus Stigonema - although not dominating the community- appeared to be the main contributors to the N2-fixation activities. Based on this result, it is suggested that this genus is responsible for the main input of N in the boreal forest ecosystems. The last aim was to understand how the relationship between cyanobacterial community composition and N2-fixation activity will be affected by climatic changes such as, increased temperature (11oC compared to 19oC) and CO2 level (500 ppm compared to 1000 ppm). Laboratory experiments highlighted that 30 weeks of combined elevation of temperature and CO2 resulted in increased N2-fixation activity and moss growth rates. The observed increases were suggested to be allocated to reduced cyanobacterial diversity and changes in community composition, resulting in the dominance of cyanobacteria adapted to the future abiotic condition. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Manuscript. Paper 4: Manuscript.</p>

Dans la nature, les relations symbiotiques sont très répandues, et d’une importance écologique fondamentale. Les animaux sont apparus, ont évolué et vivent maintenant constamment associés avec une multitude de micro-organismes. Parmi les différents types de symbioses existantes, celles liant le microbiote et son hôte occupent une place centrale et équilibrée, basée sur des relations commensales ou mutualistes entre les partenaires. Ce microbiote est de plus en plus étudié, notamment en raison du rôle crucial qu’il joue dans la santé animale ainsi que dans le développement de pathologies. Dans cette effort de recherche, Drosophila melanogaster représente un modèle de choix, grâce à la facilité de générer et maintenir des lignées de mouches axéniques, ainsi que de les réassocier avec une communauté microbienne définie.L’association de la drosophile avec l’un des ses commensaux naturels, Lactobacillus plantarum, a permis de révéler l’effet promoteur de croissance de cette bactérie. En cas de carence nutritionnelle, des larves associées avec L. plantarum se développent beaucoup plus rapidement que leurs semblables axéniques. L’ajustement du développement en fonction des conditions environnementales est cependant crucial pour la formation d’un individu à la santé optimale, et dans ce cas les individus grandissent plus vite alors que les conditions nutritionnelles sont pauvres. Nous avons donc cherché à déterminer si ce qui semble être un avantage au stade larvaire pouvait se révéler délétère pour les stades suivants et avoir un effet néfaste sur les mouches adultes. Nous avons montré que L. plantarum est bénéfique pour D. melanogaster tout au long du cycle de vie de la mouche et permet l’émergence précoce d’adultes matures et fertiles sans impact négatif sur leur santé et leurs performances. De plus, dans certaines conditions, cette souche commensale entraîne une augmentation de la durée de vie de mâles nutritionnellement carencés.Des études plus larges analysant l’interaction de la drosophile avec plusieurs espèces bactériennes peuvent informer sur la dynamique d’un microbiote de mouche. En effet, au sein de la niche environnementale, les bactéries sont échangées entre l’animal et son substrat nutritif, et ces transferts réciproques pourraient altérer la composition de la communauté. Nous avons étudié cette question en utilisant un microbiote naturel, et avons observé un haut degré de similitude entre les bactéries associées avec les mouches et la composition de la communauté bactérienne de la nourriture, illustrant le caractère stable de l’association du microbiote de la drosophile avec la population de mouches au sien de la niche.Ces résultats illustrent le pouvoir du modèle drosophile pour l’étude des interactions entre les animaux et leur microbiote, qui permet de déchiffrer la dynamique des communautés de bactéries commensales ainsi que leur impact sur la physiologie animale. / In nature, symbiotic relationships are widespread, and of paramount ecological importance. Animals have appeared, evolved, and are now living constantly associated with a variety of microorganisms. In the spectrum of different symbioses types, the microbiota occupies a central and balanced part by establishing commensalistic or mutualistic relationships with its host. Over the last years, the microbiota has been extensively studied given the crucial role it plays in animal health and disease. In this research effort, Drosophila melanogaster represents a fruitful model, thanks to the ease to generate and maintain axenic flies, and the simplicity of re-associating them with a defined microbial community.The association of Drosophila with one of its natural commensals, Lactobacillus plantarum, revealed a growth-promoting effect mediated by this bacterial species. In case of nutrient scarcity, larvae associated with L. plantarum develop twice faster than the germ-free ones. However, adjusting development to environmental cues is key to organismal fitness, and yet here animals are growing fast even though the nutritional conditions are poor. We thus questioned whether what seems like an advantage could in turn be deleterious at later stages, and adversely impact adult fitness. We showed that L. plantarum is a true beneficial partner for D. melanogaster throughout the fly life cycle. Indeed, it allows the precocious emergence of mature and fertile adults without fitness drawbacks, and in certain conditions, this commensal can even increase the lifespan of nutritionally challenged males.Broader studies assessing the interaction of Drosophila with several bacterial species can inform about the dynamics of a fly microbiota. Indeed, in the environmental niche bacteria are transferred between the fly and its nutritive substrate, and these reciprocal transfers could alter the composition of the community. We addressed this question using a wild-derived microbial community and observed a high degree of similarity between the bacteria associated with the flies and the composition of the community in the diet, illustrating the stable association of the Drosophila microbiota with the fly population in the niche.Altogether these results emphasize the power of the Drosophila model in the study of the relationships between animals and their microbiota, which allows deciphering the dynamics of commensal bacterial communities and their impact on animal physiology.

La symbiose ectomycorhizienne associe les racines d’un arbre aux hyphes d’un champignon, conduisant à un échange réciproque de nutriments entre les deux partenaires. La colonisation fongique massive du cortex racinaire est caractérisée par la formation d’une interface symbiotique, le réseau de Hartig. L’acquisition du génome du symbionte ectomycorhizien Laccaria bicolor a permis d’identifier des petites protéines prédites sécrétées, les MiSSPs (Mycorrhiza-induced Small Secreted Proteins). Mon projet de thèse avait pour objectifs la comparaison des sécrétomes, notamment les petites protéines sécrétées (SSPs), de champignons ectomycorhiziens et saprotrophes, la localisation subcellulaire in planta et l’analyse fonctionnelle de MiSSPs de L. bicolor. L’analyse bioinformatique a notamment permis de révéler des clusters de SSPs conservées entre champignons ectomycorhiziens et saprotrophes ou spécifiques de champignons ectomycorhiziens, mettant en lumière que les champignons ectomycorhiziens partagent des SSPs avec leurs ancêtres saprotrophes mais possèdent aussi d’autres SSPs spécifiques à leur mode de vie. Un jeu de MiSSPs de L. bicolor ont été localisées in planta. Trois d’entre eux ciblent spécifiquement des compartiments subcellulaires de la cellule végétale. Le motif répété DWRR présent dans la séquence de MiSSP8 est partagé par une famille de protéine fongique de champignons majoritairement saprotrophes. Ces résultats suggèrent que l’utilisation de SSPs comme moyen de communication est générique chez les champignons et démontrent aussi qu’au moins une petite protéine sécrétée requise pour la symbiose de L. bicolor a évoluée à partir de protéines de champignons saprotrophes / Roots of most trees form ectomycorrhizal (ECM) symbiosis with mutualistic soil-borne fungi, relying on a bi-directional exchange of nutrients between the two partners. Fungal colonization of cortical root cells form the Hartig net, a symbiotic interface. Functioning of this symbiotic interface is not well known. However, Laccaria bicolor genome sequencing sheds the light on upregulated small-secreted proteins, so-called MiSSPs (Mycorrhiza-Small Secreted Proteins). Several L. bicolor MiSSPs were demonstrated as symbiosis effectors. My PhD project aims to compare secretomes, in particular SSPs, of fungal with different lifestyles and pursue functional analysis of MiSSPs of L. bicolor. Based on the clustering analysis, we identified clusters of SSPs shared between saprotrophic and ECM fungi and clusters of SSPs specific to ECM-fungi. This study highlights that ECM fungi share SSPs with their saprotrophic ancestors but also possess lifestyle specific SSPs. In planta subcellular localization of a set of MiSSPs belonging to a core-regulon showed that three of them are able to target different plant subcellular compartments. Functional analysis of the symbiosis effector MiSSP8 does not lead to the identification of a putative interactor but the repetitive motif DWRR of MiSSP8 protein sequence is unique to fungi and is shared with SSPs from saprotrophic ancestors. Our results suggest the use of SSPs as mean of communication is common and generic and show at least one SSPs required for ectomycorhizal symbiosis of L. bicolor has evolved from SSPs found in saprotrophic fungi

Mopane (Colophospermum mopane) trees are browsed upon by two key species, namely mopane caterpillars (Imbrasia belina) and African elephants (Loxodonta africana), which each inflict a different type of damage while feeding, namely defoliation (leaf removal) and pruning (branch and/or stem breakage). Damage type can have a significant influence on plant responses, and these induced changes in morphological and chemical characteristics of regrowth can influence the subsequent feeding behaviour by each species. The objective of this study was therefore partly to investigate the differential effect of defoliation by mopane caterpillars and pruning by elephants on mopane trees, and then to investigate whether these two taxonomically different species interact through their shared food resource, by looking specifically at the effect of elephant utilisation of mopane on mopane caterpillar abundance. To determine the comparative effect of each browsing type, mopane trees were subjected to simulated mopane caterpillar or elephant utilisation treatments, at various frequencies and times within the year. Regrowth characteristics were then measured on treatment and control trees, as well as on naturally utilised and unutilised trees. Reproductive investment was also recorded on naturally utilised and unutilised trees. Additionally, the impact of mopane caterpillar defoliation and elephant pruning on plant stress was investigated by measuring the level of fluctuating asymmetry (FA) in leaves. Then, to determine whether there is an interaction between elephants and mopane caterpillars, mopane caterpillar egg mass abundance in areas of high elephant impact was compared to that in areas of low elephant impact. Firstly, however, in areas without elephant damage, those tree characteristics determining host tree preference by ovipositing mopane moths were identified. From this, an understanding of how elephant utilisation may influence mopane caterpillar abundance could therefore be gained. Defoliation and pruning had a significant different effect on mopane regrowth responses. Shoot and leaf length were significantly longer on pruned trees than control trees, for both naturally utilised and simulated elephant treatment trees, while there was no difference in shoot density. Defoliation, however, resulted in shorter shoots and leaves, particularly on naturally defoliated trees, which also had leaves of a higher nutritional value (tannin:protein ratio and total polyphenolic content) than control trees. A similar increase in leaf nutritional value was recorded in areas of high elephant impact in the Kruger National Park, but not after simulated or natural elephant damage in Venetia, where natural elephant utilization was less intense. Time since damage (i.e. first versus second flush) had a significant influence on regrowth after pruning, as shoot and leaf length were significantly longer on trees flushing for the first time, while within-season timing of damage was important for defoliation, as late-season defoliation had a greater negative impact than mid-season defoliation. Late-season defoliation also had a negative effect on leaf carriage into the dry season, while pruning appeared to aid leaf retention. Reproductive investment was found to be unaffected by mopane caterpillar defoliation or elephant pruning, as mean pod density and pod mass on utilised trees was no different to unutilised trees. Defoliation also had no influence on a plant’s likelihood of flowering that same season, with flowering being determined more by tree height. Unlike pod production, however, mean leaf density was significantly reduced in the regrowth of defoliated trees, presumably due to the use of stored resources for reproduction prior to the onset of regrowth. Neither simulated nor natural defoliation by mopane caterpillars and pruning by elephants was found to affect the level of leaf FA in mopane trees, even though the degree of damage inflicted on trees was considerably higher than in studies on other species where increases in FA were observed. Mopane therefore appears to be extremely tolerant of herbivory in comparison to other species. A positive relationship between leaf nutritional value (higher protein and lower tannin and polyphenolic content) and FA was detected, but only when trees from all study areas (i.e. a wide range of environmental conditions) were considered simultaneously. Environmental conditions, rather than herbivory, therefore appear to have a greater stressing affect on mopane. In the absence of heavy elephant utilisation of mopane trees, tree size, rather than shoot length, leaf length, leaf FA or leaf nutritional value, was found to have the greatest influence on oviposition behaviour of mopane moths. Ovipositing moths showed a preference for the tall riverine habitat over the shorter woodland and scrub mopane. This preference for large trees was, however, not evident at the individual tree level, as even though egg mass number per tree was positively related to tree height, large trees were not utilised more than expected according to the available canopy volume in each size class (resource availability). Heavy elephant utilisation of mopane had a negative impact on the density of tall trees within an area, due to branch and stem breakage while feeding. Unsurprisingly then, mopane caterpillar egg mass abundance was also significantly reduced in these areas, even though the nutritional value of leaves was higher than in non-elephant impacted areas. Elephants therefore appear to have a negative effect on mopane caterpillar abundance, primarily due to their negative impact on the density of tall mopane trees. This megaherbivore and invertebrate do therefore interact through their shared food resource, mopane trees. / Thesis (PhD (Zoology))--University of Pretoria, 2007. / Zoology and Entomology / unrestricted