Made available in DSpace on 2014-06-11T19:29:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-02-11Bitstream added on 2014-06-13T19:18:11Z : No. of bitstreams: 1 garcia_mrl_me_ilha.pdf: 144818 bytes, checksum: c7bfc6080d6e547db543086dc0ce6516 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Vem sendo adotado no cerrado, cada vez mais, sistemas de manejos conservacionistas, como o plantio direto ou cultivo mínimo, que auxiliam na recuperação e na busca da sustentabilidade do agrossistema. Estes sistemas favorecem numerosos processos bioquímicos que ocorrem no solo devido à atividade microbiana, com efeitos sobre as propriedades físicas e químicas do solo e reflexos sobre o desenvolvimento das plantas, a produtividade agrícola e a qualidade do ambiente. Com isso, o objetivo deste trabalho foi quantificar o carbono da biomassa microbiana (CBM), o carbono do CO2 (C-CO2) liberado e a micorrização em função da calagem e do manejo do solo, em uma área de 20 anos de plantio direto, nas culturas de feijão (cultura de inverno) e milho (cultura de verão). O experimento foi conduzido na Fazenda de Ensino e Pesquisa da Faculdade de Engenharia, UNESP, Campus de Ilha Solteira, localizada no município de Selvíria-MS. O delineamento experimental utilizado foi o de blocos ao acaso, com parcelas subdivididas, constituídas de 2 tratamentos (principais), 2 doses de calcário e 4 repetições cada. Os tratamentos foram: T1 - Plantio direto - calcário na superfície, sem incorporação; e T2 - Cultivo Mínimo - incorporação de calcário com o escarificador; e as doses de calcários foram: D1 - Testemunha (sem calcário) e D2 - 2000 kg ha-1 de calcário. O solo foi reclassificado como LATOSSOLO VERMELHO distrófico. Após amostragem (de 0 - 0,10 m de profundidade), o solo foi seco, peneirado (2 mm) e enviado para análise das características químicas. O CBM foi avaliado pelo método de fumigação-extração e a atividade respiratória foi verificada pela quantificação do C-CO2 liberado. Para as avaliações da porcentagem de segmentos de raízes colonizadas por fungos micorrízicos arbusculares as raízes foram clareadas, acidificadas, coloridas com azul de... . / There is a steady increase in the employment of conservation management systems such as no-tillage or minimum-tillage in the Brazilian 'cerrado', which help in the recovery and maintenance of the agrosystem sustainability. These systems benefits several biochemical processes that take place in the soil due to microbial activity, which impact its physical and chemical properties and reflect on the development of plants, agricultural yield and the environment quality. The objective of this research was to quantify the microbial biomas-C, the C-CO2 evaluated and the mycorrhization in relation to limestone application and soil management, in a site under no-tillage for 20 years. The experiment was deployed at the Teaching and Research Farm (Selvíria, Mato Grosso do Sul State, Brazil) of the College of Engineering of Ilha Solteira, UNESP. The experimental design was a split plot, with two managements (main) and two levels of limestone, with four replications each. Treatments were T1 - No-tillage: surface limestone application, with no incorporation and T2 - Minimum-tillage: limestone incorporation with chisel plowing, while limestone levels were D1 - control (no limestone) and D2 - 2,000 kg ha-1 limestone. The soil was reclassified as a red 'latossol' (oxisol). After sampling the soil was dried, sieved (2 mm mesh) and analyzed for its chemical properties. The microbial biomass-C was estimated by the fumigation-extraction method and respiratory activity was estimated by the quantification of the C-CO2 evaluated. Roots were clarified, acidified, stained with 0.05 trypan blue and preserved in lactoglycerol in order to estimate the percentage of root colonization by arbuscular mycorrhizal fungi. The assessment of mycorrhizal colonization was performed in 40 segments (one cm long), for each replication and treatment, under a... (Complete abstract, click electronic address below).

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / A salinizaÃÃo dos solos tem se constituÃdo um problema sÃrio para a agricultura, principalmente nas regiÃes Ãridas e semi-Ãridas em todo o mundo. O excesso de sais no solo afeta tanto as Ãreas irrigadas como as nÃo irrigadas, limitando, portanto o crescimento e a produtividade das culturas. O presente trabalho teve por objetivo avaliar os efeitos da inoculaÃÃo com fungo micorrÃzico arbuscular e da adubaÃÃo orgÃnica no desenvolvimento do sabià (Mimosa caesalpiniaefolia Benth), sob estresse salino. Portanto, foi instalado um experimento em casa de vegetaÃÃo do Departamento de CiÃncias do Solo da Universidade Federal do CearÃ, no Campus do Pici em Fortaleza. O delineamento experimental adotado foi o inteiramente casualizado, em esquema fatorial, 2 (presenÃa e ausÃncia de fungos micorrÃzicos arbusculares) X 2 (presenÃa e ausÃncia de composto orgÃnico) X 5 nÃveis de condutividade elÃtrica da Ãgua de irrigaÃÃo (0,7, 1,2, 2,2, 3,2 e 4,2 dS m1), com 4 repetiÃÃes. Ao final de 60 dias apÃs a germinaÃÃo das plantas foi coletado o experimento, onde determinou-se os fatores de crescimento, as variÃveis microbiolÃgicas, o pH do solo apÃs o cultivo, os teores minerais (N, P, K, Ca, Mg, Na, Cl) e as relaÃÃes Raiz/Parte AÃrea (R/PA) e SÃdio/PotÃssio (Na/K). A salinidade promoveu maior reduÃÃo na produÃÃo de matÃria seca das plantas nÃo micorrizadas e nÃo adubadas. A inoculaÃÃo com fungo micorrÃzico arbuscular aumentou a produÃÃo de matÃria seca das plantas de sabiÃ. As plantas adubadas com matÃria orgÃnica apresentaram maior desenvolvimento, quando comparadas com as plantas nÃo adubadas. As plantas micorrizadas apresentaram maiores conteÃdos de nutrientes, quando comparadas com as plantas nÃo micorrizadas. / Salt affected soils management is an important subject to be studied, especially when irrigated arid and semi-arid regions are considered, as soil salt excess may limit growth and plant productivity. The objective of this dissertation was to evaluate the effect of mycorrhizal arbuscular fungi (AMF) inoculation on growth of sabià plants (Mimosa caesalpiniaefolia Benth.), cultivated under salt stress in the presence or absence of organic compost. Thus, an experiment was conducted under green-house conditions to evaluate the potential of inoculated and fertilized plant establishment submitted to salt stress, in a complete randomized factorial design 2 (inoculated or non-inoculated plants) X 2 (fertilized or non-fertilized with organic compost) X 5 levels of irrigation water electrical conductivity (0.7, 1.2, 2.2, 3.2 and 4.2 dS mâ), with 4 replications. After 60 days from germination, plants were harvested and then and analyzed to evaluate growth factors, microbiological variables, soil pH, shoot-root and sodium/potassium ratios and mineral nutrient content (N, P. Ca, Mg, Na and Cl). Salinity decreased growth and plant biomass of non-mycorrhizal fertilized plants. Inoculation with AMF increased plant dry matter production when compared with non-inoculated plants under salt stress. When compared with non-fertilized plants, organic compost fertilization increased plant growth, Nutrient contents were always much higher in inoculated plants and in organic compost fertilized plants.

A pesquisa sobre bactérias diazotróficas associadas à cultura do trigo tem demonstrado a necessidade de associar bactérias eficientes a genótipos responsivos ao nitrogênio, os quais mais se beneficiariam dessa associação. Em um experimento com parcelas subdivididas instalado em condições de campo, em Mococa (SP), empregando os tratamentos: 3 doses de N (0, 60 e 120 kg ha -1 ) x 3 genótipos de trigo (IAC-24, ITD-19 e IAC-355), foi avaliada a ocorrência de microrganismos diazotróficos endofíticos em raízes desinfestadas superficialmente, utilizando-se 3 meios de cultivo distintos, NFb, semi-específico para Azospirillum spp, JNFb, semi-específico para Herbaspirillum spp., e LGI-P, semi-específico Gluconacetobacter diazotrophicus. O genótipo IAC-355 apresentou a menor quantidade de bactérias diazotróficas endofíticas. Além disso, para este genótipo, houve um ajuste linear ascendente da quantidade de bactérias diazotróficas com o aumento na quantidade de N adicionada, o que comprova a influência do genótipo da planta na associação com essas bactérias. Nenhuma bactéria pertencente aos gêneros Azospirillum ou Herbaspirillum foi isolada do genótipo IAC-355. Nas condições estudadas, não foi identificado nenhum isolado de Gluconacetobacter diazotrophicus nas raízes do trigo. Foram obtidos 8 isolados do gênero Azospirillum e 12 do gênero Herbaspirillum. Esses isolados foram testados "in vitro", no genótipo do qual foram originalmente isolados. Todos os isolados testados no genótipo ITD-19 causaram maior crescimento radicular que a testemunha e apenas 1 isolado de Herbaspirillum sp. propiciou aumento significativo do teor de N na parte aérea. A colonização micorrízica no genótipo IAC-355 foi maior que nos demais genótipos independente da dose de N, comprovando a influência do genótipo na colonização. A colonização micorrízica se correlacionou com a massa da matéria seca, e com o teor e a quantidade acumulada de P e N na parte aérea, assim como com a produtividade. A atividade da biomassa microbiana foi alterada na ausência de N, obtendo-se correlação entre o qCO2 e a relação Cmic:Corg, indicando que na ausência de N, houve perdas de C no solo cultivado com o genótipo IAC-24, enquanto que na presença do IAC-355, houve maior eficiência na utilização do C do solo pelos microrganismos. Na contagem de bactérias nitrificadoras obteve-se um ajuste linear ascendente em relação à quantidade de N adicionada, provavelmente devido à maior disponibilidade de substrato. A quantidade de microrganismos nitrificadores se correlacionou com a massa da matéria seca, e com o teor e a quantidade acumulada de N na parte aérea, assim como com a produtividade. A interação FMA-bactéria diazotrófica não propiciou benefícios para cultura do trigo. A interação FMA-bactéria diazotrófica demonstrou ser bastante especifica. As plantas associadas a Glomus, quando em presença dos isolados bacterianos apresentaram maior crescimento, acúmulo e aproveitamento dos nutrientes. Confirmou-se que o fungo micorrízico realmente é um agente transmissor de bactérias diazotróficas endofíticas, sendo que Acaullospora causou maior colonização radicular. As plantas dos tratamentos em que somente a bactéria foi inoculada apresentaram o dobro da produção de matéria seca, da quantidade acumulada e do índice de eficiência de utilização de N e P na parte aérea em relação à testemunha. A especificidade da interação planta-bactéria diazotrófica associativa indica que é possível obter benefícios desta associação, explorando bactérias e cultivares locais. / The research on diazotrophic bacteria associated to wheat has demonstrated the need to associate efficient bacteria to N-responsive genotypes, which would be more benefited from this association. A field experiment was carried out in Mococa, state of São Paulo-Brazil, with 3 genotypes of wheat (IAC-24, ITD-19 and IAC-355) under 3 nitrogen doses (0, 60 e 120 kg ha -1 ). The occurrence of diazotrophic bacteria was evaluated in three media, namely, NFb semi-specific for Azospirillum spp., JNFb semi-specific for Herbaspirillum spp., and LGI-P semi-specific for Gluconacetobacter diazotrophicus, using surface-sterilized roots. Regardless the nitrogen dose, the population of diazotrophic bacteria established poorly in the genotype IAC-355, but the infection increased with the addition of nitrogen for the same genotype, proving the influence of the host genotype for its association with these bacteria. Azospirillum spp. or Herbaspirillum spp. could not be isolated from the surface-sterilized roots of IAC-355. In the field experiment G. diazotrophicus was not found in any of the wheat-genotype roots. It was obtained 12 Herbaspirillum spp. isolates and 8 Azospirillum spp isolates. These strains were tested under gnotobiotic conditions, using the genotype from which they had been originally isolated. Inoculated ITD-19 plants showed an increase in root length, even though, only one strain showed a significant increase on shoot N accumulation. In the genotype IAC-355 mycorrhizal colonization was higher, proving the influence of the plant genotype. Mycorrhizal colonization showed significant correlation to shoot dry matter, shoot N and shoot P concentration and accumulation, as well as to the grain yield. In the absence of added N, the activity of microbial biomass was affected. The correlation between the qCO2 and biomass C-to-N ratio, showed that in absence of N, soil-C loss under IAC-24 cultivation, but a greater efficiency in the use of the soil-C by the microorganisms under IAC-355 cultivation. The populations of nitrifying bacteria increased with N addition, probably due to the N-rich substrate availability. The nitrifying bacteria showed significant correlation to shoot dry matter, shoot N concentration and accumulation, as well as to grain yield. There was no benefit from the AMF-diazotrophic bacteria co-inoculation on wheat plants. The specificity of AMF-diazotrophic bacteria interaction was demonstrated, it was confirmed that AMF indeed is a transmitting agent of endophytic diazotrophic bacteria, Acaullospora caused higher endophytic-bacteria root colonization. Plants inoculated with single strain doubled shoot dry matter, shoot N and P concentration and accumulation as compared to the control. Plant-bacteria interaction specificity demonstrates the possibility of getting benefits from this association by exploring both bacterial strains and plant genotypes from the same location.

A espécie Araucaria angustifolia, pertencente ao fragilizado Bioma Mata Atlântica, foi, durante décadas, uma das maiores fontes de madeira no Brasil. Essa espécie é de grande importância sendo fonte de alimento e matéria prima para a produção de móveis, polpa de celulose e vernizes. Devido à grande importância econômica e ambiental da araucária, estudos voltados à preservação e manejo da espécie se tornaram necessários. Este trabalho teve como finalidade isolar actinobactérias, presentes na rizosfera de araucária, antagônicos aos fungos Fusarium sp .e Armillaria sp. Estes patógenos são responsáveis por danos às raízes e sementes causando podridão e perda de mudas. Além disso, verificou-se também o efeito das actinobactérias sobre a germinação de esporos de Gigaspora rosea. Após a seleção dos melhores inibidores, identificação morfológica e seqüenciamento do gene 16S rRNA, verificou-se o efeito destes sobre o crescimento de Pinus taeda, na presença e na ausência do fungo ectomicorrízico (Suillus brevipes). Os isolados ainda foram avaliados quanto à produção de enzimas como quitinase, lipase, fosfatase, celulase, amilase e protease. Para o isolamento foram coletadas raízes de 15 árvores adultas presentes na mata nativa. Dez gramas de raízes frescas com resíduos de solo aderidos firmemente foram agitados por 30 minutos em solução salina 0,85 % padronizando como solo rizosférico aquele que soltou das raízes. Neste isolamento foram utilizadas duas metodologias: por plaqueamento e por separação física pela utilização de membrana de 0,45 micrômetros. Foram obtidos 33 possíveis actinobactérias. Os isolados foram testados quanto à capacidade antagônica pelo método de contato direto, inoculando-os a 30 mm de distância do fungo fitopatogênico Fusarium sp., em placas de petri contendo meio ISP2. Os halos de inibição foram medidos após 3, 5, 7 e 10 dias. De todos os isolados testados 6 mantiveram a inibição por 10 dias com manutenção de halos de inibição de até 4 mm contra um Fusarium sp. isolado de sementes de milho e 2 foram eficientes na inibição de Fusarium sp, patógeno de Pinus sp. A análise de inibição do fungo Armillaria sp, foi feito em meio líquido medindo o crescimento em mg/dia após 30 dias na presença de extratos de actinobactérias e também pela contagem de rizomorfas em placa de petri após 20 dias de incubação em contato direto com as actinobactérias. Verificou-se que de 28 isolados testados 24 foram capazes de inibir a produção de rizomorfas, destacando-se o isolado A43 que foi capaz de inibir ambos os fungos, Fusarium e Armillaria. Os esporos de Gigaspora rosea tiveram a taxa de germinação avaliada na presença de actinobactérias a partir da técnica de dupla camada. Todos os seis isolados testados foram capazes de estimular a germinação dos esporos desse fungo micorrizico. Nenhum dos seis isolados (A43, A43b, PNA, A64, A75 e A93) foi capaz de produzir fosfatases e lipases. Porém os isolados A93, A75, A64 e PNA produziram protease, quitinase e amilase. Em casa de vegetação, foi testado o efeito de seis isolados, na presença e não ausência de ectomicorriza (Suillus brevipes), sobre plântulas de Pinus taeda. Analisou-se o diâmetro, a altura, a massa seca da raiz e da parte aérea e também o fósforo da parte aérea. Destaca-se o isolado A43 que, quando na ausência de ectomicorriza, estimulou o desenvolvimento da planta em relação ao controletambém sem ectomicorriza, provocando aumento de 100 % para massa seca da parte aérea e da raiz. Os resultados encontrados neste trabalho poderão levar ao desenvolvimento de novas tecnologias, visando à identificação de novos metabólitos e novas técnicas de manejo, voltados ao controle de doenças de plantas, especialmente as espécies arbóreas. / The tree Araucaria angustifolia, belonging to the endangered Atlantic Forest biome, for many decades was the source of Brazilian wood. This species is also very important in providing food and feed, as well as raw material for joinery, cellulose pulp and varnish. Due to the economic and environmental importance of A. angustifolia, research projects involving the preservation and management of this species are becoming more urgent and necessary. The aim of this work was to isolate Araucaria rhizosphere actinobacteria with antagonic effects against the plant pathogens Fusarium sp. and Armillaria sp. These fungi cause root rot and seed damage, with the consequent loss of seedlings. Moreover, the effect of these actinobacteria on Gigaspora rosea spore germination was studied. After the selection of the best pathogen inhibitors, we also tested the effect of these microorganisms on Pinus taeda growth, in the presence or absence of the ectomycorrhizal fungus Suillus brevipes. The production of protease, chitinase, lipase, phosphatase, cellulase and amylase of these bacteria in culture media was also investigated. For the isolation of rhizosphere bacteria, we collected roots of 15 adult trees in a native forest. Ten grams of fresh roots with soil residues adhered to the surface were shaken in 0,85 % salt solution for 30 minutes. Two techniques were used, the dilution plate method and the coverage of the medium, utilizing a 0,45 µm membrane to separate these filamentous bacteria. About 33 actinobacteria were isolated. After isolation the actinobacteria were tested against the plant pathogenic fungi Fusarium spp., utilizing dual culture techniques and ISP2 medium. The inhibition halo was measured after 3, 5, 7 and 10 days. Six of our isolates maintained an inhibition zone measuring at least 4 mm against Fusarium sp. isolated from corn seed and 2 mm against the Fusarium, which causes root root of Pine trees. For the inhibition test of Armillaria, in liquid medium with the addition of culture extracts of actinobacteria, the growth in mg/day was measured after thirty days growth, and the number of rizomorphs produced in culture dishes after twenty days in dual culture with the actinobacteria was counted. Six bacteria proved to be antagonistic (A43, A43b, A64, PNA, A93 e A75), and only one had no effect. Possibly the elevation of the pH value played also a role in this situation. About 24 of 28 isolates inhibited the rizomorph production, especially the isolate A43 that showed a double antagonism against Fusarium and Armillaria. The dual layer test was used to investigate the reaction of the arbuscular mycorrhizal fungus Gigaspora rosea spore germination to the presence of actinobacteria. All the six actinobacteria stimulated the germination, but the germ tube did not grow straight forward as in the control. This result may indicate a negative effect against this arbuscular mycorrhizal fungus. None of the six isolates tested (A43, A43b, PNA, A64, A75 and A93) produced phosphatases and lipases, but A93, A75, A64 and PNA produced protease, amylase and chitinase. Isolates A43 and A43b did not produce any of the enzymes tested. This fact suggests that there is production of an antibiotic acting against the pathogenic fungi. Pinus taeda seedlings were grown under green-house conditions. After three months the stem diameter, shoot height, root and shoot dry weight and shoot phosphorus content were evaluated. Plants with ectomycorrhiza presented a significant growth promotion in comparison with the nonmycorrhizal ones. Among the actinobacteria in the absence of mycorrhiza only the isolate A43 produced a 100% growth enhancement in comparison with the control plant without ectomycorrhiza. The results presented in this dissertation could lead to the development of new technologies and new management techniques, with regard to the control of plant diseases, especially in tree species.

En raison des activités anthropiques croissantes, de larges sites sont contaminés par les métaux lourds qui affectent les systèmes biologiques. La souche Oidiodendron maius Zn pourrait être un organisme intéressant dans un programme de bioremédiation étant à la fois un champignon mycorhizien éricoïde et une souche tolérante aux métaux lourds. Pour comprendre les mécanismes de la tolérance de cette souche, trois approches différentes ont été menées.La première approche a abouti à la génération de mutants du gène superoxyde dismutase 1 (OmSOD1). Il s'agit de la première délétion d'un gène par recombinaison homologue chez un champignon mycorhizien. Nous démontrons que l'absence d'OmSOD1 cause un déséquilibre dans l'homéostasie rédox et un changement dans le dialogue entre le champignon et sa plante hôte.La deuxième approche a été basée sur la complémentation fonctionnelle d'un mutant de levure en utilisant une banque d'ADNc d'O. maius. Nous décrivons les premiers transporteurs d'un champignon mycorhizien éricoïde capables de conférer la tolérance au Zn dans des levures. Deux gènes ont été isolés et nommés OmCDF et OmFET. L'expression hétérologue de ces deux gènes dans différents mutants de levure a permis de conférer la tolérance au Zn. De plus, OmCDF a également permis de conférer la tolérance au Co. Nos données suggérent que OmCDF est un transporteur de Zn responsable du transfert du Zn cytoplasmique vers le réticulum endoplasmique, tandis que l'expression d'OmFET pourrait neutraliser la toxicité engendrée par le Zn en augmentant le contenu du Fe dans la cellule. La troisième approche a concerné le criblage d'une collection de mutants aléatoires d'O. maius sur Zn, Cd et ménadione. Nous décrivons la caractérisation d'un mutant dans le gène nmr. Dans ce mutant, une diminution de la teneur en glutamine et asparagine, ainsi qu'une réduction de l'activité de la glutamine synthétase ont été enregistrées. Les liens possibles entre la tolérance au stress oxydatif et le métabolisme azoté sont discutés. / Due to increasing anthropogenic activities, large areas are highly contaminated by heavy metals which are affecting biological systems. Oidiodendron maius strain Zn could be an interesting organism in a bioremediation program being both an ericoid mycorrhizal fungus and a heavy metal-tolerant strain. To understand the mechanisms underlying the oxidative stress tolerance of this strain, three different approaches were used. The first approach allowed us to obtain superoxide dismutase 1 (SOD1) null mutants. The most important technical advance in this work was the first successful disruption of a gene by homologous recombination in a mycorrhizal fungus. We demonstrate that the lack of OmSOD may cause an imbalance in the redox homeostasis and an alteration in the delicate dialogue between the fungus and its host plant. The second approach was based on a yeast functional complementation screening using an O. maius cDNA library. In this work we report the first transporters of an ericoid mycorrhizal fungus capable of conferring Zn tolerance to yeast transformants. Two full-length cDNAs were isolated and named OmCDF and OmFET. The heterologous expression of these two genes in various yeast mutants conferred resistance to zinc. Additionally, OmCDF expression also conferred Co tolerance. We provide evidence that OmCDF functions as a Zn transporter responsible for relocating cytoplasmic Zn into the endoplasmic reticulum, whereas expression of OmFET could counteract Zn toxicity by increasing Fe content of cells. The third approach consisted in the screening of a collection of O. maius random-mutants on Zn, Cd and menadione. We report the characterization of an O. maius-mutant that carries a mutation in the nmr gene. In this mutant, a decrease of glutamine and asparagine pools, and a reduction of the activity of glutamine synthase were recorded. Possible links between the oxidative stress tolerance and the nitrogen metabolism are discussed.

Fundamental processes underpinning the biotransformation of coal by fungal biocatalysts have been intensively investigated, however, limited large-scale industrial applications using such systems have been reported. The un-anticipated sporadic growth of Cynodon dactylon on the surface of un-rehabilitated discard coal dumps has been noted and this was found to be coupled with the breakdown of coal into a humic soil-like material in the top 1.5 metres of the dumps. Extensive fungal growth was observed to be associated with the Cynodon dactylon root system and examination of plant roots indicated the presence of mycorrhizal fungi. Analysis of the Cynodon dactylon plant roots around which coal biotransformation was occurring confirmed the presence of arbuscular mycorrhizal colonisation with the species Glomus clarum, Paraglomus occultum, Gigaspora gigantea and Glomus mosseae identified to be associated with the plants. Further molecular characterisation of non-mycorrhizal rhizospheric fungi showed the presence of fungal species with coal-degrading capabilities that most likely played a role in the coal biotransformation observed. The discard coal dump environment was simulated in pot and column studies and coal biotransformation was reproduced, with this process enhanced by the addition of mycorrhizal and non-mycorrhizal rhizospheric fungal inocula to the environment. Mycorrhizal and non-mycorrhizal species in the inoculum were re-isolated from the simulated environment fulfilling a number of Koch’s postulates and indicating a causal role in the biotransformation of coal. An inversion of conventional mycorrhizal colonisation was demonstrated in this system with reduction in extraradicular presence and an increase in intracellular colonisation compared to soil controls. A descriptive model was formulated suggesting a two-part fungal system involving organic carbon and nutrient exchange between the plant, mycorrhizal fungi and non-mycorrhizal coal-degrading rhizospheric fungi ultimately resulting in the biotransformation of coal. The biotransformation observed was comparable to reports of “rock-eating fungi”. Results suggest that the biological degradation of coal in situ with the production of a soil-like substrate could provide a feasible method of discard coal dump rehabilitation as well as provide a humic-rich substrate that can be utilised in further industrial applications.

This study assessed the effect of an application of mycorrhizal fungi to stormwater filter media on urban bioswale soil and stormwater in an infiltration-based bioswale aged 20 years with established vegetation. The study tested the use of commercially available general purpose biotic soil blend PermaMatrix® BSP Foundation as a treatment to enhance Earthlite™ stormwater filter media amelioration of zinc, copper, and phosphorus in an ecologically engineered structure designed to collect and infiltrate urban stormwater runoff before it entered the nearby Willamette River. These results show that the application of PermaMatrix® BSP Foundation biotic soil amendment to Earthlite™ stormwater filter media contributed to the reduction of extractable zinc in bioswale soil (-24% and -26%), as compared to the control, which received a treatment of Earthlite™ stormwater filter media only, and experienced an increase in extractable zinc levels (23% and 39%). The results presented also show evidence that after establishment mycorrhizal treatment demonstrated lowered levels of phosphorus in bioswale soil (-41%) and stormwater (-100%), in contrast to the control, which had increased phosphorus levels. The treatment contributed to reductions between 67% and 100% in every metric detected in stormwater after an establishment period of 17 weeks, while the bioswale with no mycorrhizal treatment had increases between 50% and 117%. Treatment also appeared to enhance the reduction of ammonium and nitrates, while contributing to a greater increase in soil pH.

La symbiose à Rhizobia ainsi que la symbiose endomycorhizienne à arbuscules, présentes dans la rhizosphère, possèdent un intérêt agrobiologique et écologique majeur ; elles permettent aux plantes de croître naturellement sur un sol aride et peu fertile. Il a été démontré récemment que les signaux (facteurs « Myc ») impliqués dans la mise en place de la symbiose endomycorhizienne à arbuscules appartiennent à la famille des lipo-chitooligosaccharides. Une nouvelle synthèse du facteur de mycorhization [Myc-IV (C16:0, S)], le plus abondant et bioactif, a été effectuée en utilisant une stratégie de synthèse par blocs utilisant des méthodes robustes de glycosylation, le diméthyldioxirane pour l’ouverture oxydante régiosélective des acétals de benzylidène et l’emploi d’un thiol peu toxique et peu odorant pour former les donneurs thioglycosides. Étant donné la purification laborieuse par chromatographie sur gel de silice des oligosaccharides après les étapes de glycosylation, une nouvelle méthode utilisant des liquides ioniques supportés a été appliquée permettant de modifier les propriétés physico-chimiques des saccharides. Les produits sont purifiés par de simples lavages grâce à ce motif ionique présent en position anomérique. Le chitooligosaccharide (CO-IV), intermédiaire clef pour la synthèse de lipo-chiooligosaccharides non sulfatés d’intérêts ou de la TMG-chitotriomycin, a ainsi été obtenu. / Rhizobia symbiosis and arbuscular mycorrhiza symbiosis have an agrobiological and ecological interest because they allow plants to grow on aride and infertile soil. Recently, the symbiotic signals (« Myc factors ») were identified as a mixture of lipo-chitooligosaccharides (LCOs). The preparation of Myc factor [Myc-IV (C16:0, S)], the most abundant and bioactive, was carried out using a blockwise synthesis. Dimethyldioxirane for a regioselective oxidative cleavage of benzylidene acetals and an odorless and few toxic thiol to form thioglycoside donors were employed. To eliminate the laborious purifications of oligosaccharides by chromatography on silica gel after each glycosylation step, we developped an ionic liquid supported strategy. The ionic liquid part changes the physico-chimical properties of the expected product and we isolated the glycostructures by simple phase-extractions. The chitooligosaccharide (CO-IV), key intermediate for the synthesis of non-sulfated lipo-chitooligosaccharides or TMG-chitotriomycin, was obtained by this strategy.

Soybeans (Glycine max L. Merr.) are a symbiont of two beneficial associations: biological nitrogen fixation (BNF) with Bradyrhizobium japonicum, and arbuscular mycorrhizal fungi (AMF). Within the Northern Great Plains of the USA, iron deficiency chlorosis (IDC) of soybean is a yield-limiting factor. The effects of IDC on BNF and AMF are not well defined. This study was conducted to determine the effects of IDC on BNF and AMF. A laboratory study was performed to compare three methods of measuring ureide-N, a product of BNF in soybeans. Field studies in soybean were performed at three locations at eastern N011h Dakota. The experimental design was a factorial combination of three cultivars and three treatments. The three cultivars, in order of decreasing chlorosis susceptibility, were NuTech NT-0886, Roughrider Genetics RG 607, and Syngenta S01-C9 RR. The three treatments were control, Sorghum bicolor L. companion crop planted with the soybean seed, and FeEDDHA applied with the soybean seed. Chlorosis severity was the greatest and least for the NuTech and Syngenta cultivars, respectively. The FeEDDHA treatment decreased chlorosis severity. Ureide levels were abnormally high in plants severely stunted by JDC. The excess accumulation of ureides in IDC-stunted plants suggests that plant growth was reduced more than the rate of nitrogen fixation. The AMF population \vas at an adequate level at all locations and not affected by cultivar or treatment, in general. In the laboratory study, the Patterson et al. method had greater ureide concentrations due to the non-specific measuring of ammonium compounds compared to the Vogels and Van der Drift and Goos methods. / North Dakota Soybean Council

Seagrasses are the only group of submerged plants that are permanently growing in marine environment. They play an important role in the sea bottom ecosystem. Seagrasses are primary producers capable of accumulation and deposition of carbon. They influence water flow at the sea bottom and form symbioses with variety of organisms. Our knowledge of symbiotic interactions of seagrasses is still limited even though several studies of the topic have been carried out in recent years. Unlike most of terrestrial plants, seagrasses are generally considered as plants that do not form any specific associations with mycorrhizal or endophytic fungi. Surprisingly, we have discovered a novel fungal endophytic association in roots of Mediterranean endemic seagrass species Posidonia oceanica (L.) Delile. Morphology of this symbiotic fungi strongly resembles common symbiotic fungi of terrestrial plants, dark septate endophytes (DSE). We sampled roots of P. oceanica in large area of the Mediterranean from southeastern Spain to Albania and described range and taxonomical classification of the endophyte using microscopy, in vitro cultivation and molecular determination. Roots of P. oceanica in whole area of study are colonized by mere two endophytic fungal species. Over 90 % of the fungal symbionts belong to a single...