SYNCHROTRON ANALYSIS IN NODULES OF TRIPARTITE SYMBIOSIS

• Autor(a) principal: Soraya Marx Bamberg
• Data de Publicação: 2020
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: eng
• Título da fonte: Repositório Institucional da UFLA
• Texto Completo: http://repositorio.ufla.br/jspui/handle/1/45104; http://sip.prg.ufla.br/arquivos/php/bibliotecas/repositorio/download_documento/20201_201721144

Soil symbiosis relationships are extremely important to the planet functioning, since they contribute to the cycle of chemical elements and promote benefits among live being. Plants of the Leguminosae family can symbiotically associate with nodulating nitrogen-fixing bacteria (NNFB) and arbuscular mycorrhizal fungi (AMF), simultaneously, culminating in an interaction called tripartite symbiosis. Several benefits have been described about tripartite symbiosis, with emphasis on the root extension of AMF provide to legumes, which in turn acquire nutrients with greater efficiency and expand the area for nodule formation by NNFB. Many authors report tripartite symbiosis evolving to a more specific interaction, developing a direct contact (face to face) between microorganisms, that is, fungal structures that colonize the nodular tissue, however, without absolute confirmation. The synchrotron light is a technology able to research into nano and micrometric materials and analyzing the structures present in microorganisms. Through the X-ray microtomography line of synchrotron laboratory, it is possible to scan a microorganism, without changing its structure, generating images in three dimensions. The aim of this study was check the singularities and gaps in the C.emicromorphological investigations of nodules performed by tripartite symbioses. The experiment was carried out in a greenhouse at the Soil Science Department pots of 5 kg capacity with soil filled up, using plants of soybean (Glycine Max (L.) Merrill) and Lima bean (Phaseolus lunatus L.), singly. The NNFB Bradyrhizobium japonicum was inoculated and for each culture respectively, also was inoculated the following AMF treatments Without Mycorrhizal fungi Claroideoglomus etunicatum Dentiscutata heterogama Acaulospora morrowiae Claroideoglomus etunicatum Dentiscutata heterogama Claroideoglomus etunicatum Acaulospora morrowiae Dentiscutata heterogama Acaulospora morrowiae and Claroideoglomus etunicatum Dentiscutata heterogama Acaulospora morrowiae for each culture. After three months, nodules, roots and shoot were harvest to proceed the dry mass weight. Mycorrhizal colonization was also accessed and during the harvest ten nodules of each plant were immediately and carefully helded to nitrogenase enzyme analysis by the acetylene reduction method. The IMX analyses were carried out in Campinas, SP at Brazilian Synchrotron Light Laboratory. Statistical analyses were performed in SISVAR software and the images nodules were obtained through AVIZO and PARAVIEW. The results showed the treatments C.etunicatum, C.. etunicatum D. heterogama and the mix provided significant increases in dry mass weight of soybean plants, as well as the treatments C.etunicatum D.heterogama, C.etunicatum A. morrowiae and the mix provided the same benefit for lima-bean plants. All evaluated treatments roots were highly colonized with averages greater than 60 to both plant species. The nodules weight evaluated indicated in soybean plants only one superior treatment, the C. etunicatum D. heterogama, reaching 0.2 g and differing significantly from the other treatments. The Lima-bean nodules weight obtained in the treatments C.etunicatum, D. heterogama and in the mix the highest averages. Almost all the nodules submitted to nitrogenase enzyme analysis showed ethylene measurements, indicating the nitrogenase activity. The Lima-bean nodules were very small and could not reach ethylene measurements to all treatments. The uninoculated soybean nodules treatment presented the highest nitrogenase activity followed by D.heterogama and A. morrowiae treatments, and for Lima-bean nodules, D.heterogama had the greatest values followed by D.heterogama A. morrowiae treatments. Tripartite symbiosis was not so efficient for soybean plants. The IMX synchrotron analyses allowed observed a complete soybean nodule structure and verify the bacteroids inside then. We conclude the IMX beamline is satisfactory for morphological identification of structures on legume nodules There is not mycorrhizal colonization in an active soybean nodule Mycorrhizal colonization in soybean nodule reduces the efficiency of biological N2 fixation under nutritional stress of P and N.