Assembleia de microrganismos endofíticos de Echinodorus scaber Rataj (macrophyllus) e avaliação do seu potencial biotecnológico

Abstract

The plant-microorganism interactions are the most diverse possible, ranging from parasitic to symbiotic associations. Endophytes deserve special attention among these microorganisms because their relationships with the host may result in increasing the adaptability of plant populations in an ecosystem. These microorganisms have been shown to be important sources of prospecting special metabolites with different bioactive properties of interest of the pharmaceutical and agricultural tools and key in the development of biotechnological processes such as biological control of pathogens. Echinodorus scaber Rataj (macrophyllus) is a plant known for its medicinal and ornamental found in the wetlands of the Pantanal of Mato Grosso. Therefore, this work aims to: a) isolate and identify the assembly of endophytic microorganisms by culture-dependent method b) Determine and evaluate the interaction between fungi obtained from E. scaber with other hosts and c) evaluate the ability of antagonistic endophytes obtained against pathogenic microorganisms of medical and agronomic and biological control in grain d) Check functional traits important in promoting plant growth in bank endophytic bacterium E. scaber, e) Evaluate the inoculation of bacteria with functional traits in germination and development of soybean seedlings. A database was constructed from endophyte isolation dependent in medium potato agar with fragments of roots and stems. After 15 days of incubation, 113 and 46 strains of bacteria and fungi, respectively, were obtained from stems and roots of E. scaber. After identifying molecular bacteria showed greater richness of species in 10 genera and 25 different fungal taxa and 13 genera distributed in 19 taxa. The strains of fungi and FREIII FREII-ED1-ED2 were inoculated in aseptic culture medium in vitro. Host plants Vochysia divergens, V. haenkeana, Combretum lanceolatum e Capsicum frutensces contact FREII-ED1 and ED2-FREIII remained alive and did not develop

x symptoms or signs of disease. These two fungi internally colonized the root system of the species through their myelinated and septate hyphae, differentiating microesclérodio and therefore were defined as fungi like dark

septates. The sequencing of the ITS region of strains FREII-ED1 and FREIII- ED2 ranked them in Pestalotiopsis theae and Lophiostoma cynaroidis

respectively. The selection of endophytes antagonistic to pathogens was determined by comparison performed by dual culture technique. Nine microorganisms important agronomic and medical, five pathogenic fungi (Colletotrichum lindemunthianum, C. gloeosporioides, Corynespora cassiicula, Fusarium solani e Microsporum canis) and four pathogenic bacteria (Enterococcus faecalis, Staphylococcus aureus, S. saprophyticus and Escherichia coli) were the microorganisms pathogenic used. Moreover, grains of soybeans were microbiolized with endophytic bacteria with activity against all tested microorganisms. The obtained extract, ethyl acetate fraction, fungi antagonistic to pathogenic microorganisms all in order to evaluate the production of antifungal compounds. The bactericidal activity of the extracts was evaluated autobiography against E. faecalis, S. aureus, S. saprophyticus. Reviewed Sixty-two bacteria for the production of phytohormone IAA and solubilization of calcium phosphate. To test the plant growth promotion, soybean seeds were microbiolized seven bacterial strains producing IAA and solubilizing calcium phosphate. We evaluated the germination percentage, rate of emergence and seedling dry mass at 13 days after sowing. The organisms of interest were identified using molecular techniques by partial sequencing of the 16S for bacteria and fungus-ITS region of the rRNA gene. Two bacteria, identified as Bacillus demonstrate efficiency in controlling all pathogens evaluated, and demonstrated ability to control almost 100% the development of fungi in grains of soybean. Of the 47 fungal strains 10 were effective for inhibiting the mycelial growth of all pathogenic fungi. The antagonists were classified into five genera, namely: Corynespora, Cochliobolus, Penicillium, Chaetomium and Eupenicillium. Five pathogenic fungi antagonists have demonstrated an ability to inhibit the growth of pathogenic bacterial strains. The extracts of endophytes showed

xi inhibition against all tested microorganisms. All bacteria evaluated in vitro produced IAA and 47 solubilize calcium phosphate in vitro. The bacterial strains producing IAA and phosphate solubilizing were identified as belonging to the genus Enterobacter and Klebsiella. Soybean seeds inoculated with bacteria producing IAA and phosphate solubilizing calcium were not affected their germination, and four strains of endophytic bacteria demonstrate effective in promoting dry matter accumulation in soybean seedlings.