| Congresso Brasileiro de Microbiologia 2023 | Resumo: 923-2 | ||||
Resumo:The plant microbiome, a complex ecosystem composed of various bacterial species, has gained prominence due to its direct influence on plant growth, development, and survival. Known as Plant Growth-Promoting Bacteria (PGPB), they play a crucial role in these processes, acting in various plant organs in highly complex ways. The interaction and dynamics of the microbiome are affected by biotic and abiotic factors, which, in turn, influence crucial processes for plants, such as molecule uptake, phytopathogen control, and increased tolerance to environmental stresses. Understanding the composition of the microbiome becomes essential to optimize productivity in the forestry sector, which contributed to an increase of 244.6 billion in the Brazilian economy in 2021, mainly through the use of the Eucalyptus genus as a plant material. With the advancement of modern molecular techniques, it is possible to analyze the dynamics of the endophytic community more comprehensively, even allowing the prediction of an organism's ability to promote plant growth. Consequently, research is intensifying to expand knowledge about these microorganisms and their application in agriculture. This study aims to expand knowledge of the composition of the root and rhizosphere soil microbiome of Eucalyptus and explore the distribution of bacterial communities found in Eucalyptus located in different regions of Brazil. To achieve this, we conducted massive sequencing of the gene encoding the 16S rRNA subunit, from DNA extracted from 63 root samples and 47 rhizosphere soil samples of healthy Eucalyptus trees. These trees were selected with ages equal to or greater than 2 years and 6 months, from the states of Bahia, Minas Gerais, and São Paulo, Brazil. The results showed that the samples from Eucalyptus roots differed from those found in the rhizosphere soil. Of the three states studied, the samples taken from Bahia showed greater dissimilarity when compared to samples from São Paulo and Minas Gerais. Additionally, root samples from Bahia also exhibited lower diversity compared to the other states. In both roots and soil, the most commonly found phyla were Actinobacteria, Proteobacteria, and Firmicutes (52% and 39%, 36% and 29%, and 5% and 9%, respectively). At the order level, Actinomycetales and Rhizobiales were the most abundant orders in the samples (20% and 9%, and 6% and 9%, respectively). As for the genus, Actinospica was predominant in root samples (7.4%), but this pattern was not repeated in soil samples (0.9%). Bacillus, a genus widely used in agriculture, was also found in the samples, but it was more predominant in the rhizosphere soil (4.9%) than in the root environment (1%). Ralstonia, a genus known as a phytopathogen, was also found but only in root samples (0.3%). These research efforts not only provide valuable information about the ecology and bacterial interactions in plants but also pave the way for the development of more efficient and sustainable solutions for agriculture. Understanding PGPB and their application in sustainable agriculture are essential steps towards more responsible agricultural production in harmony with the environment. Palavras-chave: Endophytic bacteria, Actinospica, Ralstonia, Bacillus, Bacterial composition Agência de fomento:Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPQ) | |||||