ABSTRACT This work aimed to characterize 20 isolates obtained from upland rice plants, based on phenotypic (morphology, enzymatic activity, inorganic phosphate solubilization, carbon source use, antagonism), genotypic assays (16S rRNA sequencing) and plant growth promotion. Results showed a great morphological, metabolic and genetic variability among bacterial isolates. All isolates showed positive activity for catalase and protease enzymes and, 90% of the isolates showed positive activity for amylase, catalase and, nitrogenase. All isolates were able to metabolize sucrose and malic acid in contrast with mannitol, which was metabolized only by one isolate. For the other carbon sources, we observed a great variability in its use by the isolates. Most isolates showed antibiosis against Rhizoctonia solani (75%) and Sclerotinia sclerotiorum (55%) and, 50% of them showed antibiosis against both pathogens. Six isolates showed simultaneous ability of antibiosis, inorganic phosphate solubilization and protease activity. Based on phylogenetic analysis of the 16S rRNA gene all the isolates belong to Bacillus genus. Under greenhouse conditions, two isolates (S4 and S22) improved to about 24%, 25%, 30% and 31% the Total N, leaf area, shoot dry weight and root dry weight, respectively, of rice plants, indicating that they should be tested for this ability under field conditions.

- O objetivo deste trabalho foi determinar os perfis de proteína total e o conteúdo das quatro principais frações proteicas (albumina, globulina, prolamina e glutelina) e de aminoácidos no endosperma da espécie de arroz silvestre Oryza glumaepatula. O experimento foi realizado com 29 acessos dessa espécie, coletados em 13 locais no Brasil, e duas cultivares comerciais. Amostras de proteínas foram preparadas com grãos secos, polidos e moídos, para obtenção de uma farinha seca e homogênea, usada no preparo dos estratos. Acessos de O. glumaepatula foram identificados com os maiores níveis de proteína total, frações proteicas de albumina e glutelina, e aminoácidos (com exceção do triptofano), em comparação às duas cultivares de arroz avaliadas. Os perfis de albumina e glutelina em SDS-PAGE foram distintos entre as cultivares de arroz e O. glumaepatula. Essa espécie silvestre tem o potencial de aumentar a qualidade nutricional da proteína de reserva do arroz por meio de cruzamentos interespecíficos.

- The objective of this work was to determine the total protein profile and the contents of the four major protein fractions (albumin, globulin, prolamin and glutelin) and of the amino acids in the endosperm of the rice wild species Oryza glumaepatula. The experiment was performed with 29 accessions of this species, collected from 13 Brazilian locations, and two commercial cultivars. Protein samples were prepared using dried, polished, and ground grains to obtain homogeneous, dry flour used in the preparation of extracts. Oryza glumaepatula accessions were identified with the highest levels of total protein, albumin and glutelin protein fractions, and amino acids (with the exception of tryptophan) in comparison to the two analized rice cultivars. The albumin and glutelin profiles in SDS-Page were distinct between rice cultivars and O. glumaepatula. This wild species has the potential to increase the nutritional quality of rice storage protein through interspecific crosses.

O objetivo deste trabalho foi quantificar o conteúdo de proteína total de reserva dos 550 acessos da Coleção Nuclear de Arroz da Embrapa (CNAE), e avaliar o perfil proteico dos 20 acessos com maior teor de proteína em SDS-PAGE. Foi encontrado alto teor de proteína total de reserva (>12,0%) em 103 acessos da CNAE, teor médio (11,9 a 9,0%) em 309 acessos e teor baixo (<8,9%) em 138 acessos. Seis dos 20 acessos com maior teor de proteína de reserva apresentaram um padrão qualitativo diferencial de glutelina, que é a fração proteica de reserva mais abundante do grão de arroz. Há ampla variabilidade para o teor de proteína total de reserva do grão de arroz nos acessos da CNAE, a qual pode ser explorada por programas de melhoramento genético para aumentar o valor nutricional do arroz consumido no Brasil

The objective of this work was to quantify the total storage protein content of 550 accessions from Coleção Nuclear de Arroz da Embrapa (Embrapa Rice Core Collection - CNAE), and to evaluate the SDS-PAGE profile of the 20 accessions that showed the highest storage protein content. High storage protein content was found in 103 CNAE accessions (>12.0%), intermediate content (11.9 to 9.0%) in 309, and low protein content (<8.9%) in 138. Six out of the 20 accessions with the highest storage protein content showed a differential profile for glutelin, which is the most abundant rice storage protein fraction. There is a large variability of rice storage protein in CNAE accessions, which can be explored in breeding programs to increase the nutritional value of the rice consumed in Brazil