Location: Plant Genetics ResearchTitle: Complete genome sequence of the broad-host-range strain Sinorhizobium fredii USDA257) Author
Submitted to: Journal of Bacteriology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/6/2012
Publication Date: 8/15/2012
Citation: Schuldes, J., Orbegoso, M.R., Schmeisser, C., Krishnan, H.B., Daniel, R., Streit, W.R. 2012. Complete genome sequence of the broad-host-range strain Sinorhizobium fredii USDA257. Journal of Bacteriology. 194(16):4483. Interpretive Summary: Sinorhizobium fredii USDA257, a soil-bacterium, forms nodules on the roots of primitive soybean plants. The nodules are specialized structures where atmospheric nitrogen is fixed by the bacterium, which in turn, is utilized by soybean plants for growth and development. This process is termed biological nitrogen fixation and it enables soybean plants to grow in nitrogen-poor soils. The legume-rhizobia association is highly specific, such that each rhizobial strain establishes a symbiosis with only a limited set of host plants and vice versa. Despite recent advances in our understanding of the nodulation pathway, the host control of nodulation specificity remains poorly understood. The complete genome sequence of USDA257 therefore will significantly increase our knowledge on molecular mechanisms involved in the determination of host range in the interaction of plants with microbes. In this study we have elucidated the complete genome sequence of USDA257. Such information is required for designing strategies targeted toward improving biological nitrogen fixation. Information obtained from the genome sequence of USDA257 will help to better understand the factors that limit the formation of nitrogen-fixing nodules on North American soybean cultivars. Such an understanding should enable scientists to manipulate biological nitrogen fixation so that farmers can increase the soybean yields with minimal use of nitrogen fertilizers
Technical Abstract: Here we announce the complete genome sequence of the symbiotic and nitrogen fixing bacterium Sinorhizobium fredii USDA257. The genome shares a high degree of similarity with the closely related broad-host-range strains S. fredii NGR234 and HH103. Most striking, the USDA257 genome encodes for a wealth of secretory systems.