Effect of Sym Plasmid Curing on Symbiotic Effectiveness in Rhizobium fredii
| Autor: | Gerald H. Elkan, W. Mark Barbour, James N. Mathis |
|---|---|
| Rok vydání: | 1985 |
| Předmět: |
Ecology
biology Mutant EcoRI food and beverages Nitrogenase Nif gene biochemical phenomena metabolism and nutrition biology.organism_classification Applied Microbiology and Biotechnology Microbiology Restriction enzyme Plasmid biology.protein Rhizobium Microorganism-Plant Interactions Bacteria Food Science Biotechnology |
| Zdroj: | Applied and Environmental Microbiology. 49:1385-1388 |
| ISSN: | 1098-5336 0099-2240 |
| DOI: | 10.1128/aem.49.6.1385-1388.1985 |
| Popis: | A mutant, USDA 206C, of Rhizobium fredii USDA 206 was obtained by passage on acridine plates. This mutant was cured of its 197-megadalton Sym plasmid but retained its symbiotic effectiveness. Multiple plasmid and chromosomally borne nif gene copies have previously been shown in R. fredii USDA 206. Hin dIII and Eco RI restriction enzyme digests of plasmid and total DNA showed that at least two nif gene copies are probably missing in USDA 206C. To compare the symbiotic effectiveness of USDA 206 and USDA 206C, plant tests were carried out. Statistically significant differences were obtained for nodule number, nodule mass, nitrogenase activity per plant, nitrogenase specific activity, and total plant dry weight. There was an apparent correlation between loss of Sym plasmidborne nif gene copies and reduction of overall symbiotic effectiveness. Delayed nodulation by strain USDA 206C relative to strain USDA 206 also indicated an association with the loss of plasmidborne nodulation functions and the reduced symbiotic effectiveness of strain USDA 206C. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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