Requirement of succinate dehydrogenase activity for symbiotic bacteroid differentiation of Rhizobium meliloti in alfalfa nodules.
نویسندگان
چکیده
Transmission electron microscopy was used to study the cellular morphologies of a wild-type Rhizobium meliloti strain (L5-30), a nitrogen fixation-ineffective (Fix-) succinate dehydrogenase mutant (Sdh-) strain, and a Fix+ Sdh+ revertant strain within alfalfa nodules and after free-living growth in a minimal medium containing 27 mM mannitol plus 20 mM succinate. The results showed a requirement of succinate dehydrogenase activity for symbiotic differentiation and maintenance of R. meliloti bacteroids within alfalfa nodules and for succinate-induced cellular pleomorphism in free-living cultures. Also, the Sdh- strain had a 3.5-fold lower rate of oxygen consumption in the defined medium than did the wild type.
منابع مشابه
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Auxotrophic mutants of Rhizobium meliloti 104A14 were isolated using nitrous acid mutagenesis followed by penicillin enrichment. Mutants in ornithine transcarbamylase, argininosuccinate synthetase or serine-glycine biosynthesis formed nitrogen-fixing (Fix+) nodules on the roots of alfalfa (Medicago sativa). Mutants with defects in ornithine, pyrimidine, purine, asparagine, leucine, methionine o...
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ورودعنوان ژورنال:
- Applied and environmental microbiology
دوره 53 8 شماره
صفحات -
تاریخ انتشار 1987