title: High-frequency induction of nodulation and nitrogen fixation mutants of Rhizobium japonicum.
abstract: More than 50 symbiotic mutants of Rhizobium japonicum were isolated by purported plasmid-curing techniques. Wild-type R. japonicum strains were grown in liquid culture at 28 or 36 degrees C in different concentrations of acridine orange, ethidium bromide, or sodium dodecyl sulfate for selection of mutants. The symbiotic traits of 133 isolates from nine treatment groups were determined. Forty-two isolates were Nod- Nif+, seven were Nod+ Nif-, and two were Nod- Nif-. The nifDH genes were deleted in three mutants and consequently showed no hybridization to a nifDH probe. None of these mutants showed any detectable loss of plasmid DNA.
mesh_terms: D000165:Acridine Orange / Q000633:toxicity; D004996:Ethidium / Q000633:toxicity; D005233:Fatty Alcohols / Q000633:toxicity; D009154:Mutation; D009586:Nitrogen Fixation; D018521:Plant Physiological Phenomena; D012231:Rhizobium / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D012967:Sodium Dodecyl Sulfate
chemical_list: D005233:Fatty Alcohols; D012967:Sodium Dodecyl Sulfate; C028913:dodecyl sulfate; D004996:Ethidium; D000165:Acridine Orange