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Rhizobium phaseoli cytochrome c ‐deficient mutant induces empty nodules on Phaseolus vulgaris L.
Author(s) -
Soberón Mario,
Aguilar Germán R.,
Sánchez Federico
Publication year - 1993
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1993.tb01212.x
Subject(s) - biology , mutant , phaseolus , rhizobium , biochemistry , cytochrome , strain (injury) , mutagenesis , wild type , electron transport complex iv , oxidase test , cytochrome c oxidase , cytochrome c , microbiology and biotechnology , mitochondrion , enzyme , botany , gene , anatomy
Summary A Rhizobium phaseoli cytochrome mutant, unable to oxidize N,N,N′,N′ ‐tetramethyl‐ p ‐phenylend(amine (TMPD), was isolated after Mu‐dl (Kan lac ) mutagenesis of the wild‐type strain CE‐3. Mutant strain CFN4202 had sixfold less haem‐ c but similar levels of b type, o and aa 3 cytochromes than the wild‐type strain. CFN402 strain also showed reduced NADH‐ and TMPD‐oxidase activity than the wild‐type strain. Succinate‐oxidase activities were very similar. Western blot experiments, using antiserum against bovine c 1 and c cytochromes, revealed that both proteins were present in CFN4202 membranes, suggesting a defect of haem binding to cytochrome c. Nodules formed by this strain in Phaseolus vulgaris did not contain bacteroids. These data suggest that the cytochrome c‐aa 3 chain or some other respiratory chain, containing c ‐type cytochromes in R. phaseoli , is essential for bacterial division during the early steps of the symbiotic interaction with the legume‐host.