Induction of the homologous recombination system by hexavalent chromium in Rhizobium etli.

Induction of homologous recombination in Rhizobium etli to repair the DNA damage caused by hexavalent chromium (Cr) was evaluated. Mutants in recombination genes such as addA, recF, recA, ruvB, recG, and a double mutant ruvBrecG showed different sensitivity levels to Cr. As expected, the recA mutant showed the highest susceptibility, while complementation restored the Cr-resistant phenotype, similar to the wild-type strain.