The importance of recA mutant strains for the study of antifungal genes in Pseudomonas aureofaciens PA147-2.
Pseudomonas aureofaciens PA147-2 shows antifungal activity toward a variety of plant pathogenic fungi. We have been investigating the molecular mechanisms underlying the fungal inhibition, and during these studies it was observed that the use of pLAFR3-based cosmids for in trans complementation of mutants lacking antifungal activity is hindered by cosmid instability. It was hypothesised that the cosmid stability could be improved by inactivation of recA. The recA gene of PA147-2 was cloned and shown to complement recA mutants of E. coli, restoring RecA-dependent functions when expressed in trans. Two recA mutants of PA147-2 were constructed. Both of these mutants show sensitivity to DNA damage. Cosmid pPS2122 restores antifungal activity to a mutant by allele exchange, but is unstable in trans. The stability of pPS2122 is shown to be improved in a recA mutant of PA147-2 with respect to the wild type.
Silby
M W
MW
Department of Plant and Microbial Sciences, University of Canterbury, Christchurch, New Zealand.
Mahanty
H K
HK
D000898:Antibiosis / Q000235:genetics*; D000935:Antifungal Agents; D003360:Cosmids; D004249:DNA Damage; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D005658:Fungi / Q000502:physiology*; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D008741:Methyl Methanesulfonate / Q000494:pharmacology; D009154:Mutation; D011549:Pseudomonas / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D011938:Rec A Recombinases / Q000235:genetics* / Q000378:metabolism; D011995:Recombination, Genetic; D013014:SOS Response, Genetics; D014466:Ultraviolet Rays
D000935:Antifungal Agents; D008741:Methyl Methanesulfonate; D011938:Rec A Recombinases