GENETIC BASIS OF COPPER RESISTANCE IN NEW ZEALAND STRAINS OF PSEUDOMONAS SYRINGAE

摘要

Strains of Pseudomonas syringae able to grow on minimal medium containing 500 mg/litre of copper sulphate were selected from a collection of streptomycin-resistant strains isolated in New Zealand. From one of these copper-resistant strains a 1.3 kb fragment of DNA was isolated by PCR using primers designed on genes reported to be associated with copper resistance. Sequencing of this fragment revealed that a 572 bp and a 275 bp portion had 98% and 95% similarity with ORF A of P. syringae pv. actinidiae, a gene that codes for copper resistance. Smaller portions of this 1.3 kb fragment were highly similar (89%- to 100%,) to portions of another gene involved in copper resistance (copk) from Pseudomonas syringae pv. tomato. Using this 1.3 kb fragment asa probe, homologous DNA was detected in eight other strains of P. syringae, which were all subsequently found to be resistant to copper.