Conjugation in Pseudomonas syringae pv. actinidiae (Psa)
Copper-resistant field isolates of the kiwifruit pathogen Pseudomonas syringae pv. actinidiae biovar 3 (Psa3) have been identified in New Zealand. These isolates invariably carry large novel genetic elements, such as plasmids or integrative conjugative elements (ICEs), acquired by horizontal transfer from non-Psa3 species of bacteria already present in New Zealand. Here, we have determined whether these acquired elements are both necessary and sufficient to produce the observed copper-resistant phenotype. Methods were developed to transfer the ~100,000-bp ICEs and large (>100,000 bp) plasmids from the copper-resistant isolates to a sensitive recipient strain using natural conjugation. The ICEs or plasmids imparted the identical copper-resistance phenotype of the donor strains, showing that these elements were necessary and sufficient to confer copper resistance.
Zhao, M., Butler, M., Taiaroa, G. and Poulter, R. (2018). Conjugation in Pseudomonas syringae pv. actinidiae (Psa). Acta Hortic. 1218, 327-332
copper resistance, bacterial canker of kiwifruit, conjugation