Figure 6. Introduction of the phr gene cluster from the shallow bathytype 3TCK into the deep bathytype SS9 confers UV resistance.

This phenotype is not observed in the deletion construct that lacks the upstream hypothetical protein and rpoX gene (pFL304). The UV resistance phenotype can be partially restored by re-adding to pFL304 the promoter region of the cluster (pFL305) but is completely restored only when both the promoter and the rpoX sigma factor are added (pFL306). The absence of P3TCK_10668 (Hypothetical Protein) does not affect UV sensitivity. The UV survival plots present the ratio of c.f.u. observed after UV exposure followed by blue-light photoreactivation (red) compared to the non-photoreactivated controls (blue) as described in the materials and methods.