Protective effect of low UVA irradiation against the action of lethal UVA on Pseudomonas aeruginosa: Role of the relA gene

► Pre-exposure of Pseudomonas aeruginosa to low UVA doses protects against subsequent lethal UVA. ► The adaptive mechanism of photo-protection depends on the relA gene. ► Cross-protection between osmotic stress and UVA is reported.