title: Endurance of the endolithic desert cyanobacterium Chroococcidiopsis under UVC radiation.
abstract: Desert cyanobacteria of the genus Chroococcidiopsis are extremely resistant to desiccation and ionizing radiation. When an endolithic strain was exposed to UVC radiation cell lysis, genome damage, photosynthetic pigment bleaching and reduced photochemical performance occurred. Nevertheless, survivors were scored after UVC doses as high as 13 kJ/m(2) and their endurance ascribed to multicellular aggregates enveloped in thick envelopes, so that attenuated UVC radiation reached the inner cells. In addition, the accumulation of carotenoids contributed to UVC resistance by providing protection against oxidative stress. Finally, in survivors repair mechanisms were responsible for the recovery of the induced damage to genome and photosynthetic apparatus.
authors.affiliation: Department of Biology, University of Rome Tor Vergata, Via Della Ricerca Scientifica snc, 00133, Rome, Italy.
authors.forename: Mickael
authors.initials: M
authors.lastname: Baqué
authors.forename: Emanuela
authors.initials: E
authors.lastname: Viaggiu
authors.forename: Giuliano
authors.initials: G
authors.lastname: Scalzi
authors.forename: Daniela
authors.initials: D
authors.lastname: Billi
mesh_terms: D002338:Carotenoids / Q000378:metabolism; D000458:Cyanobacteria / Q000502:physiology*; D003889:Desert Climate; D018384:Oxidative Stress / Q000528:radiation effects*; D010788:Photosynthesis / Q000528:radiation effects*; D011836:Radiation Tolerance / Q000502:physiology* / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D002338:Carotenoids