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Quantification of Cyclobutane Pyrimidine Dimers Induced by UVB Radiation in Conidia of the Fungi Aspergillus fumigatus , Aspergillus nidulan s, Metarhizium acridum and Metarhizium robertsii
Author(s) -
Nascimento Érika,
Da Silva Sergio H.,
Dos Reis Marques Everaldo,
Roberts Donald W.,
Braga Gilberto U. L.
Publication year - 2010
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.2010.00793.x
Subject(s) - conidium , pyrimidine dimer , aspergillus fumigatus , biology , germination , aspergillus nidulans , metarhizium , microbiology and biotechnology , botany , aspergillus , cyclobutane , dna damage , mutant , dna , chemistry , metarhizium anisopliae , biochemistry , ring (chemistry) , gene , organic chemistry
Conidia are responsible for reproduction, dispersal, environmental persistence and host infection of many fungal species. One of the main environmental factors that can kill and/or damage conidia is solar UV radiation. Cyclobutane pyrimidine dimers (CPD) are the major DNA photoproducts induced by UVB. We examined the conidial germination kinetics and the occurrence of CPD in DNA of conidia exposed to different doses of UVB radiation. Conidia of Aspergillus fumigatus , Aspergillus nidulans and Metarhizium acridum were exposed to UVB doses of 0.9, 1.8, 3.6 and 5.4 kJ m −2 . CPD were quantified using T4 endonuclease V and alkaline agarose gel electrophoresis. Most of the doses were sublethal for all three species. Exposures to UVB delayed conidial germination and the delays were directly related both to UVB doses and CPD frequencies. The frequencies of dimers also were linear and directly proportional to the UVB doses, but the CPD yields differed among species. We also evaluated the impact of conidial pigmentation on germination and CPD induction on Metarhizium robertsii . The frequency of dimers in an albino mutant was approximately 10 times higher than of its green wild‐type parent strain after exposure to a sublethal dose (1.8 kJ m −2 ) of UVB radiation.