Effect of UV-C radiation on transcription level of polyketide synthase gene (pksI) and photosystem II D1 protein gene (psbA) in Evernia prunastri

Abstract

The present work was to investigate the effects of UV-C radiation on pksI (polyketide synthase type 1 gene) and psbA (a gene for photosystem-II major D1 protein) relative gene transcription levels and glutathione reductase (GR) activity in lichen Evernia prunastri (L.) Ach. (Parmeliaceae). E. prunastri thalli were exposed to UV-C (254nm) radiation for 30, 60, 120 and 180 minutes. After treatments GR activity of samples were measured and we showed that GR activity increased for the first treatment (30 min) compared to control and then decreased to control levels for other treatments. Transcriptional analysis was performed with semi- quantitative reverse transcriptase PCR (RT-PCR) and these results were obtained: The pksI gene transcription levels decreased ~80% compared to control at 60 min UV-C treatment but then increased at 120 min UV-C treatment. Exposure to UV-C for 60 min decreased the transcript abundance of psbA ~60% compared to control. However, exposure to UV-C for 180 min increased psbA transcripts to control level again. Considered together with all data, we conclude that photosystem II D1 protein synthesis was not significantly changes by UV-C radiation and E. prunastri is tolerant to UV-C radiation for the time periods used. The mechanism of this tolerance could be related with polyketide content in this organism.