Enzymatic and non-enzymatic defense mechanisms against ultraviolet-B radiation in two Anabaena species

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• 作者：Garvita Singh^a ; ^b ; ^c ; Piyoosh K. Babele^a ; Rajeshwar P. Sinha^b ; ^{rpsinhabhu@gmail.com} ; ^{r.p.sinha@gmx.net} ; Madhu B. Tyagi^c ; Ashok Kumar^a
• 关键词：Ultraviolet-B (UV-B) radiation ; Anabaena species ; Antioxidative enzymes ; Mycosporine-like amino acids (MAAs)
• 刊名：Process Biochemistry
• 出版年：2013
• 出版时间：May-June, 2013
• 年：2013
• 卷：48
• 期：5-6
• 页码：796-802
• 全文大小：1832 K

文摘

Enzymatic and non-enzymatic defense strategies against ultraviolet-B radiation (UV-B, 280-315 nm) were studied in Anabaena doliolum and Anabaena strain L31, two of the most common strains of Indian cyanobacteria. Upon UV-B irradiation, both strains showed a 2-5-fold increase in antioxidative enzymes, such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POD), as compared to non-irradiated control cultures. These enzymes scavenge damaging reactive oxygen species (ROS), generated by UV-B radiation inside the cells. In addition, these organisms also synthesize mycosporine-like amino acids (MAAs) which are able to carry out UV-screening and/at the same time as UV-quenching. The identification and characterization of three types of MAAs from both Anabaena species were performed using absorption spectroscopy, high performance liquid chromatography (HPLC), electro spray ionization-mass spectrometry (ESI-MS), Fourier Transform Infrared (FTIR) spectroscopy and Nuclear Magnetic Resonance (NMR) spectroscopy. Shinorine was found to be the most common MAA in both Anabaena species while porphyra-334 and mycosporine-glycine were present only in A. doliolum. The results of the present investigation clearly demonstrate that both enzymatic and non-enzymatic defense mechanisms are being employed by A. doliolum and Anabaena strain L31 to counteract the damaging effects of UV-B radiation.