Publication details
REDOX STATE OF GLUTATHIONE DURING SHORT-TERM PHOTOINHIBITION AND RECOVERY IN FRUTICOSE AND FOLIOSE LICHEN SPECIES
| Authors | |
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| Year of publication | 2013 |
| Type | Appeared in Conference without Proceedings |
| MU Faculty or unit | |
| Citation | |
| Description | Lichens possess several antioxidative enzymes and substrates that help them to overcome negative effects of photoinhibition of photosyntesis. Among them, glutathione, its redox state respectively, represents one of the mechanisms exploited to cope with strong high light stress. Effects of medium light stress on glutathione, however, have not yet been investigated in lichens. In our study, we addressed a question whether or not glutathione content alters in lichens exposed to medium light stress. Wet thalli of Usnea antarctica, U. aurantiaco-atra, and Pseudocyphellaria sp. were exposed to 800 micromol.m-2.s-1 PAR for 1 h at 5 oC. After the exposition, lichens were provided 6 h recovery at 10 micromol.m-2.s-1. Thalli segments were taken during the exposition each 10 min, and after 10, 30, 60 and 360 min during recovery. Frozen, lyophylizied, powdered and homogenized samples were diluted in HCl and disulphidic groups reduced by DTT. Thiol groups were labeled by mBBr. Glutathione (GSH) was separated and quantified by a reverse-phase HPLC (Waters, USA) with fluorescence detector (Shimadzu RZ-535). In both Usnea species, GSH changed dynamically within the range of 35 – 105 nmol g-1 (DW). General trend was a GSH increase during the exposition, followed by a decrease and the second increase found after 60 min recovery. Contrastingly, GSH time course showed a decrease in light-treated Pseudocyphellaria sp. The changes in GSH might be attributed to light-dependent GSH synthesis/degradation. |