The Effect of Low Temperature on Photosynthetic Processes in an Antarctic Lichen
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| Year of publication | 2018 |
| Type | Conference abstract |
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| Description | Physiological responses of autotrophic constituents of Antarctic vegetation oasis have met a great importance in respect to recent climate variability in the region of Antarctic Peninsula. In our study, we investigated the effects of low temperature and short-term photoinhibition at high and low thallus temperature, respectively, on the fast chlorophyll fluorescence transient (OJIP) and OJIP-derived photosynthetic parameters in foliose lichen Dermatocarpon polyphyllizum. The lichen thalli were collected at James Ross Island, Antarctica. In a laboratory, the samples were expossed to a gradually decreasing temperature (22, 18, 14, 12, 10, 7, 4, 0 and -5°C). The initial phase of the transient (O-J) caused by the reduction of the primary quinone acceptor (QA) was found temperature-dependent. The K-step was apparent for the samples measured at the temperature above 12°C, but not below 10°C in light-adapted lichen thalli. In photoinhibited samples, we used OJIPs, OJIP-derived parameters, and evaluated the effect of photoinhibition on samples with scraped and intact upper cortex of a lichen at 18°C (measured temperature optimum of D. polyphyllizum) and 4°C. In conclusion, OJIP is an useful tool to investigate temperature-dependent changes in photosystem II as well as the effect of photoinhibition and consequent recovery of photosynthesis in chlorolichen photobionts. The method thus might be used in thermal resistence studies. We thank to CzechPolar2 and ECOPOLARIS for funding. p.361 |
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