Features of chlorophyll fluorescence transients can be used to investigate low temperature induced effects on photosystem II of algal lichens from polar regions

• Published in: Czech Polar Reports
• Main Authors: Mishra, A. (Anamika), Hajek, J., Tuháčková, T., Barták, M., Mishra, K. (Kumud)
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2015
• Subjects: Rhizoplaca melanophtalma; Umbilicaria antarctica; Xanthoria elegans; temperature stress; Antarc*; Antarctic; Antarctica
• Online Access: https://doi.org/10.5817/CPR2015-1-10; http://hdl.handle.net/11104/0249694

Chlorophyll fluorescence is an effective tool for investigating characteristics of any photosynthesizing organisms and its responses due to different stressors. Here, we have studied a short-term temperature response on three Antarctic green algal lichen species: Umbilicaria antarctica, Xanthoria elegans, and Rhizoplaca melanophtalma. We measured slow chlorophyll fluorescence transients in these Antarctic lichen species during slowely cooling of thallus temperature from 20°C to 5, 0 and -5°C with 20 minute acclimation at each temperature. The measurements were supplemented with saturation pulses for the analysis of chlorophyll fluorescence parameters: maximum yield of PS II photochemistry (FV/FM), effective quantum yield of PS II photochemistry (ΦPSII) and quenching parameters. In response to decreasing thallus temperature, we observed species-specific changes in chlorophyll fluorescence parameters as well as in the shape of the chlorophyll fluorescence transients. We propose that species-specific changes in the slow phase of chlorophyll fluorescence transients can be potentially used as indicators of freezing stress in photosynthetic apparatus of lichen algal photobionts.