Addition of ribitol into Xanthoparmelia somloensis thallus alters photosynthetic processes in PS II of symbiotic alga at sub-zero temperature
| Authors | |
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| Year of publication | 2008 |
| Type | Article in Proceedings |
| Conference | Physiologia Plantarum. Special Issue: Redox Signal Integration. FESPB 2008 Abstracts |
| MU Faculty or unit | |
| Citation | |
| Web | http://www.fespb2008.org |
| Field | Botany |
| Keywords | polyols; cryoprotective role; low temperature; ribitol |
| Description | Ribitol and other polyols have a cryoprotective role in plants and lichens. We tested positive effects of extrenally added ribitol (32, 50 mM)on primary photochemical processes at low temperature (5, 0, and -5 deg C) in X. somloensis. After ribitol addition, thalli segments were exposed to 300 umol m-2 s-1 at the above temperatures for 168 h. Each 24 h, chlorophyll fl uorescence parameters (Fv/Fm, effective quantum yield of PS II - Yield PS II, non-photochemical quenching - NPQ) were measured by an imaging fl uorometer (HFC-010, P.S.I., CZ). Positive effect of ribitol on Fv/Fm and Yield PS II, was apparent only at -5 deg C. The significant effect was seen early, i.e. within the fi rst 24 h. The difference in Fv/Fm and Yield PS II between control and 32 mM treated thalli was seen throughout the whole exposition period. Surprisingly, 50 mM treatment led to a decrease in Fv/Fm and Yield PS II values at -5 deg C, while no change was seen at 0, 5 deg C. Such ribitol concentration was a considerable stressor to PS II which might be documented by dramatic increase in NPQ. Supported by the GAAV KJB601630808 funding. |
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