Effects of Mediterranean summer conditions on chlorophyll a fluorescence emission in the epiphytic lichen Flavoparmelia soredians: a field study
| Autor: | Mauro Tretiach, Laurence Baruffo, Massimo Piccotto |
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| Přispěvatelé: | Tretiach, Mauro, Baruffo, L., Piccotto, Massimo |
| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: |
Mediterranean climate
Chlorophyll a Photoinhibition Photosystem II photoinhibition desiccation Mediterranean drought nonphotochemical quenching poikilohydry Poikilohydry Plant Science Biology Thallus chemistry.chemical_compound chemistry Botany Epiphyte Lichen Ecology Evolution Behavior and Systematics |
| Popis: | Recent hypotheses suppose that dry lichens emit a faint chlorophyll a fluorescence because of a “long-wavelength quencher” embedded in the antenna complex that protects photosystem II (PSII) from photodamage. To verify in the field the PSII re-activation promptness induced by water availability, chlorophyll a fluorescence was measured on the epiphytic lichen Flavoparmelia soredians after two months without rainfall events in a Mediterranean cork oak wood (Bosco Santo Pietro, Sicily, Italy). Measurements were carried out at dawn and sunset on north- and south-exposed populations under different regimes of hydration and dark-adaptation. The results show that prolonged hydration increases the photochemical conveying of energy to PSII and decreases the non-photochemical energy dissipation that otherwise might occur in the antenna complex of the lichen photobionts. A slight decrease in PSII efficiency caused by photoinhibition was observed in thalli exposed to ambient light (up to 600 µmol photons m-2 s-1) only when kept fully hydrated. The results are discussed on the basis of our knowledge on the ecology of the species, that is a representative component of Mediterranean epiphytic lichen communities. |
| Databáze: | OpenAIRE |
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