Seasonal Changes in Primary Photosynthetic Events during Low Temperature Adaptation of Pinus sylvestris in Central Yakutia
| Autor: | V. E. Sofronova, O. V. Dymova, Taras K. Antal, T. K. Golovko |
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| Rok vydání: | 2018 |
| Předmět: |
0106 biological sciences
0301 basic medicine Quenching (fluorescence) Photosystem II food and beverages Plastoquinone Plant physiology macromolecular substances Plant Science Photosynthesis 01 natural sciences Zeaxanthin 03 medical and health sciences chemistry.chemical_compound 030104 developmental biology chemistry Chlorophyll Biophysics Chlorophyll fluorescence 010606 plant biology & botany |
| Zdroj: | Russian Journal of Plant Physiology. 65:658-666 |
| ISSN: | 1608-3407 1021-4437 |
| Popis: | The methods of chlorophyll fluorescence induction and HPLC were used to study the influence of autumnal temperature decrease on photochemical electron-transport activity of photosystem II (PSII), nonphotochemical quenching of excessive excitation energy, and the composition of pigments in the firstyear needles of Pinus sуlvestris L. trees grown naturally in Central Yakutia. In the period from the beginning of September to October 10, the chlorophyll content was reduced by half, while the Chl a/b ratio increased from 2.9 to 4.3–4.5, indicating the degradation of peripheral antenna complexes. The decrease in average daily temperature to 4.9–6.4°C led to a transient increase in the quantum yield of nonphotochemical quenching (ΔpH-dependent parameter φNPQ). These changes were accompanied by a slow accumulation of unregulated zeaxanthin fraction insensitive to illumination conditions. The further decrease in average daily temperature to near-zero levels was paralleled by a sharp increase in zeaxanthin content, while the pH-dependent quenching was replaced with the constitutive quenching (parameter φf,D) because of the supposed structural reorganization of PSII. These processes were accompanied by a fast decrease in PSII functional activity, which was mostly due to the impairment of plastoquinone photochemical reduction. Freezing temperatures (from–3.6 to–12.1) destructed the oxygen-evolving complex in PSII and completely inactivated the PSII reaction centers. It is concluded that the largest changes in the condition of photosynthetic apparatus occur at a near-zero temperature range and proceed until complete inactivation of PSII under the action of freezing temperatures. |
| Databáze: | OpenAIRE |
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