Adaptive responses of mature giant chloroplasts in the deep-shade lycopod Selaginella erythropus to prolonged light and dark periods.

Autor: Ghaffar R; Core Facility Cell Imaging and Ultrastructure Research, University of Vienna, Althanstrasse 14, A-1090, Vienna, Austria.; Department of Botany, University of the Punjab, Quaid-e-Azam Campus, Lahore, 54590, Pakistan., Weidinger M; Core Facility Cell Imaging and Ultrastructure Research, University of Vienna, Althanstrasse 14, A-1090, Vienna, Austria., Mähnert B; Department of Limnology and Bio-Oceanography, University of Vienna, Althanstrasse 14, A-1090, Vienna, Austria., Schagerl M; Department of Limnology and Bio-Oceanography, University of Vienna, Althanstrasse 14, A-1090, Vienna, Austria., Lichtscheidl I; Core Facility Cell Imaging and Ultrastructure Research, University of Vienna, Althanstrasse 14, A-1090, Vienna, Austria.
Jazyk: angličtina
Zdroj: Plant, cell & environment [Plant Cell Environ] 2018 Aug; Vol. 41 (8), pp. 1791-1805. Date of Electronic Publication: 2018 Apr 19.
DOI: 10.1111/pce.13181
Abstrakt: Deep-shade plants have adapted to low-light conditions by varying morphology and physiology of cells and chloroplasts, but it still remains unclear, if prolonged periods of high-light or darkness induce additional modifications in chloroplasts' anatomy and pigment patterns. We studied giant chloroplasts (bizonoplasts) of the deep-shade lycopod Selaginella erythropus in epidermal cells of mature fully developed microphylls and subjected them to prolonged darkness and high-light conditions. Chloroplast size and ultrastructure were investigated by light and electron microscopy. Physiological traits were studied by pigment analyses, photosynthetic performance of photosystem II, and formation of reactive oxygen species. Results show that (a) thylakoid patterns and shape of mature bizonoplasts vary in response to light and dark conditions. (b) Prolonged darkness induces transitory formation of prolamellar bodies, which so far have not been described in mature chloroplasts. (c) Photosynthetic activity is linked to structural responses of chloroplasts. (d) Photosystem II is less active in the upper zone of bizonoplasts and more efficient in the grana region. (e) Formation of reactive oxygen species reflects the stress level caused by high-light. We conclude that during prolonged darkness, chlorophyll persists and even increases; prolamellar bodies form de novo in mature chloroplasts; bizonoplasts have spatial heterogeneity of photosynthetic performance.
(© 2018 The Authors Plant, Cell & Environment Published by John Wiley & Sons Ltd.)
Databáze: MEDLINE
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