Planta

, Volume 180, Issue 4, pp 582–589

Differences in the capacity for radiationless energy dissipation in the photochemical apparatus of green and blue-green algal lichens associated with differences in carotenoid composition

Authors

  • Barbara Demmig-Adams
    • Institut für Botanik und Pharmazeutische BiologieUniversität Würzburg
  • William W. AdamsIII
    • Institut für Botanik und Pharmazeutische BiologieUniversität Würzburg
  • Franz-C. Czygan
    • Institut für Botanik und Pharmazeutische BiologieUniversität Würzburg
  • Ulrich Schreiber
    • Institut für Botanik und Pharmazeutische BiologieUniversität Würzburg
  • Otto L. Lange
    • Institut für Botanik und Pharmazeutische BiologieUniversität Würzburg
Article

DOI: 10.1007/BF02411457

Cite this article as:
Demmig-Adams, B., Adams, W.W., Czygan, F. et al. Planta (1990) 180: 582. doi:10.1007/BF02411457

Abstract

Green algal lichens, which were able to form zeaxanthin rapidly via the de-epoxidation of violaxanthin, exhibited a high capacity to dissipate excess excitation energy nonradiatively in the antenna chlorophyll as indicated by the development of strong nonphotochemical quenching of chlorophyll fluorescence (FM, the maximum yield of fluorescence induced by pulses of saturating light) and, to a lesser extent, FO (the yield of instantaneous fluorescence). Blue-green algal lichens which did not contain any zeaxanthin were incapable of such radiationless energy dissipation and were unable to maintain the acceptor of photosystem II in a low reduction state upon exposure to excessive photon flux densities (PFD). Furthermore, following treatment of the thalli with an inhibitor of the violaxanthin de-epoxidase, dithiothreitol, the response of green algal lichens to light became very similar to that of the blue-green algal lichens. Conversely, blue-green algal lichens which had accumulated some zeaxanthin following long-term exposure to higher PFDs exhibited a response to light which was intermediate between that of zeaxanthin-free blue-green algal lichens and zeaxanthin-containing green algal lichens. Zeaxanthin can apparently be formed in blue-green algal lichens (which lack the xanthophyll epoxides, i.e. violaxanthin and antheraxanthin) as part of the normal biosynthetic pathway which leads to a variety of oxygenated derivatives of β-carotene during exposure to high light over several days. We conclude that the pronounced difference in the capacity for photoprotective energy dissipation in the antenna chlorophyll between (zeaxanthin-containing0 green algal lichens and (zeaxanthin-free) blue-green algal lichens is related to the presence or absence of zeaxanthin, and that this difference can explain the greater susceptibility to high-light stress in lichens with blue-green phycobionts.

Key words

CarotenoidsChlorophyll fluorescenceChlorophytaCyanobacteriaEnergy dissipationLichensLight stressPhotoinhibition in phycobiontsPhycobiontZeaxanthin

Abbreviations and symbols

DTT

dithiothreitol

FO

yield of instantaneous fluorescence

FM

maximum yield of fluorescence induced by pulses of saturating light

Fv

variable yield of fluorescence

PFD

photon flux density (400–700 nm)

PSII

photosystem II

Q

electron acceptor of PSII

qNP

quenching coefficient for nonphotochemical fluorescence quenching

qP (or 1-qP)

quenching coefficient for photochemical fluorescence quenching

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Copyright information

© Springer-Verlag 1990