Advertisement

Multiple Short Term Effects of UV-B Radiation on the Diatom Phaeodactylum Tricornutum

  • Heiko Mewes
  • Michael Richter
  • Reimund Goss
  • Christian Wilhelm
Chapter

Abstract

Increases in UV-B irradiance lead to many specific damaging effects upon the plants including damage of the thylakoid membrane, partial inhibition of PS II, decrease of chloroplast ATPase activity, loss of enzyme activities in the calvin cycle and alterations in pigment synthesis (1). Under natural conditions enhanced UV-B light is always accompanied by high intensities of photosynthetic active radiation (PAR). Damaging effects due to photoinhibitory PAR and UV-B light which lead to several oxygen radical species (2) could be reduced by photoprotection mechanisms. One of these protection mechanisms is the xanthophyll cycle. In higher plants and green algae violaxanthin is converted to zeaxanthin in the violaxanthin cycle under strong light, whereas diatoms are able to form diatoxanthin from diadinoxanthin via the diadinoxanthin cycle (3). The deepoxidised xanthophylls diatoxanthin and zeaxanthin seem to be able to convert PS II from a light harvesting state to a state where excess excitation energy is effectively dissipated as heat. This protection cycle against high light could be a potential UV-B target. The deepoxidation of diadinoxanthin is carried out by the membrane bound diadinoxanthin deepoxidase which is activated by lumen acidification and requires ascorbate as a cosubstrate. Diatoxanthin epoxidase catalyses the back reaction and is bound to the stromal side of the thylakoid membrane.

Key words

light stress photoinhibition xanthophyll cycle carotenoids microalgae diatoms 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Jordan BR (1996) Advances in Botanical Research Vol. 22: 97–161CrossRefGoogle Scholar
  2. 2.
    Asada K and Takahashi M (1987) Elsevier Science Publishers B.V., Biomedical Division: 227–228Google Scholar
  3. 3.
    Young AJ and Frank HA (1996) J Photochem Photobiol B: Biology 36: 3–15CrossRefPubMedGoogle Scholar
  4. 4.
    Mann JE and Myers J (1986) J Phycol 4: 349–355CrossRefGoogle Scholar
  5. 5.
    Kraay W, Zapata M and Velcihius MJW (1992) J Phycol 28: 708–712CrossRefGoogle Scholar
  6. 6.
    Wilhelm C, Volkmar C, Becker A and Meyer M (1995) J Water SRT-Aqua 44: 132–141Google Scholar
  7. 7.
    Zhang J, Henkow L, Jordan BR and Strid A (1994) Biochim Biophys Acta 1185: 295–302CrossRefGoogle Scholar
  8. 8.
    Vu CV, Allen LHJ and Garrard LA (1981) Physiol Plant 55: 11–16CrossRefGoogle Scholar
  9. 9.
    Strid A, Chow WS and Anderson JM (1994) Photosynth Res 39: 475–489CrossRefPubMedGoogle Scholar
  10. 10.
    Goericke R and Welschmeyer A (1991) J Phycol 28: 507–517CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 1998

Authors and Affiliations

  • Heiko Mewes
    • 1
  • Michael Richter
    • 1
  • Reimund Goss
    • 2
  • Christian Wilhelm
    • 2
  1. 1.Institut für Allgemeine BotanikJohannes Gutenberg-Universität MainzMainzGermany
  2. 2.Institut für Allgemeine BotanikUniversität LeipzigLeipzigGermany

Personalised recommendations