Photosynthesis Research

, Volume 16, Issue 3, pp 233–242 | Cite as

Effects of temperature and photosynthetic inhibitors on light activation of C4-phosphoenolpyruvate carboxylase

  • Y. Samaras
  • Y. Manetas
  • N. A. Gavalas
Regular Papers


Phosphoenolpyruvate carboxylase from leaves of the C4 plant Setaria verticillata (L.) Beauv. is activated by light; day levels of activity are reached after 30 minutes of illumination. Photoactivation is prevented by inhibitors of photosynthetic electron flow or of photophosphorylation and by D,L-glyceraldehyde, which inhibits the reductive pentose phosphate pathway.

Although the extractable activity in the dark is not affected by temperature the photoactivation is prevented when both illumination and extraction are done under low temperature (5 C). High temperature (30 C) during either illumination or extraction is needed for activation. Once the enzyme is photoactivated at 30 C, a transfer of the leaves to 5 C does not abolish the extra activity.

The results suggest that both unimpaired electron flow and photophosphorylation are prerequisites for the activation of phosphoenolpyruvate carboxylase. Low temperature apparently suppresses either the transport to the cytoplasm of a photosynthetic intermediate or the activating reaction itself. The inclusion of phosphoenolpyruvate in the extraction medium increases the night activity.

On the basis of the available information, it is suggested that phosphoenolpyruvate could be the activator in vivo. In that case, the activation of phosphoenolpyruvate carboxylase would depend on internal CO2 level and prior photoactivation of both pyruvate, orthophosphate, dikinase and NADP malate dehydrogenase.

Key words

light activation PEPCase photosynthetic inhibitors Setaria verticillata (L.) Beauv. temperature 



phosphoenolpyruvate carboxylase




photosynthetically active radiation


carbonyl cyanide m-chlorophenylhydrazone


3-(3, 4-dichlorophenyl)-1, 1-dimethylurea






malic enzyme


malate dehydrogenase


pyruvate, Pi dikinase


Crassulacean Acid Metabolism


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Anderson LE (1986) Light/dark modulation of enzyme activity in plants. In: Callow JA (ed.) Advances in Botanical Research, Vol 12, pp. 1–46. London: Academic PressGoogle Scholar
  2. Bamberger ES and Avron M (1975) Site of action of inhibitors of carbon dioxide assimilation by whole lettuce chloroplasts. Plant Physiol 56: 481–485Google Scholar
  3. Budde RJA and Chollet R (1986) In vitro phosphorylation of maize leaf phosphoenolpyruvate carboxylase. Plant Physiol 83: 1107–1114Google Scholar
  4. Gavalas NA, Caravatas S and Manetas Y (1982) Factors affecting a fast and reversible inactivation of photosynthetic phosphoenolpyruvate carboxylase. Photosynthetica 16: 49–58Google Scholar
  5. Hattersley PW and Watson L (1976) C4 grasses: an anatomical criterion for distinguishing between NADP-malic enzyme species and PCK or NAD-malic enzyme species. Aust J Bot 24: 297–308Google Scholar
  6. Huber SC and Sugiyama T (1986) Changes in sensitivity to effectors of maize leaf phosphoen-olpyruvate carboxylase during light/dark transitions. Plant Physiol 81: 674–677Google Scholar
  7. Iglesias AA and Andreo CS (1984) On the molecular mechanism of maize phospoenolpyruvate carboxylase activity by thiol compounds. Plant Physiol 75: 983–987Google Scholar
  8. Iglesias AA and Andreo CS (1984) Involvement of thiol groups in the activity of phosphoen-olpyruvate carboxylase from maize leaves. Photosynth Res 5: 215–226Google Scholar
  9. Izawa S (1977) Inhibitors of electron transport. In: Trebst A and Avron M (eds) Encyclopedia of Plant Physiology, Vol 5, pp. 266–282. Berlin: Springer-VerlagGoogle Scholar
  10. Karabourniotis G, Manetas Y and Gavalas NA (1983) Photoregulation of phosphoenolpyruvate carboxylase in Salsola soda L. and other C4 plants. Plant Physiol 73: 735–739Google Scholar
  11. Karabourniotis G, Manetas Y and Gavalas NA (1985) Detecting photoactivation of phosphoenolpyruvate carboxylase in C4 plants: an effect of pH. Plant Physiol 77: 300–302Google Scholar
  12. Manetas Y and Gavalas NA (1982) Evidence for essential sulphydryl group(s) in photosynthetic phosphoenolpyruvate carboxylase: protection by substrate, metal-substrate and glucose-6-phosphate against p-chloromercuribenzoate inhibition. Photosynthetica 16: 59–66Google Scholar
  13. Nakamoto H and Edwards GE (1986) Light activation of pyruvate, Pi dikinase and NADP-malate dehydrogenase in mesophyll protoplasts of maize. Plant Physiol 82: 312–315Google Scholar
  14. Nimmo GA, McNaughton GAL, Fewson CA, Wilkins MB and Nimmo HG (1987). Changes in the kinetic properties and phosphorylation state of phosphoenolpyruvate carboxylase in Zea mays leaves in response to light and dark. FEBS Lett 213: 18–22Google Scholar
  15. Rathnam CKM and Edwards GE (1977) C4 acid decarboxylation and CO2 donation to photosynthesis in bundle sheath strands and chloroplasts from species representing three groups of C4 plants. Arch Biochem Biophys 182: 1–13Google Scholar
  16. Stiborova M and Leblova S (1983) The role of cysteine SH groups in the phosphoenolpyruvate carboxylase molecule of maize. Physiol Veg 21: 935–942Google Scholar
  17. Stokes DM and Walker DA (1972) Photosynthesis by isolated chloroplasts. Inhibition by DL-glyceraldehyde of carbon dioxide assimilation. Biochem J 128: 1147–1157Google Scholar
  18. Usuda H (1987) Changes in levels of intermediates of C4 cycle and reduction pentose phosphate pathway under various light intensities in maize leaves. Plant Physiol 84: 549–554Google Scholar
  19. Walker GH, Ku MSB and Edwards GE (1986) Catalytic activity of maize leaf phosphoenolpyruvate carboxylase in relation to oligomerization. Plant Physiol 80: 848–855Google Scholar

Copyright information

© Kluwer Academic Publishers 1988

Authors and Affiliations

  • Y. Samaras
    • 1
  • Y. Manetas
    • 1
  • N. A. Gavalas
    • 1
  1. 1.Laboratory of Plant Physiology, Department of BiologyUniversity of PatrasPatrasGreece

Personalised recommendations