Skip to main content
NCBI home page
Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1984 Apr;81(8):2369–2373. doi: 10.1073/pnas.81.8.2369

Effects of Cu deficiency on photosynthetic electron transport

Magdolna Droppa 1,*, Norman Terry 1,†, Gabor Horvath 1,*
PMCID: PMC345061  PMID: 16593455

Abstract

The role of copper (Cu) in photosynthetic electron transport was explored by using Cu deficiency in sugar beet as an experimental approach. Copper influenced electron transport at two sites in addition to plastocyanin. Under mild deficiency (0.84 nmol of Cu per cm2 of leaf area), electron transport between the two photosystems (PS) is inhibited but not electron transport within PS I or PS II measured separately. The chlorophyll/plastoquinone ratio was normal in Cu-deficient plants. However, the breakpoint in the Arrhenius plot of electron transport was shifted towards a higher temperature. It is concluded that Cu is necessary to maintain the appropriate membrane fluidity to ensure the mobility of plastoquinone molecules to transfer electrons between the two photosystems. Under severe deficiency (0.22 nmol of Cu per cm2 of leaf area) both PS II and PS I electron transports were inhibited and to the same extent. PS II electron transport activity could not be restored by adding artificial electron donors. Polypeptides with Mrs of 28,000 and 13,500 were missing in Cu-deficient chloroplast membranes. In PS II particles prepared from normal chloroplasts of spinach, 2 atoms of Cu per reaction center are present. We conclude that Cu influences PS II electron transport either directly, by participation in electron transfer as a constituent of an electron carrier, or indirectly, via the polypeptide composition of the membrane in the PS II complex.

Keywords: phase transition of membrane lipid, photosystem II

Full text

PDF
2369

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Aikazyan V. Ts, Nalbandyan R. M. Studies on plantacyanin. I. Distribution in the plant kingdom, subcellular localization and physicochemical properties. Biochim Biophys Acta. 1981 Feb 27;667(2):421–432. doi: 10.1016/0005-2795(81)90208-7. [DOI] [PubMed] [Google Scholar]
  2. Barr R., Crane F. L. Organization of Electron Transport in Photosystem II of Spinach Chloroplasts According to Chelator Inhibition Sites. Plant Physiol. 1976 Mar;57(3):450–453. doi: 10.1104/pp.57.3.450. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bennoun P., Joliot A. Etude de la photooxydation de l'hydroxylamine par les chloroplastes d'epinards. Biochim Biophys Acta. 1969 Sep 16;189(1):85–94. doi: 10.1016/0005-2728(69)90229-1. [DOI] [PubMed] [Google Scholar]
  4. Delepelaire P., Chua N. H. Lithium dodecyl sulfate/polyacrylamide gel electrophoresis of thylakoid membranes at 4 degrees C: Characterizations of two additional chlorophyll a-protein complexes. Proc Natl Acad Sci U S A. 1979 Jan;76(1):111–115. doi: 10.1073/pnas.76.1.111. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Gol'dfel'd M. G., Khalilov R. I. Lokalizatsiia medi v fotosinteticheskom apparate khloroplasta. Biofizika. 1979 Jul-Aug;24(4):762–764. [PubMed] [Google Scholar]
  6. KATOH S. A new copper protein from Chlorella ellisoidea. Nature. 1960 May 14;186:533–534. [PubMed] [Google Scholar]
  7. KATOH S., SUGA I., SHIRATORI I., TAKAMIYA A. Distribution of plastocyanin in plants, with special reference to its localization in chloroplasts. Arch Biochem Biophys. 1961 Jul;94:136–141. doi: 10.1016/0003-9861(61)90020-0. [DOI] [PubMed] [Google Scholar]
  8. Katoh S., San Pietro A. Inhibitory effect of salicylaldoxime on chloroplast photooxidation-reduction reactions. Biochem Biophys Res Commun. 1966 Sep 22;24(6):903–908. doi: 10.1016/0006-291x(66)90335-4. [DOI] [PubMed] [Google Scholar]
  9. Katoh S., Takamiya A. Restoration of NADP photoreducing activity of sonicated chloroplasts by plastocyanin. Biochim Biophys Acta. 1965 Apr 26;99(1):156–160. doi: 10.1016/s0926-6593(65)80014-5. [DOI] [PubMed] [Google Scholar]
  10. Markossian K. A., Aikazyan V. T., Nalbandyan R. M. Two copper-containing proteins from cucumber (Cucumis sativus). Biochim Biophys Acta. 1974 Jul 7;359(1):47–54. doi: 10.1016/0005-2795(74)90130-5. [DOI] [PubMed] [Google Scholar]
  11. Melis A., Brown J. S. Stoichiometry of system I and system II reaction centers and of plastoquinone in different photosynthetic membranes. Proc Natl Acad Sci U S A. 1980 Aug;77(8):4712–4716. doi: 10.1073/pnas.77.8.4712. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Murata N. Relationships between the Transition of the Physical Phase of Membrane Lipids and Photosynthetic Parameters in Anacystis nidulans and Lettuce and Spinach Chloroplasts. Plant Physiol. 1975 Oct;56(4):508–517. doi: 10.1104/pp.56.4.508. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Plesnicar M., Bendall D. S. The plastocyanin content of chloroplasts from some higher plants estimated by a sensitive enzymatic assay. Biochim Biophys Acta. 1970 Aug 4;216(1):192–199. doi: 10.1016/0005-2728(70)90170-2. [DOI] [PubMed] [Google Scholar]
  14. Renger G., Vater J., Witt H. T. Effect of salicylaldoxime on the complete electron transport system of photosynthesis and on the isolated reaction cycle II. Biochem Biophys Res Commun. 1967 Feb 21;26(4):477–480. doi: 10.1016/0006-291x(67)90572-4. [DOI] [PubMed] [Google Scholar]
  15. Terry N. Limiting Factors in Photosynthesis: I. USE OF IRON STRESS TO CONTROL PHOTOCHEMICAL CAPACITY IN VIVO. Plant Physiol. 1980 Jan;65(1):114–120. doi: 10.1104/pp.65.1.114. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Thorne S. W., Horvath G., Kahn A., Boardman N. K. Light-dependent absorption and selective scattering changes at 518 nm in chloroplast thylakoid membranes. Proc Natl Acad Sci U S A. 1975 Oct;72(10):3858–3862. doi: 10.1073/pnas.72.10.3858. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences

RESOURCES