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. 1995 Nov;7(11):1933–1940. doi: 10.1105/tpc.7.11.1933

Two NADPH:Protochlorophyllide Oxidoreductases in Barley: Evidence for the Selective Disappearance of PORA during the Light-Induced Greening of Etiolated Seedlings.

S Reinbothe 1, C Reinbothe 1, H Holtorf 1, K Apel 1
PMCID: PMC161051  PMID: 12242364

Abstract

Chlorophyll synthesis in barley is controlled by two different light-dependent NADPH:protochlorophyllide oxidoreductases, termed PORA and PORB. PORA is present abundantly in etioplasts but selectively disappears soon after the beginning of illumination. This negative light effect is mediated simultaneously at three different levels. First, the concentration of porA mRNA declines drastically during illumination of dark-grown seedlings. Second, the plastids' ability to import the precursor of PORA (pPORA) is reduced during the transition from etioplasts to chloroplasts. This effect is due to a rapid decline in the plastidic level of protochlorophyllide (Pchlide), which is required for the translocation of the pPORA. Third, PORA becomes selectively destabilized in illuminated seedlings. When illuminated, PORA-Pchlide-NADPH complexes formed in the dark photoreduce their Pchlide to Chlide and become simultaneously susceptible to attack by plastid proteases. The PORA-degrading protease activity is not detectable in etioplasts but is induced during illumination. In contrast to PORA, the second Pchlide-reducing enzyme, PORB, remains operative in both illuminated and green plants. Its translocation into plastids does not depend on its substrate, Pchlide.

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Selected References

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  1. Apel K., Santel H. J., Redlinger T. E., Falk H. The protochlorophyllide holochrome of barley (Hordeum vulgare L.). Isolation and characterization of the NADPH:protochlorophyllide oxidoreductase. Eur J Biochem. 1980 Oct;111(1):251–258. doi: 10.1111/j.1432-1033.1980.tb06100.x. [DOI] [PubMed] [Google Scholar]
  2. Apel K. The protochlorophyllide holochrome of barley (Hordeum vulgare L.). Phytochrome-induced decrease of translatable mRNA coding for the NADPH: protochlorophyllide oxidoreductase. Eur J Biochem. 1981 Nov;120(1):89–93. doi: 10.1111/j.1432-1033.1981.tb05673.x. [DOI] [PubMed] [Google Scholar]
  3. Cline K., Werner-Washburne M., Andrews J., Keegstra K. Thermolysin is a suitable protease for probing the surface of intact pea chloroplasts. Plant Physiol. 1984 Jul;75(3):675–678. doi: 10.1104/pp.75.3.675. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Della-Cioppa G., Bauer S. C., Klein B. K., Shah D. M., Fraley R. T., Kishore G. M. Translocation of the precursor of 5-enolpyruvylshikimate-3-phosphate synthase into chloroplasts of higher plants in vitro. Proc Natl Acad Sci U S A. 1986 Sep;83(18):6873–6877. doi: 10.1073/pnas.83.18.6873. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Franck F., Strzalka K. Detection of the photoactive protochlorophyllide-protein complex in the light during the greening of barley. FEBS Lett. 1992 Aug 31;309(1):73–77. doi: 10.1016/0014-5793(92)80742-y. [DOI] [PubMed] [Google Scholar]
  6. Griffiths W. T. Reconstitution of chlorophyllide formation by isolated etioplast membranes. Biochem J. 1978 Sep 15;174(3):681–692. doi: 10.1042/bj1740681. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Grossman A. R., Bartlett S. G., Schmidt G. W., Mullet J. E., Chua N. H. Optimal conditions for post-translational uptake of proteins by isolated chloroplasts. In vitro synthesis and transport of plastocyanin, ferredoxin-NADP+ oxidoreductase, and fructose-1,6-bisphosphatase. J Biol Chem. 1982 Feb 10;257(3):1558–1563. [PubMed] [Google Scholar]
  8. Joyard J., Block M. A., Douce R. Molecular aspects of plastid envelope biochemistry. Eur J Biochem. 1991 Aug 1;199(3):489–509. doi: 10.1111/j.1432-1033.1991.tb16148.x. [DOI] [PubMed] [Google Scholar]
  9. Joyard J., Block M., Pineau B., Albrieux C., Douce R. Envelope membranes from mature spinach chloroplasts contain a NADPH:protochlorophyllide reductase on the cytosolic side of the outer membrane. J Biol Chem. 1990 Dec 15;265(35):21820–21827. [PubMed] [Google Scholar]
  10. Krieg P. A., Melton D. A. Functional messenger RNAs are produced by SP6 in vitro transcription of cloned cDNAs. Nucleic Acids Res. 1984 Sep 25;12(18):7057–7070. doi: 10.1093/nar/12.18.7057. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
  12. Li H. M., Moore T., Keegstra K. Targeting of proteins to the outer envelope membrane uses a different pathway than transport into chloroplasts. Plant Cell. 1991 Jul;3(7):709–717. doi: 10.1105/tpc.3.7.709. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Mapleston R. E., Griffiths W. T. Light modulation of the activity of protochlorophyllide reductase. Biochem J. 1980 Jul 1;189(1):125–133. doi: 10.1042/bj1890125. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Reinbothe S., Reinbothe C., Runge S., Apel K. Enzymatic product formation impairs both the chloroplast receptor-binding function as well as translocation competence of the NADPH: protochlorophyllide oxidoreductase, a nuclear-encoded plastid precursor protein. J Cell Biol. 1995 Apr;129(2):299–308. doi: 10.1083/jcb.129.2.299. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Reinbothe S., Runge S., Reinbothe C., van Cleve B., Apel K. Substrate-dependent transport of the NADPH:protochlorophyllide oxidoreductase into isolated plastids. Plant Cell. 1995 Feb;7(2):161–172. doi: 10.1105/tpc.7.2.161. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Santel H. J., Apel K. The protochlorophyllide holochrome of barley (Hordeum vulgare L.). The effect of light on the NADPH:protochlorophyllide oxidoreductase. Eur J Biochem. 1981 Nov;120(1):95–103. doi: 10.1111/j.1432-1033.1981.tb05674.x. [DOI] [PubMed] [Google Scholar]
  17. Schulz R., Steinmüller K., Klaas M., Forreiter C., Rasmussen S., Hiller C., Apel K. Nucleotide sequence of a cDNA coding for the NADPH-protochlorophyllide oxidoreductase (PCR) of barley (Hordeum vulgare L.) and its expression in Escherichia coli. Mol Gen Genet. 1989 Jun;217(2-3):355–361. doi: 10.1007/BF02464904. [DOI] [PubMed] [Google Scholar]

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