Adjustments to Photosystem Stoichiometry and Electron Transfer Proteins Are Key to the Remarkably Fast Growth of the Cyanobacterium Synechococcus elongatus UTEX 2973.

Item request has been placed! ×
Item request cannot be made. ×
loading   Processing Request
Read More Add to Saved list
  • Additional Information
    • Source:
      Publisher: American Society for Microbiology Country of Publication: United States NLM ID: 101519231 Publication Model: Electronic Cited Medium: Internet ISSN: 2150-7511 (Electronic) NLM ISO Abbreviation: mBio Subsets: MEDLINE
    • Publication Information:
      Original Publication: Washington, D.C. : American Society for Microbiology
    • Subject Terms:
      Gene Expression Regulation, Bacterial*; Electron Transport Chain Complex Proteins/*metabolism ; Photosynthetic Reaction Center Complex Proteins/*metabolism ; Synechococcus/*growth & development ; Synechococcus/*metabolism; Electron Transport ; Oxidation-Reduction
    • Abstract:
      At the genome level, Synechococcus elongatus UTEX 2973 ( Synechococcus 2973) is nearly identical to the model cyanobacterium Synechococcus elongatus PCC 7942 ( Synechococcus 7942) with only 55 single nucleotide differences separating the two strains. Despite the high similarity between the two strains, Synechococcus 2973 grows three times faster, accumulates significantly more glycogen, is tolerant to extremely high light intensities, and displays higher photosynthetic rates. The high homology between the two strains provides a unique opportunity to examine the factors that lead to increased photosynthetic rates. We compared the photophysiology of the two strains and determined the differences in Synechococcus 2973 that lead to increased photosynthetic rates and the concomitant increase in biomass production. In this study, we identified inefficiencies in the electron transport chain of Synechococcus 7942 that have been alleviated in Synechococcus 2973. Photosystem II (PSII) capacity is the same in both strains. However, Synechococcus 2973 exhibits a 1.6-fold increase in PSI content, a 1.5-fold increase in cytochrome b 6 f content, and a 2.4-fold increase in plastocyanin content on a per cell basis. The increased content of electron carriers allows a higher flux of electrons through the photosynthetic electron transport chain, while the increased PSI content provides more oxidizing power to maintain upstream carriers ready to accept electrons. These changes serve to increase the photosynthetic efficiency of Synechococcus 2973, the fastest growing cyanobacterium known. IMPORTANCE As the global population increases, the amount of arable land continues to decrease. To prevent a looming food crisis, crop productivity per acre must increase. A promising target for improving crop productivity is increasing the photosynthetic rates in crop plants. Cyanobacteria serve as models for higher plant photosynthetic systems and are an important test bed for improvements in photosynthetic productivity. In this study, we identified key factors that lead to improved photosynthetic efficiency and increased production of biomass of a cyanobacterium. We suggest that the findings presented herein will give direction to improvements that may be made in other photosynthetic organisms to improve photosynthetic efficiency.
      (Copyright © 2018 Ungerer et al.)
    • References:
      Photosynth Res. 2014 Nov;122(2):121-58. (PMID: 25119687)
      IUBMB Life. 1999 Dec;48(6):625-30. (PMID: 10683768)
      Front Bioeng Biotechnol. 2015 Jan 20;3:1. (PMID: 25654078)
      Sci Rep. 2015 Jan 30;5:8132. (PMID: 25633131)
      Plant Physiol. 1993 Nov;103(3):893-902. (PMID: 8022940)
      Biochemistry. 2002 Jun 25;41(25):8004-12. (PMID: 12069591)
      Nature. 2011 May 5;473(7345):55-60. (PMID: 21499260)
      J Biol Chem. 1995 Dec 8;270(49):29342-9. (PMID: 7493968)
      J Biol Chem. 2001 Jun 29;276(26):23450-5. (PMID: 11297562)
      PLoS One. 2013;8(3):e59861. (PMID: 23527279)
      J Biol Chem. 2008 Sep 12;283(37):25218-26. (PMID: 18635535)
      Proc Natl Acad Sci U S A. 2008 Mar 11;105(10):4050-5. (PMID: 18316743)
      J Biochem. 1981 May;89(5):1533-9. (PMID: 7275952)
      Photosynth Res. 1991 Dec;30(2-3):85-94. (PMID: 24415257)
      J Biol Chem. 1994 Nov 11;269(45):28068-75. (PMID: 7961743)
    • Contributed Indexing:
      Keywords: Synechococcus; cyanobacteria; electron transport; photosynthesis
    • Accession Number:
      0 (Electron Transport Chain Complex Proteins)
      0 (Photosynthetic Reaction Center Complex Proteins)
    • Publication Date:
      Date Created: 20180214 Date Completed: 20181211 Latest Revision: 20220408
    • Publication Date:
      20221213
    • Accession Number:
      PMC5801466
    • Accession Number:
      10.1128/mBio.02327-17
    • Accession Number:
      29437923