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Title: Competition-based phenotyping reveals a fitness cost for maintaining phycobilisomes under fluctuating light in the cyanobacterium Fremyella diplosiphon

Phycobilisomes (PBSs) are pigment-rich super-complexes required for efficient harvest and transfer of light energy to photosynthetic reaction centers of cyanobacteria. The model cyanobacterium Fremyella diplosiphon is able to adjust PBS pigmentation and size in response to the prevailing light spectrum through a process called complementary chromatic acclimation to optimize spectral light absorption, concomitantly optimizing photosynthesis and growth. We explored the fitness costs versus advantages of modulating antennae size and composition under sinusoidal continuous and fluctuating light conditions in F. diplosiphon by comparing growth of wild-type (WT) cells with a mutant strain deficient in PBSs in both monoculture and polyculture conditions. Comparative analyses of WT and the PBS-deficient FdCh1 strain under continuous vs. fluctuating sinusoidal light suggest a potential fitness advantage for maintaining PBSs in WT cells during continuous light and a fitness cost during transitions to and acclimation under fluctuating light. Here, we explored the physiological changes correlated with the observed differential growth to understand the dynamics and biochemical bases of comparative fitness of distinct strains under defined growth conditions. Wild-type F. diplosiphon appears to accumulate longer PBS rods and exhibits higher oxidative stress under fluctuating light conditions than continuous sinusoidal light, which may impact responses and the fitness ofmore » cells that do not adapt to rapid changes in external light.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [4] ;  [5] ;  [6]
  1. Michigan State Univ., East Lansing, MI (United States). Cell and Molecular Biology Graduate Program; Michigan State Univ., East Lansing, MI (United States). Dept. of of Energy Plant Research Lab.
  2. Michigan State Univ., East Lansing, MI (United States). Dept. of of Energy Plant Research Lab.
  3. Michigan State Univ., East Lansing, MI (United States). Dept. of Biochemistry and Molecular Biology; Michigan State Univ., East Lansing, MI (United States). Dept. of Chemistry
  4. Michigan State Univ., East Lansing, MI (United States). Dept. of Chemistry
  5. Michigan State Univ., East Lansing, MI (United States). Dept. of of Energy Plant Research Lab.; Michigan State Univ., East Lansing, MI (United States). Dept. of Biochemistry and Molecular Biology
  6. Michigan State Univ., East Lansing, MI (United States). Cell and Molecular Biology Graduate Program; Michigan State Univ., East Lansing, MI (United States). Dept. of of Energy Plant Research Lab.; Michigan State Univ., East Lansing, MI (United States). Dept. of Biochemistry and Molecular Biology
Publication Date:
Grant/Contract Number:
FG02-91ER20021; MCB-0643516; MCB-1243983
Type:
Published Article
Journal Name:
Algal Research
Additional Journal Information:
Journal Volume: 15; Journal Issue: C; Journal ID: ISSN 2211-9264
Publisher:
Elsevier
Research Org:
Michigan State Univ., East Lansing, MI (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; Cyanobacteria; Fluctuating light; Phycobilisomes; Polyculture competition; Reactive oxygen species (ROS)
OSTI Identifier:
1306671
Alternate Identifier(s):
OSTI ID: 1437169