Nature Communications (Jun 2024)

Central transcriptional regulator controls photosynthetic growth and carbon storage in response to high light

  • Seth Steichen,
  • Arnav Deshpande,
  • Megan Mosey,
  • Jessica Loob,
  • Damien Douchi,
  • Eric P. Knoshaug,
  • Stuart Brown,
  • Robert Nielsen,
  • Joseph Weissman,
  • L. Ruby Carrillo,
  • Lieve M. L. Laurens

DOI
https://doi.org/10.1038/s41467-024-49090-7
Journal volume & issue
Vol. 15, no. 1
pp. 1 – 14

Abstract

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Abstract Carbon capture and biochemical storage are some of the primary drivers of photosynthetic yield and productivity. To elucidate the mechanisms governing carbon allocation, we designed a photosynthetic light response test system for genetic and metabolic carbon assimilation tracking, using microalgae as simplified plant models. The systems biology mapping of high light-responsive photophysiology and carbon utilization dynamics between two variants of the same Picochlorum celeri species, TG1 and TG2 elucidated metabolic bottlenecks and transport rates of intermediates using instationary 13 C-fluxomics. Simultaneous global gene expression dynamics showed 73% of the annotated genes responding within one hour, elucidating a singular, diel-responsive transcription factor, closely related to the CCA1/LHY clock genes in plants, with significantly altered expression in TG2. Transgenic P. celeri TG1 cells expressing the TG2 CCA1/LHY gene, showed 15% increase in growth rates and 25% increase in storage carbohydrate content, supporting a coordinating regulatory function for a single transcription factor.