Photosynthetica (Dec 2023)

Single-cell microfluidics in combination with chlorophyll a fluorescence measurements to assess the lifetime of the Chlamydomonas PSBO protein

  • E. Széles,
  • S. Kuntam,
  • A. Vidal-Meireles,
  • V. Nagy,
  • K. Nagy,
  • Á. Ábrahám,
  • L. Kovács,
  • S.Z. Tóth

DOI
https://doi.org/10.32615/ps.2023.028
Journal volume & issue
Vol. 61, no. SPECIAL ISSUE 2023-2
pp. 417 – 424

Abstract

Read online

PSBO is an essential subunit of the oxygen-evolving complex and we recently demonstrated that its lifetime depends on environmental conditions in Chlamydomonas reinhardtii. To assess PSBO lifetime with a high time resolution, we employed (1) a microfluidic platform enabling the trapping of single cells and the parallel measurement of photosynthetic activity, and (2) a nitrate-inducible PSBO amiRNA line. Our microfluidic platform allowed the rapid replacement of the nutrient solution necessary for induction. It also enabled the precise monitoring of the decline in the Fv/Fm value, reflecting PSBO loss. We found that in the dark, at medium and high light intensity, the Fv/Fm value decreased with halftimes of about 25, 12.5, and 5 h, respectively. We also observed that photosynthetic activity was better sustained upon carbon limitation. In the absence of acetate, the halftimes of Fv/Fm diminishment doubled to quadrupled compared with the control, acetate-supplied cultures.

Keywords