The blue-green light-dependent state transition in the marine phytoplankton Ostreococcus tauri.

Autor: Kubota M; National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki, 444-8585, Japan.; Graduate Institute for Advanced Studies, SOKENDAI, 38 Nishigonaka, Myodaiji, Okazaki, 444-8585, Japan., Kim E; National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki, 444-8585, Japan.; Graduate Institute for Advanced Studies, SOKENDAI, 38 Nishigonaka, Myodaiji, Okazaki, 444-8585, Japan., Ishii A; National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki, 444-8585, Japan., Minagawa J; National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki, 444-8585, Japan.; Graduate Institute for Advanced Studies, SOKENDAI, 38 Nishigonaka, Myodaiji, Okazaki, 444-8585, Japan.
Jazyk: angličtina
Zdroj: The New phytologist [New Phytol] 2024 Dec; Vol. 244 (5), pp. 1837-1846. Date of Electronic Publication: 2024 Sep 23.
DOI: 10.1111/nph.20137
Abstrakt: We explored the adaptive mechanisms of Ostreococcus tauri, a marine picophytoplankton with a ubiquitous ocean presence. We aimed to understand its photosynthetic acclimation, as featured in the cryo-EM structure of its photosystem I (PSI) supercomplex. This structure revealed a unique composition involving a phosphorylated Lhcp trimer bound to the PSI core along with two additional Lhcp trimers, suggesting potential state transitions for photoacclimation. To investigate this hypothesis, we conducted a series of biochemical and physiological experiments. We analyzed absorption spectra to differentiate between PSI and PSII, particularly focusing on blue-green wavelengths, and examined the effects of specific excitation of Lhcp with green light, including its phosphorylation and the formation of the PSI-LHCI-Lhcp supercomplex. Our experiments clarified the distinctive effects attributable to absorption by pigments associated with Lhcp. Exciting Lhcp with green light induced its phosphorylation, leading to the formation of the PSI-LHCI-Lhcp supercomplex. Notably, the functional antenna size of PSI could reversibly expand in response to green light, demonstrating its state transition capability. These findings not only highlight the unique photosynthetic acclimation adapted to the marine environment but also suggest a possible ancestral role of state transitions in green plants, given the phylogenetic position of Prasinophyceae.
(© 2024 The Author(s). New Phytologist © 2024 New Phytologist Foundation.)
Databáze: MEDLINE
Externí odkaz: