The Fucoxanthin Chlorophyll a/c-Binding Protein in Tisochrysis lutea: Influence of Nitrogen and Light on Fucoxanthin and Chlorophyll a/c-Binding Protein Gene Expression and Fucoxanthin Synthesis

Abstract

We observed differences in lhc classification in Chromista. We proposed a classification of the lhcf family with two groups specific to haptophytes, one specific to diatoms, and one specific to seaweeds. Identification and characterization of the Fucoxanthin and Chlorophyll a/c-binding Protein (FCP) of the haptophyte microalgae Tisochrysis lutea were performed by similarity analysis. The FCP family contains 52 lhc genes in T. lutea. FCP pigment binding site candidates were characterized on Lhcf protein monomers of T. lutea, which possesses at least nine chlorophylls and five fucoxanthin molecules, on average, per monomer. The expression of T. lutea lhc genes was assessed during turbidostat and chemostat experiments, one with constant light (CL) and changing nitrogen phases, the second with a 12 h:12 h sinusoidal photoperiod and changing nitrogen phases. RNA-seq analysis revealed a dynamic decrease in the expression of lhc genes with nitrogen depletion. We observed that T. lutea lhcx2 was only expressed at night, suggesting that its role is to protect \cells from return of light after prolonged darkness exposure.

Light-response in two clonal strains of the haptophyte Tisochrysis lutea: Evidence for different photoprotection strategies

“…However, Lhcf can also bind Ddx, for instance in the diatom Phaeodactylum tricornutum [11], highlighting the more complex role of Lhcf within the light-harvesting antenna. Currently in the literature, there is an abundance of studies on the FCP of diatoms [12,13], whereas only a few exist for haptophytes [14,15]. We selected Tisochrysis lutea as a representative of haptophyte microalgae, and determined the composition of its FCP in a previous study [15].…”

“…Currently in the literature, there is an abundance of studies on the FCP of diatoms [12,13], whereas only a few exist for haptophytes [14,15]. We selected Tisochrysis lutea as a representative of haptophyte microalgae, and determined the composition of its FCP in a previous study [15]. 28 Lhcf, 12 Lhcr and 12 Lhcx protein sequences constitute the FCP of T. lutea, and at least five Fx molecules and nine Chl a and c molecules are bound to a majority of Lhcf monomers in this species [15].…”

“…We selected Tisochrysis lutea as a representative of haptophyte microalgae, and determined the composition of its FCP in a previous study [15]. 28 Lhcf, 12 Lhcr and 12 Lhcx protein sequences constitute the FCP of T. lutea, and at least five Fx molecules and nine Chl a and c molecules are bound to a majority of Lhcf monomers in this species [15]. In diatoms and haptophytes, a correlation was already established between the expression of the FCP and the concentration of pigments in cells.…”

Potential for the Production of Carotenoids of Interest in the Polar Diatom Fragilariopsis cylindrus

“…unit., in red), under different light spectra, photosynthetically usable radiation levels, photoperiods, and temperatures. Table S3 (attached Excel file): Synthesis of recent works on microalgae including Fx content and/or production data with growth variables and growing conditions [ 116 , 117 ]. Table S4: Culture f/2 and f media composition used in this study.…”

The effects of ocean acidification on the establishment and maintenance of a model cnidarian-dinoflagellate symbiosis

“…Seven of the 12 photosynthesis-annotated DAPs (six FCPs, and PSII CP47) were associated with the LHC at PSII. FCPs non-covalently bind the components of the LHC: fucoxanthin and chlorophylls a and c (Büchel 2020;Pajot et al 2022). While annotated as FCPs in publicly-available databases, some if not all of these proteins are likely chlorophyll a-chlorophyll c2-peridinin-protein (apcPC; Jiang et al 2014).…”