AUTHOR=Pajot Anne , Lavaud Johann , Carrier Gregory , Garnier Matthieu , Saint-Jean Bruno , Rabilloud Noémie , Baroukh Caroline , Bérard Jean-Baptiste , Bernard Olivier , Marchal Luc , Nicolau Elodie 

TITLE=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

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.830069

DOI=10.3389/fpls.2022.830069

ISSN=1664-462X

ABSTRACT=<p>We observed differences in <italic>lhc</italic> classification in Chromista. We proposed a classification of the <italic>lhcf</italic> family with two groups specific to haptophytes, one specific to diatoms, and one specific to seaweeds. Identification and characterization of the Fucoxanthin and Chlorophyll <italic>a/c</italic>-binding Protein (FCP) of the haptophyte microalgae <italic>Tisochrysis lutea</italic> were performed by similarity analysis. The FCP family contains 52 <italic>lhc</italic> genes in <italic>T. lutea</italic>. FCP pigment binding site candidates were characterized on Lhcf protein monomers of <italic>T. lutea</italic>, which possesses at least nine chlorophylls and five fucoxanthin molecules, on average, per monomer. The expression of <italic>T. lutea lhc</italic> 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 <italic>lhc</italic> genes with nitrogen depletion. We observed that <italic>T. lutea lhcx2</italic> was only expressed at night, suggesting that its role is to protect \cells from return of light after prolonged darkness exposure.</p>