Premium
The diatom P haeodactylum tricornutum adjusts nonphotochemical fluorescence quenching capacity in response to dynamic light via fine‐tuned L hcx and xanthophyll cycle pigment synthesis
Author(s) -
Lepetit Bernard,
Gélin Gautier,
Lepetit Mariana,
Sturm Sabine,
Vugrinec Sascha,
Rogato Alessandra,
Kroth Peter G.,
Falciatore Angela,
Lavaud Johann
Publication year - 2017
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.14337
Subject(s) - phaeodactylum tricornutum , quenching (fluorescence) , diatom , biophysics , chemistry , xanthophyll , photoprotection , fluorescence , photosynthesis , biology , biochemistry , botany , physics , quantum mechanics
Summary Diatoms contain a highly flexible capacity to dissipate excessively absorbed light by nonphotochemical fluorescence quenching ( NPQ ) based on the light‐induced conversion of diadinoxanthin (Dd) into diatoxanthin (Dt) and the presence of Lhcx proteins. Their NPQ fine regulation on the molecular level upon a shift to dynamic light conditions is unknown. We investigated the regulation of Dd + Dt amount, Lhcx gene and protein synthesis and NPQ capacity in the diatom Phaeodactylum tricornutum after a change from continuous low light to 3 d of sine ( SL ) or fluctuating ( FL ) light conditions. Four P. tricornutum strains with different NPQ capacities due to different expression of Lhcx1 were included. All strains responded to dynamic light comparably, independently of initial NPQ capacity. During SL , NPQ capacity was strongly enhanced due to a gradual increase of Lhcx2 and Dd + Dt amount. During FL , cells enhanced their NPQ capacity on the first day due to increased Dd + Dt, Lhcx2 and Lhcx3; already by the second day light acclimation was accomplished. While quenching efficiency of Dt was strongly lowered during SL conditions, it remained high throughout the whole FL exposure. Our results highlight a more balanced and cost‐effective photoacclimation strategy of P. tricornutum under FL than under SL conditions.