Impaired photoprotection in Phaeodactylum tricornutum KEA3 mutants reveals the proton regulatory circuit of diatoms light acclimation.

Autor: Seydoux C; CNRS, CEA, INRAE, IRIG, LPCV, Université Grenoble Alpes, Grenoble, 38000, France., Storti M; CNRS, CEA, INRAE, IRIG, LPCV, Université Grenoble Alpes, Grenoble, 38000, France., Giovagnetti V; Departement of Biochemistry, Queen Mary University of London, Mile End Road, London, E14NS, UK., Matuszyńska A; Computational Life Science, Department of Biology, RWTH Aachen University, Worringer Weg 1, Aachen, 52074, Germany., Guglielmino E; CNRS, CEA, INRAE, IRIG, LPCV, Université Grenoble Alpes, Grenoble, 38000, France., Zhao X; CNRS, CEA, INRAE, IRIG, LPCV, Université Grenoble Alpes, Grenoble, 38000, France., Giustini C; CNRS, CEA, INRAE, IRIG, LPCV, Université Grenoble Alpes, Grenoble, 38000, France., Pan Y; Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China., Blommaert L; Laboratory of Chloroplast Biology and Light Sensing in Microalgae, Institut de Biologie Physico Chimique, CNRS, Sorbonne Université, Paris, 75005, France., Angulo J; CNRS, CEA, INRAE, IRIG, LPCV, Université Grenoble Alpes, Grenoble, 38000, France., Ruban AV; Departement of Biochemistry, Queen Mary University of London, Mile End Road, London, E14NS, UK., Hu H; Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China., Bailleul B; Laboratory of Chloroplast Biology and Light Sensing in Microalgae, Institut de Biologie Physico Chimique, CNRS, Sorbonne Université, Paris, 75005, France., Courtois F; CNRS, CEA, INRAE, IRIG, LPCV, Université Grenoble Alpes, Grenoble, 38000, France., Allorent G; CNRS, CEA, INRAE, IRIG, LPCV, Université Grenoble Alpes, Grenoble, 38000, France., Finazzi G; CNRS, CEA, INRAE, IRIG, LPCV, Université Grenoble Alpes, Grenoble, 38000, France.
Jazyk: angličtina
Zdroj: The New phytologist [New Phytol] 2022 Apr; Vol. 234 (2), pp. 578-591. Date of Electronic Publication: 2022 Feb 21.
DOI: 10.1111/nph.18003
Abstrakt: Diatoms are successful phytoplankton clades able to acclimate to changing environmental conditions, including e.g. variable light intensity. Diatoms are outstanding at dissipating light energy exceeding the maximum photosynthetic electron transfer (PET) capacity via the nonphotochemical quenching (NPQ) process. While the molecular effectors of NPQ as well as the involvement of the proton motive force (PMF) in its regulation are known, the regulators of the PET/PMF relationship remain unidentified in diatoms. We generated mutants of the H + /K + antiporter KEA3 in the model diatom Phaeodactylum tricornutum. Loss of KEA3 activity affects the PET/PMF coupling and NPQ responses at the onset of illumination, during transients and in steady-state conditions. Thus, this antiporter is a main regulator of the PET/PMF coupling. Consistent with this conclusion, a parsimonious model including only two free components, KEA3 and the diadinoxanthin de-epoxidase, describes most of the feedback loops between PET and NPQ. This simple regulatory system allows for efficient responses to fast (minutes) or slow (e.g. diel) changes in light environment, thanks to the presence of a regulatory calcium ion (Ca 2+ )-binding domain in KEA3 modulating its activity. This circuit is likely tuned by the NPQ-effector proteins, LHCXs, providing diatoms with the required flexibility to thrive in different ocean provinces.
(© 2022 The Authors New Phytologist © 2022 New Phytologist Foundation.)
Databáze: MEDLINE
Externí odkaz: