A1 Refereed original research article in a scientific journal

Photodamage of iron-sulphur clusters in photosystem I induces non-photochemical energy dissipation




AuthorsArjun Tiwari, Fikret Mamedov, Michele Grieco, Marjaana Suorsa, Anjana Jajoo, Stenbjörn Styring, Mikko Tikkanen, Eva-Mari Aro

PublisherNATURE PUBLISHING GROUP

Publishing placeKarlsruhe

Publication year2016

JournalNature Plants

Journal name in sourceNATURE PLANTS

Journal acronymNAT PLANTS

Article numberARTN 16035

Volume2

Issue4

Number of pages9

ISSN2055-026X

eISSN2055-0278

DOIhttps://doi.org/10.1038/NPLANTS.2016.35(external)


Abstract
Photosystem I (PSI) uses light energy and electrons supplied by photosystem II (PSII) to reduce NADP(+) to NADPH. PSI is very tolerant of excess light but extremely sensitive to excess electrons from PSII. It has been assumed that PSI is protected from photoinhibition by strict control of the intersystem electron transfer chain (ETC). Here we demonstrate that the iron-sulphur (FeS) clusters of PSI are more sensitive to high light stress than previously anticipated, but PSI with damaged FeS clusters still functions as a non-photochemical photoprotective energy quencher (PSI-NPQ). Upon photoinhibition of PSI, the highly reduced ETC further triggers thylakoid phosphorylation-based mechanisms that increase energy flow towards PSI. It is concluded that the sensitivity of FeS clusters provides an additional photoprotective mechanism that is able to downregulate PSII, based on PSI quenching and protein phosphorylation.

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Last updated on 2024-26-11 at 20:43