Photodamage of iron–sulphur clusters in photosystem I induces non-photochemical energy dissipation
2016 (English)In: Nature Plants, ISSN 2055-026X, Vol. 2, no 4, 16035Article in journal (Refereed) Published
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.
Place, publisher, year, edition, pages
2016. Vol. 2, no 4, 16035
Biochemistry and Molecular Biology
Research subject Biochemistry
IdentifiersURN: urn:nbn:se:uu:diva-282637DOI: 10.1038/NPLANTS.2016.35ISI: 000375397600007PubMedID: 27249566OAI: oai:DiVA.org:uu-282637DiVA: diva2:917368