Yarkhunova, Yulia, Guadagno, Carmela R., Rubin, Matthew et al. (3 more authors) (2018) Circadian rhythms are associated with variation in photosystem II function and photoprotective mechanisms. Plant, Cell and Environment. ISSN 0140-7791
Abstract
The circadian clock regulates many aspects of leaf gas supply and biochemical demand for CO2 20 , and is hypothesized to improve plant performance. Yet the extent to which the clock may regulate the efficiency of photosystem II (PSII) and photoprotective mechanisms such as heat dissipation remains largely unexplored. Based on measurements of chlorophyll a fluorescence, we estimated the maximum efficiency of photosystem II in light (Fv'/Fm') and heat dissipation by non-photochemical quenching (NPQ). We further dissected total NPQ into its main components, qE (pH-dependent quenching), qT (state-transition quenching) and qI (quenching related to photoinhibition), in clock mutant genotypes of Arabidopsis thaliana, the cognate wild-type genotypes, and a panel of recombinant inbred lines (RILs) expressing quantitative variation in clock period. Compared to mutants with altered clock function, we observed that wild-type genotypes with clock period lengths of approximately 24 hr had both higher levels of Fv'/Fm ', indicative of improved PSII function, and reduced NPQ, suggestive of lower stress on PSII light harvesting complexes. In the RILs, genetic variances were significant for Fv'/Fm' and all three components of NPQ, with qE explaining the greatest proportion of NPQ. Bivariate tests of association and structural equation models of hierarchical trait relationships showed that quantitative clock variation was empirically associated with Fv'/Fm' and NPQ, with qE mediating the relationship with gas exchange. The results demonstrate significant segregating variation for all photoprotective components, and suggest the adaptive significance of the clock may partly derive from its regulation of the light reactions of photosynthesis and of photoprotective mechanisms. Key words: Arabidopsis thaliana, circadian rhythms, chlorophyll a fluorescence, maximum efficiency of PSII, non-photochemical quenching
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © John Wiley, 2018. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York > Faculty of Sciences (York) > Biology (York) |
Depositing User: | Pure (York) |
Date Deposited: | 04 Apr 2018 11:10 |
Last Modified: | 16 Oct 2024 14:37 |
Published Version: | https://doi.org/10.1111/pce.13216 |
Status: | Published |
Refereed: | Yes |
Identification Number: | 10.1111/pce.13216 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:129260 |
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