Zeaxanthin Protects Plant Photosynthesis by Modulating Chlorophyll Triplet Yield in Specific Light-harvesting Antenna Subunits*

  title={Zeaxanthin Protects Plant Photosynthesis by Modulating Chlorophyll Triplet Yield in Specific Light-harvesting Antenna Subunits*},
  author={Luca Dall’Osto and Nancy E. Holt and Shanti Kaligotla and Marcel Fuciman and Stefano Cazzaniga and Donatella Carbonera and Harry A Frank and Jean Alric and Roberto Bassi},
  journal={The Journal of Biological Chemistry},
  pages={41820 - 41834}
Background: The plant carotenoid zeaxanthin is accumulated under excess light. Results: Zeaxanthin induces a red shift in the carotenoid triplet excited state spectrum and reveals a higher efficiency in controlling chlorophyll triplet formation. Conclusion: Binding of zeaxanthin to specific proteins modulates the yield of dangerous chlorophyll excited states and protects photosynthesis from over-excitation. Significance: Functional dissection of zeaxanthin-dependent photoprotective mechanisms… 

Figures and Tables from this paper

Regulation of photosystem I light harvesting by zeaxanthin

Zeaxanthin was shown to be effective in inducing dissipative states in PSI, similar to its well-known effect on PSII, and it is proposed that, upon acclimation to high light, PSI–LHCI changes its light-harvesting efficiency by a zexanthin-dependent quenching of the absorbed excitation energy, whereas in PSII the stoichiometry of LHC antenna proteins per reaction center is reduced directly.

Interaction between avoidance of photon absorption, excess energy dissipation and zeaxanthin synthesis against photooxidative stress in Arabidopsis.

It is concluded that a decrease in leaf optical density affects the apparent non-photochemical quenching (NPQ) rise kinetic, and excess light-induced fluorescence decrease is in part due to avoidance of photon absorption rather than to a genuine quench process.

Zeaxanthin Binds to Light-Harvesting Complex Stress-Related Protein to Enhance Nonphotochemical Quenching in Physcomitrella patens[W]

It is reported that zeaxanthin, an NPQ enhancer, is far more active on LHCSR- dependent NPQ than on the PSBS-dependent NPQ, and biochemical evidence that native LH CSR protein binds zeaxAnthin upon excess light stress is provided.

Differential Roles of Carotenes and Xanthophylls in Photosystem I Photoprotection.

It is concluded that PSI-LHCI complex-bound β-carotene elicits a protective response, consisting of a reduction in the yield of harmful triplet excited states, while accumulation of zeaxanthin plays a minor role in restoring phototolerance.

Chlorophyll triplet quenching and photoprotection in the higher plant monomeric antenna protein Lhcb5.

It is shown that quenching of both singlet and triplet states is necessary for minimizing singlet oxygen formation and evidence for an indirect role of neoxanthin in chlorophyll triplet quenched is presented.

Functional modulation of LHCSR1 protein from Physcomitrella patens by zeaxanthin binding and low pH

It is suggested that energy dissipation occurs in the chloroplast by the activation of 80 ps quenching sites in LHCSR1 which spill over excitons from the photosystem II antenna system.

Sensing β-carotene oxidation in photosystem II to master plant stress tolerance.

New advances in the characterization of the apocarotenoids involved in the PSII-mediated stress response and of the pathways elicited by these molecules are summarized, among which is the xenobiotic detoxification.

Chlorophyll-Xanthophyll Antenna Complexes: In Between Light Harvesting and Energy Dissipation

Of particular importance is the mechanism called Non-Photochemical Quenching (NPQ) catalyzing energy dissipation by regulating the interactions between chlorophylls and carotenoids, likely by multiple reactions involving excited states.

An In Vivo Quantitative Comparison of Photoprotection in Arabidopsis Xanthophyll Mutants

Of the carotenoid mutants, lut2 (lutein-deficient) plants had the highest light tolerance, and the joint the highest ΦPSII with violaxanthin only plants, suggesting a strong structural effect of the molecules upon the LHCII antenna organization.



Enhanced photoprotection by protein-bound vs free xanthophyll pools: a comparative analysis of chlorophyll b and xanthophyll biosynthesis mutants.

It is proposed that the antioxidant capacity of zeaxanthin is empowered in the presence of PSII-LHCs-Zea complexes, while its effect on enhancement of qE only provides a minor contribution to chloroplast photoprotection.

Elevated Zeaxanthin Bound to Oligomeric LHCII Enhances the Resistance of Arabidopsis to Photooxidative Stress by a Lipid-protective, Antioxidant Mechanism*

It is suggested that the protein/lipid interface is the active site for the antioxidant activity of zeaxanthin, which mediates stress tolerance by the protection of bound lipids in transformed plants.

The violaxanthin cycle protects plants from photooxidative damage by more than one mechanism.

  • M. HavauxK. Niyogi
  • Environmental Science
    Proceedings of the National Academy of Sciences of the United States of America
  • 1999
It is demonstrated that the violaxanthin cycle specifically protects thylakoid membrane lipids against photooxidation, and part of this protection involves a mechanism other than quenching of singlet excited chlorophylls.

Functional architecture of the major light-harvesting complex from higher plants.

It is found that the xanthophyll to chlorophyll energy transfer is a shared property of the whole pigment-protein complex, and occurs with similar efficiency in each of the three structural domains, and suggests that non-radiative dissipation of excess energy can be regulated through allosteric modification of the protein structure by exchanging xanthphylls in these sites.

PsbS-dependent enhancement of feedback de-excitation protects photosystem II from photoinhibition

Increased qE capacity was associated with decreased photosystem II excitation pressure and changes in the fractional areas of chlorophyll a fluorescence lifetime distributions, but not the lifetime centers, suggesting that qE protects from photoinhibition by preventing overreduction of Photosystem II electron acceptors.

Chlorophyll fluorescence quenching in isolated light harvesting complexes induced by zeaxanthin

Chlamydomonas Xanthophyll Cycle Mutants Identified by Video Imaging of Chlorophyll Fluorescence Quenching.

The photosynthetic apparatus in plants is protected against oxidative damage by processes that dissipate excess absorbed light energy as heat within the light-harvesting complexes. This dissipation

A Mechanism of Nonphotochemical Energy Dissipation, Independent from PsbS, Revealed by a Conformational Change in the Antenna Protein CP26w⃞

Results confirm that LHC proteins exist in multiple conformations, an idea suggested by previous spectroscopic measurements, and imply that the switch between the different LHC protein conformations is activated by the binding of zeaxanthin to the allosteric site L2.

Zeaxanthin Has Enhanced Antioxidant Capacity with Respect to All Other Xanthophylls in Arabidopsis Leaves and Functions Independent of Binding to PSII Antennae1[C][W]

The results indicate that the antioxidant activity of zeaxanthin, distinct from NPQ, can occur in the absence of PSII light-harvesting complexes.