Molecular regulatory mechanisms of the photosynthetic antenna function in plants

Research project objectives/Hypothesis

The project will focus on the study of mechanisms responsible for regulation of the photosynthetic antenna function at the molecular level. The experiments are designed to verify our central hypothesis, according to which: under light stress conditions, trimers of LHCII, the major antenna complex in the photosynthetic apparatus of plants, disassemble into monomers which further reassemble into small, specific supramolecular structures, characterized by a high rate of excitation quenching. Such excitation quenching can protect plants against photo-damage and therefore can be recognized as a vital, photo-protective regulatory mechanism.

Research methodology

A “single molecule” spectroscopy approach will be applied to study molecular mechanisms responsible for regulation of the photosynthetic antenna function in plants. Measurements will be carried out in intact chloroplasts of model plants and in model systems composed of LHCII, the largest photosynthetic pigmentprotein antenna complex of Photosystem II, isolated from the same plants. The planned experiments are based on time-resolved and steady-state fluorescence spectroscopy, fluorescence lifetime imaging microscopy (FLIM), infrared absorption (FTIR), circular dichroism (CD) and Raman spectroscopy-based imaging microscopy of systems composed of single molecules, as well as model systems composed of low number of pigment-protein complexes. A “single molecule” approach will be implemented in fluorescence and Raman scattering experiments, in order to avoid the effect of averaging and gain precise information regarding the stoichiometry of the supramolecular structures of LHCII involved in excessive excitation quenching.

Research project impact

It is widely acknowledged that oxygenic photosynthesis is one of, if not the most, important biological process in the Biosphere as it converts sunlight into chemical forms utilized by a greater majority of the known organisms. Moreover, the photosynthetic pigment-protein complexes operate with outstanding efficiency. In recent years it has emerged, that not only the primary processes of photo-conversion are crucial in determining such extraordinary efficiency, but also regulative processes which adapt harvesting of sunlight in response to fluctuating ambient conditions. The results of the research planned will provide basic knowledge on regulation in the process of photosynthesis in plants at the molecular level and, in our opinion, pave the way to “engineering” of plant varieties highly resistant to light stress.

Pioneering nature of the research project

We will address the problems regarding regulation of the photosynthetic antenna function in plants implementing “single molecule” spectroscopy and imaging, a very up to date and powerful approach, applied by only a few laboratories in the world. The concept on formation of small supramolecular structures of monomeric LHCII, which play role of “energy traps” is innovative and consistent with all the results of the preliminary data.


Wiesław I. Gruszecki

Rafał Luchowski

Wojciech Grudziński


Renata Welc, Rafal Luchowski, Dariusz Kluczyk, Monika Zubik‐Duda, Wojciech Grudzinski, Magdalena Maksim, Emilia Reszczynska, Karol Sowinski, Radosław Mazur, Artur Nosalewicz, Wieslaw I Gruszecki

Mechanisms shaping the synergism of zeaxanthin and PsbS in photoprotective energy dissipation in the photosynthetic apparatus of plants

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Jiangtao Zhou, Sergey Sekatskii, Renata Welc, Giovanni Dietler, Wieslaw I Gruszecki

The role of xanthophylls in the supramolecular organization of the photosynthetic complex LHCII in lipid membranes studied by high-resolution imaging and nanospectroscopy

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Monika Zubik, Rafal Luchowski, Dariusz Kluczyk, Wojciech Grudzinski, Magdalena Maksim, Artur Nosalewicz, Wieslaw I. Gruszecki

Recycling of Energy Dissipated as Heat Accounts for High Activity of Photosystem II

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Ewa Janika, Joanna Bednarska, Monika Zubik, Rafal Luchowski, Radoslaw Mazur, Karol Sowinski, Wojciech Grudzinski, Maciej Garstka, Wieslaw I. Gruszecki

A chloroplast "wake up" mechanism: Illumination with weak light activates the photosynthetic antenna function in dark-adapted plants

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a. Wojciech Grudzinski, Lukasz Nierzwicki, Renata Welc, Emilia Reszczynska, Rafal Luchowski, Jacek Czub, Wieslaw I. Gruszecki

Localization and Orientation of Xanthophylls in a Lipid Bilayer

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    Project information

    Funding body:
    Foundation for the Polish Science

    Project call:
    MAESTRO 8, NZ1

    Project leader:
    prof. dr hab. Wiesław Gruszecki

    Grant allocation:
    1 978 800 PLN

    Beginning of the project:

    Project status:
    Research in progress

    Projekt realizowany w programie MAESTRO Narodowego Centrum Nauki