Increase in spillover and excitation energy dissipation during wet–dry transitions in the desert green alga Chlorella ohadii

Abstract

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  Under drought, lack of an electron source (water) reduces the capacity of oxygen-evolving photosynthesis.
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  Consequently, even under low light, excess excitation energy may be generated, which is harmful as it leads to generation of reactive oxygen species.
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  When the desert green alga Chlorella ohadii undergoes desiccation, first photosystem II binds to photosystem I via LHCII to establish energy transfer pathways, and then excitation energy dissipation induced by a quencher is initiated.
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  This strategy may provide efficient protection of the entire photosynthetic apparatus during early stages of desiccation, when the available quencher may be insufficient.