Chlorophyll–carotenoid excitation energy transfer and charge transfer in Nannochloropsis oceanica for the regulation of photosynthesis

Authors: Soomin Park, Collin J. Steen, Dagmar Lyska, Alexandra L. Fischer, Benjamin Endelman, Masakazu Iwai, Krishna Niyogi, Graham R. Fleming - Proceedings of the National Academy of Sciences, PNAS 2019 cited by 122

Significance Manipulating the nonphotochemical quenching (NPQ) capabilities of photosynthetic organisms is known to result in increased crop productivity. However, optimization of yields also requires a detailed molecular understanding of the mechanism of NPQ in vivo with specific attention to the roles of the carotenoid zeaxanthin and various ∆pH-sensing proteins, such as photosystem II subunit S and stress-related antenna proteins (e.g., LHCX). Here, to investigate such in vivo NPQ mechanisms, we report transient absorption spectroscopy measurements on live cells of Nannochloropsis oceanica . We show that two fundamental processes proposed as NPQ mechanisms are active in N. oceanica and specifically require violaxanthin de-epoxidase as well as the LHCX1 protein. These findings have implications for optimizing the yields of algal biofuels.