Carotenoid Biosynthesis in Chromalveolates

While the last decades have witnessed substantial progress in understanding the biosynthesis of carotenoids in land plants, much less is known about carotenoid formation in algae. This is particularly true for chromalveolate algae, organisms that are responsible for more than half of the marine primary production and for considerable carbon sequestration in the oceans. These algae evolved novel light-harvesting carotenoids such as fucoxanthin and peridinin, that are absent from land plants and green algae and that contributed substantially to their ecological success by extending the spectral range of light they can utilize for photosynthesis.

Although the xanthophylls violaxanthin and neoxanthin were postulated as central precursors of these light-harvesting carotenoids, none of the enzymes catalyzing the steps beyond the formation of violaxanthin had been identified so far. We recently have identified the enzyme catalyzing the first step, the formation of neoxanthin from violaxanthin, as a violaxanthin de-epoxidase-like (VDL) protein, thus demonstrating that chromalveolate algae recruited an enzyme originally involved in photoprotection for biosynthesis of novel light-harvesting carotenoids by gene duplication and neo-functionalization. Currently, we are investigating other candidate enzymes potentially involved in fucoxanthin biosynthesis.

Related publications:
Lohr & Wilhelm (1999), Lohr & Wilhelm (2001), Frommolt et al. (2008), Dautermann & Lohr (2017), Dautermann et al. (2020), Bai et al. (2022)