Marine algae are responsible for half of the world's primary productivity, but this critical carbon sink is often constrained by insufficient iron. One species of marine algae, Dunaliella tertiolecta, is remarkable for its ability to maintain photosynthesis and thrive in low-iron environments. A related species, Dunaliella salina Bardawil, shares this attribute but is an extremophile found in hypersaline environments. To elucidate how algae manage their iron requirements, we produced high-quality genome assemblies and transcriptomes for both species to serve as a foundation for a comparative multiomics analysis. We identified a host of iron-uptake proteins in both species, including a massive expansion of transferrins and a unique family of siderophore-iron-uptake proteins. Complementing these multiple iron-uptake routes, ferredoxin functions as a large iron reservoir that can be released by induction of flavodoxin. Proteomic analysis revealed reduced investment in the photosynthetic apparatus coupled with remodeling of antenna proteins by dramatic iron-deficiency induction of TIDI1, which is closely related but identifiably distinct from the chlorophyll binding protein, LHCA3. These combinatorial iron scavenging and sparing strategies make Dunaliella unique among photosynthetic organisms.
|Original language||American English|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - 25 Jul 2023|
Bibliographical noteFunding Information:
ACKNOWLEDGMENTS. We want to thank Uri Pick and Ute Kraemer for their helpful comments.L.D.was supported by the European Molecular Biology Organization (ALTF 166-2016) and by the United States–Israel Binational Agricultural Research and Development (BARD) Fund, Vaadia-BARD Postdoctoral Fellowship Award FI-531-2015. This work was supported by US Department of Energy (DOE), Office of Science,Office of Basic Energy Sciences Award (DE-FG02-04ER15529).Proteomics analyses were supported by an award (49840) from the Environmental Molecular Sciences Laboratory (grid.436923.9), which is a DOE Office of Science User Facility under contract DE-AC05-76RL01830. The research conducted by C.E.B.-H. at the US Department of Energy Joint Genome Institute (https://ror.org/04xm1d337), a DOE Office of Science User Facility, is supported by the Office of Science of the US Department of Energy operated under Contract No. DE-AC02-05CH11231.
Copyright © 2023 the Author(s).