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Divergent functions of two clades of flavodoxin in diatoms mitigate oxidative stress and iron limitation

Phytoplankton rely on diverse mechanisms to adapt to the decreased iron bioavailability and oxidative stress-inducing conditions of today’s oxygenated oceans, including replacement of the iron-requiring ferredoxin electron shuttle protein with a less-efficient iron-free flavodoxin under iron-limitin...

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Autores principales: Graff van Creveld, Shiri, Coesel, Sacha N, Blaskowski, Stephen, Groussman, Ryan D, Schatz, Megan J, Armbrust, E Virginia
Formato: Online Artículo Texto
Lenguaje:English
Publicado: eLife Sciences Publications, Ltd 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10287166/
https://www.ncbi.nlm.nih.gov/pubmed/37278403
http://dx.doi.org/10.7554/eLife.84392
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author Graff van Creveld, Shiri
Coesel, Sacha N
Blaskowski, Stephen
Groussman, Ryan D
Schatz, Megan J
Armbrust, E Virginia
author_facet Graff van Creveld, Shiri
Coesel, Sacha N
Blaskowski, Stephen
Groussman, Ryan D
Schatz, Megan J
Armbrust, E Virginia
author_sort Graff van Creveld, Shiri
collection PubMed
description Phytoplankton rely on diverse mechanisms to adapt to the decreased iron bioavailability and oxidative stress-inducing conditions of today’s oxygenated oceans, including replacement of the iron-requiring ferredoxin electron shuttle protein with a less-efficient iron-free flavodoxin under iron-limiting conditions. Yet, diatoms transcribe flavodoxins in high-iron regions in contrast to other phytoplankton. Here, we show that the two clades of flavodoxins present within diatoms exhibit a functional divergence, with only clade II flavodoxins displaying the canonical role in acclimation to iron limitation. We created CRISPR/Cas9 knock-outs of the clade I flavodoxin from the model diatom Thalassiosira pseudonana and found that these cell lines are hypersensitive to oxidative stress, while maintaining a wild-type response to iron limitation. Within natural diatom communities, clade I flavodoxin transcript abundance is regulated over the diel cycle rather than in response to iron availability, whereas clade II transcript abundances increase either in iron-limiting regions or under artificially induced iron limitation. The observed functional specialization of two flavodoxin variants within diatoms reiterates two major stressors associated with contemporary oceans and illustrates diatom strategies to flourish in diverse aquatic ecosystems.
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spelling pubmed-102871662023-06-23 Divergent functions of two clades of flavodoxin in diatoms mitigate oxidative stress and iron limitation Graff van Creveld, Shiri Coesel, Sacha N Blaskowski, Stephen Groussman, Ryan D Schatz, Megan J Armbrust, E Virginia eLife Ecology Phytoplankton rely on diverse mechanisms to adapt to the decreased iron bioavailability and oxidative stress-inducing conditions of today’s oxygenated oceans, including replacement of the iron-requiring ferredoxin electron shuttle protein with a less-efficient iron-free flavodoxin under iron-limiting conditions. Yet, diatoms transcribe flavodoxins in high-iron regions in contrast to other phytoplankton. Here, we show that the two clades of flavodoxins present within diatoms exhibit a functional divergence, with only clade II flavodoxins displaying the canonical role in acclimation to iron limitation. We created CRISPR/Cas9 knock-outs of the clade I flavodoxin from the model diatom Thalassiosira pseudonana and found that these cell lines are hypersensitive to oxidative stress, while maintaining a wild-type response to iron limitation. Within natural diatom communities, clade I flavodoxin transcript abundance is regulated over the diel cycle rather than in response to iron availability, whereas clade II transcript abundances increase either in iron-limiting regions or under artificially induced iron limitation. The observed functional specialization of two flavodoxin variants within diatoms reiterates two major stressors associated with contemporary oceans and illustrates diatom strategies to flourish in diverse aquatic ecosystems. eLife Sciences Publications, Ltd 2023-06-06 /pmc/articles/PMC10287166/ /pubmed/37278403 http://dx.doi.org/10.7554/eLife.84392 Text en © 2023, Graff van Creveld et al https://creativecommons.org/licenses/by/4.0/This article is distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use and redistribution provided that the original author and source are credited.
spellingShingle Ecology
Graff van Creveld, Shiri
Coesel, Sacha N
Blaskowski, Stephen
Groussman, Ryan D
Schatz, Megan J
Armbrust, E Virginia
Divergent functions of two clades of flavodoxin in diatoms mitigate oxidative stress and iron limitation
title Divergent functions of two clades of flavodoxin in diatoms mitigate oxidative stress and iron limitation
title_full Divergent functions of two clades of flavodoxin in diatoms mitigate oxidative stress and iron limitation
title_fullStr Divergent functions of two clades of flavodoxin in diatoms mitigate oxidative stress and iron limitation
title_full_unstemmed Divergent functions of two clades of flavodoxin in diatoms mitigate oxidative stress and iron limitation
title_short Divergent functions of two clades of flavodoxin in diatoms mitigate oxidative stress and iron limitation
title_sort divergent functions of two clades of flavodoxin in diatoms mitigate oxidative stress and iron limitation
topic Ecology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10287166/
https://www.ncbi.nlm.nih.gov/pubmed/37278403
http://dx.doi.org/10.7554/eLife.84392
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