Whole-cell response of the pennate diatom Phaeodactylum tricornutum to iron starvation
Autor: | Nicolas Schauer, Uma Maheswari, Pascal J. Lopez, Chris Bowler, Andrew E. Allen, Markus Lommer, Alisdair R. Fernie, Giovanni Finazzi, Julie LaRoche |
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Rok vydání: | 2008 |
Předmět: |
Chlorophyll
0106 biological sciences Alternative oxidase Nitrogen Photochemistry Iron Oceans and Seas Nitrogen assimilation Thalassiosira pseudonana Carbohydrates Down-Regulation Photosynthesis Models Biological 01 natural sciences Mitochondrial Proteins 03 medical and health sciences chemistry.chemical_compound Nutrient Botany 14. Life underwater Phaeodactylum tricornutum Plant Proteins 030304 developmental biology Diatoms 0303 health sciences Genome Multidisciplinary biology Pigmentation Biological Sciences biology.organism_classification Carbon Mitochondria Diatom chemistry Biochemistry Multigene Family Oxidoreductases 010606 plant biology & botany |
Zdroj: | Proceedings of the National Academy of Sciences of the United States of America, 105 (30). pp. 10438-10443. |
ISSN: | 1091-6490 0027-8424 |
Popis: | Marine primary productivity is iron (Fe)-limited in vast regions of the contemporary oceans, most notably the high nutrient low chlorophyll (HNLC) regions. Diatoms often form large blooms upon the relief of Fe limitation in HNLC regions despite their prebloom low cell density. Although Fe plays an important role in controlling diatom distribution, the mechanisms of Fe uptake and adaptation to low iron availability are largely unknown. Through a combination of nontargeted transcriptomic and metabolomic approaches, we have explored the biochemical strategies preferred by Phaeo dactylum tricornutum at growth-limiting levels of dissolved Fe. Processes carried out by components rich in Fe, such as photosynthesis, mitochondrial electron transport, and nitrate assimilation, were down-regulated. Our results show that this retrenchment is compensated by nitrogen (N) and carbon (C) reallocation from protein and carbohydrate degradation, adaptations to chlorophyll biosynthesis and pigment metabolism, removal of excess electrons by mitochondrial alternative oxidase (AOX) and non-photochemical quenching (NPQ), and augmented Fe-independent oxidative stress responses. Iron limitation leads to the elevated expression of at least three gene clusters absent from the Thalassiosira pseudonana genome that encode for components of iron capture and uptake mechanisms. |
Databáze: | OpenAIRE |
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