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Abstract Volatile Organic Compounds (VOCs) are a diverse collection of molecules critical to cell metabolism, food web interactions, and atmospheric chemistry. The eukaryotic coccolithophoreGephyrocapsa huxleyi, an abundant coastal eukaryotic phytoplankter, forms massive blooms in coastal upwelling regions, which are often terminated by viruses (EhVs).G. huxleyiproduces organosulfur VOCs such as dimethyl sulfide (DMS) and halogenated metabolites that play key roles in atmospheric chemistry. Here we resolved the role of lytic viral infection by EhV207 on VOC production of the model strainG. huxleyiCCMP374. Our analysis identified 79 VOCs significantly impacted by viral infection, particularly during cell lysis, with sulfur containing VOCs like DMS dominating the profiles. Viral lysis results in a nearly six-fold increase in VOC production and generated a previously unrecognized range of VOCs, including 15 sulfur, 22 nitrogen, 2 phosphorus, 19 oxygen and 17 halogen-containing compounds. These findings reveal that viral infection ofG. huxleyireleases VOCs which are much more diverse than previously recognized. We further show that EhV207 primarily accelerates existing metabolic processes inG. huxleyiand facilitates the release of pre-existing intracellular VOCs rather than inducing novel biochemical pathways. This wide range of VOCs may be produced on a massive scale during coccolithophore bloom-and-bust cycles, with important impacts on coastal biogeochemistry and surface ocean/atmosphere interactions.
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Molecular basis for thermogenesis and volatile production in the titan arum
The titan arum (Amorphophallus titanum), commonly known as the corpse flower, produces the largest unbranched inflorescence in the world. Its rare blooms last only a few days and are notable both for their burst of thermogenic activity and for the odor of rotting flesh by which they attract pollinators. Studies on the titan arum can therefor lend insight into the mechanisms underlying thermogenesis as well as the production of sulfur-based volatiles, about which little is known in plants. Here, we made use of transcriptome and metabolite analyses to uncover underlying mechanisms that enable thermogenesis and volatile production in the titan arum. The ability to perform thermogenesis correlated with the expression of genes involved in bypass steps for the mitochondrial electron transport chain, in particular alternative oxidase expression, and through our analysis is placed within the context of sugar transport and metabolism. The major odorants produced by the titan arum are dimethyl disulfide and dimethyl trisulfide, and we identified pathways for sulfur transport and metabolism that culminate in the production of methionine, which our analysis identifies as the amino acid substrate for production of these odorants. Putrescine, derived from arginine, was identified as an additional and previously unrecognized component of the titan arum's odor. Levels of free methionine and putrescine were rapidly depleted during thermogenesis, consistent with roles in production of the titan arum's odor. Models for how tissues of the titan arum contribute to thermogenesis and volatile production are proposed.
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- PAR ID:
- 10610884
- Publisher / Repository:
- National Academy of Sciences, Oxford University Press
- Date Published:
- Journal Name:
- PNAS Nexus
- Volume:
- 3
- Issue:
- 11
- ISSN:
- 2752-6542
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1093/pnasnexus/pgae492
