Morphological, physiological, and transcriptional responses of the freshwater diatom Fragilaria crotonensis to elevated pH conditions
Harmful algal blooms (HABs) caused by the toxin-producing cyanobacteria Microcystis spp., can increase water column pH. While the effect(s) of these basified conditions on the bloom formers are a high research priority, how these pH shifts affect other biota remains understudied. Recently, it was sh...
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| Format: | Article |
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Frontiers Media S.A.
2022-11-01
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| Series: | Frontiers in Microbiology |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fmicb.2022.1044464/full |
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| author | Brittany N. Zepernick David J. Niknejad Gwendolyn F. Stark Alexander R. Truchon Robbie M. Martin Karen L. Rossignol Hans W. Paerl Steven W. Wilhelm |
| author_facet | Brittany N. Zepernick David J. Niknejad Gwendolyn F. Stark Alexander R. Truchon Robbie M. Martin Karen L. Rossignol Hans W. Paerl Steven W. Wilhelm |
| author_sort | Brittany N. Zepernick |
| collection | DOAJ |
| description | Harmful algal blooms (HABs) caused by the toxin-producing cyanobacteria Microcystis spp., can increase water column pH. While the effect(s) of these basified conditions on the bloom formers are a high research priority, how these pH shifts affect other biota remains understudied. Recently, it was shown these high pH levels decrease growth and Si deposition rates in the freshwater diatom Fragilaria crotonensis and natural Lake Erie (Canada-US) diatom populations. However, the physiological mechanisms and transcriptional responses of diatoms associated with these observations remain to be documented. Here, we examined F. crotonensis with a set of morphological, physiological, and transcriptomic tools to identify cellular responses to high pH. We suggest 2 potential mechanisms that may contribute to morphological and physiological pH effects observed in F. crotonensis. Moreover, we identified a significant upregulation of mobile genetic elements in the F. crotonensis genome which appear to be an extreme transcriptional response to this abiotic stress to enhance cellular evolution rates–a process we have termed “genomic roulette.” We discuss the ecological and biogeochemical effects high pH conditions impose on fresh waters and suggest a means by which freshwater diatoms such as F. crotonensis may evade high pH stress to survive in a “basified” future. |
| first_indexed | 2024-04-11T07:59:03Z |
| format | Article |
| id | doaj.art-56cb069be0bb44519e888133dabca041 |
| institution | Directory Open Access Journal |
| issn | 1664-302X |
| language | English |
| last_indexed | 2024-04-11T07:59:03Z |
| publishDate | 2022-11-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Microbiology |
| spelling | doaj.art-56cb069be0bb44519e888133dabca0412022-12-22T04:35:48ZengFrontiers Media S.A.Frontiers in Microbiology1664-302X2022-11-011310.3389/fmicb.2022.10444641044464Morphological, physiological, and transcriptional responses of the freshwater diatom Fragilaria crotonensis to elevated pH conditionsBrittany N. Zepernick0David J. Niknejad1Gwendolyn F. Stark2Alexander R. Truchon3Robbie M. Martin4Karen L. Rossignol5Hans W. Paerl6Steven W. Wilhelm7Department of Microbiology, University of Tennessee, Knoxville, TN, United StatesDepartment of Microbiology, University of Tennessee, Knoxville, TN, United StatesDepartment of Microbiology, University of Tennessee, Knoxville, TN, United StatesDepartment of Microbiology, University of Tennessee, Knoxville, TN, United StatesDepartment of Microbiology, University of Tennessee, Knoxville, TN, United StatesInstitute of Marine Sciences, University of North Carolina at Chapel Hill, Morehead City, NC, United StatesInstitute of Marine Sciences, University of North Carolina at Chapel Hill, Morehead City, NC, United StatesDepartment of Microbiology, University of Tennessee, Knoxville, TN, United StatesHarmful algal blooms (HABs) caused by the toxin-producing cyanobacteria Microcystis spp., can increase water column pH. While the effect(s) of these basified conditions on the bloom formers are a high research priority, how these pH shifts affect other biota remains understudied. Recently, it was shown these high pH levels decrease growth and Si deposition rates in the freshwater diatom Fragilaria crotonensis and natural Lake Erie (Canada-US) diatom populations. However, the physiological mechanisms and transcriptional responses of diatoms associated with these observations remain to be documented. Here, we examined F. crotonensis with a set of morphological, physiological, and transcriptomic tools to identify cellular responses to high pH. We suggest 2 potential mechanisms that may contribute to morphological and physiological pH effects observed in F. crotonensis. Moreover, we identified a significant upregulation of mobile genetic elements in the F. crotonensis genome which appear to be an extreme transcriptional response to this abiotic stress to enhance cellular evolution rates–a process we have termed “genomic roulette.” We discuss the ecological and biogeochemical effects high pH conditions impose on fresh waters and suggest a means by which freshwater diatoms such as F. crotonensis may evade high pH stress to survive in a “basified” future.https://www.frontiersin.org/articles/10.3389/fmicb.2022.1044464/fullharmful algal bloomsclimate changelake basificationpH stressdiatoms |
| spellingShingle | Brittany N. Zepernick David J. Niknejad Gwendolyn F. Stark Alexander R. Truchon Robbie M. Martin Karen L. Rossignol Hans W. Paerl Steven W. Wilhelm Morphological, physiological, and transcriptional responses of the freshwater diatom Fragilaria crotonensis to elevated pH conditions Frontiers in Microbiology harmful algal blooms climate change lake basification pH stress diatoms |
| title | Morphological, physiological, and transcriptional responses of the freshwater diatom Fragilaria crotonensis to elevated pH conditions |
| title_full | Morphological, physiological, and transcriptional responses of the freshwater diatom Fragilaria crotonensis to elevated pH conditions |
| title_fullStr | Morphological, physiological, and transcriptional responses of the freshwater diatom Fragilaria crotonensis to elevated pH conditions |
| title_full_unstemmed | Morphological, physiological, and transcriptional responses of the freshwater diatom Fragilaria crotonensis to elevated pH conditions |
| title_short | Morphological, physiological, and transcriptional responses of the freshwater diatom Fragilaria crotonensis to elevated pH conditions |
| title_sort | morphological physiological and transcriptional responses of the freshwater diatom fragilaria crotonensis to elevated ph conditions |
| topic | harmful algal blooms climate change lake basification pH stress diatoms |
| url | https://www.frontiersin.org/articles/10.3389/fmicb.2022.1044464/full |
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