@booklet {barton_novel_2023,
	title = {A novel fluoro-electrochemical technique for classifying diverse marine nanophytoplankton},
	year = {2023},
	month = {apr},
	publisher = {Life Sciences},
	type = {preprint},
	abstract = {<p>To broaden our understanding of pelagic ecosystem responses to environmental change, it is essential that we improve the spatio-temporal resolution of in situ monitoring of phytoplankton communities. A key challenge for existing methods is in classifying and quantifying cells within the nanophytoplankton size range (2-20{\textmu}m). This is particularly difficult when there are similarities in morphology, making visual differentiation difficult for both trained taxonomists and machine learning based approaches. Here we present a rapid fluoro-electrochemical technique for classifying nanophytoplankton, and using a library of 52 diverse strains of nanophytoplankton we assess the accuracy of this technique based on two measurements at the individual level: charge required to reduce per cell chlorophyll a fluorescence by 50\%, and cell radius. We demonstrate a high degree of accuracy overall (\&gt;90\%) in categorising cells belonging to widely recognised key functional groups, however this is reduced when we consider the broader diversity of {\textquotedblleft}nano-phytoflagellates{\textquotedblright}. Notably, we observe that some groups, for example calcifying Isochrysidales, have much greater resilience to electrochemically driven oxidative conditions relative to others of a similar size, making them more easily categorised by the technique. The findings of this study present a promising step forward in advancing our toolkit for monitoring phytoplankton communities. We highlight that, for improved categorisation accuracy, future iterations of the method can be enhanced by measuring additional predictor variables with minimal adjustments to the set-up. In doing so, we foresee this technique being highly applicable, and potentially invaluable, for in situ classification and enumeration of the nanophytoplankton size fraction.</p>
},
	keywords = {RCC1, rcc1084, RCC1130, RCC1150, RCC1178, RCC1185, RCC1198, RCC1216, rcc1217, RCC1242, RCC1314, RCC1346, RCC1489, RCC1511, RCC1546, RCC1557, RCC1614, rcc1731, RCC191, RCC2570, RCC3598, RCC3696, RCC3776, RCC3780, RCC4207, RCC4221, RCC4273, RCC4657, RCC4660, RCC6, RCC623, RCC6516, RCC656, RCC678, RCC69, RCC74, RCC76, RCC8, RCC80, RCC81, RCC88, RCC911, RCC950},
	doi = {10.1002/lom3.10572},
	url = {https://aslopubs.onlinelibrary.wiley.com/doi/10.1002/lom3.10572},
	author = {Barton, Samuel and Yang, Minjun and Chen, Haotian and Batchelor-McAuley, Christopher and Compton, Richard and Bouman, Heather and Rickaby, Rosalind}
}
@article {bendif_rapid_2023,
	title = {Rapid diversification underlying the global dominance of a cosmopolitan phytoplankton},
	journal = {The ISME Journal},
	year = {2023},
	note = {Publisher: Nature Publishing Group},
	pages = {1{\textendash}11},
	abstract = {Marine phytoplankton play important roles in the global ecosystem, with a limited number of cosmopolitan keystone species driving their biomass. Recent studies have revealed that many of these phytoplankton are complexes composed of sibling species, but little is known about the evolutionary processes underlying their formation. Gephyrocapsa huxleyi, a widely distributed and abundant unicellular marine planktonic algae, produces calcified scales (coccoliths), thereby significantly affects global biogeochemical cycles via sequestration of inorganic carbon. This species is composed of morphotypes defined by differing degrees of coccolith calcification, the evolutionary ecology of which remains unclear. Here, we report an integrated morphological, ecological and genomic survey across globally distributed G. huxleyi strains to reconstruct evolutionary relationships between morphotypes in relation to their habitats. While G. huxleyi has been considered a single cosmopolitan species, our analyses demonstrate that it has evolved to comprise at least three distinct species, which led us to formally revise the taxonomy of the G. huxleyi complex. Moreover, the first speciation event occurred before the onset of the last interglacial period (\textasciitilde140 ka), while the second followed during this interglacial. Then, further rapid diversifications occurred during the most recent ice-sheet expansion of the last glacial period and established morphotypes as dominant populations across environmental clines. These results suggest that glacial-cycle dynamics contributed to the isolation of ocean basins and the segregations of oceans fronts as extrinsic drivers of micro-evolutionary radiations in extant marine phytoplankton.},
	keywords = {Microbial biooceanography, phylogenomics, population genetics, rcc1212, RCC1216, rcc1220, RCC1239, RCC1240, RCC1242, RCC1245, rcc1252, RCC1253, RCC1266, RCC1304, rcc1731, RCC1754, RCC1813, RCC1823, rcc1824, RCC1830, RCC1838, RCC1840, RCC1853, RCC1856, RCC3746, RCC4027, RCC4028, RCC4030, RCC5134, RCC5137, RCC5141, RCC6381, RCC6421, RCC6427, RCC6566, RCC6660, RCC6666, RCC911, RCC963},
	issn = {1751-7370},
	doi = {10.1038/s41396-023-01365-5},
	url = {https://www.nature.com/articles/s41396-023-01365-5},
	author = {Bendif, El Mahdi and Probert, Ian and Archontikis, Odysseas A. and Young, Jeremy R. and Beaufort, Luc and Rickaby, Rosalind E. and Filatov, Dmitry}
}
@article {liu_phycosphere_2022,
	title = {Phycosphere pH of unicellular nano- and micro- phytoplankton cells and consequences for iron speciation},
	journal = {The ISME Journal},
	volume = {16},
	number = {10},
	year = {2022},
	note = {Number: 10 Publisher: Nature Publishing Group},
	month = {oct},
	pages = {2329{\textendash}2336},
	abstract = {Surface ocean pH is declining due to anthropogenic atmospheric CO2 uptake with a global decline of \textasciitilde0.3 possible by 2100. Extracellular pH influences a range of biological processes, including nutrient uptake, calcification and silicification. However, there are poor constraints on how pH levels in the extracellular microenvironment surrounding phytoplankton cells (the phycosphere) differ from bulk seawater. This adds uncertainty to biological impacts of environmental change. Furthermore, previous modelling work suggests that phycosphere pH of small cells is close to bulk seawater, and this has not been experimentally verified. Here we observe under 140 μmol photons{\textperiodcentered}m-2{\textperiodcentered}s-1 the phycosphere pH of Chlamydomonas concordia (5 {\textmu}m diameter), Emiliania huxleyi (5 {\textmu}m), Coscinodiscus radiatus (50 {\textmu}m) and C. wailesii (100 {\textmu}m) are 0.11 {\textpm} 0.07, 0.20 {\textpm} 0.09, 0.41 {\textpm} 0.04 and 0.15 {\textpm} 0.20 (mean {\textpm} SD) higher than bulk seawater (pH 8.00), respectively. Thickness of the pH boundary layer of C. wailesii increases from 18 {\textpm} 4 to 122 {\textpm} 17 {\textmu}m when bulk seawater pH decreases from 8.00 to 7.78. Phycosphere pH is regulated by photosynthesis and extracellular enzymatic transformation of bicarbonate, as well as being influenced by light intensity and seawater pH and buffering capacity. The pH change alters Fe speciation in the phycosphere, and hence Fe availability to phytoplankton is likely better predicted by the phycosphere, rather than bulk seawater. Overall, the precise quantification of chemical conditions in the phycosphere is crucial for assessing the sensitivity of marine phytoplankton to ongoing ocean acidification and Fe limitation in surface oceans.},
	keywords = {Biogeochemistry, Microbial biooceanography, RCC1, rcc1731, Water microbiology},
	issn = {1751-7370},
	doi = {10.1038/s41396-022-01280-1},
	url = {https://www.nature.com/articles/s41396-022-01280-1},
	author = {Liu, Fengjie and Gledhill, Martha and Tan, Qiao-Guo and Zhu, Kechen and Zhang, Qiong and Sala{\"u}n, Pascal and Tagliabue, Alessandro and Zhang, Yanjun and Weiss, Dominik and Achterberg, Eric P. and Korchev, Yuri}
}
@article {pollara_bacterial_2021,
	title = {Bacterial Quorum-Sensing Signal Arrests Phytoplankton Cell Division and Impacts Virus-Induced Mortality},
	journal = {mSphere},
	volume = {6},
	number = {3},
	year = {2021},
	pages = {e00009{\textendash}21, /msphere/6/3/mSph.00009{\textendash}21.atom},
	abstract = {Interactions between phytoplankton and heterotrophic bacteria fundamentally shape marine ecosystems by controlling primary production, structuring marine food webs, mediating carbon export, and influencing global climate. Phytoplankton-bacterium interactions are facilitated by secreted compounds; however, linking these chemical signals, their mechanisms of action, and their resultant ecological consequences remains a fundamental challenge. The bacterial quorumsensing signal 2-heptyl-4-quinolone (HHQ) induces immediate, yet reversible, cellular stasis (no cell division or mortality) in the coccolithophore Emiliania huxleyi; however, the mechanism responsible remains unknown. Using transcriptomic and proteomic approaches in combination with diagnostic biochemical and fluorescent cell-based assays, we show that HHQ exposure leads to prolonged S-phase arrest in phytoplankton coincident with the accumulation of DNA damage and a lack of repair despite the induction of the DNA damage response (DDR). While this effect is reversible, HHQ-exposed phytoplankton were also protected from viral mortality, ascribing a new role of quorum-sensing signals in regulating multitrophic interactions. Furthermore, our data demonstrate that in situ measurements of HHQ coincide with areas of enhanced micro- and nanoplankton biomass. Our results suggest bacterial communication signals as emerging players that may be one of the contributing factors that help structure complex microbial communities throughout the ocean.},
	keywords = {rcc1731},
	issn = {2379-5042},
	doi = {10.1128/mSphere.00009-21},
	url = {https://msphere.asm.org/content/6/3/e00009-21},
	author = {Pollara, Scott B. and Becker, Jamie W. and Nunn, Brook L. and Boiteau, Rene and Repeta, Daniel and Mudge, Miranda C. and Downing, Grayton and Chase, Davis and Harvey, Elizabeth L. and Whalen, Kristen E.},
	editor = {McMahon, Katherine}
}
@article {Gebser2020,
	title = {Phytoplankton-derived zwitterionic gonyol and dimethylsulfonioacetate interfere with microbial dimethylsulfoniopropionate sulfur cycling},
	journal = {MicrobiologyOpen},
	number = {February},
	year = {2020},
	note = {tex.mendeley-tags: RCC1731,RCC75,RCC76RCC1217,RCC841},
	month = {feb},
	pages = {e1014},
	keywords = {rcc1217, rcc1731, RCC75, RCC76, RCC841, school of life sciences, university of essex},
	issn = {20458827},
	doi = {10.1002/mbo3.1014},
	url = {http://doi.wiley.com/10.1002/mbo3.1014},
	author = {Gebser, Bj{\"o}rn and Thume, Kathleen and Steinke, Michael and Pohnert, Georg}
}
@article {Barton2019,
	title = {Quantifying the temperature dependence of growth rate in marine phytoplankton within and across species},
	journal = {Limnology and Oceanography},
	year = {2019},
	note = {tex.mendeley-tags: RCC1303,RCC1512,RCC1731,RCC1773,RCC4221,RCC539,RCC6,RCC623,RCC626,RCC652,RCC653,RCC655,RCC834,RCC88},
	abstract = {Abstract Models of marine biogeochemistry capture the effects of temperature on phytoplankton growth via the monotonic, exponential Eppley coefficient, without considering the physiological or evolutionary processes that underpin this emergent, across-species temperature response. Here, we investigated both the within- and across-species temperature dependence of growth rate for 18 species of marine phytoplankton. We found that the temperature dependence of growth rate derived across species was lower than the average temperature response within species. This finding supports a {\textquotedblleft}partial compensation{\textquotedblright} model of thermal adaptation and suggests that adaptation can partially compensate for the underlying thermodynamic effects of temperature on physiological rates observed within species. We also found that thermal tolerance traits (e.g. the optimum temperature for growth) systematically covaried with a host of key functional traits (e.g. cell size, elemental composition). Consequently, turnover in species composition in a warmer ocean, linked to interspecific variability in thermal tolerance traits, could be associated with major shifts in the functional trait composition of marine phytoplankton communities with far reaching implications for ecosystem functioning.},
	keywords = {RCC1303, rcc1512, rcc1731, RCC1773, RCC4221, rcc539, RCC6, RCC623, RCC626, RCC652, RCC653, RCC655, RCC834, RCC88},
	issn = {0024-3590},
	doi = {10.1002/lno.11170},
	author = {Barton, Samuel and Yvon-Durocher, Gabriel}
}
@article {Walker2018,
	title = {The requirement for calcification differs between ecologically important coccolithophore species},
	journal = {New Phytologist},
	volume = {in press},
	year = {2018},
	note = {tex.mendeley-tags: RCC1731},
	month = {jun},
	keywords = {Calcification, coccolithophore, Coccolithus braarudii, Emiliania huxleyi, phytoplankton, rcc1731},
	issn = {0028646X},
	doi = {10.1111/nph.15272},
	url = {http://doi.wiley.com/10.1111/nph.15272},
	author = {Walker, Charlotte E. and Taylor, Alison R. and Langer, Gerald and Durak, Gra{\.z}yna M. and Heath, Sarah and Probert, Ian and Tyrrell, Toby and Brownlee, Colin and Wheeler, Glen L.}
}
@article {Blanco-Ameijeiras2016,
	title = {Phenotypic variability in the coccolithophore emiliania huxleyi.},
	journal = {PloS one},
	volume = {11},
	number = {6},
	year = {2016},
	note = {ISBN: 10.1371/journal.pone.0157697 Publisher: Public Library of Science tex.mendeley-tags: 2016,rcc1212,rcc1215,rcc1216,rcc1228,rcc1238,rcc1255,rcc1258,rcc1259,rcc1731,rcc3553},
	month = {jan},
	pages = {e0157697},
	abstract = {Coccolithophores are a vital part of oceanic phytoplankton assemblages that produce organic matter and calcium carbonate (CaCO3) containing traces of other elements (i.e. Sr and Mg). Their associated carbon export from the euphotic zone to the oceans{\textquoteright} interior plays a crucial role in CO2 feedback mechanisms and biogeochemical cycles. The coccolithophore Emiliania huxleyi has been widely studied as a model organism to understand physiological, biogeochemical, and ecological processes in marine sciences. Here, we show the inter-strain variability in physiological and biogeochemical traits in 13 strains of E. huxleyi from various biogeographical provinces obtained from culture collections commonly used in the literature. Our results demonstrate that inter-strain genetic variability has greater potential to induce larger phenotypic differences than the phenotypic plasticity of single strains cultured under a broad range of variable environmental conditions. The range of variation found in physiological parameters and calcite Sr:Ca highlights the need to reconsider phenotypic variability in paleoproxy calibrations and model parameterizations to adequately translate findings from single strain laboratory experiments to the real ocean.},
	keywords = {2016, rcc1212, RCC1215, RCC1216, RCC1228, rcc1238, RCC1255, rcc1258, RCC1259, rcc1731, rcc3553},
	issn = {1932-6203},
	doi = {10.1371/journal.pone.0157697},
	url = {http://dx.doi.org/10.1371/journal.pone.0157697},
	author = {Blanco-Ameijeiras, Sonia and Lebrato, Mario and Stoll, Heather M and Iglesias-Rodriguez, Debora and M{\"u}ller, Marius N and M{\'e}ndez-Vicente, Ana and Oschlies, Andreas}
}
