@article {zhang_stimulating_2023,
	title = {Stimulating and toxic effect of chromium on growth and photosynthesis of a marine chlorophyte},
	journal = {New Phytologist},
	volume = {n/a},
	number = {n/a},
	year = {2023},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/nph.19376},
	abstract = {Marine phytoplankton can interchange trace metals in various biochemical functions, particularly under metal-limiting conditions. Here, we investigate the stimulating and toxicity effect of chromium (Cr) on a marine Chlorophyceae Osetreococcus tauri under Fe-replete and Fe-deficient conditions. We determined the growth, photosynthesis, and proteome expressions of Osetreococcus tauri cultured under different Cr and Fe concentrations. In Fe-replete conditions, the presence of Cr(VI) stimulated significantly the growth rate and the maximum yield of photochemistry of photosystem II (Fv/Fm) of the phytoplankton, while the functional absorption cross-section of photosystem II (σPSII) did not change. Minor additions of Cr(VI) partially rescued phytoplankton growth under Fe-limited conditions. Proteomic analysis of this alga grown in Fe-replete normal and Fe-replete with Cr addition media (10 μM Cr) showed that the presence of Cr significantly decreased the expression of phosphate-transporting proteins and photosynthetic proteins, while increasing the expression of proteins related to carbon assimilation. Cr can stimulate the growth and photosynthesis of O. tauri, but the effects are dependent on both the Cr(VI) concentration and the availability of Fe. The proteomic results further suggest that Cr(VI) addition might significantly increase starch production and carbon fixation.},
	keywords = {chromium, Photosynthesis, phytoplankton, proteomics, RCC1, RCC1242, trace metal},
	issn = {1469-8137},
	doi = {10.1111/nph.19376},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/nph.19376},
	author = {Zhang, Qiong and Charles, Philip D. and Bendif, El Mahdi and Hester, Svenja S. and Mohammad, Shabaz and Rickaby, Rosalind E. M.}
}
@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 {tostevin_influence_2021,
	title = {The influence of elevated SiO2(aq) on intracellular silica uptake and microbial metabolism},
	journal = {Geobiology},
	volume = {n/a},
	number = {n/a},
	year = {2021},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/gbi.12442},
	abstract = {Microbes are known to accumulate intracellular SiO2(aq) up to 100s of mmol/l from modern seawater (SiO2(aq) <100 {\textmu}mol/l), despite having no known nutrient requirement for Si. Before the evolution of siliceous skeletons, marine silica concentrations were likely an order of magnitude higher than the modern ocean, raising the possibility that intracellular SiO2(aq) accumulation interfered with normal cellular function in non-silicifying algae. Yet, because few culturing studies have isolated the effects of SiO2(aq) at high concentration, the potential impact of elevated marine silica on early microbial evolution is unknown. Here, we test the influence of elevated SiO2(aq) on eukaryotic algae, as well as a prokaryote species. Our results demonstrate that under SiO2(aq) concentrations relevant to ancient seawater, intracellular Si accumulates to concentrations comparable to those found in siliceous algae such as diatoms. In addition, all eukaryotic algae showed a statistically significant response to the high-Si treatment, including reduced average cell sizes and/or a reduction in the maximum growth rate. In contrast, there was no consistent response to the high-Si treatment by the prokaryote species. Our results highlight the possibility that elevated marine SiO2(aq) may have been an environmental stressor during early eukaryotic evolution.},
	keywords = {Archaean, culturing, microbial metabolism, Proterozoic, RCC1, RCC1216, rcc1512, RCC1547, rcc539, silica},
	issn = {1472-4669},
	doi = {10.1111/gbi.12442},
	url = {http://onlinelibrary.wiley.com/doi/abs/10.1111/gbi.12442},
	author = {Tostevin, Rosalie and Snow, Joseph T. and Zhang, Qiong and Tosca, Nicholas J. and Rickaby, Rosalind E. M.}
}
@article {Zhang2020,
	title = {Interactions of thallium with marine phytoplankton},
	journal = {Geochimica et Cosmochimica Acta},
	volume = {276},
	year = {2020},
	note = {Publisher: The Author(s) tex.mendeley-tags: RCC1,RCC1242,RCC1353,RCC1557,RCC174,RCC834,RCC950},
	pages = {1{\textendash}13},
	keywords = {bioaccumulation, biogeochemical cycle, metallome, phytoplankton, RCC1, RCC1242, RCC1353, RCC1557, rcc174, RCC834, RCC950, thallium},
	issn = {00167037},
	doi = {10.1016/j.gca.2020.02.024},
	url = {https://doi.org/10.1016/j.gca.2020.02.024 https://linkinghub.elsevier.com/retrieve/pii/S0016703720301344},
	author = {Zhang, Qiong and Rickaby, Rosalind E.M.}
}
@article {Wilson2019,
	title = {Susceptibility of algae to Cr toxicity reveals contrasting metal management strategies},
	journal = {Limnology and Oceanography},
	volume = {64},
	number = {5},
	year = {2019},
	note = {Publisher: John Wiley \& Sons, Ltd tex.mendeley-tags: RCC1,RCC1242,RCC4221,RCC950},
	month = {sep},
	pages = {2271{\textendash}2282},
	abstract = {At the Paleozoic{\textendash}Mesozoic boundary, the dominance of marine eukaryotic algae shifted from the green (chlorophyll b) to the red (chlorophyll c) superfamily. Selection pressures caused by the bioavailability of trace metals associated with increasing oxygenation of the ocean may have played a key role in this algal revolution. From a scan of elemental compositions, a significant difference in the cellular Cr/P quota was found between the two superfamilies. Here, the different responses to high levels of Cr exposure reveal contrasting strategies for metal uptake and homeostasis in these algal lineages. At high Cr(VI) concentrations, red lineages experience growth inhibition through reduced photosynthetic capability, while green lineages are completely unaffected. Moreover, Cr(VI) has a more significant impact on the metallomes of red lineage algae, in which metal/P ratios increased with increasing Cr(VI) concentration for many trace elements. Green algae have higher specificity transporters to prevent Cr(VI) from entering the cell, and more specific intracellular stores of Cr within the membrane fraction than the red algae, which accumulate more Cr mistakenly in the cytosol fraction via lower affinity transport mechanisms. Green algal approaches require greater nutrient investments in the more numerous transport proteins required and management of specific metals, a strategy better adapted to the resource-rich coastal waters. By contrast, the red algae are nutrient-efficient with fewer and less discriminate metal transporters, which can be fast and better adapted in the oligotrophic, oxygenated open ocean, which has prevailed since the deepening of the oxygen minimum zones at the start of the Mesozoic era.},
	keywords = {RCC1, RCC1242, RCC4221, RCC950},
	issn = {0024-3590},
	doi = {10.1002/lno.11183},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/lno.11183},
	author = {Wilson, Will and Zhang, Qiong and Rickaby, Rosalind E. M.}
}
