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Chai X, Li X, Hii KS, Zhang Q, Deng Q, Wan L, Zheng L, Lim PT, Tan SN, Mohd-Din M, Song C, Song L, Zhou Y, Cao X. Blooms of diatom and dinoflagellate associated with nutrient imbalance driven by cycling of nitrogen and phosphorus in anaerobic sediments in Johor Strait (Malaysia). Mar Environ Res 2021; 169:105398. [PMID: 34171592 DOI: 10.1016/j.marenvres.2021.105398] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 06/13/2021] [Accepted: 06/14/2021] [Indexed: 06/13/2023]
Abstract
Coastal eutrophication is one of the pivotal factors driving occurrence of harmful algal blooms (HABs), whose underlying mechanism remained unclear. To better understand the nutrient regime triggering HABs and their formation process, the phytoplankton composition and its response to varying nitrogen (N) and phosphorus (P), physio-chemical parameters in water and sediment in Johor Strait in March 2019 were analyzed. Surface and sub-surface HABs were observed with the main causative species of Skeletonema, Chaetoceros and Karlodinium. The ecophysiological responses of Skeletonema to the low ambient N/P ratio such as secreting alkaline phosphatase, regulating cell morphology (volume; surface area/volume ratio) might play an important role in dominating the community. Anaerobic sediment iron-bound P release and simultaneous N removal by denitrification and anammox, shaped the stoichiometry of N and P in water column. The decrease of N/P ratio might shift the phytoplankton community into the dominance of HABs causative diatoms and dinoflagellates.
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Affiliation(s)
- Xiaojie Chai
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, PR China; University of Chinese Academy of Sciences, Beijing, 100039, PR China.
| | - Xiaowen Li
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, PR China.
| | - Kieng Soon Hii
- Bachok Marine Research Station, Institute of Ocean and Earth Sciences, University of Malaya, Bachok, 16310, Kelantan, Malaysia.
| | - Qi Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, PR China.
| | - Qinghui Deng
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, PR China; University of Chinese Academy of Sciences, Beijing, 100039, PR China.
| | - Lingling Wan
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, PR China.
| | - Lingling Zheng
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, PR China.
| | - Po Teen Lim
- Bachok Marine Research Station, Institute of Ocean and Earth Sciences, University of Malaya, Bachok, 16310, Kelantan, Malaysia.
| | - Suh Nih Tan
- Bachok Marine Research Station, Institute of Ocean and Earth Sciences, University of Malaya, Bachok, 16310, Kelantan, Malaysia; Institute of Oceanography and Environment, University of Terengganu Malaysia, Malaysia; China-ASEAN College of Marine Sciences, Xiamen University Malaysia, Sepang, 43900, Selangor Malaysia.
| | - Monaliza Mohd-Din
- Bachok Marine Research Station, Institute of Ocean and Earth Sciences, University of Malaya, Bachok, 16310, Kelantan, Malaysia.
| | - Chunlei Song
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, PR China.
| | - Lirong Song
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, PR China.
| | - Yiyong Zhou
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, PR China.
| | - Xiuyun Cao
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, PR China.
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Santin A, Caputi L, Longo A, Chiurazzi M, Ribera d'Alcalà M, Russo MT, Ferrante MI, Rogato A. Integrative omics identification, evolutionary and structural analysis of low affinity nitrate transporters in diatoms, diNPFs. Open Biol 2021; 11:200395. [PMID: 33823659 PMCID: PMC8025304 DOI: 10.1098/rsob.200395] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Diatoms are one of the major and most diverse groups of phytoplankton, with chimeric genomes harbouring a combination of genes of bacterial, animal and plant origin. They have developed sophisticated mechanisms to face environmental variations. In marine environments, nutrients concentration shows significant temporal and spatial variability, influencing phytoplankton growth. Among nutrients, nitrogen, present at micromolar levels, is often a limiting resource. Here, we report a comprehensive characterization of the Nitrate Transporter 1/Peptide Transporter Family (NPF) in diatoms, diNPFs. NPFs are well characterized in many organisms where they recognize a broad range of substrates, ranging from short-chained di- and tri-peptides in bacteria, fungi and mammals to a wide variety of molecules including nitrate in higher plants. Scarce information is available for diNPFs. We integrated-omics, phylogenetic, structural and expression analyses, to infer information on their role in diatoms. diNPF genes diverged to produce two distinct clades with strong sequence and structural homology with either bacterial or plant NPFs, with different predicted sub-cellular localization, suggesting that the divergence resulted in functional diversification. Moreover, transcription analysis of diNPF genes under different laboratory and environmental growth conditions suggests that diNPF diversification led to genetic adaptations that might contribute to diatoms ability to flourish in diverse environmental conditions.
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Affiliation(s)
- Anna Santin
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy
| | - Luigi Caputi
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy
| | - Antonella Longo
- BioDiscovery Institute, Denton, TX, USA.,Department of Biological Sciences, University of North Texas, Denton, TX, USA
| | - Maurizio Chiurazzi
- Institute of Biosciences and BioResources, CNR, Via P. Castellino 111, 80131 Naples, Italy
| | | | | | | | - Alessandra Rogato
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy.,Institute of Biosciences and BioResources, CNR, Via P. Castellino 111, 80131 Naples, Italy
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Lampe RH, Hernandez G, Lin YY, Marchetti A. Representative Diatom and Coccolithophore Species Exhibit Divergent Responses throughout Simulated Upwelling Cycles. mSystems 2021; 6:e00188-21. [PMID: 33785571 DOI: 10.1128/mSystems.00188-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Wind-driven upwelling followed by relaxation results in cycles of cold nutrient-rich water fueling intense phytoplankton blooms followed by nutrient depletion, bloom decline, and sinking of cells. Surviving cells at depth can then be vertically transported back to the surface with upwelled waters to seed another bloom. As a result of these cycles, phytoplankton communities in upwelling regions are transported through a wide range of light and nutrient conditions. Diatoms appear to be well suited for these cycles, but their responses to them remain understudied. To investigate the bases for diatoms’ ecological success in upwelling environments, we employed laboratory simulations of a complete upwelling cycle with a common diatom, Chaetoceros decipiens, and coccolithophore, Emiliania huxleyi. We show that while both organisms exhibited physiological and transcriptomic plasticity, the diatom displayed a distinct response enabling it to rapidly shift-up growth rates and nitrate assimilation when returned to light and available nutrients following dark nutrient-deplete conditions. As observed in natural diatom communities, C. decipiens highly expresses before upwelling, or frontloads, key transcriptional and nitrate assimilation genes, coordinating its rapid response to upwelling conditions. Low-iron simulations showed that C. decipiens is capable of maintaining this response when iron is limiting to growth, whereas E. huxleyi is not. Differential expression between iron treatments further revealed specific genes used by each organism under low iron availability. Overall, these results highlight the responses of two dominant phytoplankton groups to upwelling cycles, providing insight into the mechanisms fueling diatom blooms during upwelling events. IMPORTANCE Coastal upwelling regions are among the most biologically productive ecosystems. During upwelling events, nutrient-rich water is delivered from depth resulting in intense phytoplankton blooms typically dominated by diatoms. Along with nutrients, phytoplankton may also be transported from depth to seed these blooms then return to depth as upwelling subsides creating a cycle with varied conditions. To investigate diatoms’ success in upwelling regions, we compare the responses of a common diatom and coccolithophore throughout simulated upwelling cycles under iron-replete and iron-limiting conditions. The diatom exhibited a distinct rapid response to upwelling irrespective of iron status, whereas the coccolithophore’s response was either delayed or suppressed depending on iron availability. Concurrently, the diatom highly expresses, or frontloads, nitrate assimilation genes prior to upwelling, potentially enabling this rapid response. These results provide insight into the molecular mechanisms underlying diatom blooms and ecological success in upwelling regions.
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