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Filatov DA, Kirkpatrick M. How does evolution work in superabundant microbes? Trends Microbiol 2024; 32:836-846. [PMID: 38360431 DOI: 10.1016/j.tim.2024.01.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 01/24/2024] [Accepted: 01/26/2024] [Indexed: 02/17/2024]
Abstract
Marine phytoplankton play crucial roles in the Earth's ecological, chemical, and geological processes. They are responsible for about half of global primary production and drive the ocean biological carbon pump. Understanding how plankton species may adapt to the Earth's rapidly changing environments is evidently an urgent priority. This problem requires evolutionary genetic approaches as evolution occurs at the level of allele frequency change within populations driven by genetic drift and natural selection (microevolution). Plankters such as the coccolithophore Gephyrocapsa huxleyi and the cyanobacterium Prochlorococcus 'marinus' are among Earth's most abundant organisms. In this opinion paper we discuss how evolution in astronomically large populations of superabundant microbes (SAMs) may act fundamentally differently than it does in the populations of more modest size found in well-studied organisms. This offers exciting opportunities to study evolution in the conditions that have yet to be explored and also leads to unique challenges. Exploring these opportunities and challenges is the goal of this article.
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Affiliation(s)
- Dmitry A Filatov
- Department of Biology, University of Oxford, Oxford, OX1 3RB, UK.
| | - Mark Kirkpatrick
- Department of Integrative Biology, University of Texas, Austin, TX 78712, USA
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Mao Y, Lin T, Li H, He R, Ye K, Yu W, He Q. Aerobic methane production by phytoplankton as an important methane source of aquatic ecosystems: Reconsidering the global methane budget. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 907:167864. [PMID: 37866611 DOI: 10.1016/j.scitotenv.2023.167864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/09/2023] [Accepted: 10/13/2023] [Indexed: 10/24/2023]
Abstract
Biological methane, a major source of global methane budget, is traditionally thought to be produced in anaerobic environments. However, the recent reports about methane supersaturation occurring in oxygenated water layer, termed as "methane paradox", have challenged this prevailing paradigm. Significantly, growing evidence has indicated that phytoplankton including prokaryotic cyanobacteria and eukaryotic algae are capable of generating methane under aerobic conditions. In this regard, a systematic review of aerobic methane production by phytoplankton is expected to arouse the public attention, contributing to the understanding of methane paradox. Here, we comprehensively summarize the widespread phenomena of methane supersaturation in oxic layers. The remarkable correlation relationships between methane concentration and several key indicators (depth, chlorophyll a level and organic sulfide concentration) indicate the significance of phytoplankton in in-situ methane accumulation. Subsequently, four mechanisms of aerobic methane production by phytoplankton are illustrated in detail, including photosynthesis-driven metabolism, reactive oxygen species (ROS)-driven demethylation of methyl donors, methanogenesis catalyzed by nitrogenase and demethylation of phosphonates catalyzed by CP lyase. The first two pathways occur in various phytoplankton, while the latter two have been specially discovered in cyanobacteria. Additionally, the effects of four crucial factors on aerobic methane production by phytoplankton are also discussed, including phytoplankton species, light, temperature and crucial nutrients. Finally, the measures to control global methane emissions from phytoplankton, the precise intracellular mechanisms of methane production and a more complete global methane budget model are definitely required in the future research on methane production by phytoplankton. This review would provide guidance for future studies of aerobic methane production by phytoplankton and emphasize the potential contribution of aquatic ecosystems to global methane budget.
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Affiliation(s)
- Yufeng Mao
- Key Laboratory of Eco-Environment of Three Gorges Region, Ministry of Education, Chongqing University, Chongqing 400044, China; Key Laboratory of Hydraulic and Waterway Engineering, Ministry of Education, Chongqing Jiaotong University, Chongqing 400074, China; Lingzhi Environmental Protection Co., Ltd, Wuxi 214200, China
| | - Tong Lin
- Key Laboratory of Eco-Environment of Three Gorges Region, Ministry of Education, Chongqing University, Chongqing 400044, China
| | - Hong Li
- Key Laboratory of Eco-Environment of Three Gorges Region, Ministry of Education, Chongqing University, Chongqing 400044, China
| | - Ruixu He
- Key Laboratory of Hydraulic and Waterway Engineering, Ministry of Education, Chongqing Jiaotong University, Chongqing 400074, China
| | - Kailai Ye
- Key Laboratory of Hydraulic and Waterway Engineering, Ministry of Education, Chongqing Jiaotong University, Chongqing 400074, China
| | - Weiwei Yu
- Key Laboratory of Hydraulic and Waterway Engineering, Ministry of Education, Chongqing Jiaotong University, Chongqing 400074, China
| | - Qiang He
- Key Laboratory of Eco-Environment of Three Gorges Region, Ministry of Education, Chongqing University, Chongqing 400044, China.
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Wheeler GL, Sturm D, Langer G. Gephyrocapsa huxleyi (Emiliania huxleyi) as a model system for coccolithophore biology. JOURNAL OF PHYCOLOGY 2023; 59:1123-1129. [PMID: 37983837 DOI: 10.1111/jpy.13404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 10/10/2023] [Indexed: 11/22/2023]
Abstract
Coccolithophores are the most abundant calcifying organisms in modern oceans and are important primary producers in many marine ecosystems. Their ability to generate a cellular covering of calcium carbonate plates (coccoliths) plays a major role in marine biogeochemistry and the global carbon cycle. Coccolithophores also play an important role in sulfur cycling through the production of the climate-active gas dimethyl sulfide. The primary model organism for coccolithophore research is Emiliania huxleyi, now named Gephyrocapsa huxleyi. G. huxleyi has a cosmopolitan distribution, occupying coastal and oceanic environments across the globe, and is the most abundant coccolithophore in modern oceans. Research in G. huxleyi has identified many aspects of coccolithophore biology, from cell biology to ecological interactions. In this perspective, we summarize the key advances made using G. huxleyi and examine the emerging tools for research in this model organism. We discuss the key steps that need to be taken by the research community to advance G. huxleyi as a model organism and the suitability of other species as models for specific aspects of coccolithophore biology.
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Affiliation(s)
- Glen L Wheeler
- The Marine Biological Association of the United Kingdom, The Laboratory, Plymouth, UK
| | - Daniela Sturm
- The Marine Biological Association of the United Kingdom, The Laboratory, Plymouth, UK
- School of Ocean and Earth Science, University of Southampton, Southampton, UK
| | - Gerald Langer
- Institute of Environmental Science and Technology (ICTA-UAB), Universitat Autònoma de Barcelona, Barcelona, Spain
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Xu Z, Yang S, Li M, Bao M, Wu H. Warming modulates the photosynthetic performance of Thalassiosira pseudonana in response to UV radiation. Front Microbiol 2023; 14:1284792. [PMID: 38029218 PMCID: PMC10644151 DOI: 10.3389/fmicb.2023.1284792] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 10/18/2023] [Indexed: 12/01/2023] Open
Abstract
Diatoms form a major component of phytoplankton. These eukaryotic organisms are responsible for approximately 40% of primary productivity in the oceans and contribute significantly to the food web. Here, the influences of ultraviolet radiation (UVR) and ocean warming on diatom photosynthesis were investigated in Thalassiosira pseudonana. The organism was grown at two temperatures, namely, 18°C, the present surface water temperature in summer, and 24°C, an estimate of surface temperature in the year 2,100, under conditions of high photosynthetically active radiation (P, 400-700 nm) alone or in combination with UVR (P + UVR, 295-700 nm). It was found that the maximum photochemical yield of PSII (Fv/Fm) in T. pseudonana was significantly decreased by the radiation exposure with UVR at low temperature, while the rise of temperature alleviated the inhibition induced by UVR. The analysis of PSII subunits turnover showed that high temperature alone or worked synergistically with UVR provoking fast removal of PsbA protein (KPsbA), and also could maintain high PsbD pool in T. pseudonana cells. With the facilitation of PSII repair process, less non-photochemical quenching (NPQ) occurred at high temperature when cells were exposed to P or P + UVR. In addition, irrespective of radiation treatments, high temperature stimulated the induction of SOD activity, which partly contributed to the higher PSII repair rate constant (Krec) as compared to KPsbA. Our findings suggest that the rise in temperature could benefit the photosynthetic performance of T. pseudonana via modulation of its PSII repair cycle and protective capacity, affecting its abundance in phytoplankton in the future warming ocean.
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Affiliation(s)
- Zhiguang Xu
- School of Life Science, Ludong University, Yantai, China
- Key Laboratory of Marine Biotechnology in Universities of Shandong, Ludong University, Yantai, China
| | - Shunda Yang
- School of Life Science, Ludong University, Yantai, China
- Key Laboratory of Marine Biotechnology in Universities of Shandong, Ludong University, Yantai, China
| | - Mingze Li
- School of Life Science, Ludong University, Yantai, China
- Key Laboratory of Marine Biotechnology in Universities of Shandong, Ludong University, Yantai, China
| | - Menglin Bao
- School of Life Science, Ludong University, Yantai, China
- Key Laboratory of Marine Biotechnology in Universities of Shandong, Ludong University, Yantai, China
| | - Hongyan Wu
- School of Life Science, Ludong University, Yantai, China
- Key Laboratory of Marine Biotechnology in Universities of Shandong, Ludong University, Yantai, China
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