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Qu PP, Fu FX, Wang XW, Kling JD, Elghazzawy M, Huh M, Zhou QQ, Wang C, Mak EWK, Lee MD, Yang N, Hutchins DA. Two co-dominant nitrogen-fixing cyanobacteria demonstrate distinct acclimation and adaptation responses to cope with ocean warming. ENVIRONMENTAL MICROBIOLOGY REPORTS 2022; 14:203-217. [PMID: 35023627 DOI: 10.1111/1758-2229.13041] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 12/17/2021] [Accepted: 12/18/2021] [Indexed: 05/28/2023]
Abstract
The globally dominant N2 -fixing cyanobacteria Trichodesmium and Crocosphaera provide vital nitrogen supplies to subtropical and tropical oceans, but little is known about how they will be affected by long-term ocean warming. We tested their thermal responses using experimental evolution methods during 2 years of selection at optimal (28°C), supra-optimal (32°C) and suboptimal (22°C) temperatures. After several hundred generations under thermal selection, changes in growth parameters, as well as N and C fixation rates, suggested that Trichodesmium did not adapt to the three selection temperature regimes during the 2-year evolution experiment, but could instead rapidly and reversibly acclimate to temperature shifts from 20°C to 34°C. In contrast, over the same timeframe apparent thermal adaptation was observed in Crocosphaera, as evidenced by irreversible phenotypic changes as well as whole-genome sequencing and variant analysis. Especially under stressful warming conditions (34°C), 32°C-selected Crocosphaera cells had an advantage in survival and nitrogen fixation over cell lines selected at 22°C and 28°C. The distinct strategies of phenotypic plasticity versus irreversible adaptation in these two sympatric diazotrophs are both viable ways to maintain fitness despite long-term temperature changes, and so could help to stabilize key ocean nitrogen cycle functions under future warming scenarios.
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Affiliation(s)
- Ping-Ping Qu
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - Fei-Xue Fu
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - Xin-Wei Wang
- School of Marine Sciences, Ningbo University, Ningbo, Zhejiang, 315211, China
| | - Joshua D Kling
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - Mariam Elghazzawy
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - Megan Huh
- Department of Preventative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90089, USA
| | - Qian-Qian Zhou
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, Fujian, 361005, China
| | - Chunguang Wang
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, Fujian, 361005, China
| | - Esther Wing Kwan Mak
- Department of Ocean Sciences and Institute of Marine Sciences, University of California, Santa Cruz, CA, 95064, USA
| | - Michael D Lee
- Exobiology Branch, NASA Ames Research Center, Mountain View, CA, 94035, USA
- Blue Marble Space Institute of Science, Seattle, WA, 98154, USA
| | - Nina Yang
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - David A Hutchins
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA
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Abstract
Spatial organization is a hallmark of all living systems. Even bacteria, the smallest forms of cellular life, display defined shapes and complex internal organization, showcasing a highly structured genome, cytoskeletal filaments, localized scaffolding structures, dynamic spatial patterns, active transport, and occasionally, intracellular organelles. Spatial order is required for faithful and efficient cellular replication and offers a powerful means for the development of unique biological properties. Here, we discuss organizational features of bacterial cells and highlight how bacteria have evolved diverse spatial mechanisms to overcome challenges cells face as self-replicating entities.
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Wagstaff J, Löwe J. Prokaryotic cytoskeletons: protein filaments organizing small cells. Nat Rev Microbiol 2018; 16:187-201. [PMID: 29355854 DOI: 10.1038/nrmicro.2017.153] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Most, if not all, bacterial and archaeal cells contain at least one protein filament system. Although these filament systems in some cases form structures that are very similar to eukaryotic cytoskeletons, the term 'prokaryotic cytoskeletons' is used to refer to many different kinds of protein filaments. Cytoskeletons achieve their functions through polymerization of protein monomers and the resulting ability to access length scales larger than the size of the monomer. Prokaryotic cytoskeletons are involved in many fundamental aspects of prokaryotic cell biology and have important roles in cell shape determination, cell division and nonchromosomal DNA segregation. Some of the filament-forming proteins have been classified into a small number of conserved protein families, for example, the almost ubiquitous tubulin and actin superfamilies. To understand what makes filaments special and how the cytoskeletons they form enable cells to perform essential functions, the structure and function of cytoskeletal molecules and their filaments have been investigated in diverse bacteria and archaea. In this Review, we bring these data together to highlight the diverse ways that linear protein polymers can be used to organize other molecules and structures in bacteria and archaea.
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Affiliation(s)
- James Wagstaff
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Jan Löwe
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
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