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Burin G, Campbell LCE, Renner SS, Kiers ET, Chomicki G. Mutualisms drive plant trait evolution beyond interaction-related traits. Ecol Lett 2024; 27:e14379. [PMID: 38361469 DOI: 10.1111/ele.14379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 01/12/2024] [Accepted: 01/15/2024] [Indexed: 02/17/2024]
Abstract
Mutualisms have driven the evolution of extraordinary structures and behavioural traits, but their impact on traits beyond those directly involved in the interaction remains unclear. We addressed this gap using a highly evolutionarily replicated system - epiphytes in the Rubiaceae forming symbioses with ants. We employed models that allow us to test the influence of discrete mutualistic traits on continuous non-mutualistic traits. Our findings are consistent with mutualism shaping the pace of morphological evolution, strength of selection and long-term mean of non-mutualistic traits in function of mutualistic dependency. While specialised and obligate mutualisms are associated with slower trait change, less intimate, facultative and generalist mutualistic interactions - which are the most common - have a greater impact on non-mutualistic trait evolution. These results challenge the prevailing notion that mutualisms solely affect the evolution of interaction-related traits via stabilizing selection and instead demonstrate a broader role for mutualisms in shaping trait evolution.
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Affiliation(s)
| | | | - Susanne S Renner
- Department of Biology, Washington University, Saint Louis, Missouri, USA
| | - E Toby Kiers
- Amsterdam Institute for Life and Environment, Section Ecology and Evolution, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
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Luo B, Huang M, Wang W, Niu J, Shrestha M, Zeng H, Ma L, Degen AA, Liao J, Zhang T, Bai Y, Zhao J, Fraser LH, Shang Z. Ant nests increase litter decomposition to mitigate the negative effect of warming in an alpine grassland ecosystem. Proc Biol Sci 2023; 290:20230613. [PMID: 37369352 PMCID: PMC10299860 DOI: 10.1098/rspb.2023.0613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 06/05/2023] [Indexed: 06/29/2023] Open
Abstract
Warming can decrease feeding activity of soil organisms and affect biogeochemical cycles. The ant Formica manchu is active on the nest surface and prefers a hot, dry environment; therefore, warming may provide a favourable environment for its activities. We hypothesized that F. manchu benefit from warming and mitigate the negative effects of warming on litter decomposition. We examined the effects of ant nests (nest absence versus nest presence) and warming (+1.3 and +2.3°C) on litter decomposition, soil properties and the plant community in alpine grassland. Decomposition stations with two mesh sizes were used to differentiate effects of microorganisms (0.05 mm) and macroinvertebrates (1 cm) on decomposition. Ant nests increased litter decomposition with and without macroinvertebrates accessing the decomposition station when compared to plots without ant nests. Only litter decomposition in ant nests with macroinvertebrates having access to the decomposition station was not affected negatively by warming. Plots with ant nests had greater soil carbon, nutrient contents and plant growth than plots without ant nests, regardless of warming. Our results suggest that ant nests maintain ecosystem processes and functions under warming. Consequently, a management strategy in alpine grasslands should include the protection of these ants and ant nests.
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Affiliation(s)
- Binyu Luo
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Mei Huang
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Wenyin Wang
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Jiahuan Niu
- Department of Health and Environmental Sciences, Xi'an Jiaotong-Liverpool University, Suzhou 215123, People's Republic of China
| | - Mani Shrestha
- Department of Disturbance Ecology and Vegetation Dynamics, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, 95440 Bayreuth, Germany
| | - Haijun Zeng
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Lin Ma
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - A. Allan Degen
- Desert Animal Adaptations and Husbandry, Wyler Department of Dryland Agriculture, Blaustein Institutes for Desert Research, Ben-Gurion University of Negev, Beer Sheva 8410500, Israel
| | - Jingkang Liao
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, and College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, People's Republic of China
| | - Tao Zhang
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Yanfu Bai
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Jingxue Zhao
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Lauchlan H. Fraser
- Department of Natural Resource Sciences, Thompson Rivers University, Kamloops, British Columbia, Canada V2C 0C8
| | - Zhanhuan Shang
- State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, People's Republic of China
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Campbell LCE, Kiers ET, Chomicki G. The evolution of plant cultivation by ants. TRENDS IN PLANT SCIENCE 2023; 28:271-282. [PMID: 36372647 DOI: 10.1016/j.tplants.2022.09.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 09/11/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
Outside humans, true agriculture was previously thought to be restricted to social insects farming fungus. However, obligate farming of plants by ants was recently discovered in Fiji, prompting a re-examination of plant cultivation by ants. Here, we generate a database of plant cultivation by ants, identify three main types, and show that these interactions evolved primarily for shelter rather than food. We find that plant cultivation evolved at least 65 times independently for crops (~200 plant species), and 15 times in farmer lineages (~37 ant taxa) in the Neotropics and Asia/Australasia. Because of their high evolutionary replication, and variation in partner dependence, these systems are powerful models to unveil the steps in the evolution and ecology of insect agriculture.
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Affiliation(s)
| | - E Toby Kiers
- Department of Ecological Science, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Guillaume Chomicki
- Ecology and Evolutionary Biology, School of Biosciences, Alfred Denny Building, University of Sheffield, Western Bank, Sheffield S10 2TN, UK.
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Pu Y, Naikatini A, Pérez‐Escobar OA, Silber M, Renner SS, Chomicki G. Genome-wide transcriptome signatures of ant-farmed Squamellaria epiphytes reveal key functions in a unique symbiosis. Ecol Evol 2021; 11:15882-15895. [PMID: 34824797 PMCID: PMC8601933 DOI: 10.1002/ece3.8258] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 10/02/2021] [Accepted: 10/07/2021] [Indexed: 12/13/2022] Open
Abstract
Farming of fungi by ants, termites, or beetles has led to ecologically successful societies fueled by industrial-scale food production. Another type of obligate insect agriculture in Fiji involves the symbiosis between the ant Philidris nagasau and epiphytes in the genus Squamellaria (Rubiaceae) that the ants fertilize, defend, harvest, and depend on for nesting. All farmed Squamellaria form tubers (domatia) with preformed entrance holes and complex cavity networks occupied by P. nagasau. The inner surface of the domatia consists of smooth-surfaced walls where the ants nest and rear their brood, and warty-surfaced walls where they fertilize their crop by defecation. Here, we use RNA sequencing to identify gene expression patterns associated with the smooth versus warty wall types. Since wall differentiation occurred in the most recent common ancestor of all farmed species of Squamellaria, our study also identifies genetic pathways co-opted following the emergence of agriculture. Warty-surfaced walls show many upregulated genes linked to auxin transport, root development, and nitrogen transport consistent with their root-like function; their defense-related genes are also upregulated, probably to protect these permeable areas from pathogen entry. In smooth-surfaced walls, genes functioning in suberin and wax biosynthesis are upregulated, contributing to the formation of an impermeable ant-nesting area in the domatium. This study throws light on a number of functional characteristics of plant farming by ants and illustrates the power of genomic studies of symbiosis.
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Affiliation(s)
- Yuanshu Pu
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐LeipzigLeipzigGermany
| | - Alivereti Naikatini
- South Pacific Regional HerbariumInstitute of Applied SciencesThe University of the South PacificSuvaFiji
| | | | - Martina Silber
- Systematic Botany and MycologyDepartment of BiologyUniversity of Munich (LMU)MunichGermany
| | | | - Guillaume Chomicki
- Ecology and Evolutionary BiologySchool of BiosciencesUniversity of SheffieldSheffieldUK
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Chomicki G, Kiers ET, Renner SS. The Evolution of Mutualistic Dependence. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2020. [DOI: 10.1146/annurev-ecolsys-110218-024629] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
While the importance of mutualisms across the tree of life is recognized, it is not understood why some organisms evolve high levels of dependence on mutualistic partnerships, while other species remain autonomous or retain or regain minimal dependence on partners. We identify four main pathways leading to the evolution of mutualistic dependence. Then, we evaluate current evidence for three predictions: ( a) Mutualisms with different levels of dependence have distinct stabilizing mechanisms against exploitation and cheating, ( b) less dependent mutualists will return to autonomy more often than those that are highly dependent, and ( c) obligate mutualisms should be less context dependent than facultative ones. Although we find evidence supporting all three predictions, we stress that mutualistic partners follow diverse paths toward—and away from—dependence. We also highlight the need to better examine asymmetry in partner dependence. Recognizing how variation in dependence influences the stability, breakdown, and context dependence of mutualisms generates new hypotheses regarding how and why the benefits of mutualistic partnerships differ over time and space.
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Affiliation(s)
- Guillaume Chomicki
- Department of Bioscience, Durham University, Durham DH1 3LE, United Kingdom
| | - E. Toby Kiers
- Department of Ecological Science, Vrije Universiteit, 1081 HV Amsterdam, The Netherlands
| | - Susanne S. Renner
- Systematic Botany and Mycology, Department of Biology, University of Munich (LMU), 80638 Munich, Germany
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Chomicki G, Werner GDA, West SA, Kiers ET. Compartmentalization drives the evolution of symbiotic cooperation. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190602. [PMID: 32772665 DOI: 10.1098/rstb.2019.0602] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Across the tree of life, hosts have evolved mechanisms to control and mediate interactions with symbiotic partners. We suggest that the evolution of physical structures that allow hosts to spatially separate symbionts, termed compartmentalization, is a common mechanism used by hosts. Such compartmentalization allows hosts to: (i) isolate symbionts and control their reproduction; (ii) reward cooperative symbionts and punish or stop interactions with non-cooperative symbionts; and (iii) reduce direct conflict among different symbionts strains in a single host. Compartmentalization has allowed hosts to increase the benefits that they obtain from symbiotic partners across a diversity of interactions, including legumes and rhizobia, plants and fungi, squid and Vibrio, insects and nutrient provisioning bacteria, plants and insects, and the human microbiome. In cases where compartmentalization has not evolved, we ask why not. We argue that when partners interact in a competitive hierarchy, or when hosts engage in partnerships which are less costly, compartmentalization is less likely to evolve. We conclude that compartmentalization is key to understanding the evolution of symbiotic cooperation. This article is part of the theme issue 'The role of the microbiome in host evolution'.
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Affiliation(s)
- Guillaume Chomicki
- Department of Biosciences, Durham University, Stockton Road, Durham DH1 3LE, UK
| | - Gijsbert D A Werner
- Department of Zoology, University of Oxford, Zoology Research and Administration Building, 11a Mansfield Road, Oxford OX1 3SZ, UK.,Netherlands Scientific Council for Government Policy, Buitenhof 34, 2513 AH Den Haag, The Netherlands
| | - Stuart A West
- Department of Zoology, University of Oxford, Zoology Research and Administration Building, 11a Mansfield Road, Oxford OX1 3SZ, UK
| | - E Toby Kiers
- Department of Ecological Science, VU University, Amsterdam, The Netherlands
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Fijian farming ants resolve the guns-or-butter dilemma for their crop plants. Proc Natl Acad Sci U S A 2020; 117:3357-3359. [PMID: 32019888 DOI: 10.1073/pnas.1922921117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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