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Kokolo B, Attéké Nkoulémbéné C, Ibrahim B, M'Batchi B, Blatrix R. Phenotypic plasticity in size of ant-domatia. Sci Rep 2020; 10:20948. [PMID: 33262446 PMCID: PMC7708978 DOI: 10.1038/s41598-020-77995-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 11/11/2020] [Indexed: 11/26/2022] Open
Abstract
Ant-plants produce hollow structures called domatia to host protecting ants. Although size variation in domatia is well documented between related species, intraspecific variation is little explored. The central African ant-plant Barteria dewevrei exibits strong variation in domatium size, giving the opportunity to explore the mechanism underlying variation in a mutualistic trait. We showed that domatium size in Barteria dewevrei varies between sites. We transplanted individual plants between two sites in Gabon where plants have different domatium sizes. Domatium size of transplanted plants changed, revealing that variation in this mutualistic trait is driven by phenotypic plasticity. The two sites differed in their environmental conditions: highland open savanna on sandy soil vs lowland closed tropical rain forest on sandy-loam soil. However, as stomatal density and δ13C of leaves did not differ between sites or between branches produced before and after transplantation, we have no cue on the role of abiotic stress (such as light intensity and water availability) in domatium size variation. As the obligate Tetraponera ant symbionts are too large to fit in the small domatia, variation of the mutualistic trait in response to environmental change through phenotypic plasticity may impact this specialized mutualism.
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Affiliation(s)
- Bertrand Kokolo
- Laboratoire de Physiologie Animale, Unité de Recherche Agrobiologie, Université des Sciences et Techniques de Masuku (USTM), BP 901, Franceville, Gabon.
| | - Christiane Attéké Nkoulémbéné
- Laboratoire de Physiologie Animale, Unité de Recherche Agrobiologie, Université des Sciences et Techniques de Masuku (USTM), BP 901, Franceville, Gabon
| | - Brama Ibrahim
- Laboratoire de Physiologie Animale, Unité de Recherche Agrobiologie, Université des Sciences et Techniques de Masuku (USTM), BP 901, Franceville, Gabon
| | - Bertrand M'Batchi
- Laboratoire de Physiologie Animale, Unité de Recherche Agrobiologie, Université des Sciences et Techniques de Masuku (USTM), BP 901, Franceville, Gabon
| | - Rumsais Blatrix
- CEFE, Université de Montpellier - CNRS - EPHE - IRD - Université Paul Valéry Montpellier 3, Montpellier, France
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2
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Orivel J, Malé PJ, Lauth J, Roux O, Petitclerc F, Dejean A, Leroy C. Trade-offs in an ant-plant-fungus mutualism. Proc Biol Sci 2018; 284:rspb.2016.1679. [PMID: 28298342 DOI: 10.1098/rspb.2016.1679] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 08/31/2016] [Indexed: 11/12/2022] Open
Abstract
Species engaged in multiple, simultaneous mutualisms are subject to trade-offs in their mutualistic investment if the traits involved in each interaction are overlapping, which can lead to conflicts and affect the longevity of these associations. We investigate this issue via a tripartite mutualism involving an ant plant, two competing ant species and a fungus the ants cultivate to build galleries under the stems of their host plant to capture insect prey. The use of the galleries represents an innovative prey capture strategy compared with the more typical strategy of foraging on leaves. However, because of a limited worker force in their colonies, the prey capture behaviour of the ants results in a trade-off between plant protection (i.e. the ants patrol the foliage and attack intruders including herbivores) and ambushing prey in the galleries, which has a cascading effect on the fitness of all of the partners. The quantification of partners' traits and effects showed that the two ant species differed in their mutualistic investment. Less investment in the galleries (i.e. in fungal cultivation) translated into more benefits for the plant in terms of less herbivory and higher growth rates and vice versa. However, the greater vegetative growth of the plants did not produce a positive fitness effect for the better mutualistic ant species in terms of colony size and production of sexuals nor was the mutualist compensated by the wider dispersal of its queens. As a consequence, although the better ant mutualist is the one that provides more benefits to its host plant, its lower host-plant exploitation does not give this ant species a competitive advantage. The local coexistence of the ant species is thus fleeting and should eventually lead to the exclusion of the less competitive species.
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Affiliation(s)
- Jérôme Orivel
- CNRS, UMR Ecologie des Forêts de Guyane, AgroParisTech, CIRAD, INRA, Université de Guyane, Université des Antilles, Campus Agronomique, BP 316, 97379 Kourou Cedex, France
| | - Pierre-Jean Malé
- UMR Evolution et Diversité Biologique, Université de Toulouse, 118 Route de Narbonne, 31062 Toulouse Cedex 9, France
| | - Jérémie Lauth
- CNRS, UMR Ecologie des Forêts de Guyane, AgroParisTech, CIRAD, INRA, Université de Guyane, Université des Antilles, Campus Agronomique, BP 316, 97379 Kourou Cedex, France
| | - Olivier Roux
- CNRS, UMR Ecologie des Forêts de Guyane, AgroParisTech, CIRAD, INRA, Université de Guyane, Université des Antilles, Campus Agronomique, BP 316, 97379 Kourou Cedex, France
| | - Frédéric Petitclerc
- CNRS, UMR Ecologie des Forêts de Guyane, AgroParisTech, CIRAD, INRA, Université de Guyane, Université des Antilles, Campus Agronomique, BP 316, 97379 Kourou Cedex, France
| | - Alain Dejean
- CNRS, UMR Ecologie des Forêts de Guyane, AgroParisTech, CIRAD, INRA, Université de Guyane, Université des Antilles, Campus Agronomique, BP 316, 97379 Kourou Cedex, France.,Ecolab, Université de Toulouse, CNRS, INPT, UPS, 118 Route de Narbonne, 31062 Toulouse Cedex 9, France
| | - Céline Leroy
- CNRS, UMR Ecologie des Forêts de Guyane, AgroParisTech, CIRAD, INRA, Université de Guyane, Université des Antilles, Campus Agronomique, BP 316, 97379 Kourou Cedex, France.,IRD, UMR AMAP (botAnique et Modélisation de l'Architecture des Plantes et des Végétations), Boulevard de la Lironde, TA A-51/PS2, 34398 Montpellier Cedex 5, France
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Malé PJG, Leroy C, Humblot P, Dejean A, Quilichini A, Orivel J. Limited gene dispersal and spatial genetic structure as stabilizing factors in an ant-plant mutualism. J Evol Biol 2016; 29:2519-2529. [PMID: 27654029 DOI: 10.1111/jeb.12980] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 09/12/2016] [Accepted: 09/15/2016] [Indexed: 11/28/2022]
Abstract
Comparative studies of the population genetics of closely associated species are necessary to properly understand the evolution of these relationships because gene flow between populations affects the partners' evolutionary potential at the local scale. As a consequence (at least for antagonistic interactions), asymmetries in the strength of the genetic structures of the partner populations can result in one partner having a co-evolutionary advantage. Here, we assess the population genetic structure of partners engaged in a species-specific and obligatory mutualism: the Neotropical ant-plant, Hirtella physophora, and its ant associate, Allomerus decemarticulatus. Although the ant cannot complete its life cycle elsewhere than on H. physophora and the plant cannot live for long without the protection provided by A. decemarticulatus, these species also have antagonistic interactions: the ants have been shown to benefit from castrating their host plant and the plant is able to retaliate against too virulent ant colonies. We found similar short dispersal distances for both partners, resulting in the local transmission of the association and, thus, inbred populations in which too virulent castrating ants face the risk of local extinction due to the absence of H. physophora offspring. On the other hand, we show that the plant populations probably experienced greater gene flow than did the ant populations, thus enhancing the evolutionary potential of the plants. We conclude that such levels of spatial structure in the partners' populations can increase the stability of the mutualistic relationship. Indeed, the local transmission of the association enables partial alignments of the partners' interests, and population connectivity allows the plant retaliation mechanisms to be locally adapted to the castration behaviour of their symbionts.
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Affiliation(s)
- P-J G Malé
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
| | - C Leroy
- IRD, AMAP (botAnique et bioinforMatique de l'Architecture des Plantes), Montpellier Cedex, France.,CNRS, UMR Ecologie des Forêts de Guyane, Kourou Cedex, France
| | - P Humblot
- CNRS, EDB (Laboratoire Evolution et Diversité Biologique), Toulouse Cedex, France.,Université de Toulouse, EDB, Toulouse Cedex, France
| | - A Dejean
- CNRS, UMR Ecologie des Forêts de Guyane, Kourou Cedex, France.,Université de Toulouse, UMR Ecolab (Laboratoire d'Ecologie Fonctionnelle et Environnement), Toulouse Cedex 9, France
| | - A Quilichini
- CNRS, UMR Ecologie des Forêts de Guyane, Kourou Cedex, France.,Université de Toulouse, UMR Ecolab (Laboratoire d'Ecologie Fonctionnelle et Environnement), Toulouse Cedex 9, France
| | - J Orivel
- CNRS, UMR Ecologie des Forêts de Guyane, Kourou Cedex, France
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Flores JC. Competitive Exclusion and Axiomatic Set-Theory: De Morgan's Laws, Ecological Virtual Processes, Symmetries and Frozen Diversity. Acta Biotheor 2016; 64:85-98. [PMID: 26801920 DOI: 10.1007/s10441-016-9275-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 01/08/2016] [Indexed: 11/30/2022]
Abstract
This work applies the competitive exclusion principle and the concept of potential competitors as simple axiomatic tools to generalized situations in ecology. These tools enable apparent competition and its dual counterpart to be explicitly evaluated in poorly understood ecological systems. Within this set-theory framework we explore theoretical symmetries and invariances, De Morgan's laws, frozen evolutionary diversity and virtual processes. In particular, we find that the exclusion principle compromises the geometrical growth of the number of species. By theoretical extending this principle, we can describe interspecific depredation in the dual case. This study also briefly considers the debated situation of intraspecific competition. The ecological consequences of our findings are discussed; particularly, the use of our framework to reinterpret coupled mathematical differential equations describing certain ecological processes.
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Affiliation(s)
- J C Flores
- Instituto de Alta Investigación IAI, Universidad de Tarapacá, Casilla 7-D, Arica, Chile.
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Tarnita CE, Palmer TM, Pringle RM. Colonisation and competition dynamics can explain incomplete sterilisation parasitism in ant–plant symbioses. Ecol Lett 2014; 17:1290-8. [DOI: 10.1111/ele.12336] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 04/07/2014] [Accepted: 07/09/2014] [Indexed: 11/30/2022]
Affiliation(s)
- Corina E. Tarnita
- Department of Ecology & Evolutionary Biology Princeton University Princeton NJ 08544 USA
- Mpala Research Centre Box 555Nanyuki Kenya
| | - Todd M. Palmer
- Mpala Research Centre Box 555Nanyuki Kenya
- Department of Biology University of Florida Gainesville FL 32611 USA
| | - Robert M. Pringle
- Department of Ecology & Evolutionary Biology Princeton University Princeton NJ 08544 USA
- Mpala Research Centre Box 555Nanyuki Kenya
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