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Martins J, Moreira A, Assunção M, Oliveira A, Almeida J. Trade-off in plant-ant interactions: seasonal variations. BRAZ J BIOL 2020; 80:921-933. [PMID: 31967280 DOI: 10.1590/1519-6984.229848] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 11/20/2019] [Indexed: 11/21/2022] Open
Abstract
This work evaluated the effect of seasonality on ant-plant interaction in a Seasonally Dry Tropical Forests, using as an ecological model the species Ipomoea carnea subs. fistulosa (Convolvulaceae). We performed systematic collection of ants, herbivores and leaves in marked plants, evaluated the efficiency of herbivorous capture by ants, and the effects of ant presence over the pollinator behavior and plant fitness in dry and rainy seasons. The presence of ants in the plants reduced the number of herbivores (dry season: F2.27=4.7617, p=0.0166; rainy season: F2.27=5.8655, p=0.0078). However, the capture efficiency was negatively affected by the presence of myrmecophilous larvae, so that the average of ants recruited on termite leaves was 2.06 ants per termite, the average recruitment of ants on larval leaves was 22.4 larva ants. In addition, the presence of ants reduced pollinator visits and promoted fruit reduction during the dry season (ANOVA: F = 3.44; p = 0.0653). In conclusion, the association with ants can result in a balance not always favorable to the host plant, and this result actually depends on abiotic (e.g. precipitation) and biotic factors (e.g. ant species composition and abundance, influence of other trophic levels and identity of associated herbivores).
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Affiliation(s)
- J Martins
- Departamento de Botânica, Universidade Federal de Pernambuco - UFPE, Av. Professor Morais Rego, 1235, Cidade Universitária, CEP 50670-901, Recife, PE, Brasil
| | - A Moreira
- Departamento de Ciências Biológicas, Universidade Federal de Campina Grande - UFCG, Campus Patos, Av. Universitária, s/n, Santa Cecília, CEP 58708-110, Patos, PB, Brasil
| | - M Assunção
- Departamento de Botânica, Universidade Federal de Pernambuco - UFPE, Av. Professor Morais Rego, 1235, Cidade Universitária, CEP 50670-901, Recife, PE, Brasil
| | - A Oliveira
- Departamento de Botânica, Universidade Federal de Pernambuco - UFPE, Av. Professor Morais Rego, 1235, Cidade Universitária, CEP 50670-901, Recife, PE, Brasil
| | - J Almeida
- Departamento de Botânica, Universidade Federal de Pernambuco - UFPE, Av. Professor Morais Rego, 1235, Cidade Universitária, CEP 50670-901, Recife, PE, Brasil
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Functional Role of Extrafloral Nectar in Boreal Forest Ecosystems under Climate Change. FORESTS 2020. [DOI: 10.3390/f11010067] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Carbohydrate-rich extrafloral nectar (EFN) is produced in nectaries on the leaves, stipules, and stems of plants and provides a significant energy source for ants and other plant mutualists outside of the flowering period. Our review of literature on EFN indicates that only a few forest plant species in cool boreal environments bear EFN-producing nectaries and that EFN production in many boreal and subarctic plant species is poorly studied. Boreal forest, the world’s largest land biome, is dominated by coniferous trees, which, like most gymnosperms, do not produce EFN. Notably, common deciduous tree species that can be dominant in boreal forest stands, such as Betula and Alnus species, do not produce EFN, while Prunus and Populus species are the most important EFN-producing tree species. EFN together with aphid honeydew is known to play a main role in shaping ant communities. Ants are considered to be keystone species in mixed and conifer-dominated boreal and mountain forests because they transfer a significant amount of carbon from the canopy to the soil. Our review suggests that in boreal forests aphid honeydew is a more important carbohydrate source for ants than in many warmer ecosystems and that EFN-bearing plant species might not have a competitive advantage against herbivores. However, this hypothesis needs to be tested in the future. Warming of northern ecosystems under climate change might drastically promote the invasion of many EFN-producing plants and the associated insect species that consume EFN as their major carbohydrate source. This may result in substantial changes in the diet preferences of ant communities, the preventative roles of ants against insect pest outbreaks, and the ecosystem services they provide. However, wood ants have adapted to using tree sap that leaks from bark cracks in spring, which may mitigate the effects of improved EFN availability.
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Zemskova NE, Sattarov VN, Skvortsov AI, Semenov VG. Morphological characteristics of honey bees of the Volga region. BIO WEB OF CONFERENCES 2020. [DOI: 10.1051/bioconf/20201700035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Declining bee populations and decreasing marketability of apiaries pose the necessity for a comprehensive monitoring of the morphological characteristics of honeybees. The monitoring was performed in an introgressive aspect for the first time in the Volga region (Samara region) to preserve the local population of the Middle Russian race (Apis mellifera mellifera L.). Moreover, the race of queen bees was identified through the assessment of drones. Based on the race identification, small population structures of the native forest bee were revealed, which is a prerequisite for restoration of its genetic resources with the corresponding restriction of the import of bees from the southern regions where other taxonomic groups are bred.
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Amador-Vargas S, Dyer J, Arnold N, Cavanaugh L, Sánchez-Brenes E. Acacia trees with parasitic ants have fewer and less spacious spines than trees with mutualistic ants. Naturwissenschaften 2019; 107:3. [PMID: 31823014 DOI: 10.1007/s00114-019-1647-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 08/21/2019] [Accepted: 08/24/2019] [Indexed: 11/30/2022]
Abstract
Obligate ant-defended plants provide food and shelter in exchange for protection against herbivores. Mesoamerican acacia trees have an obligate ant mutualism, but parasitic non-defending ants can also nest on the tree. We assessed whether rewards corresponded to ant defense within a plant species. As we expected, we found that parasite-inhabited trees had fewer swollen spines than ant-defended trees. Spine diameter was smaller in parasite-inhabited plants, but there were no differences in spine length, suggesting that spines serve as mechanical protection against herbivory. Parasite-inhabited plants may have reduced rewards because of plant differences when establishing, a plastic response to limited resources, or differential energy allocation when sensing the lack of defense.
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Affiliation(s)
| | - Jared Dyer
- Department of Biological Sciences, Kent State University, Kent, OH, USA
| | - Natalie Arnold
- Department of Biological Sciences, Kent State University, Kent, OH, USA
| | - Leah Cavanaugh
- Department of Biological Sciences, Kent State University, Kent, OH, USA
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Gall-Colonizing Ants and Their Role as Plant Defenders: From 'Bad Job' to 'Useful Service'. INSECTS 2019; 10:insects10110392. [PMID: 31698832 PMCID: PMC6920797 DOI: 10.3390/insects10110392] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 10/31/2019] [Accepted: 11/05/2019] [Indexed: 12/18/2022]
Abstract
Galls are neoformed structures on host plant tissues caused by the attack of insects or other organisms. They support different communities of specialized parasitic insects (the gall inducers), and can also provide refuge to other insects, such as moths, beetles and ants, referred to as secondary occupants. This study focuses on galls induced by the oak gall wasp Andricus quercustozae and secondarily colonized by ants in a mixed oak forest. A field survey and two experiments were carried out to a) study ant (species-specific) preferences for different features of the galls, b) describe differences in gall architecture due to ant activity, c) analyse the effects of the presence of gall-dwelling ants on plant health. The results show that there are differences between ant species in gall colonization and in the alteration of gall opening and inner structure. We verified that gall-dwelling ants protect their host plants efficiently, offering them an indirect defence mechanism against enemies (predators and pathogens). The data suggest a new paradigm in ant–plant relationships mediated by the presence of galls on the plants whose ecological and evolutionary implications are discussed.
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Abdala-Roberts L, Reyes-Hernández M, Quijano-Medina T, Moreira X, Francisco M, Angulo DF, Parra-Tabla V, Virgen A, Rojas JC. Effects of amount and recurrence of leaf herbivory on the induction of direct and indirect defences in wild cotton. PLANT BIOLOGY (STUTTGART, GERMANY) 2019; 21:1063-1071. [PMID: 31237391 DOI: 10.1111/plb.13022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 06/19/2019] [Indexed: 06/09/2023]
Abstract
The induction of defences in response to herbivory is a key mechanism of plant resistance. While a number of studies have investigated the time course and magnitude of plant induction in response to a single event of herbivory, few have looked at the effects of recurrent herbivory. Furthermore, studies measuring the effects of the total amount and recurrence of herbivory on both direct and indirect plant defences are lacking. To address this gap, here we asked whether insect leaf herbivory induced changes in the amount and concentration of extrafloral nectar (an indirect defence) and concentration of leaf phenolic compounds (a direct defence) in wild cotton (Gossypium hirsutum). We conducted a greenhouse experiment where we tested single event or recurrent herbivory effects on defence induction by applying mechanical leaf damage and caterpillar (Spodoptera frugiperda) regurgitant. Single events of 25% and 50% leaf damage did not significantly influence extrafloral nectar production or concentration. Extrafloral nectar traits did, however, increase significantly relative to controls when plants were exposed to recurrent herbivory (two episodes of 25% damage). In contrast, phenolic compounds increased significantly in response to single events of leaf damage but not to recurrent damage. In addition, we found. that local induction of extrafloral nectar production was stronger than systemic induction, whereas the reverse pattern was observed for phenolics. Together, these results reveal seemingly inverse patterns of induction of direct and indirect defences in response to herbivory in wild cotton.
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Affiliation(s)
- L Abdala-Roberts
- Departamento de Ecología Tropical, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
| | - M Reyes-Hernández
- Departamento de Ecología Tropical, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
| | - T Quijano-Medina
- Departamento de Ecología Tropical, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
| | - X Moreira
- Misión Biológica de Galicia (MBG-CSIC), Pontevedra, Spain
| | - M Francisco
- Misión Biológica de Galicia (MBG-CSIC), Pontevedra, Spain
| | - D F Angulo
- Departamento de Ecología Tropical, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
| | - V Parra-Tabla
- Departamento de Ecología Tropical, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
| | - A Virgen
- Departamento de Agricultura, Sociedad y Ambiente, ECOSUR Unidad Tapachula, Tapachula, Chiapas, Mexico
| | - J C Rojas
- Departamento de Agricultura, Sociedad y Ambiente, ECOSUR Unidad Tapachula, Tapachula, Chiapas, Mexico
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Abstract
Certain adapted insect herbivores utilize plant toxins for self-defense against their own enemies. These adaptations structure ecosystems and limit our capacity to use biological control agents to manage specialized agricultural pests. We show that entomopathogenic nematodes that are exposed to the western corn rootworm, an important agricultural pest that sequesters defense metabolites from maize, can evolve resistance to these defenses. Resisting the plant defense metabolites likely allows the nematodes to infect and kill the western corn rootworm more efficiently. These findings illustrate how predators can counter the plant-based resistance strategies of specialized insect herbivores. Breeding or engineering biological control agents that resist plant defense metabolites may improve their capacity to kill important agricultural pests such as the western corn rootworm. Plants defend themselves against herbivores through the production of toxic and deterrent metabolites. Adapted herbivores can tolerate and sometimes sequester these metabolites, allowing them to feed on defended plants and become toxic to their own enemies. Can herbivore natural enemies overcome sequestered plant defense metabolites to prey on adapted herbivores? To address this question, we studied how entomopathogenic nematodes cope with benzoxazinoid defense metabolites that are produced by grasses and sequestered by a specialist maize herbivore, the western corn rootworm. We find that nematodes from US maize fields in regions in which the western corn rootworm was present over the last 50 y are behaviorally and metabolically resistant to sequestered benzoxazinoids and more infective toward the western corn rootworm than nematodes from other parts of the world. Exposure of a benzoxazinoid-susceptible nematode strain to the western corn rootworm for 5 generations results in higher behavioral and metabolic resistance and benzoxazinoid-dependent infectivity toward the western corn rootworm. Thus, herbivores that are exposed to a plant defense sequestering herbivore can evolve both behavioral and metabolic resistance to plant defense metabolites, and these traits are associated with higher infectivity toward a defense sequestering herbivore. We conclude that plant defense metabolites that are transferred through adapted herbivores may result in the evolution of resistance in herbivore natural enemies. Our study also identifies plant defense resistance as a potential target for the improvement of biological control agents.
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The geographical and seasonal mosaic in a plant-herbivore interaction: patterns of defences and herbivory by a specialist and a non-specialist. Sci Rep 2019; 9:15206. [PMID: 31645656 PMCID: PMC6811555 DOI: 10.1038/s41598-019-51528-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 09/24/2019] [Indexed: 12/01/2022] Open
Abstract
In order to evaluate the geographic mosaic theory of coevolution, it is crucial to investigate geographical variation on the outcome of ecological interactions and the functional traits which dictate these outcomes. Plant populations are attacked by specialist and non-specialist herbivores and may have different types of chemical and biotic defences. We investigated geographical and seasonal variation in the interaction between the plant Crotalaria pallida and its two major herbivores (the specialist Utetheisa ornatrix and the non-specialist Etiella zinckenella). We first showed that attack by the two herbivores and a chemical and a biotic defence vary greatly in time and space. Second, we performed a common garden experiment that revealed genetic variation among populations in herbivore resistance and a chemical defence, but no genetic variation in a biotic defence. Third, we sampled 20 populations on a much larger geographical scale and showed great variation in attack rates by the two herbivores and a chemical defence. Finally, we showed that herbivory is not correlated with a chemical defence in the 20 field populations. Our study shows that to understand the evolution of ecological interactions it is crucial to investigate how the outcome of the interaction and the important species traits vary geographically and seasonally.
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Giuliani C, Lastrucci L, Cresti L, Santini G, Foggi B, Lippi MM. The morphology and activity of the extrafloral nectaries in Reynoutria × bohemica (Polygonaceae). PLANT BIOLOGY (STUTTGART, GERMANY) 2019; 21:975-985. [PMID: 31062924 DOI: 10.1111/plb.13004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 05/02/2019] [Indexed: 06/09/2023]
Abstract
Reynoutria × bohemica is an invasive species causing significant damage to native ecosystems in North America and Europe. In this work, we performed an in-depth micromorphological characterisation of the extrafloral nectaries (EFN), during their secretory and post-secretory phases, in combination with field monitoring of nectary activity over time and the qualitative pool of insect visitors. EFN consist of secretory trichomes and vascularised parenchyma. Polysaccharides, lipids and proteins were histochemically detected in all trichome cells; phenolic substances were detected in parenchyma cells. Our data indicate that all nectary regions are involved in nectar production and release, constituting a functional unit. Moreover, the main compound classes of nectar and their transfer change over time: first, granulocrine secretion for sugars prevails, then eccrine secretion of the lipophilic fraction takes place. Active nectaries are mainly located in the apical portion of the stem during the growth phase (April-May), when we detected the highest number of individuals visited by ants; from mid-August onwards, during flowering, the number of active nectaries declined then ceased production (September), with a concomitant decrease in visits by the ants. The spectrum of nectar-foraging ants mainly included representatives of the genera Formica, Lasius and Camponotus. Reynoutria × bohemica produces an attractive secretion able to recruit local ants that may potentially act as 'bodyguards' for protecting young shoots, reducing secretions during the blooming stage. This defence mechanism against herbivores is the same as that displayed by the parental species in its native areas.
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Affiliation(s)
- C Giuliani
- Department of Pharmaceutical Sciences, University of Milan, Milan, Italy
| | - L Lastrucci
- University Museum System, Natural History Museum of the University of Florence, Botany, Florence, Italy
| | - L Cresti
- Department of Biology, University of Pisa, Pisa, Italy
| | - G Santini
- Department of Biology, University of Florence, Sesto Fiorentino, Florence, Italy
| | - B Foggi
- Department of Biology, University of Florence, Florence, Italy
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Congeneric mutualist ant symbionts (Tetraponera, Pseudomyrmecinae) differ in level of protection of their myrmecophyte hosts (Barteria, Passifloraceae). JOURNAL OF TROPICAL ECOLOGY 2019. [DOI: 10.1017/s026646741900021x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractBarteria fistulosa and B. dewevrei, central African rain-forest trees, provide nesting cavities for Tetraponera aethiops and T. latifrons ants, respectively, which protect them against herbivores. To compare protection efficiency between these two symbioses, for 20 plants of each species in two sites in Gabon we measured the time elapsed before ants reached a focal leaf, for host leaves that were undisturbed, damaged (cut with scissors) or subjected to slight vibration (mimicking such damage), and for damaged leaves of the non-host Barteria species. Tetraponera aethiops displayed stronger protective behaviour than did T. latifrons. Time to reach a damaged host leaf (4.5 ± 2.6 min, mean ± SD) did not differ significantly from time to reach a leaf subjected to slight vibration (5.2 ± 3.0 min) for T. aethiops, but response to a leaf subjected to slight vibration (9.5 ± 1.9 min) was significantly slower than that to a damaged leaf (7.8 ± 1.9 min) for T. latifrons. The faster response of T. aethiops to slight vibration may have masked a response of this species to chemical signalling. Both ants reached damaged host leaves faster than damaged leaves of the non-host Barteria sp., indicating host plant specificity in ant responses.
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Fonseca-Romero MA, Fornoni J, Del-Val E, Boege K. Ontogenetic trajectories of direct and indirect defenses of myrmecophytic plants colonized either by mutualistic or opportunistic ant species. Oecologia 2019; 190:857-865. [PMID: 31300924 DOI: 10.1007/s00442-019-04469-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 07/08/2019] [Indexed: 12/12/2022]
Abstract
Myrmecophytic plants are expected to produce greater direct defenses when young and switch towards indirect defenses once they reach the size and vigor to produce enough rewards for their ant mutualists. The presence of opportunistic ant species, however, is likely to promote the variation in these ontogenetic trajectories. When plants do not obtain benefits from ants, they cannot rely on this indirect defense. Hence, the expression of direct defenses is expected to remain constant or even increase during the development of plants colonized by opportunistic ants, whereas a reduction in resource allocation to indirect defenses should be observed. To assess if myrmecophytic plants adjust their ontogenetic trajectories in defense as a function of the colonizing ant species, we estimated direct and indirect defenses at four ontogenetic stages of the myrmecophytic plant Vachellia hindsii colonized by either mutualistic or opportunistic ant partners. We report that cyanogenic potential decreased while leaf thickness and the production of sugar in extrafloral nectaries increased along plant development. The magnitude of these ontogenetic changes, however, varied as a function of the identity of the colonizing ants. As expected, when colonized by opportunistic ants, plants produced more direct defenses and reduced the production of rewards. We suggest that facultative changes in the expression of ontogenetic trajectories in direct and indirect defenses could be a mechanism to reduce the fitness costs associated with opportunistic interactions.
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Affiliation(s)
- Mitzi A Fonseca-Romero
- Instituto de Ecología, Universidad Nacional Autónoma de México, A. P. 70-275. Ciudad Universitaria, Coyoacán, 04510, Mexico City, CDMX, Mexico.,Posgrado en Ciencias Biológicas, Unidad de Posgrado Edificio A, 1° Piso, Circuito de Posgrados, Ciudad Universitaria, Coyoacán, 04510, Mexico City, CDMX, Mexico
| | - Juan Fornoni
- Instituto de Ecología, Universidad Nacional Autónoma de México, A. P. 70-275. Ciudad Universitaria, Coyoacán, 04510, Mexico City, CDMX, Mexico
| | - Ek Del-Val
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro No. 8701, Ex-Hacienda de San José de La Huerta, 58190, Morelia, Michoacán, Mexico.,Escuela Nacional de Estudios Superiores Unidad Morelia, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro No. 8701, Ex-Hacienda de San José de La Huerta, 58190, Morelia, Michoacán, Mexico
| | - Karina Boege
- Instituto de Ecología, Universidad Nacional Autónoma de México, A. P. 70-275. Ciudad Universitaria, Coyoacán, 04510, Mexico City, CDMX, Mexico.
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Del-Claro K, Rodriguez-Morales D, Calixto ES, Martins AS, Torezan-Silingardi HM. Ant pollination of Paepalanthus lundii (Eriocaulaceae) in Brazilian savanna. ANNALS OF BOTANY 2019; 123:1159-1165. [PMID: 30852596 PMCID: PMC6612938 DOI: 10.1093/aob/mcz021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 01/30/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND AND AIMS Ant-plant associations are widely diverse and distributed throughout the world, leading to complex ecological networks. Regarding ant-plant mutualism, ant pollination is a very rare interaction and few studies have shown the role of ants as pollinators. Therefore, we aimed to evaluate the role of ants as effective pollinators of Paepalanthus lundii (Eriocaulaceae) in a Brazilian savanna. METHODS Fieldwork with experimental manipulation was conducted to evaluate the fitness of P. lundii, considering potential pollinators. For this, we mainly observed the number of seeds produced in different conditions: control, ant exclusion, exclusion of flying insects, and exclusion (entomophily test) of both ants and flying insects. Furthermore, we evaluated all floral visitors throughout the day, stigma receptivity, the numbers of male and female flowers, and patterns of species co-occurrence, which can indicate the presence of different pollinators in the plants at the same time. KEY RESULTS We observed a relation between seed production and ant visits; Camponotus crassus was the most frequent floral visitor and the most effective pollinator. Also, we observed a statistical difference between the numbers of male and female flowers produced, with a greater number of male flowers. Furthermore, P. lundii presented flowering asynchrony, with 12 different types of maturation sequence, which indicates a cross-pollination system. Lastly, we observed an overlap of the greatest abundance of C. crassus and the time of plant stigmatic receptivity, and a pattern of non co-occurrence of ants, which shows the pollinator role of this ant. CONCLUSIONS Our data provide evidence that previous generalizations neglecting the importance of ants as pollinators are wrong. Brazilian savanna can reveal a lot about the ant-pollination syndrome, since this environment presents peculiar characteristics related to this association. Thus, this study has great significance for the understanding of the ant-pollination syndrome, and for the understanding of the complex ecological networks present in these dry arid systems.
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Affiliation(s)
- K Del-Claro
- Instituto de Biologia, LECI (Laboratório de Ecologia Comportamental e de Interações), Pós-graduação em Ecologia e Conservação de Recursos Naturais, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - D Rodriguez-Morales
- Instituto de Ecología A.C., Red de Interacciones Multitróficas, Carretera antigua a Coatepec, El Haya, Xalapa, Veracruz, Mexico
| | - E S Calixto
- Programa de Pós-Graduação em Entomologia, Faculdade de Filosofia, Ciências e Letras, Universidade de São Paulo, Av. Bandeirantes, Ribeirão Preto, SP, Brazil
| | - A S Martins
- Instituto de Biologia, LECI (Laboratório de Ecologia Comportamental e de Interações), Pós-graduação em Ecologia e Conservação de Recursos Naturais, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - H M Torezan-Silingardi
- Instituto de Biologia, LECI (Laboratório de Ecologia Comportamental e de Interações), Pós-graduação em Ecologia e Conservação de Recursos Naturais, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
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Herbivory and inbreeding affect growth, reproduction, and resistance in the rhizomatous offshoots of Solanum carolinense (Solanaceae). Evol Ecol 2019. [DOI: 10.1007/s10682-019-09997-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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64
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Kirmse S, Chaboo CS. Extrafloral nectaries mediate the arboreal beetle community (Coleoptera) in a Neotropical rainforest. J NAT HIST 2019. [DOI: 10.1080/00222933.2019.1650211] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Susan Kirmse
- Florida State Collection of Arthropods, Museum of Entomology, Gainesville, FL, USA
| | - Caroline S. Chaboo
- University of Nebraska State Museum, Systematics Research Collections, University of Nebraska, Lincoln, NE, USA
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Villamil N, Boege K, Stone GN. Testing the Distraction Hypothesis: Do extrafloral nectaries reduce ant-pollinator conflict? THE JOURNAL OF ECOLOGY 2019; 107:1377-1391. [PMID: 31217634 PMCID: PMC6559321 DOI: 10.1111/1365-2745.13135] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 10/22/2018] [Indexed: 06/09/2023]
Abstract
Ant guards protect plants from herbivores, but can also hinder pollination by damaging reproductive structures and/or repelling pollinators. Natural selection should favour the evolution of plant traits that deter ants from visiting flowers during anthesis, without waiving their defensive services. The Distraction Hypothesis posits that rewarding ants with extrafloral nectar could reduce their visitation of flowers, reducing ant-pollinator conflict while retaining protection of other structures.We characterised the proportion of flowers occupied by ants and the number of ants per flower in a Mexican ant-plant, Turnera velutina. We clogged extrafloral nectaries on field plants and observed the effects on patrolling ants, pollinators and ants inside flowers, and quantified the effects on plant fitness. Based on the Distraction Hypothesis, we predicted that preventing extrafloral nectar secretion should result in fewer ants active at extrafloral nectaries, more ants inside flowers and a higher proportion of flowers occupied by ants, leading to ant-pollinator conflict, with reduced pollinator visitation and reduced plant fitness.Overall ant activity inside flowers was low. Preventing extrafloral nectar secretion through clogging reduced the number of ants patrolling extrafloral nectaries, significantly increased the proportion of flowers occupied by ants from 6.1% to 9.7%, and reduced plant reproductive output through a 12% increase in the probability of fruit abortion. No change in the numbers of ants or pollinators inside flowers was observed. This is the first support for the Distraction Hypothesis obtained under field conditions, showing ecological and plant fitness benefits of the distracting function of extrafloral nectar during anthesis. Synthesis. Our study provides the first field experimental support for the Distraction Hypothesis, suggesting that extrafloral nectaries located close to flowers may bribe ants away from reproductive structures during the crucial pollination period, reducing the probability of ant occupation of flowers, reducing ant-pollinator conflict and increasing plant reproductive success.
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Affiliation(s)
- Nora Villamil
- Ashworth Laboratories, Institute of Evolutionary BiologyUniversity of EdinburghEdinburghUK
| | - Karina Boege
- Instituto de Ecología, Departamento de Ecología EvolutivaUniversidad Nacional Autónoma de MéxicoCiudad de MéxicoMexico
| | - Graham N. Stone
- Ashworth Laboratories, Institute of Evolutionary BiologyUniversity of EdinburghEdinburghUK
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Fernandes GW, Aguirre-Jaimes A, Araújo-Oliveira L. Induction, engineering, and hijacking of defensive strategies of the host by a gall-inducing weevil. Ecology 2019; 100:e02693. [PMID: 30883734 DOI: 10.1002/ecy.2693] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 02/06/2019] [Accepted: 02/07/2019] [Indexed: 12/30/2022]
Affiliation(s)
- Geraldo Wilson Fernandes
- Ecologia Evolutiva and Biodiversidade, ICB/Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.,Biology Department, Stanford University, Stanford, California , 94305, USA
| | - Armando Aguirre-Jaimes
- Instituto de Ecología A.C., Red de Interacciones Multitróficas, Carretera Antigua a Coatepec 351, El Haya, Xalapa, Veracruz, 91070, México
| | - Lázaro Araújo-Oliveira
- Departamento de Ciências Biológicas, Faculdade de Filosofia, Ciências e Letras do Alto São Francisco, Avenida Laerton Paulinelli 153, 35595-000, Luz, Minas Gerais, Brazil
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Pacelhe FT, Costa FV, Neves FS, Bronstein J, Mello MAR. Nectar quality affects ant aggressiveness and biotic defense provided to plants. Biotropica 2019. [DOI: 10.1111/btp.12625] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Fábio T. Pacelhe
- Graduate School in Ecology, Conservation and Wildlife Management; Federal University of Minas Gerais; Belo Horizonte Brazil
| | - Fernanda V. Costa
- Graduate School in Ecology of Tropical Biomes; Federal University of Ouro Preto; Ouro Preto Brazil
| | - Frederico S. Neves
- Graduate School in Ecology, Conservation and Wildlife Management; Federal University of Minas Gerais; Belo Horizonte Brazil
- Department of Biological Sciences; George Washington University; Washington District of Columbia
| | - Judith Bronstein
- Department of Ecology and Evolutionary Biology; University of Arizona; Tucson Arizona
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Wenninger A, Hollingsworth T, Wagner D. Predatory hymenopteran assemblages in boreal Alaska: associations with forest composition and post-fire succession. ECOSCIENCE 2019. [DOI: 10.1080/11956860.2018.1564484] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Alexandria Wenninger
- Institute of Arctic Biology and Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Teresa Hollingsworth
- USDA Forest Service, Pacific Northwest Research Station, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Diane Wagner
- Institute of Arctic Biology and Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, USA
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von Aderkas P, Prior NA, Little SA. The Evolution of Sexual Fluids in Gymnosperms From Pollination Drops to Nectar. FRONTIERS IN PLANT SCIENCE 2018; 9:1844. [PMID: 30619413 PMCID: PMC6305574 DOI: 10.3389/fpls.2018.01844] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 11/28/2018] [Indexed: 05/23/2023]
Abstract
A current synthesis of data from modern and fossil plants paints a new picture of sexual fluids, including nectar, as a foundational component of gymnosperm reproductive evolution. We review the morpho-anatomical adaptations, their accompanying secretions, and the functional compounds involved. We discuss two types of secretions: (1) those involved in fertilization fluids produced by gametophytes and archegonia of zooidogamous gymnosperms, i.e., Ginkgo and cycads, and (2) those involved in pollen capture mechanisms (PCMs), i.e., pollination drops. Fertilization fluids provide both liquid in which sperm swim, as well as chemotactic signals that direct sperm to the egg. Such fertilization fluids were probably found among many extinct plants such as ancient cycads and others with swimming sperm, but were subsequently lost upon the evolution of siphonogamy (direct delivery of sperm to the egg by pollen tubes), as found in modern gnetophytes, conifers, and Pinaceae. Pollination drops are discussed in terms of three major types of PCMs and the unique combinations of morphological and biochemical adaptations that define each. These include their amino acids, sugars, calcium, phosphate and proteins. The evolution of PCMs is also discussed with reference to fossil taxa. The plesiomorphic state of extant gymnosperms is a sugar-containing pollination drop functioning as a pollen capture surface, and an in ovulo pollen germination medium. Additionally, these drops are involved in ovule defense, and provide nectar for pollinators. Pollination drops in anemophilous groups have low sugar concentrations that are too low to provide insects with a reward. Instead, they appear to be optimized for defense and microgametophyte development. In insect-pollinated modern Gnetales a variety of tissues produce sexual fluids that bear the biochemical signature of nectar. Complete absence of fluid secretions is restricted to a few, poorly studied modern conifers, and is presumably derived. Aspects of pollination drop dynamics, e.g., regulation of secretion and retraction, are reviewed. Lastly, we discuss pollination drops' control of pollen germination. Large gaps in our current knowledge include the composition of fertilization fluids, the pollination drops of Podocarpaceae, and the overall hydrodynamics of sexual fluids in general.
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Heil M, Vega-Muñoz I. Nucleic Acid Sensing in Mammals and Plants: Facts and Caveats. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2018; 345:225-285. [PMID: 30904194 DOI: 10.1016/bs.ircmb.2018.10.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The accumulation of nucleic acids in aberrant compartments is a signal of danger: fragments of cytosolic or extracellular self-DNA indicate cellular dysfunctions or disruption, whereas cytosolic fragments of nonself-DNA or RNA indicate infections. Therefore, nucleic acids trigger immunity in mammals and plants. In mammals, endosomal Toll-like receptors (TLRs) sense single-stranded (ss) or double-stranded (ds) RNA or CpG-rich DNA, whereas various cytosolic receptors sense dsDNA. Although a self/nonself discrimination could favor targeted immune responses, no sequence-specific sensing of nucleic acids has been reported for mammals. Specific immune responses to extracellular self-DNA versus DNA from related species were recently reported for plants, but the underlying mechanism remains unknown. The subcellular localization of mammalian receptors can favor self/nonself discrimination based on the localization of DNA fragments. However, autoantibodies and diverse damage-associated molecular patterns (DAMPs) shuttle DNA through membranes, and most of the mammalian receptors share downstream signaling elements such as stimulator of interferon genes (STING) and the master transcription regulators, nuclear factor (NF)-κB, and interferon regulatory factor 3 (IRF3). The resulting type I interferon (IFN) response stimulates innate immunity against multiple threats-from infection to physical injury or endogenous DNA damage-all of which lead to the accumulation of eDNA or cytoplasmatic dsDNA. Therefore, no or only low selective pressures might have favored a strict self/nonself discrimination in nucleic acid sensing. We conclude that the discrimination between self- and nonself-DNA is likely to be less strict-and less important-than assumed originally.
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Affiliation(s)
- Martin Heil
- Departmento de Ingeniería Genética, CINVESTAV-Irapuato, Irapuato, Guanajuato, Mexico.
| | - Isaac Vega-Muñoz
- Departmento de Ingeniería Genética, CINVESTAV-Irapuato, Irapuato, Guanajuato, Mexico
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da Silva Pereira P, de Almeida Gonçalves L, da Silva MJ, Rezende MH. Extrafloral nectaries of four varieties of Chamaecrista ramosa (Vogel) H.S.Irwin & Barneby (Fabaceae): anatomy, chemical nature, mechanisms of nectar secretion, and elimination. PROTOPLASMA 2018; 255:1635-1647. [PMID: 29704049 DOI: 10.1007/s00709-018-1253-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Accepted: 04/09/2018] [Indexed: 06/08/2023]
Abstract
Considering the importance of extrafloral nectaries (EFNs) in Fabaceae, the objectives of this research were to analyze (1) the anatomical and histochemical characteristics of the EFNs of Chamaecrista ramosa var. ramosa, C. ramosa var. curvifoliola, C. ramosa var. parvifoliola, and C. ramosa var. lucida and (2) the ultrastructure of the EFNs of C. ramosa var. ramosa. Standard techniques in plant anatomy and transmission electron microscopy were used. The anatomical analyses confirmed the characteristics described for extrafloral nectaries, evidencing three well-defined regions: epidermis, nectariferous, and subnectariferous parenchymas. Carbohydrates, proteins, pectins/mucilages, and lipids were detected by histochemical analyzes in all varieties. The ultrastructure of the EFNs of C. ramosa var. ramosa allowed the observation of microchannels at the external periclinal cell walls of the epidermis covering the secretory region. The nectariferous and subnectariferous parenchyma cells have periplasmic spaces, large plastids containing starch grains and plastoglobules, mitochondria, developed endoplasmic reticulum, large vacuoles with electron-dense contents, and membrane residues may be associated with the vacuole, suggesting the occurrence of autophagic processes. The anatomical, histochemical, and ultrastructural patterns revealed characteristics that confirm the glands of C. ramosa as extrafloral nectaries and suggest the eccrine mechanism of secretion.
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Affiliation(s)
- Priscila da Silva Pereira
- Pós-graduação em Biodiversidade Vegetal, Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Avenida Esperança, S/N, Campus Samambaia, ICB - 1, 2nd floor, room 206, Goiânia, 74690-900, Brazil.
| | - Letícia de Almeida Gonçalves
- Pós-graduação em Biodiversidade Vegetal, Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Avenida Esperança, S/N, Campus Samambaia, ICB - 1, 2nd floor, room 206, Goiânia, 74690-900, Brazil
| | - Marcos José da Silva
- Pós-graduação em Biodiversidade Vegetal, Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Avenida Esperança, S/N, Campus Samambaia, ICB - 1, 1st floor, room 114A, Goiânia, 74690-900, Brazil
| | - Maria Helena Rezende
- Pós-graduação em Biodiversidade Vegetal, Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Avenida Esperança, S/N, Campus Samambaia, ICB - 1, 2nd floor, room 206, Goiânia, 74690-900, Brazil
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Egan PA, Adler LS, Irwin RE, Farrell IW, Palmer-Young EC, Stevenson PC. Crop Domestication Alters Floral Reward Chemistry With Potential Consequences for Pollinator Health. FRONTIERS IN PLANT SCIENCE 2018; 9:1357. [PMID: 30319666 PMCID: PMC6169423 DOI: 10.3389/fpls.2018.01357] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 08/28/2018] [Indexed: 05/29/2023]
Abstract
Crop domestication can lead to weakened expression of plant defences, with repercussions for herbivore and pathogen susceptibility. However, little is known about how domestication alters traits that mediate other important ecological interactions in crops, such as pollination. Secondary metabolites, which underpin many defence responses in plants, also occur widely in nectar and pollen and influence plant-pollinator interactions. Thus, domestication may also affect secondary compounds in floral rewards, with potential consequences for pollinators. To test this hypothesis, we chemically analysed nectar and pollen from wild and cultivated plants of highbush blueberry (Vaccinium corymbosum L.), before conducting an artificial diet bioassay to examine pollinator-pathogen interactions. Our results indicated that domestication has significantly altered the chemical composition of V. corymbosum nectar and pollen, and reduced pollen chemical diversity in cultivated plants. Of 20 plant metabolites identified in floral rewards, 13 differed significantly between wild and cultivated plants, with a majority showing positive associations with wild compared to cultivated plants. These included the amino acid phenylalanine (4.5 times higher in wild nectar, 11 times higher in wild pollen), a known bee phagostimulant and essential nutrient; and the antimicrobial caffeic acid ester 4-O-caffeoylshikimic acid (two times higher in wild nectar). We assessed the possible biological relevance of variation in caffeic acid esters in bioassays, using the commercially available 3-O-caffeoylquinic acid. This compound reduced Bombus impatiens infection by a prominent gut pathogen (Crithidia) at concentrations that occurred in wild but not cultivated plants, suggesting that domestication may influence floral traits with consequences for bee health. Appreciable levels of genetic variation and heritability were found for most floral reward chemical traits, indicating good potential for selective breeding. Our study provides the first assessment of plant domestication effects on floral reward chemistry and its potential repercussions for pollinator health. Given the central importance of pollinators for agriculture, we discuss the need to extend such investigations to pollinator-dependent crops more generally and elaborate on future research directions to ascertain wider trends, consequences for pollinators, mechanisms, and breeding solutions.
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Affiliation(s)
- Paul A. Egan
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Lynn S. Adler
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, United States
| | - Rebecca E. Irwin
- Department of Applied Ecology, North Carolina State University, Raleigh, NC, United States
| | | | - Evan C. Palmer-Young
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, United States
| | - Philip C. Stevenson
- Royal Botanic Gardens, Kew, Richmond, United Kingdom
- Natural Resources Institute, University of Greenwich, London, United Kingdom
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Cruz NG, Almeida CS, Bacci L, Cristaldo PF, Santana AS, Oliveira AP, Ribeiro EJM, Araújo APA. Ant associations in the Neotropical shrubTurnera subulata(Turneraceae): Costs or benefits to the host plant? AUSTRAL ECOL 2018. [DOI: 10.1111/aec.12652] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nayara G. Cruz
- Laboratório de Interações Ecológicas; Departamento de Ecologia; Universidade Federal de Sergipe; São Cristóvão SE 49100-000 Brazil
- Programa de Pós-Graduação em Ecologia e Conservação; Universidade Federal de Sergipe; São Cristóvão SE Brazil
| | - Camilla S. Almeida
- Laboratório de Interações Ecológicas; Departamento de Ecologia; Universidade Federal de Sergipe; São Cristóvão SE 49100-000 Brazil
- Programa de Pós-Graduação em Ecologia e Conservação; Universidade Federal de Sergipe; São Cristóvão SE Brazil
| | - Leandro Bacci
- Departamento de Engenharia Agronômica; Universidade Federal de Sergipe; São Cristóvão SE Brazil
| | - Paulo F. Cristaldo
- Laboratório de Interações Ecológicas; Departamento de Ecologia; Universidade Federal de Sergipe; São Cristóvão SE 49100-000 Brazil
| | - Alisson S. Santana
- Departamento de Engenharia Agronômica; Universidade Federal de Sergipe; São Cristóvão SE Brazil
| | - Alexandre P. Oliveira
- Departamento de Engenharia Agronômica; Universidade Federal de Sergipe; São Cristóvão SE Brazil
| | - Efrem J. M. Ribeiro
- Laboratório de Interações Ecológicas; Departamento de Ecologia; Universidade Federal de Sergipe; São Cristóvão SE 49100-000 Brazil
| | - Ana P. A. Araújo
- Laboratório de Interações Ecológicas; Departamento de Ecologia; Universidade Federal de Sergipe; São Cristóvão SE 49100-000 Brazil
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Villamil N, Boege K, Stone GN. Ant-Pollinator Conflict Results in Pollinator Deterrence but no Nectar Trade-Offs. FRONTIERS IN PLANT SCIENCE 2018; 9:1093. [PMID: 30154806 PMCID: PMC6102506 DOI: 10.3389/fpls.2018.01093] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 07/05/2018] [Indexed: 06/08/2023]
Abstract
Direct and indirect negative interactions between ant guards and pollinators on ant-plants are expected for two reasons. First, aggressive ants may deter pollinators directly. Second, pollinators benefit from plant investment in reproduction whilst ants benefit from plant investment in indirect defense, and resource allocation trade-offs between these functions could lead to indirect conflict. We explored the potential for ant-pollinator conflict in a Mexican myrmecophile, Turnera velutina, which rewards ants with extrafloral nectar and pollinators with floral nectar. We characterized the daily timing of ant and pollinator activity on the plant and used experiments to test for direct and indirect conflict between these two groups of mutualists. We tested for direct conflict by quantifying pollinator responses to flowers containing dead specimens of aggressive ant species, relative to unoccupied control flowers. We assessed indirect conflict by testing for the existence of a trade-off in sugar allocation between ant and pollinator rewards, evidenced by an increase in floral nectar secretion when extrafloral nectar secretion was prevented. Secretion of floral and extrafloral nectar, activity of ants and pollinators, and pollen deposition all overlapped in daily time and peaked within the first 2 h after flowers opened. We found evidence of direct conflict, in that presence of ants inside the flowers altered pollinator behavior and reduced visit duration, although visit frequency was unchanged. We found no evidence for indirect conflict, with no significant difference in the volume or sugar content of floral nectar between control plants and those in which extrafloral nectar secretion was prevented. The presence of ants in flowers alters pollinator behavior in ways that are likely to affect pollination dynamics, though there is no apparent trade-off between plant investment in nectar rewards for pollinators and ant guards. Further studies are required to quantify the effect of the natural abundance of ants in flowers on pollinator behavior, and any associated impacts on plant reproductive success.
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Affiliation(s)
- Nora Villamil
- Ashworth Laboratories, Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Karina Boege
- Instituto de Ecología, Departamento de Ecología Evolutiva, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Graham N. Stone
- Ashworth Laboratories, Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, United Kingdom
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Duran-Flores D, Heil M. Extracellular self-DNA as a damage-associated molecular pattern (DAMP) that triggers self-specific immunity induction in plants. Brain Behav Immun 2018; 72:78-88. [PMID: 29042243 DOI: 10.1016/j.bbi.2017.10.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 10/04/2017] [Accepted: 10/13/2017] [Indexed: 12/14/2022] Open
Abstract
Mammals sense self or non-self extracellular or extranuclear DNA fragments (hereinafter collectively termed eDNA) as indicators of injury or infection and respond with immunity. We hypothesised that eDNA acts as a damage-associated molecular pattern (DAMP) also in plants and that it contributes to self versus non-self discrimination. Treating plants and suspension-cultured cells of common bean (Phaseolus vulgaris) with fragmented self eDNA (obtained from other plants of the same species) induced early, immunity-related signalling responses such as H2O2 generation and MAPK activation, decreased the infection by a bacterial pathogen (Pseudomonas syringae) and increased an indirect defence to herbivores (extrafloral nectar secretion). By contrast, non-self DNA (obtained from lima bean, Phaseolus lunatus, and Acacia farnesiana) had significantly lower or no detectable effects. Only fragments below a size of 700 bp were active, and treating the eDNA preparation DNAse abolished its inducing effects, whereas treatment with RNAse or proteinase had no detectable effect. These findings indicate that DNA fragments, rather than small RNAs, single nucleotides or proteins, accounted for the observed effects. We suggest that eDNA functions a DAMP in plants and that plants discriminate self from non-self at a species-specific level. The immune systems of plants and mammals share multiple central elements, but further work will be required to understand the mechanisms and the selective benefits of an immunity response that is triggered by eDNA in a species-specific manner.
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Affiliation(s)
- Dalia Duran-Flores
- Departamento de Ingeniería Genética, CINVESTAV-Irapuato, Irapuato, Guanajuato, Mexico
| | - Martin Heil
- Departamento de Ingeniería Genética, CINVESTAV-Irapuato, Irapuato, Guanajuato, Mexico.
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Nepi M, Grasso DA, Mancuso S. Nectar in Plant-Insect Mutualistic Relationships: From Food Reward to Partner Manipulation. FRONTIERS IN PLANT SCIENCE 2018; 9:1063. [PMID: 30073014 PMCID: PMC6060274 DOI: 10.3389/fpls.2018.01063] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 06/29/2018] [Indexed: 05/27/2023]
Abstract
It has been known for centuries that floral and extra-floral nectar secreted by plants attracts and rewards animals. Extra-floral nectar is involved in so-called indirect defense by attracting animals (generally ants) that prey on herbivores, or by discouraging herbivores from feeding on the plant. Floral nectar is presented inside the flower close to the reproductive organs and rewards animals that perform pollination while visiting the flower. In both cases nectar is a source of carbon and nitrogen compounds that feed animals, the most abundant solutes being sugars and amino acids. Plant-animal relationships involving the two types of nectar have therefore been used for a long time as text-book examples of symmetric mutualism: services provided by animals to plants in exchange for food provided by plants to animals. Cheating (or deception or exploitation), namely obtaining the reward/service without returning any counterpart, is however, well-known in mutualistic relationships, since the interacting partners have conflicting interests and selection may favor cheating strategies. A more subtle way of exploiting mutualism was recently highlighted. It implies the evolution of strategies to maximize the benefits obtained by one partner while still providing the reward/service to the other partner. Several substances other than sugars and amino acids have been found in nectar and some affect the foraging behavior of insects and potentially increase the benefits to the plant. Such substances can be considered plant cues to exploit mutualism. Recent evidence motivated some authors to use the term "manipulation" of animals by plants in nectar-mediated mutualistic relationships. This review highlights the recent background of the "manipulation" hypothesis, discussing it in the framework of new ecological and evolutionary scenarios in plant-animal interactions, as a stimulus for future research.
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Affiliation(s)
- Massimo Nepi
- Department of Life Sciences, University of Siena, Siena, Italy
| | - Donato A. Grasso
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Stefano Mancuso
- Department of Agrifood Production and Environmental Sciences, University of Florence, Florence, Italy
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Quintana-Rodríguez E, Ramírez-Rodríguez AG, Ramírez-Chávez E, Molina-Torres J, Camacho-Coronel X, Esparza-Claudio J, Heil M, Orona-Tamayo D. Biochemical Traits in the Flower Lifetime of a Mexican Mistletoe Parasitizing Mesquite Biomass. FRONTIERS IN PLANT SCIENCE 2018; 9:1031. [PMID: 30174673 PMCID: PMC6108335 DOI: 10.3389/fpls.2018.01031] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 06/25/2018] [Indexed: 05/24/2023]
Abstract
Psittacanthus calyculatus is a hemiparasitic plant that infects a wide range of trees. Mainly the biology reproduction of this mistletoe lies in bright colored flower development. Furthermore, it uses the nectar secretion as the only reward to engage different flower visitors. We investigated the physiological mechanisms of the flower phenology per hour and per day to analyze the spatial-temporal patterns of the nectar secretion, Cell Wall Invertase Activity (key enzyme in the quality of nectar), nectar chemistry, volatile organic compounds (VOCs) emission, synthesis of carotenoids and frequency of floral visitors. Flowers lasted 4 days, total nectar was loaded just before the anthesis and the secretion was maintained over day 1 and 2, decreased on day 3, and stopped on day 4. The diurnal nectar secretion dynamic per hour on day 1 and 2 showed similar patterns with high production on the morning and a decrease in the afternoon, the secretion declined on day 3 and ceased on day 4. On the other hand, CWIN activity per day was less before the anthesis and increased on day 1 and 2, this enzymatic activity decreased on the old flower phenology. Moreover, diurnal CWIN activities showed different patterns in the morning, noon, and lastly in the afternoon. Nectar chemistry varied significantly throughout of the flower lifetime, sucrose decreased along the flower phenology increasing glucose and fructose. Amino acids showed the prevalence of proline and oxo-proline, both increased on the day 1 and diminished in subsequent old flower stages. The spatial VOCs emission showed the presence of 11 compounds being β-ocimene the main volatile; its release increased on day 1 and remained constant in the flower lifetime. Lutein, lycopene, and β-carotene were concentrated in old stages of the flowers. In field, the most frequent flower visitors were the hummingbirds that usually foraging in all phenologic flower stage and their foraging events decreased with the phenological flower lifetimes. The results showed that these traits presented by P. calyculatus flowers are able to engage and manipulate the behavior of flower visitors and contribute to the reproduction of the parasitic plant.
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Affiliation(s)
- Elizabeth Quintana-Rodríguez
- Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Guanajuato, Mexico
- Departamento de Soluciones Tecnológicas, Centro de Innovación Aplicada en Tecnologías Competitivas (CIATEC), Guanajuato, Mexico
| | - Alan Gamaliel Ramírez-Rodríguez
- Departamento de Bioquímica y Biotecnología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Guanajuato, Mexico
| | - Enrique Ramírez-Chávez
- Departamento de Bioquímica y Biotecnología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Guanajuato, Mexico
| | - Jorge Molina-Torres
- Departamento de Bioquímica y Biotecnología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Guanajuato, Mexico
| | - Xicotencatl Camacho-Coronel
- Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Guanajuato, Mexico
| | - José Esparza-Claudio
- Departamento de Soluciones Tecnológicas, Centro de Innovación Aplicada en Tecnologías Competitivas (CIATEC), Guanajuato, Mexico
| | - Martin Heil
- Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Guanajuato, Mexico
| | - Domancar Orona-Tamayo
- Departamento de Soluciones Tecnológicas, Centro de Innovación Aplicada en Tecnologías Competitivas (CIATEC), Guanajuato, Mexico
- Departamento de Bioquímica y Biotecnología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Guanajuato, Mexico
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Sandoval-Molina MA, Zavaleta-Mancera HA, León-Solano HJ, Solache-Ramos LT, Jenner B, Morales-Rodríguez S, Patrón-Soberano A, Janczur MK. First description of extrafloral nectaries in Opuntia robusta (Cactaceae): Anatomy and ultrastructure. PLoS One 2018; 13:e0200422. [PMID: 30016339 PMCID: PMC6049920 DOI: 10.1371/journal.pone.0200422] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 06/26/2018] [Indexed: 11/19/2022] Open
Abstract
To our knowledge, there are no studies about the structure and ecological function of extrafloral nectaries (EFNs) in Opuntia robusta. This is the first description of EFNs in O. robusta, where young spines have an interesting structure and a secreting function, which are different from EFNs described in other Cactaceae species. We used light, scanning-electron, and transmission-electron microscopy to examine morphology, anatomy, and ultrastructure of the secretory spines in areoles in female and hermaphrodite individuals of O. robusta. Young cladodes develop areoles with modified and secretory spines as EFNs only active during the early growth phase. EFNs are non-vascularized structures, with no stomata, that consist of a basal meristematic tissue, a middle elongation region, and an apical secretory cone formed by large globular epidermal cells, containing nectar and medullar elongated cells. We observed the presence of Golgi apparatus, vesicles and plastids in the medullar and sup-epidermal cells of the spine. We propose that the nectar is stored in the globular cells at the apex of the spine and secreted by breaking through the globular cells or by pores. We recorded a more frequent presence of ants on younger cladode sprouts producing young secreting spines: this result is parallel with the predictions of Optimal Defense Hypothesis, which states that younger plant organs should be better defended than older ones because their loss produces a higher fitness impairment. Although Diaz-Castelazo's hypothesis states that a more complex structure of EFNs correlates with their lower among-organs dispersion, comparing to less complex EFNs, non-vascularized structure of EFNs in O. robusta is not associated with their higher among-organs dispersion likened to O. stricta, which produces vascularized EFNs. We provide evidence that this characteristic is not a good taxonomic feature of Opuntia genus. Moreover, the comparison of EFNs of O. robusta and O. stricta suggests that the hypothesis of Diaz-Castelazo should be revised: it is rather a rule but not a law.
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Affiliation(s)
- Mario Alberto Sandoval-Molina
- Research Group in Ecology and Evolutionary Biology, Department of Natural Sciences, Autonomous University of the State of Mexico, Toluca, Estado de México, México
- Instituto de Ecología, El Haya, Xalapa, Veracruz, México
| | - Hilda Araceli Zavaleta-Mancera
- Unidad de Microscopía Electrónica, Postgrado en Botánica, Colegio de Postgraduados, Campus Montecillo, Montecillo, Texcoco, Estado de México
| | - Héctor Javier León-Solano
- Research Group in Ecology and Evolutionary Biology, Department of Natural Sciences, Autonomous University of the State of Mexico, Toluca, Estado de México, México
- Graduate Program in Agricultural Sciences and Natural Resources (PCARN), Autonomous University of the State of Mexico, Toluca, Estado de México, México
| | - Lupita Tzenyatze Solache-Ramos
- Research Group in Ecology and Evolutionary Biology, Department of Natural Sciences, Autonomous University of the State of Mexico, Toluca, Estado de México, México
- Graduate Program in Agricultural Sciences and Natural Resources (PCARN), Autonomous University of the State of Mexico, Toluca, Estado de México, México
| | - Bartosz Jenner
- Evidence Generation & Clinical Research RB, Hull, United Kingdom
| | | | | | - Mariusz Krzysztof Janczur
- Research Group in Ecology and Evolutionary Biology, Department of Natural Sciences, Autonomous University of the State of Mexico, Toluca, Estado de México, México
- Graduate Program in Agricultural Sciences and Natural Resources (PCARN), Autonomous University of the State of Mexico, Toluca, Estado de México, México
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81
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Melati BG, Leal LC. Aggressive bodyguards are not always the best: Preferential interaction with more aggressive ant species reduces reproductive success of plant bearing extrafloral nectaries. PLoS One 2018; 13:e0199764. [PMID: 29949639 PMCID: PMC6021078 DOI: 10.1371/journal.pone.0199764] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Accepted: 06/13/2018] [Indexed: 11/19/2022] Open
Abstract
Variation in partner species and frequency of interaction between species pairs are potential drivers of the net outcome of generalized mutualisms. In ant-plant mutualisms, the quality of defence provided by ants is related to ant aggressiveness. Hence, we hypothesize that the performance of plants bearing extrafloral nectaries will be higher when they interact more frequently with more aggressive ant species. We estimated ant aggressiveness in the field by observing their behaviour towards soil baits. Afterwards, we observed the frequency with which individuals from these ant species visited plants through an entire reproductive cycle. We measured the production and persistence of plants reproductive structures through this period and the total seed production. Increasing in the interaction frequency with highly aggressive ants reduced the number of floral buds and seeds produced. Increased visitation frequency by less aggressive ants increased the number of floral buds and seeds per branch. The inverse relationship between ant aggressiveness and seed production may be influenced by the costs imposed by different mutualistic partners. Thus, frequent interaction with highly aggressive ants may lead to a higher accumulation of costs through time, resulting in a negative net outcome for the plants. Our results bring new evidence highlighting the importance to incorporate temporal aspects in the study of mutualistic interactions. We suggests that the quality of mutualistic partners must be understood as a function of its per-interaction benefit and their cumulative costs to their partner over time, what puts in check our current classification regarding partner quality in mutualistic systems.
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Affiliation(s)
- Bruno Gabriel Melati
- Programa de Pós-graduação em Ecologia e Evolução, Departamento de Ciências Biológicas, Universidade Estadual de Feira de Santana, Novo Horizonte, Bahia, Brazil
| | - Laura Carolina Leal
- Programa de Pós-graduação em Ecologia e Evolução, Departamento de Ciências Biológicas, Universidade Estadual de Feira de Santana, Novo Horizonte, Bahia, Brazil
- Departamento de Ecologia e Biologia Evolutiva, Universidade Federal de São Paulo, Diadema, São Paulo, Brazil
- * E-mail:
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Prasifka JR, Mallinger RE, Portlas ZM, Hulke BS, Fugate KK, Paradis T, Hampton ME, Carter CJ. Using Nectar-Related Traits to Enhance Crop-Pollinator Interactions. FRONTIERS IN PLANT SCIENCE 2018; 9:812. [PMID: 29967631 PMCID: PMC6015894 DOI: 10.3389/fpls.2018.00812] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 05/25/2018] [Indexed: 05/29/2023]
Abstract
Floral nectar and other reward facilitate crop pollination, and in so doing, increase the amount and breadth of food available for humans. Though abundance and diversity of pollinators (particularly bees) have declined over the past several decades, a concomitant increase in reliance on pollinators presents a challenge to food production. Development of crop varieties with specific nectar or nectar-related traits to attract and retain pollinating insects is an appealing strategy to help address needs of agriculture and pollinators for several reasons. First, many crops have specific traits which have been identified to enhance crop-pollinator interactions. Also, an improved understanding of mechanisms that govern nectar-related traits suggest simplified phenotyping and breeding are possible. Finally, the use of nectar-related traits to enhance crop pollination should complement other measures promoting pollinators and will not limit options for crop production or require any changes by growers (other than planting varieties that are more attractive or rewarding to pollinators). In this article, we review the rationale for improving crop-pollinator interactions, the effects of specific plant traits on pollinator species, and use cultivated sunflowers as a case study. Recent research in sunflower has (i) associated variation in bee visitation with specific floral traits, (ii) quantified benefits of pollinators to hybrid yields, and (iii) used genetic resources in sunflower and other plants to find markers associated with key floral traits. Forthcoming work to increase pollinator rewards should enable sunflower to act as a model for using nectar-related traits to enhance crop-pollinator interactions.
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Affiliation(s)
- Jarrad R. Prasifka
- Red River Valley Agricultural Research Center, United States Department of Agriculture-Agricultural Research Service, Fargo, ND, United States
| | - Rachel E. Mallinger
- Department of Entomology and Nematology, University of Florida, Gainesville, FL, United States
| | - Zoe M. Portlas
- Red River Valley Agricultural Research Center, United States Department of Agriculture-Agricultural Research Service, Fargo, ND, United States
| | - Brent S. Hulke
- Red River Valley Agricultural Research Center, United States Department of Agriculture-Agricultural Research Service, Fargo, ND, United States
| | - Karen K. Fugate
- Red River Valley Agricultural Research Center, United States Department of Agriculture-Agricultural Research Service, Fargo, ND, United States
| | - Travis Paradis
- Department of Plant and Microbial Biology, University of Minnesota Twin Cities, Saint Paul, MN, United States
| | - Marshall E. Hampton
- Department of Mathematics and Statistics, University of Minnesota Duluth, Duluth, MN, United States
| | - Clay J. Carter
- Department of Plant and Microbial Biology, University of Minnesota Twin Cities, Saint Paul, MN, United States
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83
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Nogueira FCS, Farias ARB, Teixeira FM, Domont GB, Campos FAP. Common Features Between the Proteomes of Floral and Extrafloral Nectar From the Castor Plant ( Ricinus Communis) and the Proteomes of Exudates From Carnivorous Plants. FRONTIERS IN PLANT SCIENCE 2018; 9:549. [PMID: 29755492 PMCID: PMC5934526 DOI: 10.3389/fpls.2018.00549] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 04/09/2018] [Indexed: 06/08/2023]
Abstract
Label-free quantitative proteome analysis of extrafloral (EFN) and floral nectar (FN) from castor (Ricinus communis) plants resulted in the identification of 72 and 37 proteins, respectively. Thirty proteins were differentially accumulated between EFN and FN, and 24 of these were more abundant in the EFN. In addition to proteins involved in maintaining the nectar pathogen free such as chitinases and glucan 1,3-beta-glucosidase, both proteomes share an array of peptidases, lipases, carbohydrases, and nucleases. A total of 39 of the identified proteins, comprising different classes of hydrolases, were found to have biochemical matching partners in the exudates of at least five genera of carnivorous plants, indicating the EFN and FN possess a potential to digest biological material from microbial, animal or plant origin equivalent to the exudates of carnivorous plants.
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Affiliation(s)
- Fábio C. S. Nogueira
- Proteomics Unit, PPGBq, Department of Biochemistry, Institute of Chemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Laboratory of Proteomics, LADETEC, Institute of Chemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Andreza R. B. Farias
- Department of Agricultural Sciences, Federal University of Ceará, Fortaleza, Brazil
| | - Fabiano M. Teixeira
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza, Brazil
| | - Gilberto B. Domont
- Proteomics Unit, PPGBq, Department of Biochemistry, Institute of Chemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Francisco A. P. Campos
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza, Brazil
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Llandres AL, Almohamad R, Brévault T, Renou A, Téréta I, Jean J, Goebel FR. Plant training for induced defense against insect pests: a promising tool for integrated pest management in cotton. PEST MANAGEMENT SCIENCE 2018; 74:2004-2012. [PMID: 29667361 DOI: 10.1002/ps.5039] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 04/04/2018] [Accepted: 04/05/2018] [Indexed: 06/08/2023]
Abstract
Enhancing cotton pest management using plant natural defenses has been described as a promising way to improve the management of crop pests. We here reviewed various studies on cotton growing systems to illustrate how an ancient technique called plant training, which includes plant topping and pruning, may contribute to this goal. Using examples from cotton crops, we show how trained plants can be brought to a state of enhanced defense that causes faster and more robust activation of their defense responses. We revisit the agricultural benefits associated with this technique in cotton crops, with a focus on its potential as a supplementary tool for integrated pest management (IPM). In particular, we examine its role in mediating plant interactions with conspecific neighboring plants, pests and associated natural enemies. We propose a new IPM tool, plant training for induced defense, which involves inducing plant defense through artificial injury. Experimental evidence from various studies shows that cotton training is a promising technique, particularly for smallholders, which can be used as part of an IPM program to significantly reduce insecticide use and to improve productivity in cotton farming. © 2018 Society of Chemical Industry.
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Affiliation(s)
- Ana L Llandres
- CIRAD, Persyst Department, UPR AIDA, Montpellier, France
| | - Raki Almohamad
- CIRAD, Persyst Department, UPR AIDA, Montpellier, France
| | - Thierry Brévault
- CIRAD, Persyst Department, UPR AIDA, Montpellier, France
- BIOPASS, ISRA-UCAD-IRD, Dakar, Senegal
| | - Alain Renou
- CIRAD, Persyst Department, UPR AIDA, Montpellier, France
- CIRAD, BP, Bamako, Mali
| | | | - Janine Jean
- CIRAD, Persyst Department, UPR AIDA, Montpellier, France
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85
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Abstract
Ekebergia capensis is a medium-sized to large evergreen to deciduous tree ranging from southern Africa to Ethiopia. Two morphologically-distinct variants of E. capensis, southern and northern, may be recognized in southern Africa. Despite its wide distribution range there appear to be no published reports on the secretory structures occurring on the leaves. In very young leaves, colleters on the petiolules, adjacent portions of the rachis and the midrib of the adaxial leaflet surfaces, secrete fluid which at least partly covers these developing areas. This is the first record of colleters in Meliaceae. In addition, several extrafloral nectaries (EFNs) are found in variable positions on the abaxial side of the leaflets. No stomata are associated with the EFNs. The glandular tissue of active EFNs is surrounded by druse crystals of calcium oxalate and consists of secretory cells some of whose walls are separated by "strands" of amorphous lipophilic material, especially in a radial orientation. EFNs on developing leaves are inconspicuous but with time, frequently become more easily visible due to the accumulation of pinkish/reddish anthocyanins. Even on senescent leaves, shed in autumn, large droplets of nectar are frequently visible on the EFNs. The secretory tissue originates from protoderm and ground tissues. Slight differences in abundance, size, shape, position and structure exist between the EFNs of the southern and northern forms. Varying proportions of glucose, fructose and sucrose were detected in the rather viscous nectar with the most abundant sugar usually being fructose. Ants were only rarely observed feeding on the nectar. This finding is in conflict with the generally accepted idea that EFNs provide food for ants which in turn protect the plant from herbivores. More detailed studies of the chemistry of the nectar, which is relatively copious, may provide clues as to the function.
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86
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Food source quality and ant dominance hierarchy influence the outcomes of ant-plant interactions in an arid environment. ACTA OECOLOGICA 2018. [DOI: 10.1016/j.actao.2018.02.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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87
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Stahl E, Hilfiker O, Reymond P. Plant-arthropod interactions: who is the winner? THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 93:703-728. [PMID: 29160609 DOI: 10.1111/tpj.13773] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 10/27/2017] [Accepted: 10/31/2017] [Indexed: 05/17/2023]
Abstract
Herbivorous arthropods have interacted with plants for millions of years. During feeding they release chemical cues that allow plants to detect the attack and mount an efficient defense response. A signaling cascade triggers the expression of hundreds of genes, which encode defensive proteins and enzymes for synthesis of toxic metabolites. This direct defense is often complemented by emission of volatiles that attract beneficial parasitoids. In return, arthropods have evolved strategies to interfere with plant defenses, either by producing effectors to inhibit detection and downstream signaling steps, or by adapting to their detrimental effect. In this review, we address the current knowledge on the molecular and chemical dialog between plants and herbivores, with an emphasis on co-evolutionary aspects.
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Affiliation(s)
- Elia Stahl
- Department of Plant Molecular Biology, University of Lausanne, Biophore Building, 1015, Lausanne, Switzerland
| | - Olivier Hilfiker
- Department of Plant Molecular Biology, University of Lausanne, Biophore Building, 1015, Lausanne, Switzerland
| | - Philippe Reymond
- Department of Plant Molecular Biology, University of Lausanne, Biophore Building, 1015, Lausanne, Switzerland
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88
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Prior KM, Palmer TM. Economy of scale: third partner strengthens a keystone ant-plant mutualism. Ecology 2018; 99:335-346. [PMID: 29328512 DOI: 10.1002/ecy.2104] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 10/31/2017] [Accepted: 11/08/2017] [Indexed: 11/06/2022]
Abstract
While foundation species can stabilize ecosystems at landscape scales, their ability to persist is often underlain by keystone interactions occurring at smaller scales. Acacia drepanolobium is a foundation tree, comprising >95% of woody cover in East African black-cotton savanna ecosystems. Its dominance is underlain by a keystone mutualistic interaction with several symbiotic ant species in which it provides housing (swollen thorns) and carbohydrate-rich nectar from extra-floral nectaries (EFN). In return, it gains protection from catastrophic damage from mega-herbivores. Crematogaster mimosae is the ecologically dominant symbiotic ant in this system, also providing the highest protection services. In addition to tending EFN, C. mimosae tend scale insects for carbohydrate-rich honeydew. We investigated the role of scale insects in this specialized ant-plant interaction. Specifically, does this putatively redundant third partner strengthen the ant-plant mutualism by making the ant a better protector of the tree? Or does it weaken the mutualism by being costly to the tree while providing no additional benefit to the ant-plant mutualism? We coupled observational surveys with two scale-manipulation experiments and found evidence that this third partner strengthens the ant-plant mutualism. Trees with scale insects experimentally removed experienced a 2.5X increase in elephant damage compared to trees with scale insects present over 10 months. Reduced protection was driven by scale removal causing a decrease in ant colony size and per capita baseline activity and defensive behavior. We also found that ants increased scale-tending and the density of scale insects on trees when EFN were experimentally reduced. Thus, in this system, scale insects and EFN are likely complementary, rather than redundant, resources with scale insects benefitting ants when EFN production is low (such as during annual dry periods in this semi-arid ecosystem). This study reveals that a third-partner strengthens an ant-plant mutualism that serves to stabilize a whole ecosystem.
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Affiliation(s)
- Kirsten M Prior
- Department of Biology, University of Florida, Gainesville, Florida, 32611, USA.,Mpala Research Centre, P.O. Box 555, Nanyuki, Kenya
| | - Todd M Palmer
- Department of Biology, University of Florida, Gainesville, Florida, 32611, USA.,Mpala Research Centre, P.O. Box 555, Nanyuki, Kenya
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Hernández-Zepeda OF, Razo-Belman R, Heil M. Reduced Responsiveness to Volatile Signals Creates a Modular Reward Provisioning in an Obligate Food-for-Protection Mutualism. FRONTIERS IN PLANT SCIENCE 2018; 9:1076. [PMID: 30087690 PMCID: PMC6066664 DOI: 10.3389/fpls.2018.01076] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 07/03/2018] [Indexed: 05/07/2023]
Abstract
Plants in more than 100 families secrete extrafloral nectar (EFN) to establish food-for-protection mutualisms with ants. Facultative ant-plants secrete EFN as a jasmonic acid (JA)-dependent response to attract generalist ants. In contrast, obligate ant-plants like the Central American "Swollen-Thorn Acacias" are colonized by specialized ants, although an individual host can carry ant colonies from different species that differ in the degree of protection they provide. We hypothesized that hosts that associate simultaneously with various partners should produce rewards in a modular manner to preferentially reward high quality partners. To test this hypothesis, we applied JA to distinct leaves and quantified cell wall invertase activity (CWIN; a regulator of nectar secretion) and EFN secretion by these "local" (i.e., treated) and the "systemic" (i.e., non-treated) leaves of the same branch. Both CWIN activity and EFN secretion increased in local and systemic leaves of the facultative ant-plant Acacia cochliacantha, but only in the local leaves of the obligate ant-plant, A. cornigera. The systemic EFN secretion in A. cochliacantha was associated with an enhanced emission of volatile organic compounds (VOCs). Such VOCs function as "external signals" that control systemic defense responses in diverse plant species. Indeed, the headspace of JA-treated branches of A. cochliacantha induced EFN secretion in both plant species, whereas the headspace of A. cornigera caused no detectable induction effect. Analyses of the headspace using GC-MS identified six VOCs in the headspace of A. cochliacantha that were not emitted by A. cornigera. Among these VOCs, β-caryophyllene and (cis)-hexenyl isovalerate have already been reported in other plant species to induce defense traits, including EFN secretion. Our observations underline the importance of VOCs as systemic within-plant signals and show that the modular rewarding in A. cornigera is likely to result from a reduced emission of the systemic signal, rather than from a reduced responsiveness to the signal. We suggest that modular rewarding allows hosts to restrict the metabolic investment to specific partners and to efficiently sanction potential exploiters.
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90
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Tao L, Hunter MD, de Roode JC. Microbial Root Mutualists Affect the Predators and Pathogens of Herbivores above Ground: Mechanisms, Magnitudes, and Missing Links. Front Ecol Evol 2017. [DOI: 10.3389/fevo.2017.00160] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
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91
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Huang Y, Ao Y, Jiang M. Reproductive Plasticity of an Invasive Insect Pest, Rice Water Weevil (Coleoptera: Curculionidae). JOURNAL OF ECONOMIC ENTOMOLOGY 2017; 110:2381-2387. [PMID: 29045676 DOI: 10.1093/jee/tox274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Indexed: 06/07/2023]
Abstract
Reproductive plasticity is a key determinant of species invasiveness. However, there are a limited number of studies addressing this issue in exotic insects. The rice water weevil Lissorhoptrus oryzophilus Kuschel (Coleoptera: Curculionidae), which is native to North America, is one of the most invasive insect pests in east Asia. In this study, we investigated the reproductive status of first-generation females (progeny of overwintered weevils) from five geographic regions in southern and northern China in the field, and reproductive status and ovipositional features of females provided with suitable host plants in the laboratory after collection. Under field conditions, a proportion of females oviposited, while the rest remained in diapause from all three southern regions investigated, but reproductive development did not take place in females from the two northern regions, where the weevil produces only one generation per year. However, when fed host plants in the laboratory, females from all regions laid eggs. They typically had a very short ovipositional period (3-6 d on average on rice at a temperature of 27°C), laid a low number of eggs, and did not die soon after oviposition; this was different from common reproductive females. We concluded that first-generation L. oryzophilus females, which largely enter diapause after emergence, are highly plastic in their reproductive performance and are ready to reproduce under favorable conditions. Our results indicate the significance of their reproductive plasticity for geographic spread and population development.
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Affiliation(s)
- Yunshang Huang
- Institute of Insect Sciences, Zhejiang University, China
| | - Yan Ao
- Institute of Insect Sciences, Zhejiang University, China
| | - Mingxing Jiang
- Institute of Insect Sciences, Zhejiang University, China
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92
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Rasmann S, Bennett A, Biere A, Karley A, Guerrieri E. Root symbionts: Powerful drivers of plant above- and belowground indirect defenses. INSECT SCIENCE 2017; 24:947-960. [PMID: 28374534 DOI: 10.1111/1744-7917.12464] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 03/08/2017] [Accepted: 03/15/2017] [Indexed: 05/04/2023]
Abstract
Soil microbial mutualists of plants, including mycorrhizal fungi, non-mycorrhizal fungi and plant growth promoting rhizobacteria, have been typically characterized for increasing nutrient acquisition and plant growth. More recently, soil microbes have also been shown to increase direct plant defense against above- and belowground herbivores. Plants, however, do not only rely on direct defenses when attacked, but they can also recruit pest antagonists such as predators and parasitoids, both above and belowground, mainly via the release of volatile organic compounds (i.e., indirect defenses). In this review, we illustrate the main features and effects of soil microbial mutualists of plants on plant indirect defenses and discuss possible applications within the framework of sustainable crop protection against root- and shoot-feeding arthropod pests. We indicate the main knowledge gaps and the future challenges to be addressed in the study and application of these multifaceted interactions.
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Affiliation(s)
- Sergio Rasmann
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Alison Bennett
- Department of Ecological Sciences, James Hutton Institute, Dundee, UK
| | - Arjen Biere
- Netherlands Institute of Ecology, Wageningen, the Netherlands
| | - Alison Karley
- Department of Ecological Sciences, James Hutton Institute, Dundee, UK
| | - Emilio Guerrieri
- Institute for Sustainable Plant Protection, National Research Council of Italy, Portici, Italy
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93
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Response of a Predatory ant to Volatiles Emitted by Aphid- and Caterpillar-Infested Cucumber and Potato Plants. J Chem Ecol 2017; 43:1007-1022. [DOI: 10.1007/s10886-017-0887-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 09/10/2017] [Accepted: 09/12/2017] [Indexed: 10/18/2022]
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94
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Roy R, Schmitt AJ, Thomas JB, Carter CJ. Review: Nectar biology: From molecules to ecosystems. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2017; 262:148-164. [PMID: 28716410 DOI: 10.1016/j.plantsci.2017.04.012] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 04/17/2017] [Accepted: 04/19/2017] [Indexed: 05/06/2023]
Abstract
Plants attract mutualistic animals by offering a reward of nectar. Specifically, floral nectar (FN) is produced to attract pollinators, whereas extrafloral nectar (EFN) mediates indirect defenses through the attraction of mutualist predatory insects to limit herbivory. Nearly 90% of all plant species, including 75% of domesticated crops, benefit from animal-mediated pollination, which is largely facilitated by FN. Moreover, EFN represents one of the few defense mechanisms for which stable effects on plant health and fitness have been demonstrated in multiple systems, and thus plays a crucial role in the resistance phenotype of plants producing it. In spite of its central role in plant-animal interactions, the molecular events involved in the development of both floral and extrafloral nectaries (the glands that produce nectar), as well as the synthesis and secretion of the nectar itself, have been poorly understood until recently. This review will cover major recent developments in the understanding of (1) nectar chemistry and its role in plant-mutualist interactions, (2) the structure and development of nectaries, (3) nectar production, and (4) its regulation by phytohormones.
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Affiliation(s)
- Rahul Roy
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN 55108, USA
| | - Anthony J Schmitt
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN 55108, USA
| | - Jason B Thomas
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN 55108, USA
| | - Clay J Carter
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN 55108, USA.
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95
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Stenberg JA. A Conceptual Framework for Integrated Pest Management. TRENDS IN PLANT SCIENCE 2017; 22:759-769. [PMID: 28687452 DOI: 10.1016/j.tplants.2017.06.010] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Revised: 06/06/2017] [Accepted: 06/12/2017] [Indexed: 05/11/2023]
Abstract
The concept of integrated pest management (IPM) has been accepted and incorporated in public policies and regulations in the European Union and elsewhere, but a holistic science of IPM has not yet been developed. Hence, current IPM programs may often be considerably less efficient than the sum of separately applied individual crop protection actions. Thus, there is a clear need to formulate general principles for synergistically combining traditional and novel IPM actions to improve efforts to optimize plant protection solutions. This paper addresses this need by presenting a conceptual framework for a modern science of IPM. The framework may assist attempts to realize the full potential of IPM and reduce risks of deficiencies in the implementation of new policies and regulations.
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Affiliation(s)
- Johan A Stenberg
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, 23053 Alnarp, Sweden.
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96
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Pappas ML, Broekgaarden C, Broufas GD, Kant MR, Messelink GJ, Steppuhn A, Wäckers F, van Dam NM. Induced plant defences in biological control of arthropod pests: a double-edged sword. PEST MANAGEMENT SCIENCE 2017; 73:1780-1788. [PMID: 28387028 PMCID: PMC5575458 DOI: 10.1002/ps.4587] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Revised: 03/31/2017] [Accepted: 03/31/2017] [Indexed: 05/21/2023]
Abstract
Biological control is an important ecosystem service delivered by natural enemies. Together with breeding for plant defence, it constitutes one of the most promising alternatives to pesticides for controlling herbivores in sustainable crop production. Especially induced plant defences may be promising targets in plant breeding for resistance against arthropod pests. Because they are activated upon herbivore damage, costs are only incurred when defence is needed. Moreover, they can be more specific than constitutive defences. Nevertheless, inducible defence traits that are harming plant pest organisms may interfere with biological control agents, such as predators and parasitoids. Despite the vast fundamental knowledge on plant defence mechanisms and their effects on natural enemies, our understanding of the feasibility of combining biological control with induced plant defence in practice is relatively poor. In this review, we focus on arthropod pest control and present the most important features of biological control with natural enemies and of induced plant defence. Furthermore, we show potential synergies and conflicts among them and, finally, identify gaps and list opportunities for their combined use in crop protection. We suggest that breeders should focus on inducible resistance traits that are compatible with the natural enemies of arthropod pests, specifically traits that help communities of natural enemies to build up. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
- Maria L Pappas
- Democritus University of Thrace, Faculty of Agricultural and Forestry SciencesDepartment of Agricultural DevelopmentOrestiadaGreece
| | - Colette Broekgaarden
- Utrecht University, Faculty of ScienceDepartment of Biology, Plant − Microbe InteractionsUtrechtThe Netherlands
| | - George D Broufas
- Democritus University of Thrace, Faculty of Agricultural and Forestry SciencesDepartment of Agricultural DevelopmentOrestiadaGreece
| | - Merijn R Kant
- University of AmsterdamInstitute for Biodiversity and Ecosystem Dynamics, Section Molecular and Chemical EcologyAmsterdamThe Netherlands
| | | | - Anke Steppuhn
- Freie Universität BerlinInstitute of Biology, Molecular Ecology, Dahlem Centre of Plant SciencesBerlinGermany
| | - Felix Wäckers
- BiobestWesterloBelgium
- Lancaster UniversityLancaster Environment CentreUK
| | - Nicole M van Dam
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐LeipzigLeipzigGermany
- Friedrich Schiller University JenaInstitute of EcologyJenaGermany
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97
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Do Refuge Plants Favour Natural Pest Control in Maize Crops? INSECTS 2017; 8:insects8030071. [PMID: 28718835 PMCID: PMC5620691 DOI: 10.3390/insects8030071] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 07/12/2017] [Accepted: 07/13/2017] [Indexed: 11/17/2022]
Abstract
The use of non-crop plants to provide the resources that herbivorous crop pests’ natural enemies need is being increasingly incorporated into integrated pest management programs. We evaluated insect functional groups found on three refuges consisting of five different plant species each, planted next to a maize crop in Lima, Peru, to investigate which refuge favoured natural control of herbivores considered as pests of maize in Peru, and which refuge plant traits were more attractive to those desirable enemies. Insects occurring in all the plants, including the maize crop itself, were sampled weekly during the crop growing cycle, from February to June 2011. All individuals collected were identified and classified into three functional groups: herbivores, parasitoids, and predators. Refuges were compared based on their effectiveness in enhancing the populations of predator and parasitoid insects of the crop enemies. Refuges A and B were the most effective, showing the highest richness and abundance of both predators and parasitoids, including several insect species that are reported to attack the main insect pests of maize (Spodoptera frugiperda and Rhopalosiphum maidis), as well as other species that serve as alternative hosts of these natural enemies.
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98
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Huang J, Zhang PJ, Zhang J, Tang YY. An ant-coccid mutualism affects the behavior of the parasitoid Aenasius bambawalei, but not that of the ghost ant Tetramorium bicarinatum. Sci Rep 2017; 7:5175. [PMID: 28701713 PMCID: PMC5507978 DOI: 10.1038/s41598-017-05442-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 05/30/2017] [Indexed: 11/09/2022] Open
Abstract
Mutualisms between honeydew-producing insects and ants change the emission of volatiles from plants, but whether such changes alter the behaviors of ants that tend honeydew-producing insects or wasps that parasitize honeydew-producing insects remain unknown. This study compared the behavioral responses of the ant Tetramorium bicarinatum and the parasitoid wasp Aenasius bambawalei to odors from cotton plants infested with the mealybug Phenacoccus solenopsis or infested with the mealybug and the ant, which tends the mealybug. The ant could not distinguish between the volatiles from plants infested with the mealybug alone and those from plants infested with the mealybug and the ant. Likewise, naïve wasps failed to distinguish between volatiles from the two treatments. In contrast, experienced wasps preferred volatiles from plants infested with the mealybug and the ant. Volatile analysis showed that the amounts of MeSA were increased and those of methyl nicotinate were decreased when plants were infested by the mealybug and the ant rather than when plants were uninfested or were infested by the mealybug alone. Thus, the mutualism between the mealybug and ant changed the volatiles emitted by cotton plants such that the attraction of A. bambawalei (but not that of the ant) to the plants was increased.
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Affiliation(s)
- Jun Huang
- Flower Research and Development Centre, Zhejiang Academy of Agricultural Sciences, Hangzhou, 311202, China.
| | - Peng-Jun Zhang
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou, 310018, China
| | - Juan Zhang
- Flower Research and Development Centre, Zhejiang Academy of Agricultural Sciences, Hangzhou, 311202, China
| | - Ya-Yuan Tang
- Flower Research and Development Centre, Zhejiang Academy of Agricultural Sciences, Hangzhou, 311202, China
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99
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Villamil N. Why are flowers sweeter than fruits or buds? Variation in extrafloral nectar secretion throughout the floral ontogeny of a myrmecophile. Biotropica 2017. [DOI: 10.1111/btp.12463] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Nora Villamil
- Instituto de Ecología; Universidad Nacional Autónoma de México; Apartado Postal 70-275, Ciudad Universitaria México D.F. 04510 Mexico
- Ashworth Laboratories; Institute of Evolutionary Biology; University of Edinburgh; The King's Buildings, West Mains Road Edinburgh EH9 3JT UK
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100
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Staab M, Fornoff F, Klein AM, Blüthgen N. Ants at Plant Wounds: A Little-Known Trophic Interaction with Evolutionary Implications for Ant-Plant Interactions. Am Nat 2017; 190:442-450. [PMID: 28829637 DOI: 10.1086/692735] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Extrafloral nectaries (EFNs) allow plants to engage in mutualisms with ants, preventing herbivory in exchange for food. EFNs occur scattered throughout the plant phylogeny and likely evolved independent from herbivore-created wounds subsequently visited by ants collecting leaked sap. Records of wound-feeding ants are, however, anecdotal. By surveying 38,000 trees from 40 species, we conducted the first quantitative ecological study of this overlooked behavior. Ant-wound interactions were widespread (0.5% of tree individuals) and occurred on 23 tree species. Interaction networks were opportunistic, closely resembling ant-EFN networks. Fagaceae, a family lacking EFNs, was strongly overrepresented. For Fagaceae, ant occurrence at wounds correlated with species-level leaf damage, potentially indicating that wounds may attract mutualistic ants, which supports the hypothesis of ant-tended wounds as precursors of ant-EFN mutualisms. Given that herbivore wounds are common, wound sap as a steadily available food source might further help to explain the overwhelming abundance of ants in (sub)tropical forest canopies.
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