Comparative anatomy and physiology of myrmecophytes: ecological and evolutionary perspectives

References

• Bronstein JL, Alarcon R, Geber M. The evolution of plant-insect mutualisms. New Phytol. 2006;172:412–428.
   PubMed Web of Science ®Google Scholar
• Heil M, McKey D. Protective ant-plant interactions as model systems in ecological and evolutionary research. Annu Rev Ecol Evol Syst. 2003;34:425–453.
   Web of Science ®Google Scholar
• Risch SJ, Rickson F. Mutualism in which ants must be present before plants produce food bodies. Nature. 1981;291:149–150.
   Web of Science ®Google Scholar
• Brouat C, Garcia N, Andary C, McKey D. Plant lock and ant key: pairwise coevolution of an exclusion filter in an ant-plant mutualism. Proc R Soc B Biol Sci. 2001;268:2131–2141.
   Web of Science ®Google Scholar
• Yu DW, Wilson HB, Pierce NE. An empirical model of species coexistence in a spatially structured environment. Ecology. 2001;82:1761–1771.
   Web of Science ®Google Scholar
• Orona-Tamayo D, Heil M. Stabilizing mutualisms threatened by exploiters: new insights from ant-plant research. Biotropica. 2013;45:654–665.
   Web of Science ®Google Scholar
• Heil M, Barajas-Barron A, Orona-Tamayo D, Wielsch N, Svatos A. Partner manipulation stabilises a horizontally transmitted mutualism. Ecol Lett. 2014;17:185–192.
   Web of Science ®Google Scholar
• Seigler DS, Ebinger JE. Cyanogenic glycosides in ant-acacias of Mexico and Central America. Southwest Nat. 1987;32:499–503.
   Web of Science ®Google Scholar
• Heil M, Delsinne T, Hilpert A, et al. Reduced chemical defence in ant-plants? A critical re-evaluation of a widely accepted hypothesis. Oikos. 2002;99:457–468.
   Web of Science ®Google Scholar
• Young TP, Stubblefield CH, Isbell LA. Ants on swollen thorn acacias: species coexistence in a simple system. Oecologia. 1997;109:98–107.
   Web of Science ®Google Scholar
• Palmer TM, Young TP, Stanton ML, Wenk E. Short-term dynamics of an acacia ant community in Laikipia, Kenya. Oecologia. 2000;123:425–435.
   Web of Science ®Google Scholar
• Yu DW, Wilson HB, Frederickson ME, et al. Experimental demonstration of species coexistence enabled by dispersal limitation. J Anim Ecol. 2004;73(6):1102–1114.
   Web of Science ®Google Scholar
• Schmitz OJ, Hamback PA, Beckerman AP. Trophic cascades in terrestrial systems: a review of the effects of carnivore removals on plants. Am Nat. 2000;155:141–153.
   PubMed Web of Science ®Google Scholar
• Rico-Gray V, Oliveira PS. The Ecology and Evolution of Ant-Plant Interactions. Chicago, IL: University of Chicago Press; 2007.
   Google Scholar
• Fiala B, Maschwitz U. Food bodies and their significance for obligate ant-association in the tree genus Macaranga (Euphorbiaceae). Bot J Linn Soc. 1992;110:61–75.
   Web of Science ®Google Scholar
• Davidson DW, McKey D. Ant-plants symbioses: stalking the chuyachaqui. Trends Ecol Evol. 1993;8:326–332.
   PubMed Web of Science ®Google Scholar
• Fonseca CR. Herbivory and the long-lived leaves of an Amazonian ant-tree. J Ecol. 1994;82:833–842.
   Web of Science ®Google Scholar
• Federle W, Maschwitz U, Fiala B. The two-partner ant-plant system of Camponotus (Colobopsis) sp. 1 and Macaranga puncticulata (Euphorbiaceae): natural history of the exceptional ant partner. Insectes Soc. 1998;45:1–16.
   Web of Science ®Google Scholar
• Letourneau DK. Ants, stem-borers, and fungal pathogens: experimental tests of a fitness advantage in Piper ant-plants. Ecology. 1998;79:593–603.
   Web of Science ®Google Scholar
• Heil M, Baumann B, Andary C, Linsenmair KE, McKey D. Extraction and quantification of “condensed tannins” as a measure of plant anti-herbivore defence? Revisiting an old problem. Naturwissenschaften. 2002;89:519–524.
   Google Scholar
• Gonzalez-Teuber M, Kaltenpoth M, Boland W. Mutualistic ants as an indirect defence against leaf pathogens. New Phytol. 2014;202:640–650.
   Web of Science ®Google Scholar
• Treseder KK, Davidson DW, Ehleringer JR. Absorption of ant-provided carbon dioxide and nitrogen by a tropical epiphyte. Nature. 1995;375:137–139.
   Web of Science ®Google Scholar
• Fischer RC, Wanek W, Richter A, Mayer V. Do ants feed plants? A 15N labelling study of nitrogen fluxes from ants to plants in the mutualism of Pheidole and Piper. J Ecol. 2003;91:126–134.
   Web of Science ®Google Scholar
• Caspary R. De nectariis. 1848. The Bavarian State Library: Marcus; 1848.
   Google Scholar
• Heil M. Extrafloral nectar at the plant-insect interface: a spotlight on chemical ecology, phenotypic plasticity, and food webs. Annu Rev Entomol. 2015;60:213–232.
   PubMed Web of Science ®Google Scholar
• Weber MG, Keeler KH. The phylogenetic distribution of extrafloral nectaries in plants. Ann Bot. 2013;111:1251–1261.
   PubMed Web of Science ®Google Scholar
• Bentley B, Elias TS. The Biology of Nectaries. New York: Columbia University Press; 1983.
   Google Scholar
• Elias TS. Foliar nectaries of unusual structure in Leonardoxa africana (Leguminosae), an African obligate myrmecophyte. Am J Bot. 1980;67:423–425.
   Web of Science ®Google Scholar
• Moran JA. Pitcher dimorphism, prey composition and the mechanisms of prey attraction in the pitcher plant Nepenthes rafflesiana in Borneo. J Ecol. 1996;84:515–525.
   Web of Science ®Google Scholar
• Merbach MA, Zizka G, Fiala B, Maschwitz U, Booth WE. Patterns of nectar secretion in five Nepenthes species from Brunei Darussalam, Northwest Borneo, and implications for ant-plant relationships. Flora. 2001;196:153–160.
   Web of Science ®Google Scholar
• Escalante-Pérez M, Heil M. Nectar secretion: its ecological context and physiological regulation. In: Vivanco J, Baluska F, editors. Secretions and Exudates in Biological Systems. Berlin: Berlin Springer; 2012: 187–220.
   Google Scholar
• Zimmermann J. über die extrafloralen Nektarien der Angiosperm. Beihefte Botanisches Centralblatt. 1932;49:99–196.
   Google Scholar
• Elias TS. Extrafloral nectaries: their structure and distribution. In: Bentley B, Elias TS, editors. The Biology of Nectaries. New York: Columbia University Press; 1983:174–203.
   Google Scholar
• Mathur V, Wagenaar R, Caissard JC, et al. A novel indirect defence in Brassicaceae: structure and function of extrafloral nectaries in Brassica juncea. Plant Cell Environ. 2013;36:528–541.
   Web of Science ®Google Scholar
• Nepi M. Nectary structure and ultrastructure. In: Nicolson S, Nepi M, Pacini E, editors. Nectaries and Nectar. Dordrecht: Springer; 2007:129–166.
   Google Scholar
• Escalante-Pérez M, Jaborsky M, Lautner S, et al. Poplar extrafloral nectaries: two types, two strategies of indirect defenses against herbivores. Plant Physiol. 2012;159:1176–1191.
   PubMed Web of Science ®Google Scholar
• Davis AR, Peterson RL, Shuel RW. Vasculature and ultrastructure of the floral and stipular nectaries of Vicia faba (Leguminosae). Can J Bot. 1988;66:1435–1448.
   Google Scholar
• Galetto L, Bernardello LM. Extrafloral nectaries that attract ants in Bromeliaceae: structure and nectar composition Can J Bot. 1992;70:1101–1106.
   Google Scholar
• Falcão PF, de A Melo-de-Pinna GF, Leal IR, Almeida-Cortez JS. Morphology and anatomy of extrafloral nectaries in Solanum stramonifolium (Solanaceae). Can J Bot. 2003;81:859–864.
   Google Scholar
• Heil M. Nectar: generation, regulation, and ecological functions. Trends Plant Sci. 2011;16:191–200.
   PubMed Web of Science ®Google Scholar
• Díaz-Castelazo C, Rico-Gray V, Ortega F, Angeles G. Morphological and secretory characterization of extrafloral nectaries in plants of coastal Veracruz, Mexico. Ann Bot. 2005;96:1175–1189.
   PubMed Web of Science ®Google Scholar
• Agthe C. über die physiologische Herkunft des Pflanzennektars. Berichte der Schweizerischen botanischen Gesellschaft. 1951;61:240–274. German.
   Google Scholar
• Lüttge U. über die Zusammensetzung des Nektars und den Mechanismus seiner Sekretion. I. Planta. 1961;56:189–212.
   Web of Science ®Google Scholar
• De la Barrera E, Nobel PS. Nectar: properties, floral aspects, and speculations on origin. Trends Plant Sci. 2004;9:65–69.
   PubMed Web of Science ®Google Scholar
• Nicolson SW. Amino acid concentrations in the nectars of southern African bird-pollinated flowers, especially Aloe and Erythrina. J Chem Ecol. 2007;33:1707–1720.
   PubMed Web of Science ®Google Scholar
• González-Teuber M, Heil M. Nectar chemistry is tailored for both attraction of mutualists and protection from exploiters. Plant Signal Behav. 2009;4:809–813.
   PubMedGoogle Scholar
• Gonzalez-Teuber M, Heil M. The role of extrafloral nectar amino acids for the preferences of facultative and obligate ant mutualists. J Chem Ecol. 2009;35:459–468.
   PubMed Web of Science ®Google Scholar
• González-Teuber M, Heil M. Pseudomyrmex ants and Acacia host plants join efforts to protect their mutualism from microbial threats. Plant Signal Behav. 2010;5:890–892.
   PubMedGoogle Scholar
• Wenzler M, Hoelscher D, Oerther T, Schneider B. Nectar formation and floral nectary anatomy of Anigozanthos flavidus: a combined magnetic resonance imaging and spectroscopy study. J Exp Bot. 2008;59:3425–3434.
   Web of Science ®Google Scholar
• Kram BW, Carter CJ. Arabidopsis thaliana as a model for functional nectary analysis. Sex Plant Reprod. 2009;22:235–246.
   Google Scholar
• Orona-Tamayo D, Wielsch N, Escalante-Perez M, et al. Short-term proteomic dynamics reveal metabolic factory for active extrafloral nectar secretion by Acacia cornigera ant-plants. Plant J. 2013;73:546–554.
   Web of Science ®Google Scholar
• Lüttge U. Green nectaries: the role of photosynthesis in secretion. Bot J Linn Soc. 2013;173:1–11.
   Web of Science ®Google Scholar
• Zimmermann M. über die Sekretion saccharosespaltender Transglukosidasen im pflanzlichen Nektar. Experientia. 1954;15:145–146.
   Google Scholar
• Gaffal KP. How common is the ability of extrafloral nectaries to produce nectar droplets, to secrete nectar during the night and to store starch? Plant Biol. 2012;14:691–695.
   Web of Science ®Google Scholar
• Heil M, Rattke J, Boland W. Postsecretory hydrolysis of nectar sucrose and specialization in ant/plant mutualism. Science. 2005;308:560–563.
   PubMed Web of Science ®Google Scholar
• Ruhlmann JM, Kram BW, Carter CJ. Cell wall invertase 4 is required for nectar production in Arabidopsis. J Exp Bot. 2010;61:395–404.
   PubMed Web of Science ®Google Scholar
• Carter C, Thornburg RW. The nectary-specific pattern of expression of the tobacco Nectarin I promoter is regulated by multiple promoter elements. Plant Mol Biol. 2003;51:451–457.
   Web of Science ®Google Scholar
• Carter C, Thornburg RW. Is the nectar redox cycle a floral defense against microbial attack? Trends Plant Sci. 2004;9:320–324.
   PubMed Web of Science ®Google Scholar
• Liu G, Ren G, Guirgis A, Thornburg RW. The MYB305 transcription factor regulates expression of nectarin genes in the ornamental tobacco floral nectary. Plant Cell. 2009;21:2672–2687.
   PubMed Web of Science ®Google Scholar
• Liu G, Thornburg RW. Knockdown of MYB305 disrupts nectary starch metabolism and floral nectar production. Plant J. 2012;70:377–388.
   PubMed Web of Science ®Google Scholar
• Kuo J, Pate JS. The extrafloral nectaries of cowpea (Vigna unguiculata (L.) Walp): I. Morphology, anatomy and fine structure. Planta. 1985;166:15–27.
   PubMed Web of Science ®Google Scholar
• Heil M, González-Teuber M, Clement LW, Kautz S, Verhaagh M, Silva Bueno JC. Divergent investment strategies of Acacia myrmecophytes and the coexistence of mutualists and exploiters. Proc Natl Acad Sci U S A. 2009;106:18091–18096.
   PubMed Web of Science ®Google Scholar
• Ness JH. A mutualism’s indirect costs: the most aggressive plant bodyguards also deter pollinators. Oikos. 2006;113:506–514.
   Web of Science ®Google Scholar
• Ness JH, Morris WF, Bronstein JL. For ant-protected plants, the best defense is a hungry offense. Ecology. 2009;90:2823–2831.
   PubMed Web of Science ®Google Scholar
• González-Teuber M, Bueno JC, Heil M, Boland W. Increased host investment in extrafloral nectar (EFN) improves the efficiency of a mutualistic defensive service. PLoS One. 2012;7:e46598.
   Web of Science ®Google Scholar
• Heil M. Let the best one stay: screening of ant defenders by Acacia host plants functions independently of partner choice or host sanctions. J Ecol. 2013;101:684–688.
   Web of Science ®Google Scholar
• Southwick EE. Photosynthate allocation to floral nectar: a neglected energy investment. Ecology. 1984;65:1775–1779.
   Web of Science ®Google Scholar
• Heil M, Fiala B, Baumann B, Linsenmair KE. Temporal, spatial and biotic variations in extrafloral nectar secretion by Macaranga tanarius. Funct Ecol. 2000;14:749–757.
   Web of Science ®Google Scholar
• Nepi M, Ciampolini F, Pacini E. Development and ultrastructure of Cucurbita pepo nectaries of male flowers. Ann Bot. 1996;78:95–104.
   Web of Science ®Google Scholar
• Stpiczynska M, Milanesi C, Faleri C, Cresti M. Ultrastructure of the nectary spur of Platanthera chlorantha (Custer) Rchb. (Orchidaceae) during successive stages of nectar secretion. Acta Biologica Cracoviensia Series Botanica. 2005;47:111–119.
   Web of Science ®Google Scholar
• Búrquez A, Corbet SA. Do flowers reabsorb nectar? Funct Ecol. 1991;5:369–379.
   Web of Science ®Google Scholar
• Nepi M, Guarnieri M, Pacini E. Nectar secretion, reabsorption, and sugar composition in male and female flowers of Cucurbita pepo. Int J Plant Sci. 2001;162:353–358.
   Web of Science ®Google Scholar
• Rickson FR. Developmental aspects of the shoot apex, leaf, and Beltian bodies of Acacia cornigera. Am J Bot. 1969;56:195–200.
   Web of Science ®Google Scholar
• Rickson FR. The ultrastructure of Acacia cornigera L. Beltian body tissue. Am J Bot. 1975;62:913–922.
   Web of Science ®Google Scholar
• Rickson FR. Anatomical development of the leaf trichilium and Müllerian bodies of Cecropia peltata L. Am J Bot. 1976;63:1266–1271.
   Web of Science ®Google Scholar
• Rickson FR. Developmental anatomy and ultrastructure of the ant-food bodies (Beccariian bodies) of Macaranga triloba and M. hypoleuca (Euphorbiaceae). Am J Bot. 1980;67:285–292.
   Web of Science ®Google Scholar
• O’Dowd DJ. Pearl bodies as ant food: an ecological role for some leaf emergences of tropical plants. Biotropica. 1982;14:40–49.
   Web of Science ®Google Scholar
• Mayer VE, Frederickson ME, McKey D, Blatrix R. Current issues in the evolutionary ecology of ant-plant symbioses. New Phytol. 2014;202:749–764.
   Web of Science ®Google Scholar
• Yamawo A, Hada Y. Effects of light on direct and indirect defences against herbivores of young plants of Mallotus japonicus demonstrate a trade-off between two indirect defence traits. Ann Bot. 2010;106:143–148.
   Web of Science ®Google Scholar
• Rickson FR, Risch SJ. Anatomical and ultrastructural aspects of the ant-food cell of Piper cenocladum C. DC. (Piperaceae). Am J Bot. 1984;71:1268–1274.
   Web of Science ®Google Scholar
• Rickson FR. Ultrastructural differentiation of the Mullerian body glycogen plastid of Cecropia peltata L. Am J Bot. 1976;63:1272–1279.
   Web of Science ®Google Scholar
• Janzen DH. Interaction of the bull’s-horn acacia (Acacia cornigera) with an ant inhabitant (Pseudomyrmex ferruginea) in eastern Mexico. Kansas Univ Sci Bull. 1967;47:315–558.
   Google Scholar
• Heil M, Fiala B, Linsenmair KE, Zotz G, Menke P, Maschwitz U. Food body production in Macaranga triloba (Euphorbiaceae): a plant investment in anti-herbivore defence via symbiotic ant partners. J Ecol. 1997;85:847–861.
   Web of Science ®Google Scholar
• Orona-Tamayo D, Wielsch N, Blanco-Labra A, Svatos A, Farias-Rodriguez R, Heil M. Exclusive rewards in mutualisms: ant proteases and plant protease inhibitors create a lock-key system to protect Acacia food bodies from exploitation. Mol Ecol. 2013;22:4087–4100.
   Web of Science ®Google Scholar
• Heil M, Fiala B, Kaiser W, Linsenmair KE. Chemical contents of Macaranga food bodies: adaptations to their role in ant attraction and nutrition. Funct Ecol. 1998;12:117–122.
   Web of Science ®Google Scholar
• Fischer RC, Richter A, Wanek W, Mayer V. Plants feed ants: food bodies of myrmecophytic Piper and their significance for the interaction with Pheidole bicornis ants. Oecologia. 2002;133:186–192.
   Web of Science ®Google Scholar
• Heil M, Baumann B, Kruger R, Linsenmair KE. Main nutrient compounds in food bodies of Mexican Acacia ant-plants. Chemoecology. 2004;14:45–52.
   Web of Science ®Google Scholar
• Heckroth HP, Fiala B, Gullan PJ, Idris AH, Maschwitz U. The soft scale (Coccidae) associates of Malaysian ant-plants. J Trop Ecol. 1998;14:427–443.
   Web of Science ®Google Scholar
• Davidson DW, Foster RB, Snelling RR, Lozada PW. Variable composition of some tropical ant-plant symbioses. In: Price PW, Lewinsohn TM, Fernandes GW, Benson WW, editors. Plant-Animal Interactions: Evolutionary Ecology in Tropical and Temperate Regions. New York: Wiley; 1991:145–162.
   Google Scholar
• Letourneau DK. Code of ant-plant mutualism broken by parasite. Science. 1990;248:215–217.
   Web of Science ®Google Scholar
• Linsenmair KE, Heil M, Kaiser WM, Fiala B, Koch T, Boland W. Adaptations to biotic and abiotic stress: Macaranga-ant plants optimize investment in biotic defence. J Exp Bot. 2001;52:2057–2065.
   Web of Science ®Google Scholar
• Folgarait PJ, Johnson HL, Davidson DW. Responses of Cecropia to experimental removal of Müllerian bodies. Funct Ecol. 1994;8:22–28.
   Web of Science ®Google Scholar
• Kautz S, Lumbsch HT, Ward PS, Heil M. How to prevent cheating: a digestive specialization ties mutualistic plant-ants to their ant-plant partners. Evolution. 2009;63:839–853.
   PubMed Web of Science ®Google Scholar
• Jacobs M. On domatia-the viewpoints and some facts. Acad Weten Amsterdam. 1966;69:275–316.
   Google Scholar
• Bequaert J. Ants in their diverse relations to the plant world. Bull Am Mus Nat Hist. 1922;45:333–621.
   Google Scholar
• Benson WW. Amazon ant plants. In: Prance GT, Lovejoy TE, editors. Amazonia. Oxford: Pergamon Press; 1985:239–266.
   Google Scholar
• Fiala B, Maschwitz U. Domatia as most important adaptations in the evolution of myrmecophytes in the paleotropical tree genus Macaranga (Euphorbiaceae). Plant Syst Evol. 1992;180:53–64.
   Web of Science ®Google Scholar
• Tepe EJ, Vincent MA, Watson LE. Stem diversity, cauline domatia, and the evolution of ant–plant associations in Piper sect. Macrostachys (Piperaceae). Am J Bot. 2007;94:1–11.
   Web of Science ®Google Scholar
• McKey D. Interaction of the ant-plant Leonardoxa africana (Caesalpiniaceae) with its obligate inhabitants in a rainforest in Cameroon. Biotropica. 1984;16:81–99.
   Web of Science ®Google Scholar
• Federle W, Fiala B, Zizka G, Maschwitz U. Incident daylight as orientation cue for hole-boring ants: prostomata in Macaranga ant-plants. Insectes Soc. 2001;48:165–177.
   Web of Science ®Google Scholar
• Tepe EJ, Kelley WA, Rodriguez-Castaneda G, Dyer LA. Characterizing the cauline domatia of two newly discovered Ecuadorian ant plants in Piper: an example of convergent evolution. J Insect Sci. 2009;9:1–9.
   Web of Science ®Google Scholar
• Bailey IW. Notes on neotropical ant-plants, II. Tachigalia paniculata Aubl. Bot Gaz. 1923;75:27–41.
   Google Scholar
• Leroy C, Jauneau A, Quilichini A, Dejean A, Orivel J. Comparison between the anatomical and morphological structure of leaf blades and foliar domatia in the ant-plant Hirtella physophora (Chrysobalanaceae). Ann Bot. 2008;101(4):501–507.
   Web of Science ®Google Scholar
• Leroy C, Jauneau A, Quilichini A, Dejean A, Orivel J. Comparative structure and ontogeny of the foliar domatia in three neotropical myrmecophytes. Am J Bot. 2010;97:557–565.
   Web of Science ®Google Scholar
• Gegenbauer C, Mayer VE, Zotz G, Richter A. Uptake of ant-derived nitrogen in the myrmecophytic orchid Caularthron bilamellatum. Ann Bot. 2012;110:757–765.
   Web of Science ®Google Scholar
• Chanam J, Sheshshayee MS, Kasinathan S, Jagdeesh A, Joshi KA, Borges RM. Nutritional benefits from domatia inhabitants in an ant-plant interaction: interlopers do pay the rent. Funct Ecol. 2014;28:1107–1116.
   Web of Science ®Google Scholar
• Solano PJ, Dejean A. Ant-fed plants: comparison between three geophytic myrmecophytes. Biol J Linn Soc. 2004;83:433–439.
   Web of Science ®Google Scholar
• Sagers CL, Ginger SM, Evans RD. Carbon and nitrogen isotopes trace nutrient exchange in an ant-plant mutualism. Oecologia. 2000;123:582–586.
   PubMed Web of Science ®Google Scholar
• Blüthgen N, Wesenberg J. Ants induce domatia in a rain forest tree (Vochysia vismiaefolia). Biotropica. 2001;33:637–642.
   Web of Science ®Google Scholar
• Frederickson ME, Ravenscraft A, Miller GA, Hernandez LMA, Booth G, Pierce NE. The direct and ecological costs of an ant-plant symbiosis. Am Nat. 2012;179:768–778.
   Web of Science ®Google Scholar
• Yu DW, Pierce NE. A castration parasite of an ant-plant mutualism. Proc R Soc Lond B Biol Sci. 1998;265:375–382.
   Web of Science ®Google Scholar
• Gaume L, Zacharias M, Borges RM. Ant-plant conflicts and a novel case of castration parasitism in a myrmecophyte. Evol Ecol Res. 2005;7:435–452.
   Web of Science ®Google Scholar
• Fiala B, Meyer U, bin Hashim R, Maschwitz U. Temporary sterilization behavior of mutualistic partner ants in a Southeast Asian myrmecophyte. Ecol Res. 2014;29:815–822.
   Web of Science ®Google Scholar
• O’Dowd DJ. Pearl bodies of a neotropical tree, Ochroma pyramidale: ecological implications. Am J Bot. 1980;67:543–549.
   Web of Science ®Google Scholar
• Rudgers JA, Strauss SY. A selection mosaic in the facultative mutualism between ants and wild cotton. Proc R Soc Lond B Biol Sci. 2004;271:2481–2488.
   Web of Science ®Google Scholar
• Rutter MT, Rausher MD. Natural selection on extrafloral nectar production in Chamaecrista fasciculata: the costs and benefits of a mutualism trait. Evolution. 2004;58:2657–2668.
   Web of Science ®Google Scholar
• Radhika V, Kost C, Bartram S, Heil M, Boland W. Testing the optimal defence hypothesis for two indirect defences: extrafloral nectar and volatile organic compounds. Planta. 2008;228:449–457.
   PubMed Web of Science ®Google Scholar
• Millán-Cañongo C, Orona-Tamayo D, Heil M. Phloem sugar flux and jasmonic acid-responsive cell wall invertase control extrafloral nectar secretion in Ricinus communis. J Chem Ecol. 2014;40:760–769.
   Web of Science ®Google Scholar
• Koricheva J, Romero GQ. You get what you pay for: reward-specific trade-offs among direct and ant-mediated defences in plants. Biol Lett. 2012;8:628–630.
   Web of Science ®Google Scholar
• Stanton ML, Palmer TM. The high cost of mutualism: effects of four species of East African ant symbionts on their myrmecophyte host tree. Ecology. 2011;92:1073–1082.
   Web of Science ®Google Scholar
• Romero GQ, Antiqueira PA, Koricheva J. A meta-analysis of predation risk effects on pollinator behaviour. PLoS One. 2011;6:e20689.
   Web of Science ®Google Scholar
• Rosumek FB, Silveira FAO, Neves FS, et al. Ants on plants: a meta-analysis of the role of ants as plant biotic defenses. Oecologia. 2009;160:537–549.
   Web of Science ®Google Scholar
• Chamberlain SA, Holland JN. Quantitative synthesis of context dependency in ant-plant protection mutualisms. Ecology. 2009;90:2384–2392.
   PubMed Web of Science ®Google Scholar
• Sachs JL, Mueller UG, Wilcox TP, Bull JJ. The evolution of cooperation. Q Rev Biol. 2004;79:135–160.
   PubMed Web of Science ®Google Scholar
• Trager MD, Bhotika S, Hostetler JA, et al. Benefits for plants in ant-plant protective mutualisms: a meta-analysis. PLoS One. 2010;5:e14308.
   PubMed Web of Science ®Google Scholar
• Bull JJ, Rice WR. Distinguishing mechanisms for the evolution of cooperation. J Theor Biol. 1991;149:63–74.
   PubMed Web of Science ®Google Scholar
• Fisher BL. Facultative ant association benefits a neotropical orchid. J Trop Ecol. 1992;8:109–114.
   Web of Science ®Google Scholar
• Trager MD, Bruna EM. Effects of plant age, experimental nutrient addition and ant occupancy on herbivory in a neotropical myrmecophyte. J Ecol. 2006;94:1156–1163.
   Web of Science ®Google Scholar
• Heil M, Hilpert A, Fiala B, et al. Nutrient allocation of Macaranga triloba ant plants to growth, photosynthesis and indirect defence. Funct Ecol. 2002;16:475–483.
   Web of Science ®Google Scholar
• Folgarait PJ, Davidson DW. Myrmecophytic Cecropia: antiherbivore defenses under different nutrient treatments. Oecologia. 1995;104:189–206.
   Web of Science ®Google Scholar
• Palmer TM, Stanton ML, Young TP, Goheen JR, Pringle RM, Karban R. Putting ant-Acacia mutualisms to the fire. Science. 2008;319:1760–1761.
   Web of Science ®Google Scholar
• González-Teuber M, Eilmus S, Muck A, Svatos A, Heil M. Pathogenesis-related proteins protect extrafloral nectar from microbial infestation. Plant J. 2009;58:464–473.
   PubMed Web of Science ®Google Scholar
• Maslin BR, Miller JT, Seigler, DS. Overview of the generic status of Acacia (Leguminosae: Mimosoideae). Australyan Systematic Botany. 2003;16:1–18.
   Web of Science ®Google Scholar
• Maslin BR. Generic and subgeneric names in Acacia following retypification of the genus. Muelleria. 2008;26:7–9.
   Google Scholar