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Author Barraza, F.; Schreck, E.; Lévêque, T.; Uzu, G.; Lopez, F.; Ruales, J.; Prunier, J.; Marquet, A.; Maurice, L. url  doi
openurl 
  Title (up) Cadmium bioaccumulation and gastric bioaccessibility in cacao: A field study in areas impacted by oil activities in Ecuador Type Journal Article
  Year 2017 Publication Environmental Pollution Abbreviated Journal  
  Volume 229 Issue Pages 950-963  
  Keywords Cacao; Cadmium; Ecuador; Health risk assessment; Uptake and bioaccumulation  
  Abstract Cacao from South America is especially used to produce premium quality chocolate. Although the European Food Safety Authority has not established a limit for cadmium (Cd) in chocolate raw material, recent studies demonstrate that Cd concentrations in cacao beans can reach levels higher than the legal limits for dark chocolate (0.8 mg kg−1, effective January 1st, 2019). Despite the fact that the presence of Cd in agricultural soils is related to contamination by fertilizers, other potential sources must be considered in Ecuador. This field study was conducted to investigate Cd content in soils and cacao cultivated on Ecuadorian farms in areas impacted by oil activities. Soils, cacao leaves, and pod husks were collected from 31 farms in the northern Amazon and Pacific coastal regions exposed to oil production and refining and compared to two control areas. Human gastric bioaccessibility was determined in raw cacao beans and cacao liquor samples in order to assess potential health risks involved. Our results show that topsoils (0–20 cm) have higher Cd concentrations than deeper layers, exceeding the Ecuadorian legislation limit in 39% of the sampling sites. Cacao leaves accumulate more Cd than pod husks or beans but, nevertheless, 50% of the sampled beans have Cd contents above 0.8 mg kg−1. Root-to-cacao transfer seems to be the main pathway of Cd uptake, which is not only regulated by physico-chemical soil properties but also agricultural practices. Additionally, natural Cd enrichment by volcanic inputs must not be neglected. Finally, Cd in cacao trees cannot be considered as a tracer of oil activities. Assuming that total Cd content and its bioaccessible fraction (up to 90%) in cacao beans and liquor is directly linked to those in chocolate, the health risk associated with Cd exposure varies from low to moderate.  
  Address Laboratoire des Sciences du Bois, UMR EcoFoG, ZI Pariacabo, Kourou, French Guiana  
  Corporate Author Thesis  
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  Notes Cited By :1; Export Date: 4 June 2018 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 806  
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Author Cabanillas, B.J.; Le Lamer, A.C.; Castillo, D.; Arevalo, J.; Rojas, R.; Odonne, G.; Bourdy, G.; Moukarzel, B.; Sauvain, M.; Fabre, N. openurl 
  Title (up) Caffeic Acid Esters and Lignans from Piper sanguineispicum Type Journal Article
  Year 2010 Publication Journal of Natural Products Abbreviated Journal J. Nat. Prod.  
  Volume 73 Issue 11 Pages 1884-1890  
  Keywords  
  Abstract Three new caffeic acid esters (1-3), four new lignans (4-7), and the known compounds (7'S)-parabenzlactone (8), dihydrocubebin (9), and justiflorinol (10) have been isolated from leaves of Piper sanguineispicum. Their structures were determined by spectroscopic methods, including 1D and 2D NMR, HRCIMS, CD experiments, and chemical methods. Compounds 1-10 were assessed for their antileishmanial potential against axenic amastigote forms of Leishmania amazonensis. Caffeic acid esters 1 and 3 exhibited the best antileishmanial activity (IC50 2.0 and 1.8 μM, respectively) with moderate cytotoxicity on murine macrophages.  
  Address [Cabanillas, Billy Joel; Le Lamer, Anne-Cecile; Odonne, Guillaume; Bourdy, Genevieve; Moukarzel, Beatrice; Sauvain, Michel; Fabre, Nicolas] Univ Toulouse, UPS, UMR 152, Lab Pharmacochim Subst Nat & Pharmacophores Redox, F-31062 Toulouse 9, France, Email: michel.sauvain@ird.fr  
  Corporate Author Thesis  
  Publisher AMER CHEMICAL SOC Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0163-3864 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000284559100024 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 74  
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Author Verryckt, L.T.; Ellsworth, D.S.; Vicca, S.; Van Langenhove, L.; Peñuelas, J.; Ciais, P.; Posada, J.M.; Stahl, C.; Coste, S.; Courtois, E.A.; Obersteiner, M.; Chave, J.; Janssens, I.A. doi  openurl
  Title (up) Can light-saturated photosynthesis in lowland tropical forests be estimated by one light level? Type Journal Article
  Year 2020 Publication Biotropica Abbreviated Journal Biotropica  
  Volume 52 Issue 6 Pages 1183-1193  
  Keywords canopy architecture; interspecific variation; light intensity; lowland environment; parameter estimation; photon flux density; photosynthesis; saturation; tropical forest; French Guiana  
  Abstract Leaf-level net photosynthesis (An) estimates and associated photosynthetic parameters are crucial for accurately parameterizing photosynthesis models. For tropical forests, such data are poorly available and collected at variable light conditions. To avoid over- or underestimation of modeled photosynthesis, it is critical to know at which photosynthetic photon flux density (PPFD) photosynthesis becomes light-saturated. We studied the dependence of An on PPFD in two tropical forests in French Guiana. We estimated the light saturation range, including the lowest PPFD level at which Asat (An at light saturation) is reached, as well as the PPFD range at which Asat remained unaltered. The light saturation range was derived from photosynthetic light-response curves, and within-canopy and interspecific differences were studied. We observed wide light saturation ranges of An. Light saturation ranges differed among canopy heights, but a PPFD level of 1,000 µmol m−2 s−1 was common across all heights, except for pioneer trees species that did not reach light saturation below 2,000 µmol m−2 s−1. A light intensity of 1,000 µmol m−2 s−1 sufficed for measuring Asat of climax species at our study sites, independent of the species or the canopy height. Because of the wide light saturation ranges, results from studies measuring Asat at higher PPFD levels (for upper canopy leaves up to 1,600 µmol m−2 s−1) are comparable with studies measuring at 1,000 µmol m−2 s−1. © 2020 The Association for Tropical Biology and Conservation  
  Address UMR 5174, Laboratoire Evolution et Diversité Biologique, CNRS, Université Paul Sabatier, Toulouse, France  
  Corporate Author Thesis  
  Publisher Blackwell Publishing Ltd Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 00063606 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 948  
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Author Piponiot, C.; Rödig, E.; Putz, F.E.; Rutishauser, E.; Sist, P.; Ascarrunz, N.; Blanc, L.; Derroire, G.; Descroix, L.; Guedes, M.C.; Coronado, E.H.; Huth, A.; Kanashiro, M.; Licona, J.C.; Mazzei, L.; d’Oliveira, M.V.N.; Peña-Claros, M.; Rodney, K.; Shenkin, A.; de Souza, C.R.; Vidal, E.; West, T.A.P.; Wortel, V.; Herault, B. pdf  doi
openurl 
  Title (up) Can timber provision from Amazonian production forests be sustainable? Type Journal Article
  Year 2019 Publication Environmental Research Letters Abbreviated Journal Environmental Research Letters  
  Volume 14 Issue 6 Pages 064014  
  Keywords  
  Abstract Around 30 Mm3 of sawlogs are extracted annually by selective logging of natural production forests in Amazonia, Earth’s most extensive tropical forest. Decisions concerning the management of these production forests will be of major importance for Amazonian forests’ fate. To date, no regional assessment of selective logging sustainability supports decision-making. Based on data from 3500 ha of forest inventory plots, our modelling results show that the average periodic harvests of 20 m3 ha−1 will not recover by the end of a standard 30 year cutting cycle. Timber recovery within a cutting cycle is enhanced by commercial acceptance of more species and with the adoption of longer cutting cycles and lower logging intensities. Recovery rates are faster in Western Amazonia than on the Guiana Shield. Our simulations suggest that regardless of cutting cycle duration and logging intensities, selectively logged forests are unlikely to meet timber demands over the long term as timber stocks are predicted to steadily decline. There is thus an urgent need to develop an integrated forest resource management policy that combines active management of production forests with the restoration of degraded and secondary forests for timber production. Without better management, reduced timber harvests and continued timber production declines are unavoidable.  
  Address  
  Corporate Author Thesis  
  Publisher IOP Publishing Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1748-9326 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 875  
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Author Schmitt, Sylvain ; Raevel, Valérie ; Réjou-Méchain, Maxime ; Ayyappan, Narayanan ; Balachandran, Natesan ; Barathan, Narayanan ; Rajashekar, Gopalakrishnan ; Munoz, François doi  openurl
  Title (up) Canopy and understorey tree guilds respond differently to the environment in an Indian rain forest Type Journal Article
  Year 2021 Publication Journal of Végétation Science Abbreviated Journal  
  Volume 32 Issue 5 Pages e13075  
  Keywords  
  Abstract Questions Changes in the functional composition of tree communities along resource availability gradients have received attention, but it is unclear whether understorey and canopy guilds respond similarly to different light, biomechanical, and hydraulic constraints. Location An anthropically undisturbed, old-growth wet evergreen dipterocarp forest plot located in Karnataka State, India. Methods We measured leaf and wood traits of 89 tree species representing 99% of all individuals in a 10-ha permanent plot with varying topographic and canopy conditions inferred from Light Detection And Ranging (LiDAR) data. We assigned tree species to guilds of canopy and understorey species and assessed the variation of the guild-weighted means of functional-trait values with canopy height and topography. Results The functional-trait space did not differ between canopy and understorey tree species. However, environmental filtering led to significantly different functional composition of canopy and understorey guild assemblages. Furthermore, they responded differently along environmental gradients related to water, nutrients, light, and wind exposure. For example, the canopy guild responded to wind exposure while the understorey guild did not. Conclusions The pools of understorey and canopy species are functionally similar. However, fine-scale environmental heterogeneity impacts differently on these two guilds, generating striking differences in functional composition between understorey and canopy guild assemblages. Accounting for vertical guilds improves our understanding of forest communities' assembly processes.  
  Address  
  Corporate Author Thesis  
  Publisher International Association for Vegetation Science Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
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  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 1038  
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Author Henkel, T.W.; Wilson, A.W.; Aime, M.C.; Dierks, J.; Uehling, J.K.; Roy, M.; Schimann, H.; Wartchow, F.; Mueller, G.M. url  openurl
  Title (up) Cantharellaceae of Guyana II: New species of Craterellus, new South American distribution records for Cantharellus guyanensis and Craterellus excelsus, and a key to the Neotropical taxa Type Journal Article
  Year 2014 Publication Mycologia Abbreviated Journal Mycologia  
  Volume 106 Issue 2 Pages 307-324  
  Keywords Cantharellales; Coccoloba; Dicymbe; Ectomycorrhizae; Guiana shield; Tropical fungi  
  Abstract Craterellus olivaceoluteus sp. nov. and Craterellus cinereofimbriatus sp. nov. are described as new to science. These fungi were collected from Guyana in association with ectomycorrhizal host trees in the genera Dicymbe (Fabaceae subfam. Caesalpinioideae) and Pakaraimaea (Dipterocarpaceae). Cantharellus guyanensis Mont., originally described from French Guiana, is redescribed from recent collections from Guyana, with additional range extensions for the species provided based on material examined from French Guiana, Venezuela, and north central, northeastern and southern Brazil, circumscribing nearly the entire Guiana Shield region and beyond. A new distribution record from French Guiana is provided for Craterellus excelsus T.W. Henkel & Aime. Macromorphological, micromorphological and habitat data are provided for the new species and C. guyanensis as well as DNA sequence data from the nuclear ribosomal regions of the internal transcribed spacer (ITS) and 28S large subunit (LSU); additional sequence data is provided for C. guyanensis and C. excelsus specimens collected outside Guyana. The relationships of these taxa within the Cantharellaceae were evaluated with phylogenetic analyses of ITS and LSU sequence data. This work brings the total number of Cantharellaceae species known from Guyana to eight. A key to the Cantharellus and Craterellus species known from the lowland Neotropics and extralimital montane Central and South America is provided. © 2014 by The Mycological Society of America.  
  Address Department of Biological Sciences, Boise State University, Boise, ID, 83725, United States  
  Corporate Author Thesis  
  Publisher Allen Press Inc. Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 15572536 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Export Date: 10 June 2014; Coden: Mycoa; Correspondence Address: Henkel, T.W.; Department of Biological Sciences, Humboldt State University, Arcata, CA 95521, United States; email: twh5@humboldt.edu; Funding Details: DEB-0732968, NSF, National Science Foundation Approved no  
  Call Number EcoFoG @ webmaster @ Serial 546  
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Author Zaremski, A.; Gastonguay, L.; Zaremski, C.; Chaffanel, F.; Le Floch, G.; Beauchene, J. url  openurl
  Title (up) Capacity of tropical forest soils of french guiana and réunion for depolluting the woods impregnated with biocides Type Journal Article
  Year 2013 Publication Bois et Forets des Tropiques Abbreviated Journal Bois Forets Tropiques  
  Volume 67 Issue 318 Pages 51-58  
  Keywords Bioremediation; Copper chromium arsenic(CCA) wood-destroying fungi; Depollution; Loss of mass; Pentachlorophenol(PCP); Treated timber; Tropical soil  
  Abstract Wood material for a long time was treated with fungicides or insecticides whose impact on the soil after leaching constitutes a real environmental problem. Nowadays, most of the studies on degradation of these toxic products was carried out with microorganisms which have been isolated in the laboratory. The present study sought to refine the knowledge vis-à-vis these microorganisms, especially wood-destroying fungi degrading pollutants in situ, from which few data are actually available. To decontaminate treated wood, the capacity of wooddestroying microorganisms from tropical forest soils of French Guiana and Reunion was evaluated to degrade toxic biocides. These are pentachlorophenol (PCP) and copper- chromium arsenic based compounds (CCA). Monitoring the degradation of samples of red pine, Pinus resinosa, shows that soils of French Guiana are more efficient than those of Reunion Island in terms of microbial activity vis-àvis these two biocides. A significant difference in loss of mass in specimens of red pine treated with CCA and PCP can range from single to double (respectively 18% and 30%). These findings confirm that CCA is less leacher and less degradable than the PCP by microorganisms in the soil. According to the scale of mass loss in laboratory tests, the wood so treated would be classified very not durable after three years of contact with soil, while the treatment is expected to be very durable.  
  Address Cirad Umr Ecofog, BP 701, 97387 Kourou cedex, France  
  Corporate Author Thesis  
  Publisher Lavoisier Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 17775760 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Export Date: 12 May 2014; Source: Scopus; Language of Original Document: French Approved no  
  Call Number EcoFoG @ webmaster @ Serial 540  
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Author Piponiot, C.; Sist, P.; Mazzei, L.; Peña-Claros, M.; Putz, F.E.; Rutishauser, E.; Shenkin, A.; Ascarrunz, N.; de Azevedo, C.P.; Baraloto, C.; França, M.; Guedes, M.; Honorio Coronado, E.N.; d'Oliveira, M.V.N.; Ruschel, A.R.; da Silva, K.E.; Doff Sotta, E.; de Souza, C.R.; Vidal, E.; West, T.A.P.; Herault, B. pdf  url
doi  openurl
  Title (up) Carbon recovery dynamics following disturbance by selective logging in Amazonian forests Type Journal Article
  Year 2016 Publication eLife Abbreviated Journal  
  Volume 5 Issue Pages e21394  
  Keywords  
  Abstract When 2 Mha of Amazonian forests are disturbed by selective logging each year, more than 90 Tg of carbon (C) is emitted to the atmosphere. Emissions are then counterbalanced by forest regrowth. With an original modelling approach, calibrated on a network of 133 permanent forest plots (175 ha total) across Amazonia, we link regional differences in climate, soil and initial biomass with survivors' and recruits' C fluxes to provide Amazon-wide predictions of post-logging C recovery. We show that net aboveground C recovery over 10 years is higher in the Guiana Shield and in the west (21{plus minus}3 MgC ha-1) than in the south (12{plus minus}3 MgC ha-1) where environmental stress is high (low rainfall, high seasonality). We highlight the key role of survivors in the forest regrowth and elaborate a comprehensive map of post-disturbance C recovery potential in Amazonia.  
  Address  
  Corporate Author Thesis  
  Publisher eLife Sciences Publications, Ltd Place of Publication Editor Trumbore, S.  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2050-084x ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 702  
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Author Phillips, O.L.; Brienen, R.J.W.; Gloor, E.; Baker, T.R.; Lloyd, J.; Lopez-Gonzalez, G.; Monteagudo-Mendoza, A.; Malhi, Y.; Lewis, S.L.; Vásquez Martinez, R.; Alexiades, M.; Álvarez Dávila, E.; Alvarez-Loayza, P.; Andrade, A.; Aragão, L.E.O.C.; Araujo-Murakami, A.; Arets, E.J.M.M.; Arroyo, L.; Aymard, G.A.; Bánki, O.S.; Baraloto, C.; Barroso, J.; Bonal, D.; Boot, R.G.A.; Camargo, J.L.C.; Castilho, C.V.; Chama, V.; Chao, K.J.; Chave, J.; Comiskey, J.A.; Valverde, F.C.; da Costa, L.; de Oliveira, E.A.; Di Fiore, A.; Erwin, T.L.; Fauset, S.; Forsthofer, M.; Galbraith, D.R.; Grahame, E.S.; Groot, N.; Herault, B.; Higuchi, N.; Honorio Coronado, E.N.; Keeling, H.; Killeen, T.J.; Laurance, W.F.; Laurance, S.; Licona, J.; Magnusson, W.E.; Marimon, B.S.; Marimon-Junior, B.H.; Mendoza, C.; Neill, D.A.; Nogueira, E.M.; Núñez, P.; Pallqui Camacho, N.C.; Parada, A.; Pardo-Molina, G.; Peacock, J.; Peña-Claros, M.; Pickavance, G.C.; Pitman, N.C.A.; Poorter, L.; Prieto, A.; Quesada, C.A.; Ramírez, F.; Ramírez-Angulo, H.; Restrepo, Z.; Roopsind, A.; Rudas, A.; Salomão, R.P.; Schwarz, M.; Silva, N.; Silva-Espejo, J.E.; Silveira, M.; Stropp, J.; Talbot, J.; ter Steege, H.; Teran-Aguilar, J.; Terborgh, J.; Thomas-Caesar, R.; Toledo, M.; Torello-Raventos, M.; Umetsu, R.; van der Heijden, G.M.F.; van der Hout, P.; Guimarães Vieira, I.C.; Vieira, S.A.; Vilanova, E.; Vos, V.A.; Zagt, R.J.; Alarcon, A.; Amaral, I.; Camargo, P.B.; Brown, I.F.; Blanc, L.; Burban, B.; Cardozo, N.; Engel, J.; de Freitas, M.A.; de Oliveira, A.; Fredericksen, T.S.; Ferreira, L.; Hinojosa, N.T.; Jimenez, E.; Lenza, E.; Mendoza, C.; Mendoza Polo, I.; Peña Cruz, A.; Peñuela, M.C.; Petronelli, P.; Singh, J.; Maquirino, P.; Serano, J.; Sota, A.; Oliveira dos Santos, C.; Ybarnegaray, J.; Ricardo, J. pdf  url
doi  openurl
  Title (up) Carbon uptake by mature Amazon forests has mitigated Amazon nations' carbon emissions Type Journal Article
  Year 2017 Publication Carbon Balance and Management Abbreviated Journal Carbon Balance and Management  
  Volume 12 Issue 1 Pages  
  Keywords Amazonia; Carbon balance; Carbon sink; Climate change; Ecosystem service; Land use change; Sequestration; Tropical forests  
  Abstract Background: Several independent lines of evidence suggest that Amazon forests have provided a significant carbon sink service, and also that the Amazon carbon sink in intact, mature forests may now be threatened as a result of different processes. There has however been no work done to quantify non-land-use-change forest carbon fluxes on a national basis within Amazonia, or to place these national fluxes and their possible changes in the context of the major anthropogenic carbon fluxes in the region. Here we present a first attempt to interpret results from ground-based monitoring of mature forest carbon fluxes in a biogeographically, politically, and temporally differentiated way. Specifically, using results from a large long-term network of forest plots, we estimate the Amazon biomass carbon balance over the last three decades for the different regions and nine nations of Amazonia, and evaluate the magnitude and trajectory of these differentiated balances in relation to major national anthropogenic carbon emissions. Results: The sink of carbon into mature forests has been remarkably geographically ubiquitous across Amazonia, being substantial and persistent in each of the five biogeographic regions within Amazonia. Between 1980 and 2010, it has more than mitigated the fossil fuel emissions of every single national economy, except that of Venezuela. For most nations (Bolivia, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname) the sink has probably additionally mitigated all anthropogenic carbon emissions due to Amazon deforestation and other land use change. While the sink has weakened in some regions since 2000, our analysis suggests that Amazon nations which are able to conserve large areas of natural and semi-natural landscape still contribute globally-significant carbon sequestration. Conclusions: Mature forests across all of Amazonia have contributed significantly to mitigating climate change for decades. Yet Amazon nations have not directly benefited from providing this global scale ecosystem service. We suggest that better monitoring and reporting of the carbon fluxes within mature forests, and understanding the drivers of changes in their balance, must become national, as well as international, priorities. © 2017 The Author(s).  
  Address University of Leeds, School of Geography, Leeds, United Kingdom  
  Corporate Author Thesis  
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  Notes Export Date: 20 February 2017 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 735  
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Author Agrawal, Anurag A. ; Boroczky, Katalin ; Haribal, Meena ; Hastings, Amy P. ; White, Ronald, A. ; Jiang, Ren-Wang ; Duplais, Christophe doi  openurl
  Title (up) Cardenolides, toxicity, and the costs of sequestration in the coevolutionary interaction between monarchs and milkweeds Type Journal Article
  Year 2021 Publication PNAS Abbreviated Journal  
  Volume 118 Issue 16 Pages e2024463118  
  Keywords  
  Abstract For highly specialized insect herbivores, plant chemical defenses are often co-opted as cues for oviposition and sequestration. In such interactions, can plants evolve novel defenses, pushing herbivores to trade off benefits of specialization with costs of coping with toxins? We tested how variation in milkweed toxins (cardenolides) impacted monarch butterfly ( Danaus plexippus ) growth, sequestration, and oviposition when consuming tropical milkweed ( Asclepias curassavica ), one of two critical host plants worldwide. The most abundant leaf toxin, highly apolar and thiazolidine ring–containing voruscharin, accounted for 40% of leaf cardenolides, negatively predicted caterpillar growth, and was not sequestered. Using whole plants and purified voruscharin, we show that monarch caterpillars convert voruscharin to calotropin and calactin in vivo, imposing a burden on growth. As shown by in vitro experiments, this conversion is facilitated by temperature and alkaline pH. We next employed toxin-target site experiments with isolated cardenolides and the monarch’s neural Na + /K + -ATPase, revealing that voruscharin is highly inhibitory compared with several standards and sequestered cardenolides. The monarch’s typical >50-fold enhanced resistance to cardenolides compared with sensitive animals was absent for voruscharin, suggesting highly specific plant defense. Finally, oviposition was greatest on intermediate cardenolide plants, supporting the notion of a trade-off between benefits and costs of sequestration for this highly specialized herbivore. There is apparently ample opportunity for continued coevolution between monarchs and milkweeds, although the diffuse nature of the interaction, due to migration and interaction with multiple milkweeds, may limit the ability of monarchs to counteradapt.  
  Address  
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  Publisher National Academy of Sciences Place of Publication Editor  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 1014  
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