title: Insect attraction versus plant defense: young leaves high in glucosinolates stimulate oviposition by a specialist herbivore despite poor larval survival due to high saponin content.
abstract: Glucosinolates are plant secondary metabolites used in plant defense. For insects specialized on Brassicaceae, such as the diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae), glucosinolates act as "fingerprints" that are essential in host plant recognition. Some plants in the genus Barbarea (Brassicaceae) contain, besides glucosinolates, saponins that act as feeding deterrents for P. xylostella larvae, preventing their survival on the plant. Two-choice oviposition tests were conducted to study the preference of P. xylostella among Barbarea leaves of different size within the same plant. P. xylostella laid more eggs per leaf area on younger leaves compared to older ones. Higher concentrations of glucosinolates and saponins were found in younger leaves than in older ones. In 4-week-old plants, saponins were present in true leaves, while cotyledons contained little or no saponins. When analyzing the whole foliage of the plant, the content of glucosinolates and saponins also varied significantly in comparisons among plants that were 4, 8, and 12 weeks old. In Barbarea plants and leaves of different ages, there was a positive correlation between glucosinolate and saponin levels. This research shows that, in Barbarea plants, ontogenetical changes in glucosinolate and saponin content affect both attraction and resistance to P. xylostella. Co-occurrence of a high content of glucosinolates and saponins in the Barbarea leaves that are most valuable for the plant, but are also the most attractive to P. xylostella, provides protection against this specialist herbivore, which oviposition behavior on Barbarea seems to be an evolutionary mistake.
authors.affiliation: Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany; Instituto de Ciencias Agrarias, Consejo Superior de Investigaciones Científicas, Madrid, Spain.
authors.forename: Francisco R
authors.initials: FR
authors.lastname: Badenes-Perez
authors.affiliation: Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Gershenzon
authors.affiliation: Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany.
authors.forename: David G
authors.initials: DG
authors.lastname: Heckel
mesh_terms: D000818:Animals; D031216:Barbarea / Q000033:anatomy & histology / Q000737:chemistry* / Q000469:parasitology*; D005260:Female; D005961:Glucosinolates / Q000737:chemistry / Q000494:pharmacology*; D060434:Herbivory / Q000187:drug effects / Q000502:physiology*; D007814:Larva / Q000187:drug effects / Q000502:physiology*; D009036:Moths / Q000187:drug effects / Q000472:pathogenicity*; D010058:Oviposition / Q000187:drug effects*; D018515:Plant Leaves / Q000033:anatomy & histology / Q000737:chemistry / Q000469:parasitology*; D012503:Saponins / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D005961:Glucosinolates; D012503:Saponins
references.citation: J Chem Ecol. 2006 Apr;32(4):755-66
references.pmid: 16718569
references.citation: Pest Manag Sci. 2010 Aug;66(8):832-8
references.pmid: 20603876
references.citation: J Chem Ecol. 2002 Mar;28(3):587-99
references.pmid: 11944835
references.citation: J Chem Ecol. 2005 Aug;31(8):1711-32
references.pmid: 16222804
references.citation: J Sci Food Agric. 2010 Nov;90(14):2405-10
references.pmid: 20672341
references.citation: Trends Ecol Evol. 2005 Aug;20(8):441-8
references.pmid: 16701415
references.citation: J Econ Entomol. 2004 Aug;97(4):1365-72
references.pmid: 15384349
references.citation: Planta. 2002 Feb;214(4):562-71
references.pmid: 11925040
references.citation: Phytochemistry. 2006 Jun;67(12):1214-23
references.pmid: 16777152
references.citation: Annu Rev Entomol. 2009;54:57-83
references.pmid: 18811249
references.citation: New Phytol. 2011 Jan;189(2):549-56
references.pmid: 21029103
references.citation: Oecologia. 1989 Mar;78(3):322-329
references.pmid: 28312577
references.citation: Oecologia. 1989 Mar;80(1):53-8
references.pmid: 23494345
references.citation: J Chem Ecol. 2002 Feb;28(2):243-56
references.pmid: 11925065
references.citation: Phytochemistry. 2001 Sep;58(1):91-100
references.pmid: 11524118
references.citation: Phytochemistry. 2014 Feb;98:137-44
references.pmid: 24342111
references.citation: Br J Nutr. 2002 Dec;88(6):587-605
references.pmid: 12493081
references.citation: J Ethnopharmacol. 2004 Oct;94(2-3):219-43
references.pmid: 15325725
references.citation: Bull Entomol Res. 2004 Dec;94(6):509-16
references.pmid: 15541190
references.citation: Proc Natl Acad Sci U S A. 2002 Aug 20;99(17):11223-8
references.pmid: 12161563
references.citation: Plant Physiol. 2008 May;147(1):415-28
references.pmid: 18359845
references.citation: Annu Rev Entomol. 2016;61:277-96
references.pmid: 26667272
references.citation: Phytochemistry. 2003 Feb;62(3):471-81
references.pmid: 12620360
references.citation: Annu Rev Entomol. 2013;58:517-41
references.pmid: 23020617
references.citation: J Agric Food Chem. 2010 May 12;58(9):5509-14
references.pmid: 20387830
references.citation: J Chem Ecol. 2003 Jun;29(6):1417-33
references.pmid: 12918925
references.citation: Annu Rev Entomol. 2006;51:285-308
references.pmid: 16332213
references.citation: J Chem Ecol. 2010 Mar;36(3):277-85
references.pmid: 20177743
references.citation: J Integr Plant Biol. 2009 Jun;51(6):529-36
references.pmid: 19522811
references.citation: Pest Manag Sci. 2012 Aug;68(8):1199-205
references.pmid: 22461401
references.citation: Oecologia. 1999 Jul;120(1):102-112
references.pmid: 28308041
references.citation: Annu Rev Plant Biol. 2006;57:303-33
references.pmid: 16669764
references.citation: J Econ Entomol. 2005 Jun;98(3):836-44
references.pmid: 16022312