Chemical mediation of organismal interactions: Molisch allelopathy; juglone walnut; plant VOCs; jasmonate-induced defense; phytoalexins; glucosinolate-myrosinase; tannins; cyanogenic glycosides; cardenolide-monarch sequestration;…
Chemical Ecology
Molisch allelopathy
Molisch 1937 Der Einfluss einer Pflanze auf die andere; coined allelopathy; biochemical interactions between plants (and microbes) via…
Juglone (black walnut)
Juglans nigra leaves and roots release juglone (5-hydroxy-1,4-naphthoquinone); allelopathic inhibition of nightshade and apple-family…
Plant volatile organic compounds
Green-leaf volatiles (C6 aldehydes, alcohols, esters), isoprene, monoterpenes; constitutive and damage-induced; signalling, defence,…
Jasmonate-induced defence
Wound-induced jasmonic-acid biosynthesis triggers protease-inhibitor and secondary-metabolite gene expression via COI1-JAZ signalling;…
Phytoalexins
Inducible antimicrobial secondary metabolites synthesised on pathogen attack; resveratrol (grape), glyceollin (soy), camalexin…
Glucosinolate-myrosinase system
Brassicaceae sequester glucosinolates in vacuoles; tissue damage releases myrosinase, producing toxic isothiocyanates (mustard oil bomb);…
Tannin protein-binding defence
Condensed and hydrolyzable tannins precipitate herbivore proteins, reducing digestibility; broadly distributed across woody and herbaceous…
Cyanogenic glycosides
Linamarin/lotaustralin (cassava), amygdalin (almond), dhurrin (sorghum); release HCN on tissue damage via host beta-glucosidase activation;…
Cardenolide / monarch sequestration
Asclepias milkweed cardenolides inhibit Na+/K+-ATPase; monarch caterpillars sequester cardenolides and become unpalatable to bird…
Bombykol sex pheromone
Butenandt et al 1959; first chemically identified animal sex pheromone (Bombyx mori silkmoth); 10E,12Z-hexadecadien-1-ol; established…
Queen mandibular pheromone
Honeybee 9-ODA (9-oxo-2-decenoic acid) queen mandibular pheromone; suppresses worker ovary development; retinue-attraction; primer +…
Ant trail pheromone
Wilson 1962 fire-ant trail pheromone; Dufour-gland undecane and Z,E-alpha-farnesene; recruitment to food sources; positive feedback drives…
Floral volatiles and pollinator attraction
Linalool, beta-ocimene, methyl benzoate and species-specific blends attract pollinators; species-specific filters underlie…
Strigolactone signalling
Akiyama-Matsuzaki-Hayashi 2005 Nature; root-exuded strigolactones recruit arbuscular mycorrhizal fungi via hyphal branching; also stimulate…
Bacterial quorum sensing
Bassler-Greenberg; Gram-negative AHL (LuxI/R), Gram-positive AIP, AI-2 universal language; density-dependent gene expression; biofilm and…
Coral mass-spawning cues
Harrison et al 1984; Great Barrier Reef multi-species synchronous spawning at full moon; lunar light, temperature and species-specific…
Conifer resin defence
Constitutive and induced monoterpene + diterpene resin in pines; toxic and physical defence against bark beetles; beetle-symbiont fungi…
Optimal-defence theory
McKey-Rhoades 1979; plants allocate costly secondary metabolites preferentially to high-fitness-value tissues with high attack risk;…