title: Burning vegetation produces cyanohydrins that liberate cyanide and stimulate seed germination.
abstract: Cyanide is well known for its toxicity towards living organisms. Many plants use cyanide as a defensive agent against herbivores, releasing it through the enzymatic hydrolysis of endogenous cyanogenic compounds. At low concentrations, cyanide has been proposed to have a regulatory role in many plant processes including stimulation of seed germination. However, no ecological role for cyanide in seed germination has been established. In the present study, we show that burning plant material produces the cyanohydrin, glyceronitrile. We also show that, in the presence of water, glyceronitrile is slowly hydrolysed to release cyanide that stimulates seed germination of a diverse range of fire-responsive species from different continents. We propose that glyceronitrile serves as an ecological store for cyanide and is an important cue for stimulating seed germination and landscape regeneration after fires.
authors.affiliation: School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Crawley, Western Australia 6009, Australia. gavin.flematti@uwa.edu.au
authors.forename: Gavin R
authors.initials: GR
authors.lastname: Flematti
authors.forename: David J
authors.initials: DJ
authors.lastname: Merritt
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Piggott
authors.forename: Robert D
authors.initials: RD
authors.lastname: Trengove
authors.forename: Steven M
authors.initials: SM
authors.lastname: Smith
authors.forename: Kingsley W
authors.initials: KW
authors.lastname: Dixon
authors.forename: Emilio L
authors.initials: EL
authors.lastname: Ghisalberti
mesh_terms: D000704:Analysis of Variance; D002851:Chromatography, High Pressure Liquid; D005390:Fires; D008401:Gas Chromatography-Mass Spectrometry; D018525:Germination / Q000502:physiology*; D006856:Hydrogen Cyanide / Q000737:chemistry / Q000378:metabolism*; D019684:Magnoliopsida / Q000737:chemistry* / Q000254:growth & development*; D015394:Molecular Structure; D009570:Nitriles / Q000737:chemistry*; D012906:Smoke / Q000032:analysis*; D013045:Species Specificity; D014904:Western Australia
chemical_list: D009570:Nitriles; D012906:Smoke; C430593:cyanohydrin; D006856:Hydrogen Cyanide