title: Octadecanoid and hexadecanoid signalling in plant defence.
abstract: Plants respond to situations requiring the initiation of inducible defence reactions with a complex array of signalling events that ultimately result in the activation of sets of defence genes. Among the chemical signals involved in the induction of defence reactions are cyclic oxylipins derived from C18- or C16-unsaturated fatty acids, the octadecanoids and the hexadecanoids. Key to understanding octadecanoid biology are the C18-metabolite 12-oxophytodienoic acid (OPDA) and the C12-compound jasmonic acid which is biosynthetically derived from 12-oxophytodienoic acid. Different octadecanoids likely have different biological functions. The bouquet of signalling compounds, rather than any single compound, is probably decisive for the biological response that results. This means that the processes regulating the pool sizes of different octadecanoids and their distribution within the plant are key to understanding octadecanoid biology. Recent results, including the cloning of several enzymes of the octadecanoid biosynthetic pathway, have provided first insights into these processes and into how the octadecanoid system is linked to other defence-related signalling pathways of the plant cell.
authors.affiliation: Lehrstuhl für Pflanzenphysiologie, Ruhr-Universität, Bochum, Germany.
authors.forename: E W
authors.initials: EW
authors.lastname: Weiler
authors.forename: D
authors.initials: D
authors.lastname: Laudert
authors.forename: B A
authors.initials: BA
authors.lastname: Stelmach
authors.forename: P
authors.initials: P
authors.lastname: Hennig
authors.forename: C
authors.initials: C
authors.lastname: Biesgen
authors.forename: I
authors.initials: I
authors.lastname: Kubigsteltig
mesh_terms: D003517:Cyclopentanes / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000378:metabolism / Q000502:physiology*; D008956:Models, Chemical; D054883:Oxylipins; D010935:Plant Diseases; D015398:Signal Transduction
chemical_list: D003517:Cyclopentanes; D005231:Fatty Acids, Unsaturated; D054883:Oxylipins; C025999:12-oxophytodienoic acid; C011006:jasmonic acid