title: Strigolactones: structures and biological activities.
abstract: Strigolactones released from plant roots induce seed germination of root parasitic weeds, witchweeds (Striga spp.) and broomrapes (Orobanche spp.), and hyphal branching of symbiotic arbuscular mycorrhizal (AM) fungi. In addition to these functions in the rhizosphere, strigolactones have recently been shown to be a novel class of plant hormones regulating shoot outgrowth. The natural strigolactones identified so far have the common C-D ring moiety, which is thought to be the essential structure for exhibiting biological activity. The introduction of substitutions on the A-B ring moiety of 5-deoxystrigol, the basic strigolactone, affords various strigolactones, e.g. hydroxylation on C-4, C-5 and C-9 leads to orobanchol, strigol and sorgomol respectively. Then, acetylation and probably other derivatisations of these hydroxy-strigolactones would occur. Although the C-2'-(R) stereochemistry was thought to be an important structural feature for potent germination stimulation activity, 2'-epi-strigolactones were found in root exudates of tobacco, rice, pea and other plant species, indicating that at least some plants produce both epimers.
authors.affiliation: Weed Science Centre, Utsunomiya University, Utsunomiya, Japan. yoneyama@cc.utsunomiya-u.ac.jp
authors.forename: Koichi
authors.initials: K
authors.lastname: Yoneyama
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Xie
authors.forename: Kaori
authors.initials: K
authors.lastname: Yoneyama
authors.forename: Yasutomo
authors.initials: Y
authors.lastname: Takeuchi
mesh_terms: D018525:Germination / Q000187:drug effects; D007783:Lactones / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D038821:Mycorrhizae / Q000187:drug effects / Q000254:growth & development; D031672:Orobanche / Q000187:drug effects / Q000502:physiology; D063245:Plant Development; D018517:Plant Roots / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism; D010944:Plants / Q000737:chemistry / Q000378:metabolism*; D034362:Striga / Q000187:drug effects / Q000502:physiology
chemical_list: D007783:Lactones; C483518:strigol