title: Detection of parasitic plant suicide germination compounds using a high-throughput Arabidopsis HTL/KAI2 strigolactone perception system.
abstract: Strigolactones are terpenoid-based plant hormones that act as communication signals within a plant, between plants and fungi, and between parasitic plants and their hosts. Here we show that an active enantiomer form of the strigolactone GR24, the germination stimulant karrikin, and a number of structurally related small molecules called cotylimides all bind the HTL/KAI2 α/β hydrolase in Arabidopsis. Strigolactones and cotylimides also promoted an interaction between HTL/KAI2 and the F-box protein MAX2 in yeast. Identification of this chemically dependent protein-protein interaction prompted the development of a yeast-based, high-throughput chemical screen for potential strigolactone mimics. Of the 40 lead compounds identified, three were found to have in planta strigolactone activity using Arabidopsis-based assays. More importantly, these three compounds were all found to stimulate suicide germination of the obligate parasitic plant Striga hermonthica. These results suggest that screening strategies involving yeast/Arabidopsis models may be useful in combating parasitic plant infestations.
authors.affiliation: Cell and Systems Biology, University of Toronto and the Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto ON M5S 3B2, Canada.
authors.forename: Shigeo
authors.initials: S
authors.lastname: Toh
authors.affiliation: Cell and Systems Biology, University of Toronto and the Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto ON M5S 3B2, Canada.
authors.forename: Duncan
authors.initials: D
authors.lastname: Holbrook-Smith
authors.affiliation: Cell and Systems Biology, University of Toronto and the Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto ON M5S 3B2, Canada.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Stokes
authors.affiliation: Cell and Systems Biology, University of Toronto and the Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto ON M5S 3B2, Canada. Electronic address: yuichiro.tsuchiya@bio.nagoya-u.ac.jp.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Tsuchiya
authors.affiliation: Cell and Systems Biology, University of Toronto and the Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto ON M5S 3B2, Canada. Electronic address: peter.mccourt@utoronto.ca.
authors.forename: Peter
authors.initials: P
authors.lastname: McCourt
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism*; D005663:Furans / Q000032:analysis* / Q000378:metabolism; D018525:Germination; D057166:High-Throughput Screening Assays; D006867:Hydrolases / Q000737:chemistry / Q000378:metabolism*; D007094:Imides / Q000032:analysis* / Q000378:metabolism; D007783:Lactones / Q000032:analysis* / Q000378:metabolism; D015394:Molecular Structure; D011714:Pyrans / Q000032:analysis* / Q000378:metabolism; D012677:Sensation
chemical_list: C488803:3-methyl-2H-furo(2,3-c)pyran-2-one; D029681:Arabidopsis Proteins; D005663:Furans; D007094:Imides; D007783:Lactones; D011714:Pyrans; C558280:HTL protein, Arabidopsis; D006867:Hydrolases