title: Allelopathy and exotic plant invasion: from molecules and genes to species interactions.
abstract: Here we present evidence that Centaurea maculosa (spotted knapweed), an invasive species in the western United States, displaces native plant species by exuding the phytotoxin (-)-catechin from its roots. Our results show inhibition of native species' growth and germination in field soils at natural concentrations of (-)-catechin. In susceptible species such as Arabidopsis thaliana, the allelochemical triggers a wave of reactive oxygen species (ROS) initiated at the root meristem, which leads to a Ca2+ signaling cascade triggering genome-wide changes in gene expression and, ultimately, death of the root system. Our results support a "novel weapons hypothesis" for invasive success.
authors.affiliation: Department of Horticulture and Landscape Architecture, Cell and Molecular Biology Program, and Graduate Degree Program in Ecology, Colorado State University, Fort Collins, CO 80523, USA.
authors.forename: Harsh P
authors.initials: HP
authors.lastname: Bais
authors.forename: Ramarao
authors.initials: R
authors.lastname: Vepachedu
authors.forename: Simon
authors.initials: S
authors.lastname: Gilroy
authors.forename: Ragan M
authors.initials: RM
authors.lastname: Callaway
authors.forename: Jorge M
authors.initials: JM
authors.lastname: Vivanco
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D001205:Ascorbic Acid / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling; D002392:Catechin / Q000378:metabolism* / Q000633:toxicity*; D016923:Cell Death; D002470:Cell Survival; D031179:Centaurea / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D017753:Ecosystem; D004777:Environment; D005060:Europe; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant; D006861:Hydrogen Peroxide / Q000494:pharmacology; D018517:Plant Roots / Q000166:cytology / Q000378:metabolism; D006109:Poaceae / Q000187:drug effects / Q000254:growth & development; D017382:Reactive Oxygen Species / Q000378:metabolism; D012987:Soil / Q000032:analysis; D014481:United States
chemical_list: D017382:Reactive Oxygen Species; D012987:Soil; D002392:Catechin; D006861:Hydrogen Peroxide; D001205:Ascorbic Acid; D002118:Calcium