Allelopathy and Exotic Plant Invasion: From Molecules and Genes to Species Interactions

  title={Allelopathy and Exotic Plant Invasion: From Molecules and Genes to Species Interactions},
  author={Harsh Pal Bais and Ramarao Vepachedu and Simon Gilroy and Ragan M. Callaway and Jorge M Vivanco},
  pages={1377 - 1380}
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… 
Allelopathic Impacts of the Invasive Tree Cedrela odorata L. (Meliaceae, Sapindales = Magnoliidae) in the Galapagos Flora
There are comparatively very few studies detailing the presence of this explanatory mechanism in one of the most invaded biomes of the globe, oceanic islands, allelopathy.
Insect herbivory stimulates allelopathic exudation by an invasive plant and the suppression of natives
It is found that one of the most destructive invasive plants in North America, Centaurea maculosa, exudes far higher amounts of (±)-catechin, an allelopathic chemical known to have deleterious effects on native plants, when attacked by larvae of two different root boring biocontrol insects and a parasitic fungus.
Root exudate is allelopathic in invaded community but not in native community: field evidence for the novel weapons hypothesis
This first in situ test of the novel weapons hypothesis supports the notion that novel biochemical constituents of some invasive species may contribute to their success, and indicates that some species in the native range of C. maculosa may be adapted to its particular biochemical traits.
Catechin–metal interactions as a mechanism for conditional allelopathy by the invasive plant Centaurea maculosa
The findings serve to illustrate that the precise chemical forms, interactions and effects of catechin in the environment are highly variable and that further examination is warranted to increase the understanding of its role in invasion and allelopathy.
Biogeographical variation in community response to root allelochemistry: novel weapons and exotic invasion
Eurasian plants and soil microbes may have evolved natural resistance to 8-hydroxyquinoline while North American plants have not, suggesting a remarkable potential for evolutionary compatibility and homeostasis among plants within natural communities and a mechanism by which exotic weeds destroy these communities.
Allelopathy and Exotic Plant Invasion
This chapter revise and expand the biochemical hypothesis that some invaders may succeed because they possess unique allelopathic biochemistry to which naive natives have not adapted, and discusses experimental and conceptual advances and limitations.
Allelopathic effects of Chromolaena odorata on native and non-native invasive herbs
It is suggested that allelopathy may contribute to the ability of C. odorata to become dominant in invaded plant communities in southern China.
The Allelopathic Potentials of the Non-Native Invasive Plant Microstegium vimineum and the Native Ageratina altissima: Two Dominant Species of the Eastern Forest Herb Layer
Results show that a native species had stronger allelopathic potential than an aggressive, non-native invader from the same forest and that allelopathy was effective on the earliest developmental stages of the target plant species.
Allelopathy of Knotweeds as Invasive Plants
The accumulated evidence suggests that some of those allelochemicals in knotweeds may be released into the rhizosphere soil through the decomposition process of their plant parts, and the exudation from their rhizomes and roots.
Can plant biochemistry contribute to understanding of invasion ecology?


Invasive plants versus their new and old neighbors: a mechanism for exotic invasion.
It is found that Centaurea diffusa, a noxious weed in North America, has much stronger negative effects on grass species from North America than on closely relatedgrass species from communities to which CentAurea is native.
Root-specific metabolism: The biology and biochemistry of underground organs
Recent progress in growing roots in isolation with other elements of the rhizosphere has greatly facilitated the study of root-specific metabolism and contributed to the understanding of this organ.
Enantiomeric-Dependent Phytotoxic and Antimicrobial Activity of (±)-Catechin. A Rhizosecreted Racemic Mixture from Spotted Knapweed1
It is found that (−)-catechin is a root-secreted phytotoxin that undoubtedly contributes to spotted knapweed's invasive behavior in the wild.
Effect of aluminum on cytoplasmic Ca2+ homeostasis in root hairs of Arabidopsis thaliana (L.)
The lack of a tight correlation between Al exposure, growth inhibition and altered [Ca2+]c dynamics suggests that although exposure of root hairs to toxic levels of Al causes an alteration in cellular Ca2+ homeostasis, this may not be a required event for Al toxicity.
Changes in Root Cap pH Are Required for the Gravity Response of the Arabidopsis Root
Results suggest that alterations in root cap pH likely are involved in the initial events that mediate root gravity perception or signal transduction.
Role of reactive oxygen intermediates and cognate redox signaling in disease resistance.
Plants have evolved a plethora of sophisticated defense mechanisms to resist their potential colonization by microbial pathogens and parasites. Preformed physical and chemical barriers constitute the
Calcium channels activated by hydrogen peroxide mediate abscisic acid signalling in guard cells
Activation of Ca2+-permeable channels in the plasma membrane of Arabidopsis guard cells by hydrogen peroxide indicates that ABA-induced H2O2 production and the H 2O 2-activated Ca2-activated channels are important mechanisms for A BA-induced stomatal closing.