Editors' ChoiceInterspecies Communication

The Root Cause of an Invading Plant

STKE  09 Sep 2003:
Vol. 2003, Issue 199, pp. tw353-TW353
DOI: 10.1126/stke.2003.199.tw353

Certain plants, when introduced into new environments, can be much more pesky than they ever were in their original environment. Spotted knapweed was accidentally introduced from Eastern Europe to North America some time ago, and in the western United States it is an aggressive weed that diminishes the productivity of pastures. Bais et al. show that knapweed exudes a chemical from its roots that initiates a cell-death cascade in the roots of nearby susceptible plants. Thus, the roots of knapweed's invasiveness lie not so much in lack of predators or unused ecological niches, but rather in the weak defenses of its new plant neighbors.

H. P. Bais, R. Vepachedu, S. Gilroy, R. M. Callaway, J. M. Vivanco, Allelopathy and exotic plant invasion: From molecules and genes to species interactions. Science 301, 1377-1380 (2003). [Abstract] [Full Text]