Tuesday, October 16, 2007

Dissolve And Conquer

Did you ever wonder how Phragmites gets that amber waves style of monocultural sheen? Turns out it's burning its competitors right out of the picture. Newswise reports on new research from the Bais Lab at the University of Delaware, showing that Phragmites reed (Phragmites australis) exudes an acid from its roots that dissolves the roots of its neighbors.

The ability of plants to release chemicals that impact their competitors is known as allelopathy. Phragmites does it with gallic acid, an allelochemical that degrades the tubulin that maintains root structures, causing exposed roots to simply collapse.

To read more about this research, see the original article in the Journal of Chemical Ecology (abstract only unless you've got a subscription), or check out this press release from the University of Delaware that includes some cool images of degrading roots. Tip of the virtual hat to budak for pointing to the article.


Anonymous said...

Very interesting, but not by itself very explanatory unless there was some observed difference between the native and nonnative genotypes, right?

Anonymous said...

My first comment just goes to show that (1) plant biologists are not stupid and (2) one should read the article before one comments on it. The nonnative Phragmites secretes substantially higher levels of the acid than the native varieties do. That's very interesting. One point of confusion remains for me, though: I recall reading somewhere that native Phragmites in Europe (the same variety, probably, as the invasive stuff in the US) is being outcompeted by some species of Spartina (an American grass, one of the victims of Phragmites here) -- it would be interesting to see if the increased allelopathy were found there, as well, or whether it is the product of some amount of hybridization, or what.