Saliva from big grazing animals sabotages plants’ chemical weaponry
Veronika Ronkos/Wikimedia Commons (CC BY-SA 3.0)
The slobbering of moose and reindeer as they eat may be big, wet countermeasures against the chemical defenses of grasses.
Some otherwise inviting grasses harbor live-in fungi such as Epichloë species, which can produce strong alkaloid toxins. Those compounds can make grazing animals sick enough to shy away from these grasses. Big animals, however, have a previously unappreciated way of fighting back, says ecologist Andrew Tanentzap of the University of Cambridge: They drool.
In lab tests, moose saliva dabbed onto grasses two or four times could lower the concentrations of the toxin ergovaline by 40 to 70 percent over the course of two months, Tanentzap and colleagues report July 23 in Biology Letters. Also, dripping the drool on Epichloë fungus in lab dishes slowed the spread of its thready networks, the team found.