Moose Drool Detoxifies Fungus
Saliva contains important substances helps us digest food. It also plays a part in keeping our mouths clean and healthy. Another newly discovered use? Making toxic plants less toxic. Not for us of course, but according to new research, moose and reindeer saliva can help can slow the growth of a toxic grass fungus, and subsequently make it less toxic for them, allowing the animals to graze on the grass without negative effects.
"Plants have evolved defense mechanisms to protect themselves, such as thorns, bitter-tasting berries, and in the case of certain types of grass, by harbouring toxic fungus deep within them that can be dangerous or even fatal for grazing animals," says York U Biology Professor Dawn Bazely, who worked with University of Cambridge researcher Andrew Tanentzap and York U researcher Mark Vicari on the project. These adaptations improve plants survival and reproduction.
In the case of red fescue grass, the plant hosts a toxic fungus called epichloë festucae. So when an earlier study showed that moose grazing and saliva distribution can have a positive effect on plant growth, researchers conducted a study to see if in fact moose saliva was "detoxifying" the grass before it was eaten.
Working in partnership with the Toronto Zoo, the team collected saliva samples from moose and reindeer. The saliva was distributed onto samples of red fescue grass carrying the toxic fungus, simulating the effect of grazing. They found that the application of saliva produced rapid results, inhibiting fungus growth within 12-36 hours.
"We found that the saliva worked very quickly in slowing the growth of the fungus, and the fungus colonies," says Bazely. "In addition, by applying multiple applications of saliva to the grass over the course of two months, we found we could lower the concentration of ergovaline [the toxin produced by the fungus] between 41 and 70 per cent."
Bazely says that because moose tend to graze within a defined home range, it's possible that certain groups of plants are receiving repeated exposure to the moose saliva, which over time has resulted in fewer toxins within their preferred area.
"We know that animals can remember if certain plants have made them feel ill, and they may avoid these plants in future," says Bazely. "This study the first evidence, to our knowledge, of herbivore saliva being shown to 'fight back' and slow down the growth of the fungus."
The study is published in this month's Biology Letters.
Read more at York University.
Moose image via Shutterstock.