by Mason Scher
Detritivores like fungi are often heralded as forest heros: they are absolutely integral to the breakdown of dead matter and nutrient cycling. Not to mention, they look pretty neat. However, a humongous fungus is taking over and wreaking havoc in North America, Europe and Asia, as New York Times reports. In fact, in one spot in Oregon a single body is as large as three central parks!
The sheer size of this organism is impressive, but the way it kills its victims is even more interesting. By comparing the genome of this species, Armillaria ostoyae, to over 20 other fungi, researchers from Hungary have identified several reasons as to why the habits of this organism vary so far from the norm.
They found that the way genes are replicated in this species is quite unusual: certain chunks of DNA are replicated within the genome, and often these are bits that code for some pretty detrimental traits. Some of the areas that have been replicated code for proteins that destroy plant cell walls or kill other cells, often root cells of trees.
Many trees have developed “sensors” that can monitor changes in soil chemistry that would alert the tree to send out defense mechanisms. The humongous fungus is able to absorb these compounds and remain in a kind of “stealth mode,” killing the tree before it knows it’s being attacked.
In many forests, this rhizomorph (rootlike structure of fungi) would cause some damage but not be devastating as it would only be able to overtake the weakest of trees, leaving behind stronger or particular species of trees that are more resistant to the fungus. However, as monoculture becomes more and more popular, forests become more and more susceptible to this killer. By identifying what makes this fungus so different, scientists can take steps in creating fungicides that will be able to stop its rapid expanse which is currently up to three feet per year.
It’s all fungus and games in our forests until something humongous is found among us.