Portuguese researcher in chilling death cap mushroom ‘discovery’

Susana C. Gonçalves identifies “strange sex life” of a deadly native fungus

An international study involving a Portuguese scientist has found that the Amanita phalloides mushroom, a deadly fungus native to Europe – and more popularly known as a ‘death cap’ – is able to reproduce on its own.

This, chillingly, is why the deadly mushroom has been spreading so rapidly – at least in California.

Susana C. Gonçalves, a researcher at the Centre for Functional Ecology (CFE) of the Faculty of Science and Technology of the University of Coimbra (FCTUC), is one of the researchers who has come to this surprising conclusion.

As Lusa explains, the deadly mushroom species originated in Europe but was inadvertently introduced to the United States, where it has been spreading voraciously, especially on the West Coast.

Entitled “Invasive Californian death caps develop mushrooms unisexually and bisexually” and published in the journal Nature Communications, this latest study has determined “that, in California, the fungus is capable of reproducing without a partner, self-fertilising”.

According to Anne Pringle from the University of Wisconsin-Madison, USA, coordinator and senior author of the study, this is “an unusual type of sexual reproduction in fungi that has rarely been observed outside the laboratory“.

“This species normally reproduces in a bisexual way: the underground structures, the mycelium, of two different compatible individuals fuse and produce mushrooms that contain DNA from both individuals,” she explains.

This type of reproduction “still happens in Europe”, and the team of researchers sequenced the DNA of mushrooms from Europe, including several populations from Portugal, and discovered that “they contained two sets of genetic material, one from each parent”.

However, in California, where mushrooms of this species were first observed at the beginning of the 20th century, “the fungus seems to be doing something quite different”.

“The DNA of some California mushrooms contained only one set of genetic material, indicating that each one had arisen from a single individual. How it does this is not very clear,” note the authors.

According to the researchers, Amanita phalloides “somehow circumvents the genetic controls that ensure that mushrooms are only produced after two individuals have merged”.

The ability to self-fertilise can be an advantage when you arrive in a new habitat where there are no compatible partners,” Susana C. Gonçalves notes. 

Thus, ‘unisexuality’ may help explain the rapid spread of the species along the West Coast of the United States.

“The next step is to find out if other invasive fungal species are using similar strategies in the wild,” says the Portuguese researcher.

Susana C. Gonçalves out in the field. Image: University of Coimbra

Source material: LUSA

For more information on death cap mushrooms, click here