Austrian scientists are putting the ‘fun’ in ‘fungus’ by forcing organisms which are usually asexual to have sex instead.
The hope is that the fungus would then be easier to breed, which would allow researchers to create organisms that are more efficient at degrading cellulose for the purpose of making biofuel.
Originally discovered in the Solomon Islands during World War II eating away at the canvas and garments of the U.S. Army, scientists have long known that the soil fungus Trichoderma reesei was particularly good at converting cellulose– a major component of plant biomass– into glucose. But until now it has been difficult for researchers to improve the fungus because it was believed to be asexual.
Due to the fact that sexual organisms exchange and mix their genetic material when they breed, their traits can be more easily manipulated artificially. Under the assumption that Trichoderma reesei was asexual, scientists looking to improve the fungus were instead limited to techniques like dosing the fungus with radiation or chemicals in order to alter its genetic profile. But that process only created random or unpredictable mutations.
But for the first time since its discovery 50 years ago, scientists can now make the fungus have sex.
Past studies have shown that Trichoderma reesei is genetically identical to another species of fungus, Hypocrea jecorina, which it so happens is capable of sexual reproduction. The primary difference between the two organisms was that Hypocrea jecorina seemed capable of assuming both the male and female roles, whereas Trichoderma reesei seemed only capable of assuming the male role.
So scientists got a novel idea: Why not breed the male-oriented Trichoderma with a female-oriented Hypocrea? The result was a successful mating– the Trichoderma lured into having sex could now be artificially selected for their advantageous genetic traits.
The findings could have largescale ramifications. Researchers want to employ the organisms to make use of the otherwise useless cellulose in sawdust, weeds and other plant scrap to make biofuel. Thus, the primary benefit of fungus sex could be to turn bush into biofuel. But the newly sexualized fungus can also help farmers. Since Trichoderma includes species that help plants by killing harmful fungi, they can be put to use protecting crops we use for food.
Image Credit: V. Seidl, Vienna University of Technology