Virus turns deadly fungus from foe to friend in plants

Researchers have discovered that a fungal virus (also called a mycovirus) can convert deadly fungal pathogens into beneficial fungus in rapeseed plants. Once transformed, the fungus boosts the plant's immune system, making the plant healthier and more resistant to diseases.

These findings, published on September 29 in the journal Molecular Plant, indicate that some fungal viruses can be used for developing "plant vaccines" to improve crop health and enhance crop yield.

Rapeseed farms experience significant losses from the fungal pathogen, Sclerotinia sclerotiorum, which causes stem rot, lesions and kills the plants within a few days after infection.

"The virus we identified can convert the fungus from a deadly pathogen in different plants to an endophytic fungus like a gentle sheep and protect these plants," says the senior author Daohong Jiang, a professor at Huazhong Agricultural University in China.

Endophytic organisms live within a plant for at least part of its life cycle without causing diseases, maintaining a symbiotic relationship. "The research is important because we know plants have endophytic fungus, but where did it come from? The fungal virus might have played a role in the evolution of these fungi and that's something we can look into in the future."