Betaendornavirus sclerotiniae

Betaendornavirus sclerotiniae is a mycovirus that specifically infects Sclerotinia sclerotiorum, the fungal pathogen responsible for white mold disease in a wide range of crops. As an endornavirus, it exists as a persistent, non-lytic agent within the cytoplasm of the host fungus, modulating its biological functions without immediately killing the host cell.

The significance of this virus lies in its interaction with the host fungus rather than the plants themselves. In many cases, infection with Betaendornavirus sclerotiniae results in hypovirulence, meaning the fungal pathogen exhibits significantly reduced capacity to invade and damage host tissues such as stems, leaves, and fruits of various agricultural crops.

The host range of the underlying fungus is vast, including important agricultural commodities like sunflowers, oilseed rape, soybeans, and various vegetables. Because the virus is transmitted vertically through fungal spores and horizontally through hyphal anastomosis, it can persist within fungal populations in the soil, potentially acting as a natural regulator of pathogen fitness.

Key indicators of viral infection within the fungal culture include:

• reduced radial growth rates;
• impaired formation of sclerotia;
• altered hyphal morphology and pigmentation;
• decreased enzymatic activity involved in host penetration.

Current research efforts are focused on the potential of this mycovirus for the biological control of plant diseases. By deploying hypovirulent strains of Sclerotinia sclerotiorum containing Betaendornavirus sclerotiniae, farmers and researchers hope to reduce the overall disease pressure in fields, offering a sustainable alternative to chemical fungicides in the long term.