A mycovirus modulates the endophytic and pathogenic traits of a plant associated fungus

Area of Science:

• Plant Pathology
• Mycology
• Virology
• Biological Control

Background:

• Fungi exhibit parasitic, commensal, or mutualistic lifestyles in host plants.
• Phytopathogenic fungi cause significant agricultural losses annually.
• Endophytic fungi can enhance host plant fitness, but factors modulating fungal traits are unclear.

Purpose of the Study:

• To investigate whether biological factors can modulate the parasitic and mutualistic traits of fungi.
• To characterize a novel mycovirus isolated from an endophytic fungus.
• To evaluate the potential of this mycovirus for biological control of plant diseases.

Main Methods:

• Isolation and molecular characterization of a mycovirus from an endophytic strain of Pestalotiopsis theae.
• Determination of the mycovirus genome structure (four double-stranded RNAs) and particle morphology.
• In vitro and in planta assays to assess the effect of the mycovirus on fungal growth, virulence, and host plant resistance.

Main Results:

• A novel chrysovirus, tentatively named Pestalotiopsis theae chrysovirus-1 (PtCV1), was identified.
• PtCV1 significantly reduced the growth rate of its host fungus and abolished its virulence on tea plants.
• PtCV1 converted the pathogenic fungus into a non-pathogenic endophyte and conferred resistance to host plants against virulent strains.

Conclusions:

• A mycovirus can modulate the endophytic and phytopathogenic traits of its fungal host.
• PtCV1 offers a promising avenue for the biological control of fungal plant diseases.
• This discovery provides an alternative approach to managing plant diseases caused by phytopathogenic fungi.