DEVELOPING GEMYCIRCULARVIRUS-BASED PESTICIDE FOR THE CONTROL OF SCLEROTINIA SCLEROTIORUM

Mycoviruses hold great potential in controlling plant pathogenic fungi. The overall goal of this project is to develop methods to efficiently deliver debilitating mycoviruses in the field. The objectives include: 1) evaluating the feasibility of expressing in transgenic plants a proven mycovirus biopesticide and another related but uncharacterized mycovirus triggered by Sclerotinia sclerotiorum infection; 2) comparing in vitro expression systems for production of self-assembled virions as biopesticides; 3) optimizing the conditions for scale-up of the production of the biopesticides. Proposed mycovirus candidates include a recently discovered ssDNA mycovirus, named as soybean leaf-associated gemycircularvirus 1 (SlaGemV1; KT598248) and a demonstrated field-effective biopesticide, Sclerotinia sclerotiorum hypovirulence associated DNA virus 1 (SsHADV1; NC 03116, KM598382~4). SlaGemV1 was recently discovered via a metatranscriptomic search of soybean leaves infected by fungal pathogens in Southern Illinois that is 55% identical to SsHADV1 in the amino acid sequence of the replicase. SsHADV1 has been shown to be effective either as a suspension of virus-infected hyphal fragments or purified virus particles applied directly on fungal hyphal mats or on plant leaves.