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POSTERS: Chemical control

Evaluation of SP2700 antiviral activities in three model patho-systems
Tim Sit - North Carolina State University. Bangya Ma- SePRO Corporation

SP2700 (Trade name: NinjaTM) is a biochemical product extracted from soil bacterial fermentation. This compound activates the innate plant defense system and demonstrates antiviral properties. It has been used extensively in plant viral disease management outside of the US. In this study, SP2700’s curative antiviral property was examined using three model patho-systems: 1) Tobacco mosaic virus (TMV) on tobacco (Nicotiana tabacum var. Hicks MR) as a local lesion host, 2) Tomato bushy stunt virus (TBSV) on pinto bean (Phaseolus vulgaris cv. Pinto) as a local lesion host, 3) TBSV with a green fluorescent protein (GFP) reporter gene on Nicotiana benthamiana as a susceptible systemic host. Inoculations with purified TMV virions via a soft brush or TBSV RNA transcripts via rubbing were conducted 1 hour before the application of the product. A half-leaf assay was used for these studies where SP2700 was brushed onto one half of the leaves and water to the other half leaves serving as the control. SP2700 treated half leaves had consistently less TMV local lesions compared to the control with reduction from 76% to 49% on older leaves and 89% to 20% on young leaves based on 4 experiments. A similar effect was observed with TBSV on pinto half leaves. Surprisingly, fewer fluorescent foci were observed in the TBSV-GFP SP2700 treated half leaves despite the total susceptibility of N. benthamiana to TBSV systemic infection. This demonstrates that SP2700 is able to decrease viral infections using a non-specific mechanism and shows great promise as an antiviral compound.