Location: Horticultural Crops Research
Project Number: 2072-21220-003-28-G
Project Type: Grant
Start Date: Sep 1, 2018
End Date: Sep 30, 2019
1. Engineer six variants of the virus-induced gene silencing (VIGS) vector based on Grapevine leafroll-associated virus-2 (GLRaV-2) targeting Grapevine red blotch virus (GRBV) and generate grapevine plants systemically expressing this vector for GRBV resistance assays. 2. Identify the vector variants that confer the strongest resistance to GRBV infection using grafting of the GRBV-infected material to VIGS vector-harboring grapevine plants followed by monitoring virus accumulation every 2 months via quantitative polymerase chain reaction (PCR).
Tissue cultured plantlets of the Cabernet franc (most susceptible variety for agroinoculation) will be vacuum-infiltrated with Agrobacterium harboring one of the vector variants and transferred to soil. Upon plant propagation for 8 weeks, petiole samples are used to isolate RNA and test for the vector accumulation via Reverse transcription polymerase chain reaction (RT-PCR) assays. As we have demonstrated, Agrobacterium is eliminated at this time point such that the RNA of the vaccinating GLRaV-2 vector remains the only source of the anti-GRBV VIGS triggers. Our target is to identify 20 VIGS-vector positive plants for each of the six anti-GRBV variants.