Virus-based delivery of interfering RNAs targeting Grapevine leafroll-associated virus(es) and associated mealybugs

Project Leader: Yen-Wen Kuo

Grapevine leafroll is the most complex viral disease of grapevines worldwide and is economically important in all grape-growing regions. At least eleven viruses and several species of mealybugs and scale insects were reported to be associated with the disease complex. Given the lack of natural resistance in vinifera grapevines and challenges in developing disease resistance by conventional breeding, more control strategies are needed for this disease and associated insect vectors. In this project, we utilize our knowledge, expertise, and experience with using virus-based RNAi to target hemipteran insect vectors and of producing closterovirus-immune plants, to develop grapevine virus-based approaches for RNA interference (RNAi) targeting Grapevine leafroll-associated viruses and the insect vector mealybugs. We modify two grapevine viruses to be non-pathogenic viral vectors and attempt to use them to deliver and enhance the RNAi efficacy in the grapevine rootstocks and scions. Agroinfiltration and grafting techniques are included in our methodology to determine the RNAi effects towards mealybugs. This project will provide new important information and contemporary strategies to incorporate into the existing management approaches for the Grapevine leafroll disease and associated mealybugs.

VIPER: Viruses and Insects as Plant Enhancement Resources

Project Leader: Jun Jiang

In this project, both plant-infecting viruses and their hemipteran insect vectors will be engineered to optimize expression of transgenes or silence endogenous genes in mature maize plants, thereby providing protection against insect herbivory, either occurring naturally or through pests introduced by hostile acts, and enhancing drought tolerance.