Project Number
GENUS 17-03
Project title
Application of virus vectors against grapevine leafroll disease
Project leader
Maree, H J
Institution
Stellenbosch University: Department of Genetics
Team members
Carstens, R
Burger, J T
Bester, R
EXECUTIVE SUMMARY
Objectives and Rationale
Grapevine leafroll-associated virus 3 (GLRaV-3) and grapevine proteins that interact with each other can be targeted by control strategies to develop plant immunity. The aim of this study was to identify these proteins and to evaluate the use of an infectious clone to suppress the replication and spread of GLRaV-3.
Methods
The use of a grapevine virus A (GVA)-based RNAi infectious clone to deliver silencing information to Nicotiana benthamiana and Vitis vinifera was optimised. Interacting virus and/or plant proteins involved in GLRaV-3 infection were identified using a Yeast-two-hybrid (Y2H) system and Bimolecular fluorescence complementation (BiFC). All interactions were validated in plants.
Key results
Two different methods were used to screen for and validate the interaction of eight virus protein pairs. A Y2H library for the screening of V. vinifera proteins was constructed. Five grapevine proteins that possibly interact with GLRaV-3 proteins were identified. Two of these could be validated in plants.
Key conclusion of discussion
Infiltration of V. vinifera with the GVA infectious clone was unsuccessful. We identified interacting protein pairs that could be possible targets for a control strategy for GLRaV-3. This study provides information on the functional role of GLRaV-3 ORFs and increases our understanding of the pathogenic role of GLRaV-3 in GLD.
Take home message for the industry
Potential targets for GLRaV-3 control were identified that can be exploited by future research. We propose the use of genome editing technology to investigate the two host genes identified.