IMMUNIZING PLANTS - DEVELOPING SINGLE-CHAIN ANTIBODY FRAGMENTS AGAINST THE CYLINDRICAL INCLUSION PROTEIN OF TAMARILLO MOSAIC POTYVIRUS FOR VIRUS RESISTANCE
D WEBSTER1, P GUY1 and R FORSTER2
1Department of Botany, University of Otago, PO Box 56, Dunedin, New Zealand; 2Hort Research, Private Bag 92169, Auckland, New Zealand
Background and objectives
When expressed in plants, single-chain antibody fragments can reduce and delay symptoms of a tombusvirus infection . This single-chain antibody fragment was specific to the tombusvirus coat protein. We propose to produce single-chain antibody fragments that bind to the potyvirus cylindrical inclusion (Cl) protein. The Cl protein is a replication protein with well characterized helicase properties . Our aim is to find a single-chain antibody fragment that is able to bind to a highly conserved helicase motif, such as the NTP binding domain. Such an antibody fragment has the potential to confer resistance to a broad spectrum of potyviruses. By targeting a functional replication protein rather than structural proteins, we hope to improve the level of resistance that can be obtained using single-chain antibody fragments.
Results and conclusions
The library is currently being screened for Cl-specific single-chain antibody fragments by phage display. This Cl-specific subset will be analysed for their ability to successfully interfere with the helicase activity of the potyvirus Cl protein. Future research projects will investigate the ability of specific single-chain antibody fragments to generate both individual and broad-spectrum potyvirus resistance.