Location: Vegetable Crops Research
Project Number: 5090-21220-002-16-R
Project Type: Reimbursable
Start Date: Jan 1, 2014
End Date: Dec 31, 2016
We will demonstrate that bZIP60, SKP1 and SGT1 are critical components of PVX and PVY infection and immunity processes. We predict that these genes are valuable targets for potato germplasm improvement in order to reduce the impact of viral diseases on yield and marketability. They may also be vital components of a genetic background that ensures stable resistance to invading viruses. Comparing the role of bZIP60, SKP1 and SGT1 in PVX and PVY infection will help to clarify their role in regulating disease and host resistance.
1. Determine if bZIP60, SGT1 and SKP1 contribute to the replication, cell-to-cell movement, and disease related necrosis of PVX and PVY strain N (necrosis inducing strain) in tobacco and potato protoplasts and plants. Genes will be silenced in plants or protoplasts. 2. IRE1 is an ER resident stress sensor that activates bZIP60 by mRNA splicing (bZIP60s). We will examine whether IRE1 is required for virus infection, whether bZIP60 mRNA is spliced in virus infected plants and if the bZIP60s transcription factor is translocated to the nucleus in virus infected plants. Transgenic potato and tobacco expressing bZIP60-GUS fusions will be used. Experiments will be carried out to determine if the PVX TGBp3 is responsible for cleavage and nuclear localization of bZIP60 in tobacco and potato. 3. bZIP60 activates promoters containing cis elements, P-UPRE and ERSE, including activating its own transcription and BiP genes. We will develop a reporter system using promoters from potato bZIP60, SGT1 and SKP1 fused with GUS to produce stable transgenic tobacco and potato plants. These reporter plants will help us determine if cloned bZIP60 activates transcription via the SKP1 promoter and if PVX TGBp3 protein or PVY infection activates GUS expression. Using these reporters, we will also determine if a specific PVY gene can induce promoter expression or if virus infection in general can induce expression of these genes.