Location: Grape Genetics Research Unit (GGRU)Title: Silencing of grapevine pectate lyase-like genes VvPLL2 and VvPLL3 confers resistance against Erysiphe necator and differentially modulates gene expression
|MAHANIL, SIRAPRAPA - Former ARS Employee|
|OSIER, MICHAEL - Rochester Institute Of Technology|
|REISCH, BRUCE - Cornell University - New York|
Submitted to: Annual International Plant & Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: 10/31/2014
Publication Date: 1/1/2015
Citation: Majumdar, R., Mahanil, S., Lillis, J.A., Osier, M., Reisch, B., Cadle Davidson, L.E. 2015. Silencing of grapevine pectate lyase-like genes VvPLL2 and VvPLL3 confers resistance against Erysiphe necator and differentially modulates gene expression. Annual International Plant & Animal Genome Conference, San Diego, CA.
Technical Abstract: Broad-spectrum resistance against powdery mildew (PM) has been reported by silencing susceptibility genes in the model plant Arabidopsis. Here we used artificial microRNA constructs in PM-susceptible Vitis vinifera cv. Chardonnay to stably silence two pectate lyase-like orthologs (VvPLL2 and VvPLL3) of the Arabidopsis susceptibility gene AtPmr6. Incomplete silencing of each target gene resulted in increased foliar resistance against PM, seen at 2 days post-inoculation as a significant reduction (16-35%) of tertiary hyphal branching, but not affecting penetration or microcolony success rate. Genome wide RNA-seq expression analyses of the silenced lines versus empty-vector control lines revealed both distinct and shared consequences to non-target gene expression. While silencing of VvPLL3 significantly affected expression of only 37 genes, silencing of VvPLL2 affected 263 genes (FDR<0.001), including enrichment of genes involved in glucosinolate and galactose biosynthesis regardless of the target. In addition, VvPLL2 lines were enriched for genes involved in stress pathways, including involvement in abscisic acid and secondary metabolite biosynthesis. These results indicate compensating pathways involved in Atpmr6-mediated resistance, and suggest that VvPLL2 and VvPLL3 might be promising targets to knock out for broad-spectrum resistance against grapevine PM.