ARS | Publication request: Expression of siRNA Conferring Resistance to PVY in Transgenic Potatoes

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 13, 2010
Publication Date: N/A

Technical Abstract: Virus resistance by expression of viral coat protein (CP) is well documented. The mechanism of virus suppression by small RNAs (sRNA) has only recently been described. Next generation sequencing provides large data sets to analyze sRNAs resulting from transcript degradation and to identify regulatory micro RNA (miRNA) involved in gene regulation and small inhibitory RNA (siRNA) conferring virus resistance. Transgenic potatoes expressing a hairpin PVY-CP construct with a GBSS6 intron spacer driven by the S. bulbocastanum 409s promoter in the pBINPLUS/ARS binary vector exhibited resistance to PVY in glass house studies using PVYN, PVYNWi and PVYO as inocula. Genomic analysis indicates that most transgenic lines contained one or two copies of the transgene. Sequencing of sRNA from transgenic plants revealed high levels of siRNA production. Forty seven different siRNA attributable to the PVY-CP construct were identified in the top two hundred sRNA reads from three different transgenic lines. Nine sRNAs matched known miRNA gene families described in other species. This combination of the high-expression 409s promoter and efficient GBSS6 intron-spaced hairpin processing to produce abundant siRNA is suitable for constructing capable resistance cassettes for crop protection.