Enhanced Bacterial Wilt Resistance in Potato Through Expression of EFR and Introgression of Quantitative Resistance from .

Bacterial wilt (BW) caused by is responsible for substantial losses in cultivated potato () crops worldwide. Resistance genes have been identified in wild species; however, introduction of these through classical breeding has achieved only partial resistance, which has been linked to poor agronomic performance. The (At) pattern recognition receptor elongation factor-Tu (EF-Tu) receptor (EFR) recognizes the bacterial pathogen-associated molecular pattern EF-Tu (and its derived peptide elf18) to confer anti-bacterial immunity. Previous work has shown that transfer of AtEFR into tomato confers increased resistance to . Here, we evaluated whether the transgenic expression of would similarly increase BW resistance in a commercial potato line (INIA Iporá), as well as in a breeding potato line (09509.6) in which quantitative resistance has been introgressed from the wild potato relative Resistance to was evaluated by damaged root inoculation under controlled conditions. Both INIA Iporá and 09509.6 potato lines expressing showed greater resistance to , with no detectable bacteria in tubers evaluated by multiplex-PCR and plate counting. Notably, AtEFR expression and the introgression of quantitative resistance from had a significant additive effect in 09509.6-AtEFR lines. These results show that the combination of heterologous expression of with quantitative resistance introgressed from wild relatives is a promising strategy to develop BW resistance in potato.