RT Journal Article SR Electronic T1 The Arabidopsis pattern recognition receptor EFR enhances fire blight resistance in apple JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.01.22.427734 DO 10.1101/2021.01.22.427734 A1 Piazza, Stefano A1 Campa, Manuela A1 Pompili, Valerio A1 Costa, Lorenza Dalla A1 Salvagnin, Umberta A1 Nekrasov, Vladimir A1 Zipfel, Cyril A1 Malnoy, Mickael YR 2021 UL http://biorxiv.org/content/early/2021/01/22/2021.01.22.427734.abstract AB Fire blight disease, caused by the bacterium Erwinia amylovora (E. amylovora), is responsible for substantial losses in cultivated apple worldwide. An important mechanism of plant immunity is based on the recognition of conserved microbial molecules, named pathogen- or microbe-associated molecular patterns (PAMPs or MAMPs), through pattern recognition receptors (PRRs), leading to pattern-triggered immunity (PTI). The interspecies transfer of PRRs represents a promising strategy to engineer broad spectrum and durable disease resistance in crops. EFR, the Arabidopsis thaliana PRR for the PAMP elf18 derived from the elongation factor thermal unstable (EF-Tu) proved to be effective in improving bacterial resistance when expressed into Solanaceae and other plant species,. In this study, we tested whether EFR can affect the interaction of apple with E. amylovora by its ectopic expression in the susceptible apple rootstock M.26. Stable EFR expression led to the activation of PAMP-triggered immune response in apple leaves upon treatment with supernatant of E. amylovora, as measured by production of reactive oxygen species and the induction of known defense genes. The amount of tissue necrosis associated with E. amylovora infection was significantly reduced in the EFR transgenic rootstock compared to the wild-type. Our results show that the expression of EFR in apple rootstock may be a valuable biotechnology strategy to improve the resistance of apple to fire blight.Competing Interest StatementThe authors have declared no competing interest.