title: Effector-driven marker development and cloning of resistance genes against Phytophthora infestans in potato breeding clone SW93-1015.
abstract: We show the usefulness of integrating effector screening in a breeding program and in resistance gene cloning, with Phytophthora resistance in the Swedish potato breeding clone SW93-1015 as an example. Phytophthora infestans is one of the most devastating plant pathogens worldwide. We have earlier found that the SW93-1015 potato breeding clone has an efficient resistance against P. infestans under field conditions in Sweden, which has an unusually high local diversity of the pathogen. This potato clone has characteristics that are different from classical R-gene-mediated resistance such as elevated levels of hydrogen peroxide (H2O2) under controlled conditions. Analysis of 76 F1 potato progenies from two individual crosses resulted in nearly 50% resistant clones, from both crosses. This result suggests that the SW93-1015 clone has a simplex genotype for this trait. Screening with over 50 different P. infestans effectors, containing the conserved motif RXLR (for Arg, any amino acid, Leu, Arg), revealed a specific response to Avr2, which suggests that SW93-1015 might contain a functional homolog of the R2 resistance gene. We cloned eight R2 gene homologs from SW93-1015, whereof seven have not been described before and one gene encoded a protein identical to Rpi-ABPT. Expression of this gene in potato cultivar Désirée provided R2-specific resistance, whereas other homologues did not. Using RNAseq analyses we designed a new DNA marker for the R2 resistance in SW93-1015. In summary, we have demonstrated the use of effector screening in practical breeding material and revealed the key resistance mechanism for SW93-1015.
authors.affiliation: Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden. marit.lenman@slu.se.
authors.forename: Marit
authors.identifier: http://orcid.org/0000-0002-6612-7085
authors.initials: M
authors.lastname: Lenman
authors.affiliation: Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden.
authors.forename: Ashfaq
authors.initials: A
authors.lastname: Ali
authors.affiliation: Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Mühlenbock
authors.affiliation: Department of Plant Breeding, Swedish University of Agricultural Sciences, Alnarp, Sweden.
authors.forename: Ulrika
authors.initials: U
authors.lastname: Carlson-Nilsson
authors.affiliation: Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden.
authors.forename: Erland
authors.initials: E
authors.lastname: Liljeroth
authors.affiliation: Wageningen UR Plant Breeding, Wageningen University and Research Centre, Wageningen, The Netherlands.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Champouret
authors.affiliation: Wageningen UR Plant Breeding, Wageningen University and Research Centre, Wageningen, The Netherlands.
authors.forename: Vivianne G A A
authors.initials: VG
authors.lastname: Vleeshouwers
authors.affiliation: Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden.
authors.forename: Erik
authors.initials: E
authors.lastname: Andreasson
mesh_terms: D000595:Amino Acid Sequence; D001947:Breeding; D003001:Cloning, Molecular; D060467:Disease Resistance / Q000235:genetics*; D017343:Genes, Plant; D005819:Genetic Markers; D005838:Genotype; D008969:Molecular Sequence Data; D055750:Phytophthora infestans; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D030821:Plants, Genetically Modified / Q000235:genetics / Q000382:microbiology; D011198:Solanum tuberosum / Q000235:genetics* / Q000382:microbiology
chemical_list: D005819:Genetic Markers