“…However, single amino acid exchanges in CesA3 have been detected, conferring resistance to CAA fungicides in different plant pathogens of the Peronosporales such as P. infestans (Blum et al 2010a), Phytophthora capsici, Phytophthora melonis (Chen et al 2011), Plasmopara viticola (Blum et al 2010b), and Pseudoperonospora cubensis . In most cases, resistance was based on a single point mutation in the CesA3 gene, leading to a change at amino acid position 1105 from a conserved glycine to either alanine, serine, valine or tryptophan (G1105A, G1105S, G1105V, G1105W) (Blum et al 2010a;Blum et al 2010b;Blum et al 2011;Sierotzki et al 2011). In artificially generated mutants of P. infestans, P. capsici and P. melonis, a change from valine to leucine or methionine at position 1109 (V1109L, V1109M) also confers resistance to CAAs (Chen et al 2011, Syngenta internal data).…”