*4.1. Plant Materials*

*H. villosa* (genome VV, accession no. 91C43), from the Cambridge Botanical Garden, Cambridge, UK, was used for gene cloning and expression analysis. Powdery mildew susceptible variety Sumai 3 was used for propagation of fresh spores of powdery mildew isolate *E26*. *Nicotiana benthamiana* plants were used for subcellular localization analysis. All the materials were grown in a greenhouse under a 14 h light/10 h dark cycle at 24 ◦C/18 ◦C, with 70% relative air humidity.
