**4. Materials and Methods**

#### *4.1. Plant and Microbial Materials and Inoculation*

Rice (*Oryza sativa* L. cv. Nipponbare) was used as the wild-type (WT) plant material. The *BSR1*-knockout lines *bsr1-1*#13-1 (KO#1), *bsr1-2*#16-2 (KO#2), and *bsr1-8*#5-1 (KO#8) generated with the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9) system in our previous study [39,46] were used. Rice calli were prepared from dehusked seeds and cultivated on N6D medium containing 0.4% gellan gum [47]. The *Pyricularia oryzae* isolate Kyu89-246 (MAFF101506, race 003.0), which is compatible with Nipponbare rice plants, was used to prepare the elicitor and for inoculations. *Xanthomonas oryzae* pv. *oryzae* (isolate T7174) was used to prepare the

elicitor fraction. The culturing methods and *P. oryzae* and *X. oryzae* pv. *oryzae* inoculation techniques were as previously described [38].
