Fig. 1 Illustration of CRISPR/Cas9-bdfls2 gene editing vector in B. distachyon OsU3：sgRNA-Cas9-pHUE411 vector. Light blue indicates the Oryzae U3 promoter. Yellow and green portions indicate the sgRNA sequence. The yellow portion indicates the target sequence of the gene. The grey portion indicates the Oryzae U3 terminator

Fig. 2 Identification of gene editing vector and edited target gene A：Identification of CRISPR/Cas9-bdfls2 gene editing vector. 1-4 are the assayed Agrobacterium tumefaciens strains for transformed CRISPR/Cas9-bdfls2. B：Amplification and identification of target gene. 1-5 are genome-DNA-amplified fragments containing target gene editing sites extracted from transgenic plants. M is the DNA marker. Bd21 is the wild type（WT）. - indicates the negative control

Fig. 3 Genotyping of bdfls2 mutants in B. distachyon A：Genotyping of bdfls2 mutants. Red underline refers to sgRNA：Cas9-edited bdfls2 mutation. Blue underline refer to schematic illustration of the sgRNA：Cas9 targets and the corresponding protospacer-adjacent motif（PAM）（blue）of the targeted genes. The 1# and 2# stands for different mutant plants,A1 and A2 for Allele 1 and Allele 2,and the red lines in sequences stands for base deletion. B：Sequencing of bdfls2 mutants. WT is the Bd21 wild type as control

Fig. 4 ROS burst of wild-type B. distachyon and bdfls2 mutants under flg22 treatment

Fig. 5 Detection of defense gene expression induced upon different PAMPs treatment by real-time quantitative RT-PCR The relative BdChit8 and PR2 expression in the leaves of B. distachyon seedlings treated with 5 μmol/L flg22（A）or 100 μg/mL chitin（B）were determined by quantitative real-time PCR. Data are presented as the mean ± standard error of three biological replicates.* or ** above the bars indicate P < 0.05 or P < 0.01