*3.2. Knockout of OsCAF1 Using the CRISPR*/*Cas9 System*

The rice genome editing strategy was based on the CRISPR/Cas9 system according to a previous study [30]. Two gRNA target sequences (AAGCCCAGTACCCCATCTCACGG, CCGAGGTACCA AGCGGCGTCCAG) were designed from exon 1 to construct the intermediate vector (Figure 1B) namely SK-gRNA- g*OsCAF1-g1* and SK-gRNA- g*OsCAF1-g2*. The binary expression vector transferred into *Agrobacterium tumefaciens* strain EHA105 was constructed using the isocaudamer ligation method; the intermediate vectors were digested with *Kpn* I/*Xho* I, *Sal* I/*Bgl* II, and then assembled into the pC1300-Cas9 binary vector (digested with *Kpn* I/*BamH* I). The schematic for the development of the plant expression vector is illustrated in Figure 1A,B. The intermediate vector SK-gRNA and the expression vector pC1300-Cas9 were provided by Kejian Wang and were kept in our laboratory. All of the primers are listed in Supplementary Table S1.
