Genomic DNA Extraction and Mutagenesis Detection

Genomic DNA was extracted from Arabidopsis leaves using the CTAB method following the published protocol^{48 (link)}. To detect mutagenesis at the desired sites, the target regions were amplified with specific primers (see supplementary information for primer sequences) using Premix Taq DNA Polymerase (Takara, Japan) with the following protocol: 94 °C for 10 min (94 °C for 30 s, 60–48 °C for 30 s, 72 °C for 2 min) for 13 cycles with touchdown −1 °C in each cycle (94 °C for 30 s, 52 °C for 30 s, 72 °C for 2 min) for 25 cycles, 72 °C for 10 min, 4 °C to hold. The PCR product was separated in a 1% agarose gel and stained with GelStain (TransGen Biotech, China) to detect chromosomal fragment deletions. Selected PCR products were cloned into the pGEM-T Easy Vector (Promega, USA) for Sanger DNA sequencing.