Abstract:Pre-harvest sprouting (PHS) is one of the most serious problems in indica rice production. Generating new germplasm with elevated PHS resistance is applicable by editing dormancy-related gene. Taifeng B (TB) is a maintainer line of indica hybrid rice showing high eating quality, whereas this line shows higher PHS. Two genes MPK7 and MPK14 negatively regulates seed dormancy in japonica rice, but whether both result in elevated PHS resistance in indica rice remains unclear. In this study, in order to generate the germplasms with PHS resistance, we deployed CRISPR/Cas9 technology to edit MPK7 and MPK14 in TB via Agrobacterium-guided transformation. Six lines harboring modified target sequences were screened from the transgenic offspring by sequencing, and two were selected for analyzing the seed dormancy. The results showed that the homozygous mutant significantly delayed the seed germination, rather than heterozygous mutants which also exhibited improved PHS resistance if compared to the wild type TB. No significant difference in plant height, number of tillers and grains per spike between the homozygous mutant and TB was observed. As a result, this study generated PHS resistant lines by CRISPR/Cas9 strategy, which provided theoretical technology and material support for the PHS resistance research and rice breeding.