CRISPR/Cas9-mediated genome editing in rice cv. IPB3S results in a semi-dwarf phenotypic mutant

IPB3S is Indonesian lowland rice and high-yielding cultivar. However, plant height posture makes it prone to lodging which could reduce the yield. This study aimed to edit the GA20Ox2 gene by introducing CRISPR/Cas9 GA20Ox2 construct into IPB3S and developing the semidwarf rice mutants. Immature embryo explants of IPB3S were used for the transformation process mediated by EHA105 strain of Agrobacterium tumefaciens carrying pC1300-Cas9/GA20Ox2 and by changing the regeneration medium composition. PCR analysis showed that rice cv. IPB3S genetic transformation gained putative mutant T0 lines carrying the hpt gene (growth efficiency was 47.9%, while transformation efficiency was 19.3%). Using the developed regeneration medium, we have obtained 24 putative rice cv. IPB3S T0 mutant lines carrying hpt. The best medium for regenerating IPB3S was the A medium (regeneration efficiency 73.3%). IPB 8 and IPB 14 were potential to evaluate in the next generation. The shortest plant height for the T1 generation was observed in the IPB 8-3 mutant.