利用 CRISPR/Cas9 技术编辑GS3、GS9 和GW2 基因改良水稻粒型OA

The CRISPR/Cas9 gene-editing technique was used to simultaneously modify the grain shape-related genes GS3,GS9,and GW2 in the rice cultivar Xigong 6.The aim was to improve the rice grain shape through a multi-gene editing strategy.Knockout target sites were designed within the first exons of each gene,and CRISPR/Cas9 expression vectors were constructed to produce T0 generation transgenic plants via Agrobacterium-mediated genetic transformation.The results showed that various types of gene-editing mutations,including biallelic homozygous and double heterozygous mutations,were observed in the T0 generation.T1 generation plants were obtained through self-pollination,and mutant materials lacking exogenous transgenic components,while mutations in the GS3,GS9,and GW2 consistent with those in the T0 generation were screened.Agronomic trait analysis of T1 generation mutants revealed significant improvements in grain morphology:mutants 1188-42-1 showed a maximum grain length increase of 21.62%,1188-4-12 exhibited a 13.16%increase in grain width,and 1188-4-13 displayed a 26.65%enhancement in length-width ratio.Concurrently,1000-grain weight,grain weight per plant,yield per plant,brown rice rate,rice milling rate,head rice rate,and chalkiness degree were all significantly increased.However,a minor reduction in seed-setting rate 4.12%-13.40%was observed across all mutants.Notable variations in chalky rate were recorded:line 1188-18-8 showed a 175.00%increase,while 1188-42-2 demonstrated a 50.50%decrease.