【摘要】 在水稻种植生产上，因其种子经常发芽率不齐，导致水稻直播困难，不仅影响水稻的生产成本还影响其产量，因此水稻直播的突出问题要保持优良的种子萌发力。ABA是种子萌发的抑制因子，它通过诱导ABI5的表达来抑制种子萌发，在种子正常萌发的过程中，随着种子吸胀和GA生物合成，ABA和ABI5的含量都迅速下降，促使种子萌发。本研究利用CRISPR/Cas9技术构建OsABI5突变体，以期提高种子的萌发率和萌发速度。通过农杆菌介导法将构建好的OsABI5敲除质粒转化‘日本晴’水稻的愈伤组织，经PCR和Western Blot鉴定筛选得到两株OsABI5弱表达的阳性突变株系。通过对osabi5-2突变体和‘日本晴’萌发表型的观察，发现osabi5-2突变体2 d发芽率显著高于‘日本晴’，二者4 d的萌发势也是osabi5-2突变体略高。本研究利用CRISPR/Cas9技术构建了OsABI5突变体，对研究水稻OsABI5调控种子萌发的分子机制具有重要意义。更多还原

【Abstract】 In agricultural production, proble ms such as uneven germination rate of rice seeds and difficulty in direct seeding seriously affect the yield and production cost of rice. Maintaining good seed germination ability has become a prominent problem in rice production. ABA is an inhibitor of seed germination. It inhibits seed germination by inducing ABI5 expression. In the process of normal seed germination, the contents of ABA and ABI5 decrease rapidly with seed imbibition and GA biosynthesis, which promotes seed germination. In this study,OsABI5 mutant was constructed using CRISPR/Cas9 technology to improve seed germination rate and germination speed. The constructed OsABI5 knockout plasmid was transformated into callus of ’Nipponbare’ by Agrobacterium tumefaciens mediated transformation. Two positive mutant lines with weak expression of OsABI5 were identified by PCR and Western Blot. The results showed that the germination rate of osabi5-2 mutant in 2 days was significantly higher than that of ’Nipponbare’, and the germination potential of osabi5-2 mutant in 4 days was slightly higher. In this study, we used CRISPR/cas9 technology to construct OsABI5 mutant, which is of great significance to study the molecular mechanism of OsABI5 regulating rice seed germination.更多还原