利用CRISPR/CAS9技术编辑水稻香味基因Badh2

【目的】香稻作为一类特殊的水稻群体,以其清香可口的品质特性备受消费者的欢迎。到目前为止,水稻中的香味主要受第8染色体上编码甜菜碱醛脱氢酶基因Badh2控制。【方法】通过CRISPR/CAS9技术对中花11的香味基因Badh2进行编辑。【结果】获得转基因T_0代植株并对其所衍生的T_1代20个单株进行了鉴定分析,获得了一个剔除了载体骨架且第1外显子上插入一个碱基T的突变体材料。该材料中Badh2 RNA水平显著下调;利用GC-MS技术测定野生型及突变体材料籽粒2-乙酰-1-吡咯啉含量,结果表明突变体材料中的香味物质显著增加;此外,我们还对野生型及T_2代香型植株水稻产量及稻米蒸煮食味品质进行了考查及测定分析,发现除分蘖数及结实率呈现出显著差异外(P0.05),其余各项指标在两组材料间都无显著差异。【结论】通过CRISPR/CAS9技术成功地对水稻香味基因进行了编辑,可为香稻育种提供丰富的理论指导,加快香稻的育种进程。

CRISPR/CAS9-mediated Editing of the Fragrant Gene Badh2 in Rice

【Objective】Fragrant rice, which is favored because of its quality characteristics of faint scent and tastiness, is a special rice type. Fragrance in rice is mainly controlled by the gene encoding betaine aldehyde dehydrogenase on chromosome 8.【Method】The fragrant gene Badh2 in Zhonghua 11 was edited by CRISPR/CAS9.【Result】Twenty T1 individuals derived from T0 generation were genotyped. One plant, which contains an additional T base in the first exon of Badh2 without the vector skeleton, was finally produced. qRT-PCR result suggested that Badh2 RNA level was decreased in the mutant. Compared with the wild type, the mutant increased 2-acetyl-1-pyrroline content by the GC-MS method. Furthermore, two rice yield-related traits including tiller numbers and seed-setting rate showed significant difference at the 0.05 level among five traits related to yield and three traits related to cooking and eating quality.【Conclusion】We succeed editing the Badh2 by CRISPR-CAS9 technical in rice, and it would provide abundant theoretical guidance and accelerate the breeding process of fragrant rice.