利用CRISPR/Cas9 技术编辑 Badh2基因改良水稻优质恢复系 QR79 的香味OA

In this research,the elite restorer line QR79 was used as the recipient for CRISPR/Cas9-mediated editing of the badh2 gene,with two targeting sites designed within exon 1 and exon 2.The primary aim was to obtain homozygous mutant lines characterized by a distinct aroma profile,complete absence of transgenic elements,and stable inheritance of main agronomic traits.The expression level of the Badh2 gene,the concentration of 2-acetyl-1-pyrroline(2AP),the content of γ-aminobutyric acid(GABA),as well as the key agronomic traits of both the wild-type and mutant genotypes were systematically quantified and comprehensively analyzed.The results showed that,compared with the wild type,the expression levels of the Badh2 gene in the homozygous mutant plants QR79-badh2-1 and QR79-badh2-2 were significantly reduced,the content of 2AP were significantly increased,while the content of GABA were significantly decreased.At the same time,the main agronomic traits such as grain length,1000-grain weight,head rice rate,and the seed-setting rate remained stable,but the yield components were affected to a certain extent.In conclusion,the genetic improvement of the aroma characteristics of the high-quality rice restorer line QR79 was successfully achieved through the CRISPR/Cas9 gene editing technology,which significantly increased the content of the aroma component 2AP,provided theoretical support and genetic resources for accelerating the research and development of new fragrant indica rice varieties.