Creating a novel herbicide-tolerance OsALS allele using CRISPR/Cas9-mediated gene editing

• Main Authors: Fangquan Wang, Yang Xu, Wenqi Li, Zhihui Chen, Jun Wang, Fangjun Fan, Yajun Tao, Yanjie Jiang, Qian-Hao Zhu, Jie Yang
• Format: Article
• Language: English
• Published: KeAi Communications Co., Ltd. 2021-04-01
• Series: Crop Journal
• Subjects: Rice; CRISPR/Cas9; ALS; Herbicide-tolerance; Crop breeding
• Online Access: http://www.sciencedirect.com/science/article/pii/S2214514120300878

Weeds and weedy rice plague commercial rice fields in many countries. Developing herbicide-tolerance rice is the most efficient strategy to control weed proliferation. CRISPR/Cas9-mediated gene editing, which generates small InDels and nucleotide substitutions at and around target sites using error-prone non-homologous end joining DNA repairing, has been widely adopted for generation of novel crop germplasm with a wide range of genetic variation in important agronomic traits. We created a novel herbicide-tolerance allele in rice by targeting the acetolactate synthase (OsALS) gene using CRISPR/Cas9-mediated gene editing. The novel allele (G628W) arose from a G-to-T transversion at position 1882 of OsALS and conferred a high level of herbicide tolerance. Transgene-free progeny carrying homozygous G628W allele were identified and showed agronomic performance similar to that of wild-type plants, suggesting that the G628W allele is a valuable resource for developing elite rice varieties with strong herbicide tolerance. To promote use of the G628W allele and to accelerate introgression and/or pyramiding of the G628W allele with other elite alleles, we developed a DNA marker for the G628W allele that accurately and robustly distinguished homozygous from heterozygous segregants. Our result further demonstrates the feasibility of CRISPR/Cas9-mediated gene editing in creating novel genetic variation for crop breeding.