Precise base editing of non-allelic acetolactate synthase genes confers sulfonylurea herbicide resistance in maize  

作　　者：Yanmin Li Jinjie Zhu Hao Wu Changlin Liu Changling Huang Jinhao Lan Yanming Zhao Chuanxiao Xie 

机构地区：[1]Institute of Crop Sciences,Chinese Academy of Agricultural Sciences,National Key Facility for Crop Gene Resources and Genetic Improvement,Beijing 100081,China [2]Qingdao Agricultural University,Qingdao 266109,Shandong,China [3]Anhui Agricultural University,Hefei 230036,Anhui,China

出　　处：《The Crop Journal》2020年第3期449-456,共8页作物学报（英文版）

基　　金：supported by the Key Area Research and Development Program of Guangdong Province(2018B020202008);the National Natural Science Foundation of China(31771808);Beijing Municipal Science and Technology Project(D171100007717001);the National Key Research and Development Program of China(2016YFD0101803);National Engineering Laboratory for Crop Molecular Breeding。

摘　　要：Single-nucleotide polymorphisms contribute to phenotypic diversity in maize. Creation and functional annotation of point mutations has been limited by the low efficiency of conventional methods based on random mutation. An efficient tool for generating targeted single-base mutations is desirable for both functional genomics and precise genetic improvement. The objective of this study was to test the efficiency of targeted C-to-T base editing of two non-allelic acetolactate synthase(ALS) in generating sulfonylurea herbicide-resistant mutants. A CRISPR/Cas9 nickase-cytidine deaminase fused with uracil DNA glycosylase inhibitor(UGI) was employed to achieve targeted conversion of cytosine to thymine in ZmALS1 and ZmALS2. Both protoplasts and recovered mutant plants showed the activity of the cytosine base editor, with an in vivo efficiency of up to 13.8%. Transgene-free edited plants harboring a homozygous ZmALS1 mutation or a ZmALS1 and ZmALS2 double mutation were tested for their resistance at a dose of up to 15-fold the recommended limit of chlorsulfuron, a sulfonylurea herbicide widely used in agriculture. Targeted base editing of C-to-T per se and a phenotype verified in the generated mutants demonstrates the power of base editing in precise maize breeding.

关 键 词：Precise base editing of non-allelic acetolactate synthase genes confers sulfonylurea herbicide resistance in maize 

分 类 号：S513[农业科学—作物学] Q943.2[生物学—植物学]