1
|
Dong S, Qin YL, Vakulskas CA, Collingwood MA, Marand M, Rigoulot S, Zhu L, Jiang Y, Gu W, Fan C, Mangum A, Chen Z, Yarnall M, Zhong H, Elumalai S, Shi L, Que Q. Efficient Targeted Mutagenesis Mediated by CRISPR-Cas12a Ribonucleoprotein Complexes in Maize. Front Genome Ed 2021; 3:670529. [PMID: 34713259 PMCID: PMC8525364 DOI: 10.3389/fgeed.2021.670529] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 04/14/2021] [Indexed: 12/26/2022] Open
Abstract
Recent advances in the development of CRISPR-Cas genome editing technologies have made it possible to perform targeted mutagenesis and precise gene replacement in crop plants. CRISPR-Cas9 and CRISPR-Cas12a are two main types of widely used genome editing systems. However, when CRISPR-Cas12a editing machinery is expressed from a transgene, some chromosomal targets encountered low editing frequency in important crops like maize and soybean. Here, we report efficient methods to directly generate genome edited lines by delivering Cas12a-gRNA ribonucleoprotein complex (RNP) to immature maize embryos through particle bombardment in an elite maize variety. Genome edited lines were obtained at ~7% frequency without any selection during regeneration via biolistic delivery of Cas12a RNP into immature embryos. Strikingly, the gene editing rate was increased to 60% on average and up to 100% in some experiments when the Cas12a RNP was co-delivered with a PMI selectable marker gene cassette and the induced callus cultures were selected with mannose. We also show that use of higher activity Cas12a mutants resulted in improved editing efficiency in more recalcitrant target sequence. The advances described here provide useful tools for genetic improvement of maize.
Collapse
Affiliation(s)
- Shujie Dong
- Syngenta Crop Protection, Research Triangle Park, Durham, NC, United States
| | - Yinping Lucy Qin
- Syngenta Crop Protection, Research Triangle Park, Durham, NC, United States
| | | | | | - Mariam Marand
- Syngenta Crop Protection, Research Triangle Park, Durham, NC, United States
| | - Stephen Rigoulot
- Syngenta Crop Protection, Research Triangle Park, Durham, NC, United States
| | - Ling Zhu
- Syngenta Crop Protection, Research Triangle Park, Durham, NC, United States
| | - Yaping Jiang
- Syngenta Crop Protection, Research Triangle Park, Durham, NC, United States
| | - Weining Gu
- Syngenta Crop Protection, Research Triangle Park, Durham, NC, United States
| | - Chunyang Fan
- Syngenta Crop Protection, Research Triangle Park, Durham, NC, United States
| | - Anna Mangum
- Syngenta Crop Protection, Research Triangle Park, Durham, NC, United States
| | - Zhongying Chen
- Syngenta Crop Protection, Research Triangle Park, Durham, NC, United States
| | - Michele Yarnall
- Syngenta Crop Protection, Research Triangle Park, Durham, NC, United States
| | - Heng Zhong
- Syngenta Crop Protection, Research Triangle Park, Durham, NC, United States
| | - Sivamani Elumalai
- Syngenta Crop Protection, Research Triangle Park, Durham, NC, United States
| | - Liang Shi
- Syngenta Crop Protection, Research Triangle Park, Durham, NC, United States
| | - Qiudeng Que
- Syngenta Crop Protection, Research Triangle Park, Durham, NC, United States
| |
Collapse
|