Editing of StSR4 by Cas9-RNPs confers resistance to Phytophthora infestans in potato

Ki-Beom Moon; Su-Jin Park; Ji-Sun Park; Hyo-Jun Lee; Seung Young Shin; Soo Min Lee; Gyung Ja Choi; Sang-Gyu Kim; Hye Sun Cho; Jae-Heung Jeon; Yong-Sam Kim; Youn-Il Park; Hyun-Soon Kim

doi:10.3389/fpls.2022.997888

Editing of StSR4 by Cas9-RNPs confers resistance to Phytophthora infestans in potato

Front Plant Sci. 2022 Sep 23:13:997888. doi: 10.3389/fpls.2022.997888. eCollection 2022.

Authors

Ki-Beom Moon¹, Su-Jin Park^{1

2}, Ji-Sun Park¹, Hyo-Jun Lee^{1

3}, Seung Young Shin^{1

3}, Soo Min Lee⁴, Gyung Ja Choi⁴, Sang-Gyu Kim⁵, Hye Sun Cho^{1

2}, Jae-Heung Jeon¹, Yong-Sam Kim^{6

7}, Youn-Il Park⁸, Hyun-Soon Kim^{1

2}

Affiliations

¹ Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea.
² Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology, Daejeon, South Korea.
³ Department of Functional Genomics, KRIBB School of Bioscience, University of Science and Technology, Daejeon, South Korea.
⁴ Center for Eco-Friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon, Republic of Korea.
⁵ Department of Biological Sciences, Korea Advanced Institute for Science and Technology, Daejeon, South Korea.
⁶ Genome Editing Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea.
⁷ GenKOre, Daejeon, South Korea.
⁸ Department of Biological Sciences, Chungnam National University, Daejeon, South Korea.

Abstract

Potato (Solanum tuberosum L.) cultivation is threatened by various environmental stresses, especially disease. Genome editing technologies are effective tools for generating pathogen-resistant potatoes. Here, we established an efficient RNP-mediated CRISPR/Cas9 genome editing protocol in potato to develop Phytophthora infestans resistant mutants by targeting the susceptibility gene, Signal Responsive 4 (SR4), in protoplasts. Mutations in StSR4 were efficiently introduced into the regenerated potato plants, with a maximum efficiency of 34%. High co-expression of StEDS1 and StPAD4 in stsr4 mutants induced the accumulation of salicylic acid (SA), and enhanced the expression of the pathogen resistance marker StPR1. In addition, increased SA content in the stsr4 mutant enhanced its resistance to P. infestans more than that in wild type. However, the growth of stsr4_3-19 and stsr4_3-698 mutants with significantly high SA was strongly inhibited, and a dwarf phenotype was induced. Therefore, it is important to adequate SA accumulation in order to overcome StSR4 editing-triggered growth inhibition and take full advantages of the improved pathogen resistance of stsr4 mutants. This RNP-mediated CRISPR/Cas9-based potato genome editing protocol will accelerate the development of pathogen-resistant Solanaceae crops via molecular breeding.

Keywords: RNPs; genome editing; late blight; protoplast; susceptibility gene.

Grants and funding

This research was funded by grants from the National Research Foundation (NRF-2019R1A2C1003798), New Breeding Technologies Development Program (Project No. PJ01653001) of the Rural Development Administration, and the KRIBB Research Initiative Program funded by the government of the Republic of Korea.