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Article|28 Jan 2022|OPEN
Modification of tomato breeding traits and plant hormone signaling by Target-AID, the genome-editing system inducing efficient nucleotide substitution
Sachiko Kashojiya1,2 ,† , Yu Lu1,2 ,† , Mariko Takayama1 , Hiroki Komatsu1 , Luyen Hieu Thi Minh1 , Keiji Nishida3,4 , Kenta Shirasawa5 , Kenji Miura1 , Satoko Nonaka1 and Jun-ichiro Masuda1,6 , Akihiko Kondo3,4 , Hiroshi Ezura1,7 , , Tohru Ariizumi,1,7 ,
1Faculty of Life and Environmental Sciences, University of Tsukuba, Gene Research Center, Tsukuba, Ibaraki 305-8572, Japan
2Japan Society for Promotion of Science, 5-3-1, Kojimachi, Tokyo 102-0083, Japan
3Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, Hyogo 657-8501, Japan
4Engineering Biology Research Center, Kobe University, 7-1-49, Minatojima Minami Machi, Chuo-ku, Kobe 650-0047, Japan
5Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu, Chiba 292-0818, Japan
6Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadai-nishi, Miyazaki, Miyazaki 889-2192, Japan
7Tsukuba Plant Innovation Research Center, University of Tsukuba, Ibaraki 305-8572, Japan
*Corresponding author. E-mail: ezura.hiroshi.fa@u.tsukuba.ac.jp,ariizumi.toru.ge@u.tsukuba.ac.jp
Both authors contributed equally to the study.

Horticulture Research 9,
Article number: uhab004 (2022)
doi: https://doi.org/10.1093/hr/uhab004
Views: 169

Received: 01 Apr 2021
Revised: 19 Jan 2022
Accepted: 21 Oct 2021
Published online: 28 Jan 2022

Abstract

Target activation-induced cytidine deaminase (Target-AID), a novel CRISPR/Cas9-based genome-editing tool, confers the base-editing capability on the Cas9 genome-editing system. It involves the fusion of cytidine deaminase (CDA), which catalyzes cytidine (C) to uridine (U) substitutions, to the mutated nickase-type nCas9 or deactivated-type dCas9. To confirm and extend the applicability of the Target-AID genome-editing system in tomatoes (Solanum lycopersicum L.), we transformed the model tomato cultivar “Micro-Tom” and commercial tomato cultivars using this system by targeting SlDELLA, which encodes a negative regulator of the plant phytohormone gibberellic acid (GA) signaling pathway. We confirmed that the nucleotide substitutions were induced by the Target-AID system, and we isolated mutants showing high GA sensitivity in both “Micro-Tom” and the commercial cultivars. Moreover, by successfully applying this system to ETHYLENE RECEPTOR 1 (SlETR1) with single sgRNA targeting, double sgRNA targeting, as well as dual-targeting of both SlETR1 and SlETR2 with a single sgRNA, we demonstrated that the Target-AID genome-editing system is a promising tool for molecular breeding in tomato crops. This study highlights an important aspect of the scientific and agricultural potential of the combinatorial use of the Target-AID and other base-editing systems.