title: DNA-Free Genetically Edited Grapevine and Apple Protoplast Using CRISPR/Cas9 Ribonucleoproteins.
abstract: The combined availability of whole genome sequences and genome editing tools is set to revolutionize the field of fruit biotechnology by enabling the introduction of targeted genetic changes with unprecedented control and accuracy, both to explore emergent phenotypes and to introduce new functionalities. Although plasmid-mediated delivery of genome editing components to plant cells is very efficient, it also presents some drawbacks, such as possible random integration of plasmid sequences in the host genome. Additionally, it may well be intercepted by current process-based GMO regulations, complicating the path to commercialization of improved varieties. Here, we explore direct delivery of purified CRISPR/Cas9 ribonucleoproteins (RNPs) to the protoplast of grape cultivarChardonnayand apple cultivar such asGolden deliciousfruit crop plants for efficient targeted mutagenesis. We targetedMLO-7, a susceptible gene in order to increase resistance to powdery mildew in grape cultivar andDIPM-1, DIPM-2, andDIPM-4in the apple to increase resistance to fire blight disease. Furthermore, efficient protoplast transformation, the molar ratio of Cas9 and sgRNAs were optimized for each grape and apple cultivar. The targeted mutagenesis insertion and deletion rate was analyzed using targeted deep sequencing. Our results demonstrate that direct delivery of CRISPR/Cas9 RNPs to the protoplast system enables targeted gene editing and paves the way to the generation of DNA-free genome edited grapevine and apple plants.
authors.affiliation: Research and Innovation Centre, Genomics and Biology of Fruit Crop Department, Fondazione Edmund Mach Trento, Italy.
authors.forename: Mickael
authors.initials: M
authors.lastname: Malnoy
authors.affiliation: Research and Innovation Centre, Genomics and Biology of Fruit Crop Department, Fondazione Edmund Mach Trento, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Viola
authors.affiliation: ToolGen Inc. Seoul, Republic of Korea.
authors.forename: Min-Hee
authors.initials: MH
authors.lastname: Jung
authors.affiliation: ToolGen Inc. Seoul, Republic of Korea.
authors.forename: Ok-Jae
authors.initials: OJ
authors.lastname: Koo
authors.affiliation: ToolGen Inc. Seoul, Republic of Korea.
authors.forename: Seokjoong
authors.initials: S
authors.lastname: Kim
authors.affiliation: Center for Genome Engineering, Institute for Basic ScienceSeoul, Republic of Korea; Department of Chemistry, Seoul National UniversitySeoul, Republic of Korea.
authors.forename: Jin-Soo
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Research and Innovation Centre, Genomics and Biology of Fruit Crop Department, Fondazione Edmund Mach Trento, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Velasco
authors.affiliation: Research and Innovation Centre, Genomics and Biology of Fruit Crop Department, Fondazione Edmund Mach Trento, Italy.
authors.forename: Chidananda
authors.initials: C
authors.lastname: Nagamangala Kanchiswamy
keywords: CRISPR/Cas9; DNA-free; apple; genome editing; grapevine; non-GMO