aBIOTECHJun 30, 2026

Genome editing in plants without using foreign genes

CRISPR Gene Editing Weekly Brief ↗PubMed ↗DOI ↗

Updated Jul 1, 2026

Abstract

Transgene-free genome editing may enable precise and stable genomic modifications without the integration of foreign DNA.

Conventional genome editing can lead to unintended gene fragments and off-target effects.
Transgene-free methods utilize DNA-free or transient delivery of CRISPR components to minimize foreign DNA integration.
Ribonucleoprotein complexes (RNPs) or mRNA can be delivered directly into host organisms.
Techniques such as cytosine and adenine base editors allow for precise substitution of single nucleotides.
Prime editing methods use templates for reverse transcriptases to achieve targeted modifications.
These advancements contribute to the development of nongenetically modified crops.

Simplified

Genome-editing tools for the precise, efficient modification of DNA have led to groundbreaking advances in crop improvement and basic plant science research. However, conventional genome editing may result in the integration of unintended gene fragments into the host genome, along with off-target effects and the risk of genetic drift of resistance genes. By contrast, transgene-free genome editing represents a revolutionary breakthrough due to its ability to 1) achieve precise and stable genomic modifications while minimizing foreign DNA integration through DNA-free or transient delivery of CRISPR components; and 2) deliver ribonucleoprotein complexes (RNPs) or mRNA into the host. In this review, we discuss the core principles of transgene-free genome-editing technologies, including the direct delivery of RNPs, mRNA delivery systems, the precise substitution of single nucleotides using cytosine or adenine base editors (CBEs, ABEs), and the mechanisms behind multiple types of prime editing that use templates for reverse transcriptases. These techniques have driven the development of crops considered nongenetically modified, as they do not contain stably integrated foreign DNA. Finally, we discuss future prospects, including the development of transgene-free genome-editing tools that combine delivery systems with artificial intelligence-assisted optimization, with promising applications for agriculture.