AUTHOR=Lopos Louie Cris , Bykova Natalia V. , Robinson Janeen , Brown Susan , Ward Kerry , Bilichak Andriy 

TITLE=Diversity of transgene integration and gene-editing events in wheat (Triticum aestivum L.) transgenic plants generated using Agrobacterium-mediated transformation

JOURNAL=Frontiers in Genome Editing

VOLUME=5

YEAR=2023

URL=https://www.frontiersin.org/journals/genome-editing/articles/10.3389/fgeed.2023.1265103

DOI=10.3389/fgeed.2023.1265103

ISSN=2673-3439

ABSTRACT=<p>Improvement in agronomic traits in crops through gene editing (GE) relies on efficient transformation protocols for delivering the CRISPR/Cas9-coded transgenes. Recently, a few embryogenesis-related genes have been described, the co-delivery of which significantly increases the transformation efficiency with reduced genotype-dependency. Here, we characterized the transgenic and GE events in wheat (cv. Fielder) when transformed with <italic>GROWTH-REGULATING FACTOR 4</italic> (<italic>GRF4</italic>) and its cofactor <italic>GRF-INTERACTING FACTOR 1</italic> (<italic>GIF1</italic>) chimeric gene. Transformation efficiency in our experiments ranged from 22% to 68%, and the editing events were faithfully propagated into the following generation. Both low- and high-copy-number integration events were recovered in the T<sub>0</sub> population with various levels of integrity of the left and right T-DNA borders. We also generated a population of wheat plants with 10 different gRNAs targeting 30 loci in the genome. A comparison of the epigenetic profiles at the target sites and editing efficiency revealed a significant positive correlation between chromatin accessibility and mutagenesis rate. Overall, the preliminary screening of transgene quality and GE events in the T<sub>0</sub> population of plants regenerated through the co-delivery of <italic>GRF–GIF</italic> can allow for the propagation of the best candidates for further phenotypic analysis.</p>