The Plant journal : for cell and molecular biologyNov 27, 2025

Multiple mutations in repeated AHAS genes increase soybean resistance to sulfonylurea herbicides

CRISPR Gene Editing Weekly Brief ↗PubMed ↗DOI ↗OA ↗

Updated Jan 3, 2026

Abstract

Six genome-edited soybean lines with distinct mutations in GmAHAS genes were evaluated for herbicide resistance.

Herbicide-resistant germlines are essential for effective weed management.
Sulfonylurea- and pyrimidinyl benzoate-based herbicides target a key enzyme involved in amino acid synthesis in plants.
Base editing was used to modify specific codons in three variants of the gene.
The mutation patterns and the number of modified genes were found to significantly affect resistance to herbicides.
Predictions of off-target editing in other AHAS genes were supported by the selection of edited lines.

Simplified

Weeds are a major factor that negatively impact crop yields. Developing herbicide-resistant germlines is crucial for efficient weed control. Sulfonylurea- and pyrimidinyl benzoate-based herbicides inhibit the function of (AHAS), a key enzyme in the biosynthesis of branched-chain amino acids in plants. To create soybean plants resistant to these classes of herbicides, we performed base editing of AHAS genes in Glycine max. A guide RNA was designed to target the codon for proline-182 in GmAHAS2, with the prediction that off-target base editing might also occur in the GmAHAS3 and GmAHAS4 genes. We selected six genome-edited soybean lines, each carrying distinct mutations in GmAHAS2, GmAHAS3, or GmAHAS4. These lines were treated with three different AHAS-targeting herbicides to evaluate resistance. The results show that the number of mutated GmAHAS genes and the mutation patterns significantly influence herbicide resistance.