Generation of Herbicide-Resistant Soybean by Base Editing

Area of Science:

• Agricultural Science
• Biotechnology
• Genetics

Background:

• Weed infestation is a primary cause of yield reduction in soybean cultivation.
• Developing herbicide resistance in soybean is crucial for efficient weed control and enhancing crop yields.

Purpose of the Study:

• To engineer herbicide-resistant soybean using cytosine base editor (BE3).
• To assess the herbicide resistance and agronomic performance of the developed soybean mutants.

Main Methods:

• Utilized CRISPR/Cas9-mediated base editing (BE3) to introduce base substitutions in soybean genes *GmAHAS3* and *GmAHAS4*.
• Generated a heritable, transgene-free soybean line with a homozygous P180S mutation in the *GmAHAS4* gene.
• Developed allele-specific PCR markers for distinguishing mutant genotypes.

Main Results:

• Successfully created soybean mutants with a homozygous P180S mutation in *GmAHAS4*.
• GmAHAS4 P180S mutants demonstrated significant resistance to chlorsulfuron, flucarbazone-sodium, and flumetsulam.
• Chlorsulfuron resistance in mutants was over 100-fold greater than in wild-type TL-1.
• Agronomic performance of the GmAHAS4 P180S mutants was comparable to wild-type TL-1 under natural conditions.

Conclusions:

• CRISPR/Cas9-mediated base editing provides an effective method for generating herbicide-resistant soybean.
• The developed GmAHAS4 P180S mutation confers substantial herbicide resistance without adverse effects on essential agronomic traits.
• Allele-specific markers facilitate efficient identification and selection of herbicide-resistant soybean lines.