Highly Efficient Targeted Gene Editing in Upland Cotton Using the CRISPR/Cas9 System.

Area of Science:

• Plant Biotechnology
• Genetics
• Molecular Biology

Background:

• The CRISPR/Cas9 system is a powerful tool for gene editing in plants, including cotton.
• Investigating gene function and improving crops are key applications of CRISPR/Cas9 technology.

Purpose of the Study:

• To develop and demonstrate a simple, efficient CRISPR/Cas9 system for targeted gene mutagenesis in cotton.
• To investigate the editing efficiency of CRISPR/Cas9 on the GhALARP gene in cotton.

Main Methods:

• Development of a user-friendly CRISPR/Cas9 system for cotton.
• Targeting the alanine-rich protein (ALARP) gene, crucial for cotton fiber development.
• Sequence analysis of target sites in transgenic cotton plants to determine mutation frequencies and types.

Main Results:

• High mutation frequencies were observed at the GhALARP-A (71.4–100%) and GhALARP-D (92.9–100%) target sites.
• Deletions were the predominant editing event, with some instances of combined deletion and insertion.
• Mosaic mutations were detected in most transgenic plants, with no off-target mutations found in analyzed sites.

Conclusions:

• The developed CRISPR/Cas9 system demonstrates high efficiency for targeted mutagenesis in cotton.
• This study provides valuable gene-edited cotton mutants for studying GhALARP function in fiber development.
• The findings confirm the feasibility and efficiency of CRISPR/Cas9 for functional genomics and crop improvement in cotton.