Breaking boundaries: PAM-less genome editing in soybean

Scientists have unveiled a revolutionary protospacer adjacent motif (PAM)-less genome editing system using CRISPR-SpRY, marking a major advancement in soybean breeding. This innovative method eliminates the traditional PAM sequence constraints, enabling precise editing at specific loci. The approach opens up new possibilities for improving soybean traits and overcoming challenges in crop genetic enhancement.

CRISPR-Cas9 has transformed crop genetic improvement, yet its reliance on specific protospacer adjacent motif (PAM), sequences limits editing scope and efficiency. In soybean, a critical source of protein and oil, these limitations hinder the development of high-quality, high-yield varieties. As conventional breeding methods struggle to keep pace with demand, there is a pressing need for advanced genome editing tools that bypass PAM-related barriers, unlocking the full potential of precise genetic enhancements in soybean.

The study (DOI: 10.1093/hr/uhae160), led by researchers at the Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, and published on June 7, 2024, in Horticulture Research, introduces a CRISPR-SpRY-based PAM-less editing system that successfully circumvents the limitations of traditional genome editing. This breakthrough allows for broader application in crop improvement, enhancing the efficiency and precision of genetic modifications in soybean breeding.

Researchers developed a novel SpRY protein-based editing system that removes the need for specific PAM sequences, targeting key agronomic genes like GmLOXs and GmFAD2-1A/B. The study demonstrated that SpRY could achieve precise mutations at previously unreachable sites in the soybean genome. Additionally, the introduction of SpRY-based base editors enabled cytosine-to-thymine and adenine-to-guanine conversions, enhancing editing accuracy. The high efficiency of SpRY across multiple loci broadens the soybean genome editing landscape, providing a robust tool for molecular breeding and functional genomics.

Dr. Xianzhong Feng, a lead researcher, noted, “The SpRY system represents a pivotal advancement in crop genome editing. By removing the restrictive need for PAM sequences, we can target previously inaccessible sites, significantly boosting precision and flexibility in breeding. This technology is poised to revolutionize soybean genetic improvement and provide new breeding resources.”

The SpRY genome editing system holds promising implications for soybean breeding and genetic research, enabling accelerated development of high-yield, superior quality varieties. Its capability for base editing expands functional genomics research, allowing precise modifications to enhance agronomic traits. Beyond soybeans, this technology can be adapted to other crops, contributing to sustainable agriculture and global food security.

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References

DOI

10.1093/hr/uhae160

Original Source URL

https://doi.org/10.1093/hr/uhae160

Funding information

This research was supported by National Natural Science Foundation of China awards 32301801 and U21A20215 to X.C. and X.F., and National Natural Science Foundation of China awards 32270433, 32072045, and 31960423 to Yong Zhang and X.Z.

About Horticulture Research

Horticulture Research is an open access journal of Nanjing Agricultural University and ranked number two in the Horticulture category of the Journal Citation Reports ™ from Clarivate, 2023. The journal is committed to publishing original research articles, reviews, perspectives, comments, correspondence articles and letters to the editor related to all major horticultural plants and disciplines, including biotechnology, breeding, cellular and molecular biology, evolution, genetics, inter-species interactions, physiology, and the origination and domestication of crops.