Scientists at Cold Spring Harbor Laboratory (CSHL) have tapped genome editing to improve agricultural crops. Using tomato as an example, they used CRISPR-Cas9 technology to rapidly generate variants of the plant that display a broad continuum of three separate, agriculturally important traits: fruit size, branching architecture, and overall plant shape -- components that determine plant yield. The method is designed to work in all food, feed, and fuel crops, including the staples rice, maize, sorghum, and wheat.

The team used CRISPR "scissors" to make multiple cuts within three tomato genome sequences known as promoters — areas of DNA near associated genes which help regulate when, where, and at what level these "yield" genes are active during growth. The scientists were able to induce a wide range of changes in each of the three targeted traits.

By using CRISPR to mutate regulatory sequences, the CSHL team found that a much subtler impact on quantitative traits is possible. Fine-tuning gene expression rather than deleting or inactivating the proteins they encode is most likely to benefit commercial agriculture because of the flexibility such genetic variation provides for improving yield traits.

CSHL Professor Zachary Lippman, who led the research says, "Traditional breeding involves great time and effort to adapt beneficial variants of relevant genes to the best varieties, which must continuously be improved every year. Our approach can help bypass this constraint by directly generating and selecting for the most desirable variants controlling gene activity in the context of other natural mutations that benefit breeding. We can now work with the native DNA and enhance what nature has provided, which we believe can help break yield barriers."

For more details, read the CSHL News and Features.