March 5 (UPI) -- Scientists have developed a new genome engineering strategy for boosting the levels of beta carotene, the precursor of vitamin A, in rice.
The novel CRISPR technology method, described this week in the journal Nature Communications, could help plant scientists engineer healthier, more robust crops.
Typically, genetic engineers use a special bacterium to transfer beta carotene-producing genes into the rice genome, but the technique is imprecise. Transgenes can end up in unwanted locations in the genome, compromising the plant's health and reducing yields.
Scientists at the University of California Davis came up with a better way.
"We used CRISPR to precisely target those genes onto genomic safe harbors, or chromosomal regions that we know won't cause any adverse effects on the host organism," lead study author Oliver Dong, a postdoctoral scholar and expert in plant pathology at UC Davis, said in news release.
The scientists chose rice because it's an important staple food for much of the world, and particularly popular in countries like the Philippines where many children are deficient in vitamin A.
Additionally, traditional engineering techniques require marker genes, which remain in the genome as plants are bred over generations. Using the new method, scientists were able to transfer a large DNA fragment and precisely splice it into the rice genome without the use of marker genes.
"Scientists have done targeted insertions before and without marker genes, but we haven't been able to do it with such big fragments of DNA," Dong said. "The larger the fragment of DNA, the more biological function or complex traits we can provide the plants."
By precisely transferring such a large DNA fragment, the technique paves the way for the engineering of multiple beneficial traits. With one splice, scientists could potentially engineer better nutritional values, increased resiliency and higher yields -- simplifying the breeding process and producing healthier, higher quality crops.