Biotech Updates

Genome Editing of Citrus Susceptibility Gene CsLOB1 Confers Resistance to Citrus Canker

January 11, 2017

Citrus production has many biotic challenges, such as bacterial canker and Huanglongbing (HLB), and using resistant varieties is the most effective way of controlling these diseases. However, traditional breeding of citrus is challenging due to polyploidy and long crossing cycles.

Targeted genome editing technology can potentially shorten the development of resistant citrus varieties. Using CRISPR/Cas9 technology, scientists from the University of Florida edited the canker susceptibility gene, CsLOB1, in Duncan grapefruit. Six independent lines, DLOB2, DLOB3, DLOB9, DLOB10, DLOB11 and DLOB12, were generated.

When inoculated with the canker pathogen Xanthomonas citri subsp. citri (Xcc), DLOB2 and DLOB3 showed symptoms similar to wild-type grapefruit. No canker symptoms were observed on DLOB9, DLOB10, DLOB11 and DLOB12 at 4 days after inoculation.

Pustules caused by Xcc were also observed on DLOB9, DLOB10, DLOB11 and DLOB12 in later stages, but were significantly less compared to pustules in wildtypes. Furthermore, the pustules on DLOB9 and DLOB10 did not develop into typical canker symptoms.

No side effects or off-target mutations were detected in the mutated plants.

For more information, read the full article in Plant Biotechnology Journal.