CRISPR/Cas9-based Gene Knockout in Watermelon

Genome editing offers a great advantage to reveal gene function and generate agronomically important mutations to crops. Recently, RNA-guided genome editing system using the CRISPR-Cas9 system has been successfully applied to several plant species.

Researchers, led by Shouwei Tian of the Beijing Key Laboratory of Vegetable Germplasm Improvement, now report their use of the CRISPR-Cas9 system in genome editing of watermelon (Citrullus lanatus), an important fruit crop. ClPDS, the phytoene desaturase gene in watermelon, was selected as the target gene since its mutant bears the evident albino phenotype. CRISPR/Cas9 system was performed in watermelon protoplast cells.

All transgenic watermelon plants harbored ClPDS mutations and showed clear or mosaic albino phenotype, indicating that CRISPR/Cas9 system has technically 100% of genome editing efficiency in transgenic watermelon lines. Furthermore, there were very likely no off-target mutations, indicated by examining regions highly homologous to the sgRNA sequences.

These results show that CRISPR/Cas9 system can also effectively create knockout mutations in watermelon.

For more on this study, read the article in Plant Cell Reports.