CRISPR-Cas9-mediated editing of PHYTOENE DESATURASE (AcPDS) gene in onion (Allium cepa L.)
Scientists from the Directorate of Onion and Garlic Research in India and Iowa State University are reporting for the first time about the successful application of CRISPR -Cas9 to alter an onion trait. Their work provides supporting evidence for further basic and applied molecular and breeding research work on onions.
Two exons of gene coding were targeted for Phytoene desaturase (AcPDS) in onion. Constructs carrying sgRNA were developed using 2-month old embryogenic calli and Agrobacterium-mediated transformation. The constructs were incubated to produce regenerated shoots that exhibited albino, chimeric, and pale green characteristics.
The albino phenotypes were used for further tests to confirm that the AcPDS gene was successfully edited, given that the mutation caused a drastic reduction in chlorophyll content in the albino shoots. According to the scientists, this is the first time that a CRISPR-Cas9 genome editing protocol was successfully established in onion.