Enhancement of sweet basil downy mildew resistance by CRISPR/Cas9

BOT4734C, Hirko

Sweet basil (Ocimum basilicum) is an economically important herb and is threatened by basil downy mildew caused by the obligate biotrophic oomycete Peronospora belbahrii. Furthermore, Genetic engineering of sweet basil offers a platform to study molecular biology, broaden sources of desirable traits and accelerate the breeding process. Clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 gene-editing technology has revolutionized crop breeding and functional genomics. Testing this system by editing a potential susceptibility (S) gene ObDMR6, the basil homolog of Arabidopsis DMR1 (Downy Mildew Resistant 1) which corresponds to nearly complete resistance against Arabidopsis downy mildew pathogen, Hyaloperonospora arabidopsidis. A single RNA targeting one site of the ObDMR6 coding sequence was used to knock out alleles from only one site. Transgenic lines were obtained via Agrobacterium-mediated transformation from sweet basil in a hydroponics system and confirmed by polymerase chain reaction. Using this Gene-editing system for target mutagenesis is expected to help against downy mildew disease, facilitate the production, and breeding of sweet basil.

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