The most effective way to control the viral disease is to breed disease-resistance plants. However, melon breeding hasn't made much progress for lacking virus-resistance varieties. The new plant breeding technology such as the CRISPR/Cas9 technique provided an efficient way to knock out host factors such as eIF4E protein which may therefore confer plant viral resistance in plants. Last year, we constructed sgRNA/Cas9 expression vectors with different GC contents and targeted different regions of the eIF4E gene. At present, we have used a protoplast transient assay to evaluate the performance of these vectors. We pooled all protoplast DNAs after PEG-mediated transfection and carried out a small-scale metagenomics analysis for the target gene to quickly evaluate the gene editing efficiency. In addition, Agrobacterium-mediated transformation was also carried out to deliver the sgRNA/Cas9 expression vectors into melon explants to induce mutants for further screening of the successfully edited plants.

▲Fig.1. Gene editing efficiency evaluation of eIF4E-g2 vecto

▲Fig.2. Regenerated plants obtained after Agrobacterium-mediated transformation