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. Since melon regeneration and gene editing are highly genotype-dependent, this year we conducted gene editing on six melon varieties using CRISPR vectors targeting the melon PDS gene to evaluate which varieties are more prone to gene editing. The results showed a higher probability of obtaining albino mutant plants in the Charentais and Silver Light melon varieties. Additionally, Agrobacterium-mediated transformation of melon was performed using previously constructed CRISPR vectors, resulting in a total of 206 regenerated plants. Transgenic confirmation was conducted, and the target gene was sequenced in 104 transgenic plants; however, no successfully edited plants were obtained. According to the literature, overexpression or induced expression of morphogenic transcription factors can enhance transformation efficiency and broaden the range of applicable genotypes. Therefore, this year, we constructed CRISPR vectors containing the morphogenic regulatory genes WUS2 and AtSTM and conducted preliminary tests on transformation methods. Future work will focus on evaluating whether these vectors can enhance gene-editing efficiency in melon to develop virus-resistant breeding materials. 

▲Fig1. Regenerated plants obtained after Agrobacterium-mediated transformation		▲Fig2. Conducting gene editing tests on different melon varieties using CRISPR vectors targeting the melon PDS gene
		▲Fig. 3. Transformation testing in Nicotiana benthamiana and melon using developmental regulatory gene constructs.