An LTR retrotransposon may activate the PsMYB10.2 gene expression and promote anthocyanin biosynthesis in the fruit flesh of Japanese plum a success story of CRISPR-Cas9 enrichment sequencing strategy
In this study, we review the methodology used to develop a molecular marker for fruit flesh color in Japanese plum, a species in which marker-assisted breeding is still in its infancy. We focus on the use and potential of the CRISPR-Cas9 enrichment sequencing, a novel methodology that attains the long-read target sequencing of genomic regions of interest. This technology allowed the sequencing of the highly polymorphic and duplicated LG3-MYB10 region of five plum cultivars in a cost-effective manner. This resulted in the identification of a structural variant associated with flesh color, which was an LTR retrotransposon of 2.8 kb inserted in the promoter of the PsMYB10.2 gene and allowed the design of an efficient molecular marker for the trait. The role of the PsMYB10.2 gene as an inducer of anthocyanin biosynthesis in the flesh was validated by transient overexpression in Japanese plum fruits. The long-terminal repeat retrotransposon might have a role in gene activation, as reported in other species. The study reviewed here is a great example that highlights the potential of CRISPR-Cas9 enrichment sequencing as a tool to identify genetic variations in genomic regions of interest, even if these are highly complex. As with Japanese plum and flesh color, this methodology could be a powerful tool for the development of molecular markers linked to traits of interest and agronomic value in any species.
Fiol, A., Jurado-Ruiz, F., García, S., Dujak, C., López-Girona, E., Pacheco, I., Infante, R. and Aranzana, M.J. (2023). An LTR retrotransposon may activate the PsMYB10.2 gene expression and promote anthocyanin biosynthesis in the fruit flesh of Japanese plum a success story of CRISPR-Cas9 enrichment sequencing strategy. Acta Hortic. 1362, 15-20
CRISPR-Cas9, long-read sequencing, molecular marker, fruit color, MYB10