Development of Agrobacterium tumefaciens- mediated transformation of Solanum nigrum  and expression of AcMYB110  in S. nigrum

Abstract Solanum nigrum L. is an annual herb of Solanaceae and Solanum genus. S. nigrum produces a small, spherical, black, highly nutritious edible fruit and is an orphan crop. To realize the potential of large-scale production of S. nigrum fruits, it is necessary to improve undesirable characteristics, such as tiny fruits, by using available methods of genetic engineering and gene editing. The genetic transformation system of S. nigrum is the basis for genetic improvement through transgenic and gene-editing technology. In this study, an efficient Agrobacterium tumefaciens -mediated transformation method was established. The R2R3-MYB transcription factor AcMYB110 from kiwifruit was used as a foreign gene to transform S. nigrum . The results showed that anthocyanin accumulation was accumulated in the transformed cells and tissues, which could visually track and monitor each stage of the transformation process. AcMYB110 could be used as a reporter gene in the genetic transformation of S. nigrum . The petals of AcMYB110 transgenic S. nigrum plants are pink, and anthocyanins were accumulated in the pericarp from young fruit to maturity, especially in the central part of the flesh of the S. nigrum fruit. The phenotype produced by overexpression of AcMYB110 in kiwi and S. nigrum is consistent. It indicates that AcMYB110 is relatively conservative in regulating plant anthocyanin synthesis.