Anthocyanins are key secondary metabolites responsible for fruit coloration in plants, and their biosynthesis is largely regulated by R2R3-MYB transcription factors. However, the R2R3-MYB regulators controlling fruit anthocyanin accumulation in wild
Solanum species remain poorly understood. Here,
Solanum americanum was used to identify
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Anthocyanins are key secondary metabolites responsible for fruit coloration in plants, and their biosynthesis is largely regulated by R2R3-MYB transcription factors. However, the R2R3-MYB regulators controlling fruit anthocyanin accumulation in wild
Solanum species remain poorly understood. Here,
Solanum americanum was used to identify candidate R2R3-MYB genes associated with fruit coloration through genome-wide identification, phylogenetic analysis, synteny analysis, expression profiling, and virus-induced gene silencing (VIGS). A total of 122 SaMYB genes were identified, and phylogenetic analysis revealed that SaMYB proteins clustered with
Arabidopsis thaliana R2R3-MYB members in conserved subgroups, suggesting evolutionary conservation of this family. Synteny analysis identified 37 syntenic gene pairs among SaMYB genes, and the Ka/Ks values of all analyzable gene pairs were below 1, indicating that these duplicated genes are subject to functional constraint. Integrated analysis of phylogenetic relationships, protein structures, promoter cis-elements, and fruit developmental expression patterns identified
SaMYB59 and
SaMYB106 as candidate regulators of anthocyanin accumulation. VIGS analysis demonstrated that silencing
SaMYB106 reduced purple coloration, decreased anthocyanin content, and downregulated the expression of the structural gene
DFR. These results indicate that
SaMYB106 functions as a positive regulator of fruit anthocyanin accumulation in
S. americanum. This study provides insights into the molecular basis of fruit coloration in wild
Solanum species.
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