Expression of MYB transcription factors and target genes and its association with phenolic content and antioxidant activity of selected Solanum lycopersicum var. cerasiforme accessions from Mexico

Eight Solanum lycopersicum var. cerasiforme accessions from Mexico were evaluated for total phenolics (TP) and flavonoids (TF), phenolic profiles (UPLC-DAD-MS), antioxidant capacity (AC) (ABTS, DPPH, and FRAP), and expression of transcription factors (MYB12 and MYB14) and target genes (PAL, CHS and CHI) by RT-qPCR. The AC (mmol TE/kg fw; TE, Trolox Equivalents) by ABTS (5.27-11.81), DPPH (1.43-3.67), and FRAP (4.41-9.22) correlated with TP (0.53-1.20 g GAE/kg fw; GAE, Gallic Acid Equivalents), TF (1.03-2.10 g QE/kg; QE, Quercetin Equivalents), and the levels of chlorogenic and dicaffeoylquinic acids and rutin. The expression of MYB12 and MYB14 correlated with that of PAL and CHS, while CHI was only associated with MYB12. The accessions Tumbisca and Kilim showed the highest gene expression, phenolics content, and AC, suggesting they can be used in breeding programs to produce tomatoes with better AC.

Automated summary

In this study, eight accessions of Solanum lycopersicum var. cerasiforme from Mexico were evaluated for their antioxidant capacity, expression of transcription factors and target genes. The results showed a positive correlation between antioxidant capacity and the content of total phenolics and flavonoids, as well as specific phenolic compounds. Tumbisca and Kilim accessions exhibited the highest gene expression levels and antioxidant capacity.