Effect of pH on the expression of RsMYB1 that regulates anthocyanin production in Petunia plants

We established an in vitro system to investigate transcription levels of the RsMYB1 gene expressed in T2 20-day-old transgenic Petunia plants (three independent lines: PhRs1, PhRs2, and PhRs3), and the association between those transcription levels and anthocyanin production at various pH values (3.0 to 8.0) for a period of 10 days. All the lines treated with pH 5.0-7.0 exhibited increased anthocyanin content and delays in growth compared to the wild-type (WT) seedlings. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis confirmed that the enhancement of anthocyanin production in the transgenic lines was due to the upregulation of RsMYB1 transcription at various pH values. The results suggest that pH value can control expression of RsMYB1 which is associated with anthocyanin production.