Abstract
The main flavonoid compound rutin is highly expressed in the crop plant buckwheat (Fagopyrum tataricum (L.) Gaertn.) and plays important roles in the human diet. In this study, phenylpropanoid production in buckwheat hairy roots was evaluated following ethephon treatment. Using quantitative real-time polymerase chain reaction and high-performance liquid chromatography, we analysed the relationship between flavonoid and anthocyanin biosynthetic pathway gene regulation and the relative accumulation of the secondary compounds in ethephon-treated buckwheat hairy roots. Generally, the transcription of the biosynthetic pathway genes varied between the treated samples and controls. Most of the flavonoid biosynthetic genes were upregulated by ethephon, typically after four days of treatment. The application of 0.5 mg/L ethephon markedly induced anthocyanin production in hairy roots compared to that induced by the other concentrations tested (0, 1 and 2 mg/L). These data indicate that anthocyanin biosynthesis may play an important role in the response of buckwheat to ethephon-induced stress.