Isolation of PlANS and PlDFR genes from herbaceous peony ( Paeonia lactiflora Pall.) and its functional characterization in Arabidopsis and tobacco

Flower colour, which is largely determined by anthocyanin, is an important ornamental value of herbaceous peony (Paeonia lactiflora Pall.). Anthocyanin synthesis genes encode enzymes acting at different stages of flavonoid biosynthetic pathway. In this research, we cloned anthocyanin synthesis genes PlANS and PlDFR from red dominated herbaceous peony cultivar ‘Hongyanzhenghui’ and explore their functionality with respect to colour formation by genetic engineering techniques. The over-expression vectors pB1301-PlANS and pB1301-PlDFR were constructed and transformed as heterologous genes into Arabidopsis thaliana (A. thaliana) and tobacco (K326). The quantitative real-time PCR results showed the over expression of PlANS and PlDFR in transgenic plants from 10 to 1600 times. Phenotypic observation and HPLC detection at OD 525 nm also revealed the elevated anthocyanin content in the transgenic Arabidopsis. The a* and c* value of transgenic flower increased 3–4 times compared with control tobacco which are consistent with the observed colour change. Taken together, our findings showed that PlANS, PlDFR is participated in the anthocyanin biosynthesis pathway which could provide a theoretical basis for further research of flower colour in herbaceous peony. Our results provided an important research work of two P. lactiflora genes which are related to the red petal colour formation. It provides a theoretical basis for further identification of flower colour-related gene function study in P. lactiflora.