Preparation and Function Verification of Recombinant Protein of Chalcone Isomerase Gene from Rhododendron Delavayi

  Objective  Recombinant protein of chalcone isomerase (CHI) gene in Rhododendron delavayi was prepared and its activity was verified. This will provide theoretical basis for analyzing the function of CHI, and also lays a foundation for improving flower color and increasing medicinal ingredientst.

  Method  Primers were designed based on the sequence of RdCHI1, and the prokaryotic expression vector constructed. Conditions to induce the expression of soluble recombinant protein were optimized. Activity of the prepared protein was verified by an in vitro enzymatic assay.

  Result   The successfully constructed RdCHI1 prokaryotic expression vector was expressed in the supernatant under the optimized induction that applied 0.35 mmol·L⁻¹ IPTG at 15 ℃ for 36 h. The nickel column-purified recombinant protein significantly hastened the conversion of naringin chalcone to naringin in an in vitro assay.

  Conclusion   As a type I CHI, RdCHI1 significantly accelerated the convertion from naringin chalcone to naringin and increase the accumulation od flavonoids.