Overexpression of the Glycine max chalcone isomerase (GmCHI) gene in transgenic Talinum paniculatum plants

Abstract

Talinum paniculatum plants contain flavonoids and saponins, which have strong antioxidant properties and are used inthe treatment of numerous diseases, such as inflammation, allergies, and gastric ulcers. Currently, there is no published research onthe flavonoid content of T. paniculatum plants; however, it has been determined that the species in the genus Talinum have very lowflavonoid content, and therefore the effective approach to enhance the flavonoid content in T. paniculatum plants is overexpressionof the Glycine max chalcone isomerase (GmCHI) gene. In this study, we analyzed GmCHI gene overexpression, which has increasedtotal flavonoid content in transgenic T. paniculatum lines. We have successfully transformed T. paniculatum plants with the pCB301-GmCHI vector and created 2 lines in generation T1 (T1-2.2 and T1-10) with a transgenic frequency of 0.27%. Recombinant CHIprotein expressed in transgenic lines has a molecular weight of approximately 25 kDa, and the concentration of this protein in thetwo transgenic lines T1-2.2 and T1-10 was 4.29 μg mg–1 and 6.14 μg mg–1, respectively. Total flavonoid contents of the two transgeniclines T1-2.2 and T1-10 were 4.24 mg g–1 and 2.74 mg g–1, respectively, which showed increases of 7.4-fold and 4.8-fold compared tothat of the nontransgenic plants, respectively. Thus, overexpression of the GmCHI gene enabled T. paniculatum plants to improve theirtotal flavonoid content. This work also confirmed the effectiveness of Agrobacterium-mediated plant transformation in enhancement offlavonoid accumulation in T. paniculatum plants.