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

Authors: THI NHU TRANG VU, THI HONG TRANG LE, PHU HIEP HOANG, DANH THUONG SY, THI THU THUY VU, HOANG MAU CHU

Abstract: Talinum paniculatum plants contain flavonoids and saponins, which have strong antioxidant properties and are used in the treatment of numerous diseases, such as inflammation, allergies, and gastric ulcers. Currently, there is no published research on the flavonoid content of T. paniculatum plants; however, it has been determined that the species in the genus Talinum have very low flavonoid content, and therefore the effective approach to enhance the flavonoid content in T. paniculatum plants is overexpression of the Glycine max chalcone isomerase (GmCHI) gene. In this study, we analyzed GmCHI gene overexpression, which has increased total 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 CHI protein expressed in transgenic lines has a molecular weight of approximately 25 kDa, and the concentration of this protein in the two transgenic lines T1-2.2 and T1-10 was 4.29 ?g mg^?1 and 6.14 ?g mg^?1, respectively. Total flavonoid contents of the two transgenic lines 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 to that of the nontransgenic plants, respectively. Thus, overexpression of the GmCHI gene enabled T. paniculatum plants to improve their total flavonoid content. This work also confirmed the effectiveness of Agrobacterium-mediated plant transformation in enhancement of flavonoid accumulation in T. paniculatum plants.

Keywords: GmCHI gene expression, chalcone isomerase, flavonoid, Talinum paniculatum, Agrobacterium-mediated transformation

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