Characterization of Carnivorous Plants Sarracenia purpurea L. Transformed with Agrobacterium rhizogenes

Abstract

People have used carnivorous plants of the genus Sarracenia in folk medicine for centuries due to the biochemical composition of Sarracenia plants, which are rich in numerous bioactive compounds with anti-inflammatory, antioxidant, antiviral and antibacterial properties. The subject of this study was the genetic transformation of Sarracenia purpurea L. with Agrobacterium rhizogenes strains 15834, 9402 and A4 using two different methods: bacterial injection or co-culture of the bacteria with plant explants. This study confirmed the possibility of hairy root induction in S. purpurea using A. rhizogenes strain 15834 and the injection method. Seven lines of transformed plants, exhibiting the integration of the rolB gene, were obtained. The hairy roots formed showed morphological differences in comparison to the roots of unmodified plants. A mathematical model was used to optimize the conditions for the extraction of bioactive compounds. Extracts isolated under optimal conditions from the transformed plants showed biochemical changes, i.e., an increase in the accumulation of total polyphenols (line 7#1 in hairy roots: 71.048 mg GAE g−1 DW; in leaves: 9.662 mg GAE g−1 DW) and triterpenes (line 7#1 in hairy roots: 1.248 mg BA g−1 DW; in leaves: 0.463 mg BA g−1 DW) in comparison to untransformed plants (polyphenols in roots: 7.957 mg GAE g−1 DW and in leaves: 5.091 mg GAE g−1 DW; triterpenes in roots: 0.298 mg BA g−1 DW and in leaves: 0.296 mg BA g−1 DW), especially when induced roots were analyzed. HPLC analysis showed an increase in the level of betulinic acid in some transformed Sarracenia lines. Betulinic acid is a pentacyclic triterpenoid compound with high pharmacological significance.