Study on obtaining of hairy root of Panax vietnamensis by using rol gene transformation via Agrobacterium rhizogenes

Abstract

Having the higher saponin content in comparison with other plants of the genus Panax, Panax vietnamensis has been considered as one of the most valuable medical plants in Vietnam. Using Agrobacterium rhizogenes to transfer rol gene to increase hairy root formation is a high potential method in producing secondary metabolites in this plant. The experiment was conducted on 2 different kinds of tissues of in vitro seedling including leaves and petioles. These tissues were used as source of infection. The purpose of this experiment is to induct hairy root by using Agrobacterium rhizogenes to transfer rol gene to these tissues. Leaves and petioles of in vitro plantlets were infected and incubated in 30 mins, then cultured for 72 hrs.  The result showed that the hairy root induction rate and the number of roots were higher in petiole tissues compared with those in leaf tissues (14.8%, 2.8% and 3.3%, 1.6% respectively). Hairy root induction in petiole tissues was in 5 weeks and that in leaves tissues was in 6 weeks. The presence of rolC in produced hair roots was confirmed by PCR. Secondary metabolite analysis of transgenic plants also showed the presence of MR2, Rb1 and Rg1 which are typically active elements inPanax vietnamensis. Liquid culture with shaking is the most suitable condition for proper hairy root development. The success of promoting root formation in our study will be potential to produce saponin in industrial scale.