transformation was
carried out as described in our previous study [39]. After
cultivation for one or two months, roots started to appear
at the infection sites and single roots were subsequently
picked out and placed on fresh MS media with kanamycin
(500 mg L −1 ) to eliminate any bacteria. Hairy roots with
no bacterial contamination were cultured on hormone-
free half-strength MS solid medium in the dark at 26°C.
Hairy root lines were sub-cultured at 4 week intervals.
Transgenic hairy roots of Panax ginseng were verified by
PCR and RT-PCR using the forward primer 5’-CCG GAT
CCA TGG AAA ACA TAA CAC AGT GG-3’ and the re-
verse primer 5’-GCG AGC TCT TAA GCG TAT GCT
CCA AAC CAC GT-3’. Ginseng explants were also infil-
trated with a wild-type Agrobacterium rhizogenes A4
strain to obtain negative controls.