Auxins Affected Ginsenoside Production and Growth of Hairy Roots in Panax Hybrid

Hairy roots of interspecific hybrid ginseng (Panax ginseng×P. quinquefolium), induced by Agrobacterium rhizogenes ATCC 15834, grew well in B5 liquid media supplemented with 2.5 μM auxins (3-indole butyric acid (IBA), 1-naphtaleneacetic acid (NAA) and 3-indoleacetic acid (IAA)). The hairy roots cultured in B5 liquid medium supplemented with 2.5 μM IBA showed best growth (6.39 g fresh weight per a flask, at week 8). The highest content of the total ginsenosides was 1.63% as dry weight at week 8 when cultured with 2.5 μM NAA. The different auxins affected the numbers and lateral branching roots. Especially, 2.5 μM IBA promoted the lateral root formation (43.7±4.0 roots, at week 8), and 2.5 μM NAA promoted the lateral root growth (45.3±5.6 mm, at week 8). The growth and ginsenosides production of 8-week old hairy roots cultured in B5 liquid media supplemented with IBA and NAA combinations were also investigated. Hairy roots produced higher amounts of ginsenosides in B5 liquid media supplemented with 0.5—1.0 μM IBA and NAA combinations than that cultured in B5 liquid media supplemented with only IBA and NAA. The highest yield of ginsenoside was obtained when cultured with 0.5 μM IBA and 1.0 μM IBA combination (6.38 mg per a flask, at week 8).