Comparison on profiling of hairy root of two Tibetan medicinal plants Przewalskia tangutica Maxim and Anisodus tanguticus Maxim

: Tropane alkaloids (TAs) are important drugs for curing many diseases in the medical industry. To sustainably exploit TA resources in traditional endangered Tibetan herbs, the hairy root (HR) systems of Przewalskia tangutica Maxim. and Anisodus tanguticus Maxim. were compared under the same culture conditions. The results indicated that the Agrobacterium rhizogenes strains and explants both affected the HR induction frequency, MSU440, A4 and LBA9402 strains could induce hairy roots following infection of cotyledon and hypocotyl of A. tanguticus while LBA9402 could not induce HR on either explants of P. tangutica. The efficiency of LBA9402 was higher than A4 and MSU440 on A. tanguticus and A4 was better strain than MSU440 on P. tangutica. The hypocotyl explant was more suitable for P.tangutica and cotyledon explant was better for A.tangutica with a transformation frequency of 33.3% (P. tangutica) and 82.5% (A. tanguticus), respectively. In a flask reactor system, the growth curves of HR for two species both appeared to be "S" curve; however, the HR of P. tangutica grew more quickly than that of A. tanguticus, and the latter accumulated more biomass than the former. As the culture volume increased, the HR proliferation coefficient increased on both species. HPLC analysis results showed that the content of TAs in the HR of P. tangutica is 257.24mg/100g•DW, which is more than that of A. tanguticus HR (251.08mg/100g•DW), and the anisodamine in the Pt-HR is significantly higher than that of At-HR. Moreover, tropane alkaloids in the HR of the two species are all significantly higher than that of the roots in aseptic seedlings. Our results suggest that HR of P. tangutica and A. tanguticus both could provide a useful platform for sustainable utilization of two Tibetan medicinal plants on the Qinghai-Tibetan Plateau in the future.