Salvia miltiorrhiza (commonly known in China as Danshen) is widely used in traditional Chinese medicine, and it is applied in the treatment of many diseases, particularly cardiovascular disease. Commercial propagation of Danshen is carried out either through seed germination or in vitro regeneration (micropropagation). However, it is not clear if the different propagation methods affect the chemical properties of the derived plants. In the present study, we first established a highly efficient tissue culture system for Danshen propagation. The addition of 1.0 mg·L−1 6-benzyladenine (BA) and 0.1 mg·L−1 α-naphthalene acetic acid (NAA) to Murashige and Skoog (MS) medium was optimal for inducing adventitious shoots; the highest rate of rooting was recorded on MS medium with 0.2 mg·L−1 NAA, on which the survival rate of transplanted plantlets was 95%. Next, we assessed antioxidant properties in the different tissues of plants of the same age, derived from micropropagation or seed germination, and measured tanshinone, total phenol, and total flavonoid contents. Our results showed that tissues of micropropagated plantlets had higher antioxidant activities than tissues of seed-derived plantlets; the micropropagated plantlets also had higher tanshinone contents in their roots. Thus, a rapid and efficient micropropagation system was established for Danshen, and it can be used for cultivating this plant to obtain therapeutic compounds.
Bo-Ling Liu, Zhi-Bin Fan, Ze-Qun Liu, Xun-Hong Qiu and Yan-Hong Jiang
Zhibin Fan, Kai Zhang, Fengyun Wang, Xiaodan Zhao, Ruiqin Bai and Boling Liu
Salvia miltiorrhiza, known as danshen, is one of most valued medicinal plants in China. Although it has been cultivated since ancient times, an optimal culture system needs to be standardized for this important species. Here, we explored the phytochemical properties of S. miltiorrhiza with the treatments of rare earth elements (REEs) to develop an optimal tissue culture system. Four-week-old in vitro-grown S. miltiorrhiza plantlets were used as explants. The experiment was conducted in a randomized block design on a Murashige and Skoog (MS) medium containing 0.2 mg·L−1 naphthaleneacetic acid (NAA) to induce rooting at four different concentrations (50, 100, 200, and 300 μM) of REEs such as cerium (Ce), lanthanum (La), or praseodymium (Pr), respectively. Compared with all REEs at different concentrations, 100 μM Pr induced greater root length than Ce or La at any concentrations. Concomitantly, 0.38 μg tanshinone IIA/mg dry weight (DW) was observed, which was 54.84% higher than in the control. Similarly, chlorophyll content, antioxidant enzyme activity, and secondary metabolite were enhanced in rooting medium supplemented with 100 μM Pr. Therefore, this study showed that 100 μM Pr is an adequate concentration in the optimal culture system for promoting plant growth as well as enhancing secondary metabolite content in S. miltiorrhiza.