ObjectiveThe rapid development of the global industry has led to the enhancement of UV-B radiation in the atmosphere, which directly affects the growth and development of plants and their physiological activities. All kinds of secondary metabolites in plants are greatly influenced by the environment, how to respond to the enhancement of UV-B radiation is also increasingly emphasized by the planting industry. In this paper, Phellodendron amurense, the important medicinal plant in the Northeast China was taken as the object of research to study the responses of the contents of antioxidant substances and main medicinal active components in the seedlings of P. amurense to different intensities of UV-B radiation.

MethodExperiments were carried out in greenhouse with controlled environment. Three levels of UV-B radiation intensity treatments were set as control (CK, natural light), low radiation (T1, supplement UV-B radiation intensity 3.26 μW/cm², and high radiation(T2, supplement UV-B radiation intensity 9.78 μW/cm², to study the responses of antioxidants and the main active ingredients (three alkaloids of bererine, jatrorrhizine and palmatine) contents in P. amurense seedlings to different UV-B radiation intensity.

ResultThe results showed that the content of malondialdehyde (MDA), hydroxyl radical, tannin and soluble protein in P. amurense seedlings significantly increased along with the radiation intensity. The total flavonoid contents in the root of P. amurense seedlings declined with UV-B radiation intensity, except those in treatments of 40 days. On the contrary, the total flavonoid contents in the stem rose with radiation intensity. At the time of radiation treatment for 40 days, the contents of three alkaloids in the stem of P. amurense seedlings were higher than in the CK group, and the T1 group with low intensity radiation was higher than the T2 group with high intensity radiation (P < 0.05).The content of three alkaloids in the root and leaf increased with the 40 days of radiation treatment, but it was still lower than the CK group and the difference was significant (P < 0.05).

ConclusionUV-B radiation enhancement will lead to different changes in the content of antioxidants and medicinal active ingredients in different organs of P. amurense seedling, which is of great significance for the large-scale cultivation of different utilization patterns of P. amurense as the traditional Chinese medicinal plant.