Page 145 - 2025中醫藥與天然藥物聯合學術研討會-中醫藥與天然藥物的挑戰Ｘ機遇與未來大會手冊

PC-27

Far-red light serves as an environmental signal modulating the growth and

rosmarinic acid biosynthesis of Prunella vulgaris L.

1
1
1,4
Chi-Han Hsu, 1,2,3 Ying‐Hsuan Chen, Y u -Ling Shih, Chia-Yi Wang, Yi-Zhen Chen,
1,3
,1
Wen-Dar Huang, Chang-Chang Chen*
3

1 National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei
112026, Taiwan
2 International Master in Horticultural Sciences, Humboldt‑Universität zu Berlin, Berlin
10115, Germany
3 Department of Agronomy, National Taiwan University, Taipei 106319, Taiwan
4 Department of Life Science, National Taiwan University, Taipei 106319, Taiwan
* E-mail: chencc@nricm.edu.tw

Abstract
Prunella vulgaris L., a native medicinal herb in Taiwan, is traditionally used in Chinese
medicine for its heat-clearing properties, with its spikes being the primary medicinal part.
Rosmarinic acid is recognized as its marker compound. Additionally, the shoot parts are
commonly used in folk herbal medicine. Far-red light (FR) serves as an important
environmental signal that regulates plant growth and development and also influences
secondary metabolite biosynthesis. This study aimed to investigate the effects of FR on the
growth and rosmarinic acid biosynthesis in P. vulgaris. Pot experiments were conducted under
three levels of FR conditions, including low (LFR), medium (MFR), and high FR (HFR), and
growth parameters as well as rosmarinic acid biosynthesis were assessed. A treatment without
FR served as the control (CK). Results showed that increasing far-red light intensity promoted
stem elongation and leaf length, although no significant differences in dry weight were observed.
Under MFR, rosmarinic acid content in the shoot parts during the early growth stage was 3.33
times higher than that of the CK (0.15%). Under HFR, the content significantly exceeded that
of other treatments, reaching 1.57 times the CK level (3.96%) in the later growth stage. Gene
expression analysis further revealed that HFR effectively induced the expression of PvPAL and
PvC4H, key genes involved in phenylpropanoid biosynthesis. In conclusion, modulating FR
intensity during cultivation would regulate the growth and secondary metabolism of P. vulgaris.
Specifically, a high FR could enhance rosmarinic acid biosynthesis, thereby improving the
quality and consistency of medicinal raw materials.

Keywords: Prunella vulgaris; Far-red light; Plant growth; Rosmarinic acid biosynthesis; Gene
expression