Changes in marker secondary metabolites revealed the medicinal parts, harvest time, and possible synthetic sites of Rubia cordifolia L

Yanlin Wang; Huanchu Liu; Shuai Yu; Yanqing Huang; Yue Zhang; Xingyuan He; Wei Chen

doi:10.1016/j.plaphy.2023.108024

Changes in marker secondary metabolites revealed the medicinal parts, harvest time, and possible synthetic sites of Rubia cordifolia L

Plant Physiol Biochem. 2023 Oct:203:108024. doi: 10.1016/j.plaphy.2023.108024. Epub 2023 Sep 7.

Authors

Yanlin Wang¹, Huanchu Liu², Shuai Yu², Yanqing Huang³, Yue Zhang³, Xingyuan He⁴, Wei Chen⁵

Affiliations

¹ Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Liaoning Shenyang Urban Ecosystem Research Station, National Forestry and Grassland Administration, Shenyang, 110164, China.
² Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China; Liaoning Shenyang Urban Ecosystem Research Station, National Forestry and Grassland Administration, Shenyang, 110164, China.
³ Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China; Shenyang Arboretum, Chinese Academy of Sciences, Shenyang, 110016, China; Liaoning Shenyang Urban Ecosystem Research Station, National Forestry and Grassland Administration, Shenyang, 110164, China.
⁴ Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Shenyang Arboretum, Chinese Academy of Sciences, Shenyang, 110016, China; Liaoning Shenyang Urban Ecosystem Research Station, National Forestry and Grassland Administration, Shenyang, 110164, China.
⁵ Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Shenyang Arboretum, Chinese Academy of Sciences, Shenyang, 110016, China; Liaoning Shenyang Urban Ecosystem Research Station, National Forestry and Grassland Administration, Shenyang, 110164, China. Electronic address: chenwei@iae.ac.cn.

PMID: 37699290
DOI: 10.1016/j.plaphy.2023.108024

Abstract

Rubia cordifolia L. is a significant medicinal plant. To investigate the changes of marker metabolites of R. cordifolia, the purpurin, mollugin, carbon, nitrogen contents, and the expression of genes involved in anthraquinones synthesis were examined. The findings indicated that the two secondary metabolites were only detected in stems and roots. Root purpurin content was 5-26 times higher than in stems, and root mollugin content was 92 times higher than in stems in June. These findings suggest that the potential of the roots as a medicinal part. The roots were found to have highest purpurin content in October (2.406 mg g^-1), whereas the mollugin content was highest in August (6.193 mg g^-1). However, the purpurin content in August was only 0.029 mg g^-1 lower than that in October, making August a suitable harvest period for R. cordifolia. The expression 1-deoxy-D-xylulose 5-phosphate synthase (dxs) and 1-deoxy-D-xylulose-5-phosphate reductorisomerase (dxr) genes in roots showed an upward trend. However, the expression level of dxr gene was significantly higher than dxs with the range of 60-518 times higher, indicating the important role of dxr gene. Through correlation and redundancy analyses, it was found that mollugin showed positive correlation with carbon contents and carbon-nitrogen ratio of aerial parts. Additionally, purpurin showed a positive correlation with the expression of both genes. As a result, mollugin is likely to be synthesized in the aerial parts and then stored in the roots, whereas purpurin might be synthesized in the stems and roots. These findings could provide cultivation guidelines for R. cordifolia.

Keywords: Dynamic change; Harvesting time; Mollugin; Purpurin; Rubia cordifolia L.; Tissue specificity.