Phosphoproteomics Reveals Regulation of Secondary Metabolites in Mahonia bealei Exposed to Ultraviolet-B Radiation.

Amin Liu,Wei Zhu,Minglei Tao,Shengzhi Liu,Haote Han,Yaohan Li,Jingkui Tian,Zhuoheng Zhong

doi:10.3389/fpls.2021.794906

Abstract

Mahonia bealei (M. bealei) is a traditional Chinese medicine containing a high alkaloid content used to treat various diseases. Generally, only dried root and stem are used as medicines, considering that the alkaloid content in M. bealei leaves is lower than in the stems and roots. Some previous research found that alkaloid and flavonoid contents in the M. bealei leaves may increase when exposed to ultraviolet B (UV-B) radiation. However, the underlying mechanism of action is still unclear. In this study, we used titanium dioxide material enrichment and mass-based label-free quantitative proteomics techniques to explore the effect and mechanism of M. bealei leaves when exposed to UV-B treatment. Our data suggest that UV-B radiation increases the ATP content, photosynthetic pigment content, and some enzymatic/nonenzymatic indicators in the leaves of M. bealei. Moreover, phosphoproteomics suggests phosphoproteins related to mitogen-activated protein kinase (MAPK) signal transduction and the plant hormone brassinosteroid signaling pathway as well as phosphoproteins related to photosynthesis, glycolysis, the tricarboxylic acid cycle, and the amino acid synthesis/metabolism pathway are all affected by UV-B radiation. These results suggest that the UV-B radiation activates the oxidative stress response, MAPK signal transduction pathway, and photosynthetic energy metabolism pathway, which may lead to the accumulation of secondary metabolites in M. bealei leaves.

Highlights

Mahonia Bealei is a kind of evergreen shrub widely grown in China and some other countries in Asia, Europe, and America
MDA content, H2O2 content, peroxidase activity (POD) activity, superoxide dismutase activity (SOD) activity, total antioxidant capacity (T-AOC), and Phenylalanine ammonia-lyase (PAL) activity in M. bealei leaves exposed to ultraviolet B (UV-B) radiation were determined (Figures 2A–F and Supplementary Table 1)
We analyze the phosphoproteomics of M. bealei leaves that were exposed to UV-B radiation for

Summary

Introduction

Mahonia Bealei is a kind of evergreen shrub widely grown in China and some other countries in Asia, Europe, and America. Its main active ingredients are berberine, jatrorrhizine, and palmatine, which have heat-clearing, detoxifying, and antiphlogistic effects and may be used to treat stomach disorders, inflammation, infections like hepatitis, and skin-related diseases. A previous study (Deng et al, 2013) points out that, besides berberine, jatrorrhizine, and palmatine, Alishan Mahonia contains columbamine, and its 1-diphenyl-2-trinitrophenylhydrazine (DPPH) radical scavenging activity is five times higher than the activity of vitamin C. Only dried roots and stems named Gonglaomu were officially used as medicines in China, considering that the alkaloid contents in M. bealei leaves are lower than those in stems and roots (Zhu et al, 2015). Studies on increasing the alkaloid contents in M. bealei leaves could be valuable for improving medicinal material utilization

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