Mechanism of Laccase Induction via Emodin in Trametes versicolor.

Lin Wang,Liang Zhang,Xuecai Luo,Zai Zheng,Xiaohe Tian,Ruochun Yin,Yu Pan

doi:10.3389/fbioe.2021.653800

Lin Wang, Liang Zhang + Show 5 more

Open Access

https://doi.org/10.3389/fbioe.2021.653800

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Abstract

Secondary metabolites of traditional Chinese herbs can prominently stimulate the production of laccase from white rot fungi during submerged fermentation. However, the molecular mechanism through which these natural products induce the production of laccase remains unknown. In this study, the Chinese herbal medicine Polygonum cuspidatum was used to induce laccase production in Trametes versicolor, and the best inducer was identified in emodin, even under conditions of 1000-L, large-scale fermentation. Proteomics analysis identified a selection of proteins that were differentially expressed in the presence of emodin, indicating that emodin may affect the expression of laccase genes through three mechanisms: reducing bioenergy productivity, the aryl hydrocarbon receptor (AHR)/xenobiotic response element (XRE) pathway, and the nuclear erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway. Combined with protoplast flow cytometry and fluorescence, it is revealed that emodin might reduce the synthesis of ATP by lowering the mitochondrial membrane potential, leading to the subsequent responses.

Highlights

Polygonum cuspidatum is a common raw material used during the extraction of traditional Chinese herbs (TCH) and serves as a source of emodin, resveratrol, and other natural products
Several groups have explored the ability of T. versicolor to secrete laccase isozymes (Iimura et al, 2018; Pinheiro et al, 2020) and have attempted to optimize enzyme production (Yang et al, 2015; Zdarta et al, 2017), the abilities of TCH to induce the production of laccase has not been well-explored
The addition of the ethyl ether extract and extraction residue to the T. versicolor medium had no effects on fermentation efficiency, and the highest laccase activity was measured at 6358.1 U·L−1 following the addition of the ethyl acetate extract, which represented a 93.1% increase compared with the enzymatic activity measured in the control

Summary

Introduction

Polygonum cuspidatum is a common raw material used during the extraction of traditional Chinese herbs (TCH) and serves as a source of emodin, resveratrol, and other natural products. The medicinal mushroom Trametes versicolor had been used for the microbial fermentation and transformation of TCH (Bains and Chawla, 2020). Several groups have explored the ability of T. versicolor to secrete laccase isozymes (Iimura et al, 2018; Pinheiro et al, 2020) and have attempted to optimize enzyme production (Yang et al, 2015; Zdarta et al, 2017), the abilities of TCH to induce the production of laccase has not been well-explored. Various strategies have been developed to enhance laccase production, such as controlling the carbon-to-nitrogen

Results

Discussion

Conclusion